Mar-Apr Cover_SID Cover 3/15/2015 4:57 PM Page 1

DISPLAY WEEK PREVIEW / TOPICS IN APPLIED VISION

Mar./Apr. 2015 Official Monthly Publication of the Society for Information Display • www.informationdisplay.org Vol. 31, No. 2

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Radiant Vision Systems, LLC Global Headquarters - Redmond, WA USA | +1 425 844-0152 | www.RadiantVisionSystems.com | [email protected] ID TOC Issue2 p1_Layout 1 3/18/2015 6:31 PM Page 1

SOCIETY FOR INFORMATION DISPLAY Information SID MARCH/APRIL 2015 DISPLAY VOL. 31, NO. 2

ON THE COVER: This year’s winners of the Society for Information Display’s Honors and Awards include Dr. Junji Kido, who will receive the Karl Ferdinand Braun Prize; Dr. Shohei contents Naemura, who will receive the Jan Rajchman 2 Editorial: The Pace of Innovation Prize; Dr. Ingrid Heynderickx, who will be awardedMar-Apr Cover_SID Coverthe 3/15/2015 Otto 4:57 PM Page 1 Schade Prize; Dr. Jin Jang, n By Stephen P. Atwood who DISPLAYwill WEEKbe awardedPREVIEW / TOPICS the IN APPLIED Slottow–Owaki VISION Prize; and Dr. Allan Kmetz, who will receive the 3 Industry News: 700 Million Apple iPhones Sold to Date Lewis and Beatrice Winner Award. n By Jenny Donelan Mar./Apr. 2015 Official Monthly Publication of the Society for Information Display • www.informationdisplay.org Vol. 31, No. 2 4 Guest Editorial: Properly Controlling Light Is a Human-Factors Engineering Problem n By Jim Larimer 6 SID’s Best and Brightest: 2015 SID Honors and Awards This year’s winners of the Society for Information Display’s Honors and Awards include Junji Kido, who will receive the Karl Ferdinand Braun Prize; Shohei Naemura, who will be awarded the Jan Rajchman Prize; Ingrid Heynderickx, who will receive the Otto Schade Prize; Jin Jang, who will be awarded the Slottow–Owaki Award; and Allan R. Kmetz, who will receive the Lewis and Beatrice Winner Award. n By Jenny Donelan

Cover Design: Acapella Studios, Inc. 12 Frontline Technology: Solid-State Lighting for Illumination and Displays: Opportunities and Challenges for Color Excellence Solid-state light sources are transforming luminaires and information displays, enabling screens to illuminate rooms and luminaires to form images. Maintaining color excellence, from all perspectives, will be challenging but worthwhile. In the Next Issue of By Lorne Whitehead Information Display n Display Week Show Issue and 22 Frontline Technology: Why People Should Care About Light-Field Displays Light-field displays have a wide range of potential applications, including 3-D television and Automotive Displays projection systems, technologies for vision assessment and correction, and small form factors • 2014 Display Industry Awards with support for focus cues in head-mounted displays. • Products on Display n By Gordon Wetzstein • Automotive Overview • Touch in Vehicle Displays 30 Symposium Preview: Inspiration and Innovation Abound at Display Week’s • ID Magazine Retrospective Annual Technical Symposium This year’s technical program at Display Week features more than 460 papers on topics ranging from quantum dots to light-field displays. n By Jenny Donelan

INFORMATION DISPLAY (ISSN 0362-0972) is published 6 times a year for the Society for Information Display by Palisades Convention 36 Show Review: CES 2015: The Show of Everything (SoE) Management, 411 Lafayette Street, 2nd Floor, New York, NY 10003; William Klein, President and CEO. EDITORIAL AND BUSINESS For a consumer-electronics show, CES 2015 was noticeably shorter on traditional consumer- OFFICES: Jay Morreale, Editor-in-Chief, Palisades Convention electronic products than in previous years. Enterprise solutions – such as automotive electronics Management, 411 Lafayette Street, 2nd Floor, New York, NY 10003; telephone 212/460-9700. Send manuscripts to the attention of the and displays – received as much attention as TVs. Editor, ID. SID HEADQUARTERS, for correspondence on sub- scriptions and membership: Society for Information Display, 1475 n By Ken Werner S. Bascom Ave., Ste. 114, Campbell, CA 95008; telephone 408/879- 3901, fax -3833. SUB SCRIPTIONS: Information Display is distributed without charge to those qualified and to SID members as a benefit of 43 SID News: SID New England Chapter Hears about Advanced Display membership (annual dues $100.00). Subscriptions to others: U.S. & Canada: $75.00 one year, $7.50 single copy; elsewhere: $100.00 one Technology year, $7.50 single copy. PRINTED by Wiley & Sons. PERMISSIONS: Abstracting is permitted with credit to the source. Libraries are per- mitted to photocopy beyond the limits of the U.S. copyright law for 48 Sustaining Members private use of patrons, providing a fee of $2.00 per article is paid to the Copyright Clearance Center, 21 Congress Street, Salem, MA 01970 (reference serial code 0362-0972/15/$1.00 + $0.00). Instructors are permitted to photocopy isolated articles for noncommercial classroom 48 Index to Advertisers use without fee. This permission does not apply to any special reports or lists published in this magazine. For other copying, reprint or For Industry News, New Products, Current and Forthcoming Articles, republication permission, write to Society for Information Display, 1475 S. Bascom Ave., Ste. 114, Campbell, CA 95008. Copyright © 2015 see www.informationdisplay.org Society for Information Display. All rights reserved.

Information Display 2/15 1 ID Editorial Issue2 p2,44_Layout 1 3/15/2015 8:15 PM Page 2

Information editorial DISPLAY Executive Editor: Stephen P. Atwood The Pace of Innovation 617/306-9729, [email protected] Editor-in-Chief: Jay Morreale by Stephen Atwood 212/46 0-9700, [email protected] It seems that everywhere I turn I hear or read something Managing Editor: Jenny Donelan referring to the rapidly increasing “pace of innovation.” 603/924-9628, [email protected] Any reasonable person could look at the breadth of technology Global Advertising Director: developed over the last few decades and compare that to a Stephen Jezzard, [email protected] comparable period of time a couple of centuries ago and see the difference. It is not just in electronics but all fields Senior Account Manager of science, including agriculture, medicine, atmospheric Print & E Advertising: studies, astronomy, geology, genetics, and on and on. In a Wired magazine essay Roland Espinosa (November 2013), Bill Gates said key innovations such as synthesizing ammonia and 201-748-6819, [email protected] immunizing against polio are reasons why as much as 40% of our world’s population 1 is alive today. Certainly among those 40% are some really good innovators them- Editorial Advisory Board selves, helping to feed the growing trend with their own achievements. Stephen P. Atwood, Chair A question we might pose is how to quantify this increasing pace and in so doing Azonix Corp., U.S.A. derive a model similar to Gordon Moore and his “Moore’s Law” about the rate of Helge Seetzen increasing density of transistors in integrated circuits. Possibly, one could start with TandemLaunch Technologies, Westmont, Quebec, Canada a similar premise that some arbitrary metric of human-science output could or would Allan Kmetz double every X years. Pick a field, pick a problem area, and start measuring. Consultant, U.S.A. In any attempt to model a system, you need to define the inputs and outputs in some Larry Weber rational way. The outputs are relatively easy to define and measure: better weather Consultant, U.S.A. forecasts, lower mortality rates, cleaner air, improved quality of life, etc. In terms of inputs, innovation is fueled by the need to solve a problem, the human drive for Guest Editors creativity and achievement, and the availability of vital resources. Those resources almost always include money and time – both of which can be in short supply. But, as Flexible Technology and Wearables Ruiqing (Ray) Ma, Universal Display Corp. anyone at a high-tech company can tell you, the right innovation, properly monetized and nurtured, can become a veritable flood of additional income that can then be Applied Vision James Larimer, ImageMetrics re-invested to solve all kinds of future problems. Of course, true innovation can happen without regard to money but in many cases, Automotive Displays and especially in our industry, money is a necessary input to the process and that Silvio Pala, Denso International America money usually must come from the commercial success of ongoing efforts. In other Touch and Interactivity words, we need our current ideas to make money so we can invest in the commercial- Bob Senior,Canatu ization of our new ideas. Because of this reality, it would be great if we could apply Display Metrology some form of empirical model that would tell us which ideas will be commercially Tom Fiske, Consultant successful and which will not – so we could focus our resources on the best ideas first. TV Technology But, clearly, history has shown that it is practically impossible to know in advance Achin Bhowmik, Intel Corp. which ideas will lead to commercial success and which ones will not. The challenge develops when people try to predict the future potential of ideas based Contributing Editors on the framework they have in the present time. Without being able to “see” the future, Alfred Poor, Consultant we are stuck in a tug of war between our imaginations and our practical senses. Being Steve Sechrist, Consultant practical means it is almost always easier to see what can go wrong, to understand Paul Semenza, Consultant how an idea can fail, and to say “no” when asked for support. It is harder to take risks Jason Heikenfeld, University of Cincinnati (especially financial ones) by saying “yes” to new ideas. Consider the last hundred Raymond M. Soneira, DisplayMate Technologies years of work on computer technology and all the incredibly creative milestones along the way. At almost every step there were decision makers rejecting the new ideas as

either unreasonable or too unlikely to succeed based on what they knew at the time. The opinions expressed in editorials, columns, and This negative pressure slowed the pace of computer innovation, but did not stop the feature articles do not necessarily reflect the opinions of true believers who, when met with seemingly endless resistance, went their own way, the Executive Editor or Publisher of Information Display Magazine, nor do they necessarily reflect the position of found their own resources, and proved the conventional establishment wrong. the Society for Information Display. (continued on page 44)

2 Information Display 2/15 ID Industry News Issue2 p3,43_Layout 1 3/18/2015 7:45 PM Page 3

industry news

3 years that Apple’s iPhones have been the But Apple’s iPhone 6 and 6 Plus launched 700 Million Apple iPhones Sold best-selling smartphones in a given quarter. with non-sapphire screens and GT Advanced to Date The breakthrough is largely the result of an filed for bankruptcy in October 2014. A set- Competitors and industry pundits have been Apple deal with China’s largest mobile tlement agreement between GT Advanced and saying for years that Apple’s ascendancy is provider, China Mobile. Apple’s sales in Apple was announced late in 2014. 2 over, but to paraphrase Liberace, Apple is China increased 70% last quarter. The next mobile Apple device to launch crying all the way to the bank. In March, Sales like these are obviously keeping will be the Apple Watch, scheduled for release Apple CEO Tim Cook announced that the iPhone suppliers happy. While Apple is close- on April 24. According to the feature list mak- company had sold more than 700 million mouthed regarding its supply chain, manufac- ing the rounds of the technology press, the iPhones since the launch of the product in 2007. turers such as LG, Japan Display, and Innolux Apple Watch will have sapphire glass. In the fourth quarter of 2014 alone, according are widely assumed to be among its display 3 to Apple Insider, Apple sold nearly 75 million suppliers. One supplier that did not reap the ______iPhone 6 and 6 Plus units, which works out to benefits of iPhone 6 sales is GT Advanced 1 http://appleinsider.com/articles/15/03/09/ 34,000 iPhones every hour, 24 hours a day, Technologies, which Apple, as reported earlier 1 apple-shipped-700-million-iphone-6-iphone-6-plus- every day of the quarter. The iPhone 6 and in ID magazine, had contracted with in units-since-launch 6 Plus were released in September 2014. November 2013 to build a new facility to pro- 2http://money.cnn.com/2015/03/03/technology/ A recent article in Money noted that the duce sapphire, a scratch-resistant transparent mobile/apple-iphone-top-smartphone/ fourth quarter of 2014 was the first time in material that can be used for mobile devices. 3http://bgr.com/2014/05/19/iphone-6-display-specs/

. . . All about Those Dots . . . At CES last January, major TV manufacturers like Samsung and LG were showing LCD TVs enhanced with quantum dots for increased color saturation and gamut. Quantum-dot-enhanced TVs, writes ID contributor Ken Werner in his review of CES in this issue, are the 4K TVs of last year, meaning that 4K has become more commoditized, and quantum dots are the current high-priced differentiator for TVs. Certainly, 2015 is the year that QDs move from something a few people know about to something a lot of people know about. “As is typically the case,” says display industry analyst Paul Semenza, “the development of quantum dots was an instance of technology push, not market pull. However, once the materials became available, they came to be viewed by some as a way for LCD to improve its color performance relative to that of OLED.” A few quantum-dot facts and updates: • Quantum dots, which are tiny nanocrystals, were discovered in the 1980s by Russian scientists Alexander Efros and Aleksey Ekimov, as well as by Louis Brus at Bell Labs.4 • Quantum dots are somewhat controversial from an environmental standpoint because many contain heavy metals such as cadmium. Even the extremely small size of cadmium dots (thousands of times smaller than the width of a human hair) makes them potentially more hazardous to humans than larger particles. However, in a typical display the quantum dots would be so encapsulated as to pose negligible risk to humans, according to a recent report from phys.org. Of greater concern are manufacturing safety and end-of-life issues.5 • Quantum-dot-maker QD Vision is addressing these concerns and received a Presidential Green Chemistry Challenge Award last year from the EPA for its use of quantum-dot technology in energy-efficient commercial display and lighting products. QD Vision’s processes involve fewer hazardous building blocks and solvents, reduce solvent waste, and increase yields in such a way as to ensure a net positive environmental benefit. In addition, TVs using the company’s quantum dots use substantially less power than non-QD counterparts.5 • Nanoco Technologies makes cadmium- and heavy-metal-free quantum dots. Last fall, the company entered into a partnership with Dow Chemical Company in which Dow was to manufacture quantum dots using technology licensed from Nanoco at a facility Dow was building in Korea. In January 2015, LG and Dow announced that LG would be using the Dow/Nanoco quantum dots to produce TVs. • The Vermont-based company VerLase won a patent last year for quantum-well technology that it hopes will replace phosphors and quantum dots in multiple LED applications. Its Versulite G material incorporates wurtzite ZnCdSe quantum wells on 2-D layered semiconductor crystal. Product development is still in early stages. ______4http://en.wikipedia.org/wiki/Quantum_dot 5http://phys.org/news/2015-01-quantum-dot-tvs-toxic-ingredients.html

(continued on page 43)

Information Display 2/15 3 ID Guest Editorial Issue2 p4_Layout 1 3/15/2015 8:03 PM Page 4

SID EXECUTIVE COMMITTEE President: President-Elect: Regional VP, Americas: Regional VP, Asia: Regional VP,A. Europe: Ghosh guest editorial Treasurer: Y. S. Kim Secretary: A. Bhowmik Past President: B. Wang DIRECTORSP. Kathirgamanathan Properly Controlling Light Is a Human-Factors H. Seetzen Bangalore: T. Tsujimura Engineering Problem Bay Area: B. Berkeley Beijing: Belarus: by Jim Larimer Canada: T. Ruckmongathen Greater Dayton:J. Pollack DelawareX. Valley: Yan The idea that through every point in space rays of light are MetropolitanA. Smirnov Detroit: traveling, carrying information about the surfaces of objects France: J. Vieth Hong Kong: D. G. Hopper the light has interacted with as it ricochets through space, is India: J. W. Parker III Israel: J. Kanicki a concept as old as the camera obscura. Leonardo da Vinci Japan: F. Templier Korea: H. S. Kwok referred to the light passing through a point in space as a Latin America: 1 S. Sambandan “radiant pyramid.” It has only been possible recently to use the insights da Vinci had Los Angeles:G. Golan Mid-Atlantic:K. Kondoh 500 years ago to build imaging products that can capture and replicate some of the Mid-Europe:K.-W. Whang New England: A. Mammana information contained in these radiant pyramids. Today, we stand on the threshold of Pacific Northwest:L. Tannas that possibility. Light-field imaging, or as it is also called, computational photography, Russia: J. Kymissis Singapore: H. De Smet is now the future for cameras and displays. Southwest: S. Atwood Taipei: A. Abileah To effectively use these ancient insights requires an understanding of how optics, Texas: V. Belyaev U.K. & Ireland: computing, and human vision work together. To create stereo-pair imagery that T. Wong Ukraine: S. O’Rourke requires no head gear and that will work at any head orientation relative to the display Upper Mid-West:J. Chen Z. YanivCOMMITTEE CHAIRS requires two different images for each head position separated by 6 cm and containing S. Day Academic:V. Sergan information unique to each eye location. A light-field display holds the promise that Archives: B. Bahadur Audit: this may soon be feasible. Bylaws: It is even possible to imagine a future where every aspect of looking through an Chapter FormationP. Bos – Europe: Conventions:L. Tannas, Jr. ordinary window, including focusing your eye anywhere that attracts your attention, ConventionsS. O’Rourke Vice-Chair, BC and MC: can someday be replicated on a display. Several seemingly solvable technical hard- ConventionsA. Silzars Vice-Chair, Europe: Conventions Vice-Chair, Asia: H. De Smet ware problems need to be worked out to do this. Equally important will be determining Definitions & Standards:P. Drzaic Display Industry Awards: J. Jacobs how many rays must pass through the observer’s pupils from every point on the virtual Honors & Awards: I. Sage I-Zone: objects for the rendered scene to seem real to the observer. K.-W. Whang Investment: T. Fiske One of the articles in this issue of Information Display, by Gordon Wetzstein, Long-Range Planning: W. Chen Membership: F. Luo delves into those insights and relates how this new and exciting technology will work. MembershipB. Schowengerdt Vice-Chair, Social Media: Nominating: H. Seetzen Compressive light-field ideas tap the advantage provided by the relatively long temporal Publications: Y. S. Kim integration time of the human eye compared to the speed of electrical devices. Senior MemberH.-S. Grade: Kwok Web Site: H. Atkuri Da Vinci was aware that if several pinholes are placed in the front surface of a B. BerkeleyCHAPTER CHAIRS H. Seetzen camera obscura, several radiant pyramids will form images on the rear surface of the Bangalore: Y. S. Kim 2 Bay Area: H. Seetzen camera. These images are slightly different from each other due to parallax, and they Beijing: are not in register. As the number of pinholes is increased, the resulting projections Belarus: Canada: S. Sambadam lose the distinctive sharpness of the camera obscura image and tend towards blur. Dayton: R. Rao The entrance aperture of a camera, and the pupils in our eyes, collect a connected DelawareN. Valley: Xu Detroit: V. A. Vyssotski set of pinholes, i.e., a finite sample of the light field; without a lens the rays passing France: A. Kitai Hong Kong:J. Luu through the aperture would form a blurry image on the retina or on the projection India: J. Blake Israel: surface of a camera. A larger aperture allows more light to reach the projection J. Byrd Japan: L. Vignau surface, making the resulting image brighter but also less sharp. With a lens placed in Korea: M. Wong Latin America:S. Kaura the plane of the aperture, objects in the visual scene that are at the focal distance of the Los Angeles:I. Ben David Mid-Atlantic:K. Kondo lens are brought into register on the retina or projection surface. Objects that are Mid-Europe:S. T. Shin nearer or farther away from this focal distance remain blurry in projection. The New England: V. Mammana Pacific Northwest:L. Iboshi distances within which the edges formed in the image are sharp-appearing define the Russia: G. Melnik Singapore/Malaysia:H. J. Lemp depth of field of the camera and lens. Lenses were discovered within a couple of Southwest: J. Gandhi Taipei: hundred years of the camera obscura and were soon incorporated into these cameras K. Yugawa Texas: M. Sychov to form a brighter image, trading off brightness for depth of field. U.K. & Ireland: C. C. Chao Ukraine: M. Strnad At the time of the discovery of the camera obscura and the lens, there was no way Upper Mid-West:C. C. Wu SOCIETYR. Fink FOR INFORMATION DISPLAY to exploit the sharpness and parallax information contained in each pinhole camera M. Jones V. Sorokin (continued on page 45) R. D. Polak

1475 S. Bascom Ave., Ste. 114, Campbell, CA 95008 4 Information Display 2/15 408/879-3901 e-mail: [email protected] http://www.sid.org A display that outperforms all others – elegantly, efficiently and affordably.

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See Us at Display Week 2015, Booth #834 ID Donelan H&A p6-11_Layout 1 3/17/2015 7:48 PM Page 6

SID’s best and brightest

2015 SID Honors and Awards

This year’s winners of the Society for Information Display’s Honors and Awards include Junji Kido, who will receive the Karl Ferdinand Braun Prize for his outstanding contributions to the science and technology of OLEDs and pioneering contributions to commercializing white OLEDs for general lighting applications; Shohei Naemura, who will be awarded the Jan Rajchman Prize for his outstanding achievements in the chemical physics of liquid crystals and contributions to research on LCDs; Ingrid Heynderickx, who will receive the Otto Schade Prize for her outstanding contributions to the measurement, specification, and improvement of the image quality of electronic-display technologies; Jin Jang, who will be awarded the Slottow–Owaki Award for his major contributions to display education and active-matrix-display development, including AMOLED displays, AMLCDs, and flexible displays; and Allan R. Kmetz, who will receive the Lewis and Beatrice Winner Award for his exceptional and sustained service to the Society for Information Display.

by Jenny Donelan

NCE AGAIN, the Society for Information order to perpetuate the display industry. Four “paid back” SID through volunteer activities. ODisplay honors those individuals who have of the five awardees are professors. Junji Lewis and Beatrice Winner award recipient made outstanding contributions to the field Kido from Yamagata University not only Allan Kmetz has held numerous roles within of displays, with awards in the category of teaches graduate students, but works with jun- SID, from president to editorial advisor (he Fellow and Special Recognition, as well as ior-high and high-school students so they can still serves in the latter capacity to this maga- the Braun, Rajchman, Otto Schade, Slottow– gain hands-on experience with OLED devices. zine). Although these activities represented Owaki, and Lewis and Beatrice Winner Ingrid Heynderickx found that a teaching work above and beyond his regular job, “I awards. Recipients are nominated by SID environment permitted her to gain valuable never really considered not volunteering,” members and selected by a process involving insights from students. Jin Jang has advised says Kmetz. the Honors and Awards Committee and SID’s 183 graduate students at Kyung Hee Univer- This comment illustrates something else Board of Directors. Fan Luo, chairman of the sity, and the vast majority of these have this year’s winners have in common – their awards committee, notes that it is always moved on to work in the display industry not willingness to take action, whether through difficult to select the award winners because only in Korea, but all over the world. These research, teaching, or volunteering. When there are so many candidates who have made are but three examples of how this year’s asked what his advice would be to a young major contributions to the display industry. award winners are nurturing the next generation person looking to start a career in display Therefore, this year’s winners represent the of display professionals. research, Naemura says, “I would convey best of the best. Another way to grow the display industry messages from two great persons out of the A striking commonality among this year’s is to become involved in the Society for Western and the Eastern worlds: award recipients is their willingness to pass Information Display, and all of this year’s What we have to learn, we learn by doing. along their knowledge and enthusiasm in winners have engaged in SID activities over – Aristotle the years. As a young researcher, Shohei Jenny Donelan is the Managing Editor of Naemura helped promote his career by I see and I forget. I hear and I remember. Information Display Magazine. She can be presenting at SID’s technical symposium. As I do and I understand. reached at [email protected]. he matured and became more successful, he – Confucius

6 Information Display 2/15 0362-0972/2/2015-006$1.00 + .00 © SID 2015 ID Donelan H&A p6-11_Layout 1 3/17/2015 7:48 PM Page 7

Karl Ferdinand Braun Prize Shohei Naemura first discovered liquid This award is presented for an outstanding crystals as a student at Kyoto University in 1968. technical achievement in, or contribution to, He didn’t know what they were – they just display technology. sounded interesting to him. His initial hunch Dr. Junji Kido, SID Fellow and Professor paid off. Forty-seven years later, he is still find- in the Department of Organic Device Engineer- ing out interesting things about liquid crystals, ing at Yamagata University, will receive the and these discoveries have forwarded the industry. Karl Ferdinand Braun Prize “for his outstand- Naemura’s results include the operation ing contributions to the science and technol- mechanism of liquid-crystal displays (LCDs) ogy of OLEDs and pioneering contributions by focusing on the interfacial region between to commercializing white OLEDs for general the liquid-crystal (LC) material and the display lighting applications.” panel substrate, and also the relationship Junji Kido has spent a lifetime researching between the macroscopic physical properties OLED technologies and applications. Among and the chemical structures of LC materials. his major accomplishments are the invention His achievements in these areas were indis- of the first white-light-emitting OLED and the pensable to the development of LC materials invention of tandem OLEDs that result in very and their commercialization as well as to the long lifespans at high luminance levels with research and development of modern LCDs an internal quantum efficiency that can exceed with improved picture quality. 100%. According to Hoi-Sing Kwok, Director of “In Japan,” explains Ching Tang, a Professor Dr. Junji Kido the Center for Display Research at the Hong at the University of Rochester and the Hong Kong University of Science and Technology: Kong University of Science and Technology, Kido is also training and inspiring future “His research is both theoretically interesting “Junji Kido is not only a towering figure generations of display and organic electronics as well as important to practical applications. among OLED researchers, he is probably the scientists. “He is an eager educator, not only This is the hallmark of a good applied physicist.” best known public spokesman and the for his students at Yamagata University, but Looking back on his research career, strongest advocate for everything related to also for younger generations,” notes Toshio Naemura says: “The biggest challenge was to OLEDs.” Suzuki, Vice-President of R&D at Kuraray make organic materials (liquid-crystalline Kido is the primary pioneer of the develop- America. “He invites junior-high and high compounds) functional in electronic devices ment of white OLEDs. His first white OLED school students to his laboratory to let them (display devices, especially active-matrix used a polymer emitter layer dispersed with experience the preparation and characteriza- LCDs).” Going forward, he says, “[The fields several kinds of fluorescent dyes. The second tion of their own OLED devices. Many students of] chemistry and physics, including electron- was fabricated with successive vacuum depo- become inspired by organic electronics and ics, should work cooperatively in developing sition of blue, green, and red emitter layers some of them eventually join Kido Lab in LC materials, which work together with thin- so that the resulting emission became white. order to further their interests.” film transistors in display panels, for instance.” These latter results were so notable that they Kido has also founded commercial enter- were reported by major international publica- prises such as Lumiotec, Inc., created in 2008 tions. In 1995, The Wall Street Journal as a joint venture with Mitsubishi Heavy described his work in an article entitled Industry, Toppan Printing, Rohm, and Mitsui “Japanese Light Researcher May Turn LED Company to manufacture white OLED panels into Gold.” for lighting. He is a co-founder of Organic Tang also points out another important Lighting Corp., which manufactures OLED aspect of Kido’s work. “It is widely acknowl- lighting fixtures. He is also the recipient of edged that the tandem device structure holds many prizes, including, in 2013, the Medal with the key to solving the short-lifetime problem Purple Ribbon from the Emperor of Japan. in OLED devices, which has been a major obstacle in the development of practical OLED Jan Rajchman Prize technology. Because the tandem structure This award is presented for an outstanding essentially allows an arbitrary number of scientific or technical achievement in, or con- individual OLED devices to be connected in tribution to, research on flat-panel displays. series, a tandem OLED device can therefore Dr. Shohei Naemura, SID Fellow and produce high luminance (at a low current Guest Professor at Tottori University, will density) without compromising the operational receive the Jan Rajchman Prize “for his out- stability. This invention has made possible a standing achievements in the chemical wide range of applications from large-area physics of liquid crystals and contributions to HDTVs to lighting based on OLEDs.” research on LCDs.” Dr. Shohei Naemura

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SID’s best and brightest

Naemura notes that his involvement with produced pioneering work in the areas of company she has been affiliated with for her SID was essential to his career. “When I started psychophysical methods, saliency and atten- entire career. my research as a young engineer, it was my tion measurement, eye-tracking, and large According to Scott Daly (Senior Researcher target to present a paper every year at the SID subjective rating databases. It is difficult to at Dolby Laboratories and previous Otto technical symposium, and thus I may say that find an aspect of display image quality to Schade winner): “Professor Heynderickx’s I was developed by SID as a researcher. which she has not made a contribution. She research career has included a wide range of Later, in gratitude, I became involved in the has also shepherded these research results into topics, with results that have found significant society in order to make SID more attractive practical commercial advances, such as the usage by engineers in the display-industry and instructive, especially for young engineers technologies Pixel Plus, Ambilight, and pipeline – from capture and generation to in the display science and technology field.” LifePix at Philips Research Laboratories, a transmission and display.” To that end, he served as General Chair of IDW ’02, Chair of SID’s Japan Chapter, General Chair of Asia Display/IDW ’01, Executive Chair of IDW ’00, Program Chair 2015 SID Fellow Awards of IDW ’98, and President of the Japan The grade of Fellow is conferred annually upon SID members of outstanding Chapter, as well as in numerous other roles. qualifications and experience as scientists or engineers whose significant contributions to the field of information display have been widely recognized. Otto Schade Prize The Otto Schade Prize is awarded for out- Hidefumi Yoshida, “for Anne Chiang, “for her standing scientific or technical achievement his many significant pioneering contributions in, or contribution to, the advancement of contributions to LCD to electrophoretic display functional performance and/or image quality technology, especially technology and significant of information displays. wide-viewing multi- innovations in the devel- Dr. Ingrid Heynderickx, SID Fellow, domain vertical-alignment opment of polysilicon-TFT and Dean of Industrial Engineering and Inno- LCDs, including protru- technology.” vation Sciences at Eindhoven University of sion geometry, photo-alignment process, Dr. Chiang is Principal of Chiang Con- Technology, “for her outstanding contribu- halftone technology, and fast-response sulting. She received her Ph.D. in physical tions to the measurement, specification, and architecture.” chemistry from the University of Southern improvement of the image quality of elec- Dr. Yoshida is a Department General California. tronic-display technologies.” Manager with Sharp Corporation. He Ingrid Heynderickx has played a leading earned his Ph.D. in engineering from the role over the last two decades in the applica- Tokyo Institute of Technology. tion of psychophysics and human subjective testing to the optimization of image quality in John F. Wager, “for his Ryuichi Murai, “for his electronic displays. In particular, she has pioneering contributions outstanding contributions to the development of to the research and devel- oxide TFTs.” opment of PDPs, CRTs, Dr. Wager is a professor flat CRTs, and OLED dis- The 2015 winners and holds the Michael and plays and nurturing and will be honored at the SID Judith Gaulke Endowed leadership in the PDP as Honors & Awards Banquet, Chair in the School of Electrical Engineer- well as other display communities.“ ing and Computer Science at Oregon State Mr. Murai is a researcher with Panasonic which takes place Monday evening, University. He has a Ph.D. in electrical Corporation. He has a B.S. from Osaka June 1, 2015, during engineering from Colorado State University. University. Display Week at the Fairmont Hotel in San Jose. Fujio Okumura, “for his pioneering Tickets cost $95 and must be contributions to the research and development of LTPS-TFTs and SOG purchased in advance – they will devices and significant contributions not be available on-site. to the advancement of the display community.” Visit www.displayweek.org Mr. Okumura is a Senior Manager for more information. with NEC Corporation. He has an M.S. in electrical engineering from Yokohama National University.

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chair of the European Program Committee. “I really learned a lot from the interaction with various committee members and regular visitors of SID. I yearly met people that I admired a lot for their expertise in the field of applied visual perception, and they were always willing to listen to my research and give advice. Especially for me, being rather iso- lated in this area of research here in Europe, it was great to have the opportunity to meet other members of the global visual-perception research community.”

Slottow–Owaki Prize The Slottow–Owaki Prize is awarded for out- standing contributions to the education and training of students and professionals in the field of information displays. Dr. Jin Jang, SID Fellow and Professor at Dr. Ingrid Heynderickx Kyung Hee University, will receive the Dr. Jin Jang Slottow-Owaki Prize “for his major contribu- Heynderickx’s degrees are in physics, but tions to display education and active-matrix- cal research and creates manufacturing proto- she discovered human factors early on in her display developments including AMOLED types – the teaching is automatically com- career. Her first task at Philips Research, where displays, AMLCDs, and flexible displays.” bined with those activities. His advice to she began working in 1987, was to find a To date, Jin Jang has advised the thesis and young students anywhere currently consider- solution for the poor image quality of LCDs dissertation research of 183 graduate students ing a career in displays: “Flexible displays under oblique viewing angles. She developed (43 Ph.D. and 144 Master’s degrees.) Most of have been a hot area recently, so job opportu- an electro-optical model for LCDs and used it these graduates are now working in the display nities would be good for students who study to evaluate the performance of an LCD under industry, with 54 at Samsung Display Co., 40 oxide TFTs on plastic, LTPS TFTs on plastic, different viewing angles. But she immediately at LG Display, and others at numerous compa- thin-film encapsulation for OLEDs, and realized that she needed visual-perception nies in Korea as well as in Japan, the U.S., the plastic AMOLEDs.” knowledge in order to understand which devi- U.K, France, Taiwan, and China. “I have met Jang himself started out in the display ations from optimal performance would be many students from Jin Jang’s group,” says industry as a doctoral student in physics, visible to humans. So she visited the Institute Heiju Uchiike, a former colleague of Jang’s at working on TFTs and thin-film solar cells. for Perception Research (then at Eindhoven Kyung Hee University. “They are very hard Shortly after graduating, he collaborated with University of Technology) to find out more. working and have a wide vision of display Samsung on TFT-LCD research; this experi- It was a lightbulb moment for her. “From the research. In particular, the students that have ence, he says, set him solidly in the direction first, I envied their research area,” says Heyn- graduated from his laboratory are making of display research. derickx, who afterwards gradually but steadily great contributions by developing displays in Jang also became involved with SID early became more involved in the applied visual many areas of the private sector.” on, joining the organization in the late 1980s perception of displays and lighting systems. At the graduate school of Kyung Hee and becoming a program committee member In 2005, she began teaching at both the University, where he is currently a professor, in 1995. He has served in many other roles as Southeast University of Nanjing in China and Jang established a display major in 1997 and well since then, including program chair of at the University of Technology in Delft, The then a Department of Information Display in the SID symposium and general chair of Netherlands. She eventually moved to full- 2004. The latter now accepts 60 students Display Week and IMID. He estimates that he time teaching in part so that she could pursue every year and has 12 professors. has attended all the SID symposia in the U.S. the kinds of long-term research more com- In addition to being a prolific teacher, Jang and all the IDW conferences in Japan for the monly found at universities than at private is also known for research. Among his last 20 years. “I have made many friends in companies. She has also found it inspiring to discoveries have been a novel technique to Japan, Taiwan, the U.S., and Europe by attend- work with students. “They force you to care- crystallize a-Si at low temperatures as well as ing SID-sponsored conferences,” says Jang. fully think through and formulate your reason- well-received research on self-organized dep- ing and to continuously look at your findings osition, flexible displays, oxide TFTs, QLED Lewis and Beatrice Winner Award from a different perspective.” displays, and more. The Lewis and Beatrice Winner Award for Heynderickx has been an active member of Jang says that he has been lucky enough to Distinguished Service is awarded to a Society SID for many years, having served as chair of pursue both teaching and research because his member for exceptional and sustained service the applied-vision subcommittee and also as department at the university performs practi- to SID.

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SID’s best and brightest

Dr. Allan R. Kmetz, SID Fellow and conference on displays. I was a new face in a In this last capacity, “Allan was wonderful display-industry consultant, will receive the new field and the SID program committee to work for and with,” says Jenny Bach, for- Lewis and Beatrice Winner Award “for his invited me to join them. I agreed and appar- mer SID Data Manager and previous recipient exceptional and sustained service to the ently couldn’t stop.” of the Lewis and Beatrice Winner Award. “As Society for Information Display.” He has not stopped yet. Kmetz is currently president of SID from 2002 to 2004, Allan Forty years of involvement with SID began on the editorial board of this magazine, having made fantastic achievements,” says Shigeo in graduate school for Lewis and Beatrice assisted for more than 10 years in helping ID Mikoshiba, also a past-president. “His super- Winner recipient Allan R. Kmetz. “My thesis to be technically (and also grammatically) clear and systematic way of thinking clarified advisor at Yale was an officer of the IEEE accurate. He has served SID in a multitude of the path to progress for SID. Academic as Magnetics Society and he dragged me along capacities, including lecturer and seminar well as financial activities were significantly to conferences he organized,” explains Kmetz. organizer, program committee member, chair promoted through his efforts.” “After switching to displays in my first year at of the SID Technical Symposium, Honors and Many who worked with Kmetz over the Texas Instruments, it just seemed natural to Awards Committee member, bylaws chair, years are quick to cite his work on the organi- submit two papers to the first joint IEEE/SID and last but not least, president of the Society. zation’s bylaws. Says Past-President

2015 SID Special Recognition Awards Presented to members of the technical, scientific, and business community (not necessarily SID members) for distinguished and valued contributions to the information-display field.

Jun Ho Song, “for his invention and product Toshio Kamiya, “for his outstanding contribution development in simplifying the TFT process for to the material science of amorphous-oxide semi- LCD devices and the development of 22-in. TFT- conductors.” LCD TV in 1995 and integrated a-Si gate driving Dr. Kamiya is a professor and the Vice-Director in TFT-LCDs in 2005.” of the Materials Structures Laboratory at the Tokyo Dr. Song is a master researcher at Samsung Institute of Technology. He earned a Ph.D. in engi- Display Company. He has a Ph.D. in quantum neering at the Tokyo Institute of Technology. optical physics from Korea University.

Byoungho Lee, “for his leading contributions to Yasuhiro Koike and Akihiro Tagaya, “for their three-dimensional display technologies based on leading contributions to the research of zero- integral imaging and holography.” birefringence polymers, highly birefringent poly- Dr. Lee is a professor in the Electrical Engineer- mers, and highly scattered optical-transmission ing Department at Seoul National University. He polymers and their applications in LCDs.” has a Ph.D. in electrical engineering and computer Dr. Koike is a professor with the Faculty of science from the University of California at Berkeley. Science and Technology at Keio University. He has a Ph.D. in engineering from Keio University. Dr. Tagaya is a Project Professor at the Graduate Byeongkoo Kim, “for his leading contributions to School of Science and Technology, Keio Univer- the research and development of AH-IPS technol- sity. He has a Ph.D. in engineering from Keio ogy for high-end displays including smartphones, University. tablets, notebooks, monitors, and automotive displays.” Dr. Kim is Vice-President of LG Display. He has a Ph.D. in electrical and computer engineering from Pohang University of Science and Technology. Shunpei Yamazaki, “for discovering CAAC-IGZO semiconductors, leading their practical applica- tion, and paving the way to next-generation displays by developing new information-display devices such as foldable or 8K x 4K displays.” Dr. Yamazaki is president of Semiconductor Energy Laboratory. He received his Ph.D. in engi- neering from Doshisha University.

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SID International Symposium, Seminar & Exhibition May 31–June 5, 2015 San Jose Convention Center San Jose, California, USA

Dr. Allan R. Kmetz Munisamy Anandan: “Allan was bylaws chair Rolling Out the Red Carpet during my term as president. He examined in detail the bylaws of the student branches and I-Zone new chapters. He spent an enormous amount of time editing the drafts of bylaws submitted by student branches from regions where English was not the first language. Allan was also responsible for defining different categories of membership accurately in SID Competition of live demonstrations bylaws.” Individualregarding emerging Honors information-display and Awards From Kmetz’s own standpoint, one of the technologies, such as not-yet-commercialized prototypes and more rewarding aspects of his volunteer proof of concepts. career at SID has been the annual paper- selection process with the liquid-crystal subcommittee. “This has been one part of SID that has put me face to face with the very The SID Board of Directors, based on recommendations made brightest in the field of displays,” says Kmetz. Displayby the Honors Industry & Awards Awards Committee, grants several annual “The value I gained from this has been both awards based upon outstanding achievements and significant professional and personal.” contributions. Kmetz received his doctoral degree in engi- neering from Yale University in 1969 and went on to work for Texas Instruments, Brown Boveri Research Center in Switzer- BestEach in year, Show the AwardsSID awards Gold and Silver Display of the Year land, Bell Laboratories, and Agere Systems Awards in three categories: Display of the Year, Display Appli- before retiring in 2003 to become an inde- cation of the Year, and Display Component of the Year. pendent display consultant. He is the author of numerous technical papers and co-editor of the book Nonemissive Electrooptic Displays. The Society for Information Display highlights the most signif- He holds 16 U.S. and 45 foreign patents. His Journal of the Society for Information Display (JSID) icant new products and technologies shown on the exhibit active display technology and intellectual- Outstanding Student Paper of the Year Award property consulting duties include aiding in floor during Display Week. JSID portfolio evaluation and serving as an expert witness. n

Each year a sub-committee of the Editorial Board of selects one paper for this award which consists of a plaque Information Display 2/15 11 and a $2000 prize. ID Whitehead p12-20_Layout 1 3/17/2015 8:00 PM Page 12

frontline technology

Solid-State Lighting for Illumination and Displays: Opportunities and Challenges for Color Excellence

Solid-state light sources are transforming luminaires and information displays, enabling screens to illuminate rooms and luminaires to form images. Maintaining color excellence, from all perspectives, will be challenging but worthwhile.

by Lorne Whitehead

T is interesting to compare the simple displays will soon start making significant The purpose of this article is to make a incandescentI lamps that dominated the early contributions to general illumination, similar contribution toward that shared understanding. days of lighting with today’s flat-screen to the way windows contribute significantly to It provides an overview of the key design televisions. TVs are impressive, but in two indoor illumination while also making rooms factors in both fields and suggests that soon important ways the lowly incandescent lamp more interesting. Another way to think of this there may be improved solutions for optimally “outshines” them: first, incandescent lamps is that we should reasonably expect our electric satisfying all of the main requirements. emit more than 10 lm of visible light for each light sources to provide more than just light – watt of electrical power, whereas a typical why shouldn’t they also provide the added The Significance of Solid-State LED-illuminated LCD TV emits less than value of visual information? Lighting 1 lm. Second, incandescent lamps emit very As the blending of illumination and infor- By now, people are well aware that solid-state high-color-quality light, yet most TVs emit mation display gets under way, society will lighting devices, such as light-emitting diodes light that has unacceptably poor color quality face some important human-factors issues (LEDs) and organic light-emitting diodes for illumination purposes. In short, today’s involving color perception. These relate to (OLEDs), are a revolutionary addition to the displays make for great televisions but terrible the spectral power distribution (SPD) of light field of lighting. A common assumption is lamps! Some find this quite surprising since and its impact on the accuracy and range of that their primary distinguishing feature is LEDs themselves are now much more efficient color reproduction in displays, as well as the high efficiency. But while these devices are than incandescent lamps and they can be color-rendering quality and photo-biological indeed efficient, they do not dramatically blended to make high-color-quality light. influences of the light emitted by displays. surpass the efficiency of previous sources Of course, some may feel this comparison As it becomes practical to produce light with such as high-intensity discharge and mercury is irrelevant because screens are rarely used almost any desired SPD, designers will have fluorescent lamps. The characteristic of LEDs for illumination, but that is bound to change. the freedom to adjust these factors, but in that may be the most transformative is their After all, for decades, screens have become doing so they will face design trade-offs ability to efficiently produce light in a narrow cheaper, brighter, larger, clearer, and more because what is best from one perspective is band of wavelengths and for the center of that commonplace and that trend is certainly often not best from another. Often the parties output band to be selectable, during manufac- continuing. We can anticipate that image influencing an overall design may have differ- ture, at almost any desired points in the visible ing views of the relative importance of these spectrum. As a result, it is possible to com- Lorne Whitehead is a Professor in the factors. For this reason, it is important to bine the light from a number of LEDs to Department of Physics and Astronomy at achieve a shared understanding of them. produce almost any desired SPD. For the first the University of British Columbia located in Lighting designers and display designers will time, engineers have spectral design freedom. Vancouver, Canada. He can be reached at need to coordinate closely for optimal success Here, it is argued that they also have a respon- [email protected]. as their areas of work begin to overlap. sibility to exercise this freedom wisely.

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Figure 1 shows an SPD for each of three light sources: a typical non-LED lamp (a fluorescent lamp that contains numerous peaks associated with the underlying mercury- vapor discharge) and two quite different LED lamps. Note that the vertical axis in Fig. 1 is dimensionless because the curves in this figure depict, for each lamp, the ratio of the light intensity at each wavelength to the peak value, which, by definition, is 1.0. In order to explore the key perceptual phenomena arising from a very wide choice of SPDs, it will first be helpful to review some basic concepts of human color vision.

Key Characteristics of Human Color Vision In human color vision, wavelength informa- tion concerning light is detected by means of three types of light-sensitive retinal cone cells (labeled L, M, and S), which have peak wave- length sensitivities in, respectively, longer, medium, and shorter wavelength regions of the visible spectrum. Their sensitivity functions are shown in Fig. 2. It is important to note that the response Fig. 1: Shown are spectral power distribution (SPDs) for a mercury fluorescent lamp, a white functions shown in Fig. 2 are relative. One phosphor LED, and a lamp that blends three narrow-band LEDs. way to think of this is that if a certain degree of stimulation of a particular cone cell is produced by one unit of radiant power at that cone’s wavelength of peak sensitivity, then two units of radiant power would be required to produce the same stimulation using a radiation wavelength for which that cone sensitivity is half of its peak value. When calculating a cone’s response to light consisting of a blend of wavelengths, the radiant power at each wavelength must be multiplied by the cone’s sensitivity at the same wavelength and so these individual contributions can then be added up. Thus, the response of each cone contains no information about specific wavelengths that caused its stimulation; color information is known to the visual system only by means of the relative degree of stimu- lation of the three cone types. For example, longer-wavelength light will stimulate the L cones to a greater degree than the M or S cones because L cones have greater sensitivity at longer wavelengths than do the M or S cones. In turn, this pattern of cone stimulation (which creates the sensation of red light) indi- cates that the stimulus must have consisted of predominantly longer-wavelength light. Overall, this means that the brain can obtain Fig. 2: The relative spectral sensitivity functions for the L, M, and S retinal cone cells appear information about the spectral distribution of in red, green, and blue, respectively.

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light by observing the pattern of stimulation Fortunately, in this article, it is not neces- by the light SPD, and the results, summed to of the three cone cell types. Interestingly, this sary to fully describe this remarkable percep- give the resultant L, M, and S values for the need to assess the intensity of cone stimula- tion process and indeed that is not even SPD in question, are shown in the last row. tion is somewhat problematic because of the completely possible since there are still a (The numbers shown are real – they were very wide range of lighting conditions that the number of unanswered questions. The primary calculated using this procedure with the SPD eye routinely encounters. In rough terms, the point here is that color vision is an extremely shown and the L,M,S sensitivity functions, a intensity range over which color vision oper- sophisticated system. In evolution, sophisti- process that is repeated in Figs. 4 and 5.) The ates spans a factor of 1,000,0001 (from sun- cated systems develop when they enhance sur- numerical values show roughly how closely light to moonlight). However, the optic nerve vival over vast time periods.8 In modern the light-source spectrum matches the sensi- (a bundle of nerve cells that carry information times, people generally greatly value aspects tivity function for the L, M, and S cones. from the eye’s retina to the brain) can only of life that were necessary for survival, such Sources with predominantly longer wave- convey a limited number of signal levels. The as health and fitness, good food, and security. lengths stimulate the L cones the most, while number of discernable signal levels probably From this perspective, it makes sense that the predominantly shorter wavelengths stimulate depends on the kind of optical information beauty and subtlety of color perception is very the S cones most. being transmitted and is not precisely known, important to many people, and this is further Since we only have three cone types, this but there are clues that can provide a rough evidenced by the vast color-related businesses information is only approximate, but neverthe- idea. in paints, dyes, fabric, cosmetics, industrial less it can be very useful in distinguishing One of these clues is that, as recognized by design, and marketing. Therefore, it is very between different light sources. (It should also typical reference books of sample colors,2 important to maintain high color quality both be noted that the raw L, M, and S values shown there are only about 40 distinguishable hues in information displays and interior illumina- here represent information at the beginning of around the color circle. The exact number is tion, and it stands to reason this will matter the signal-processing stages mentioned earlier, not critical to the following comparison: Using even more as the two fields begin to overlap. and the subsequent stages leading to what we 40 levels as an example, if one attempted to Studies of how people use color information actually perceive are more complex, but fortu- evenly represent the required million-fold have led to the realization that color vision nately not needed for the present discussion.) range of intensity in just 40 equal ratiometric serves two purposes that are related but differ- While information about light-source color steps, each of those steps would represent ent. In the first, people perceive color as an is useful, that is not the most important, nor about a 40% intensity change. But the typical informative property of light.9 In the second, the most sophisticated use of color vision. just-noticeable difference in light intensities is people perceive color as an informative property actually a lot less – often on the order of 8% of the manner in which a surface reflects light10 for shades of gray, and in certain cases of (a distinction that will be made clearer shortly). color perception as little as a 1% difference in We’ll begin with the first – assessing the relative cone stimulation may be noticeable.3 color of light. Not only is it the simpler of the Clearly, this sensitivity would not be possible two, but also it is a building block for the if the intensity of cone stimulation was directly perception of surface color. Figure 3 shows communicated by the optic nerve, and yet the symbolically how the eye assesses the color of color-vision system does exhibit this high light landing on the retina. sensitivity over most of the million-fold range The top row in Fig. 3 is simply an arbitrarily of illumination intensity previously men- selected SPD; it is a graph of spectral power tioned. This remarkable perception accuracy intensity vs. wavelength, which is useful is achieved through sophisticated signal pro- information. For example, moonlight and cessing, beginning with adaptive non-linear firelight have quite different spectral distribu- compression within the cones4 followed by tions, as do a clear and cloudy sky. Therefore, sophisticated signal processing in the retina.5 information about the intensity and spectral Furthermore, after the resultant processed distribution of a light could help a person information is received by the brain, even determine the source that emitted it. The more complex processing takes place,6 pro- same can be true in the human-made environ- viding to our conscious awareness a remark- ment. For example, we are familiar with the ably stable and reliable depiction of color idea that a red traffic light is a universal information. The last processing stages are so symbol for “Danger! Stop!” The visual important that some say we “see” mainly with system can recognize a red light through the our brain,7 not our eyes. In other words, what corresponding heightened stimulation of L we consciously perceive is an image gener- cones, which are the most sensitive to the long ated by a massive computer (the brain), based wavelengths associated with the color red. upon many factors, including information The next row in Fig. 3 shows the L, M, and Fig. 3: The stimulation of the S, M, and L from the eyes about how objects in the world S cone responses while the remaining rows cones is determined by spectral power distri- are influencing the incident light field. depict the way they are effectively multiplied bution (SPD).

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Fig. 4: Surface color is determined by comparing the S, M, and L cone Fig. 5: The schematic represents an extreme case of poor color stimulations arising from light reflected from an object of interest to the rendering in which a white source illuminates a normally gray surface S, M, and L cone stimulations arising from light reflected by a white and causes it to appear orange. surface, when both the object of interest and the white surface are illu- minated by the same light source.

Color vision’s second purpose, the assessment reflected light is the product of the surface here, but this simple division calculation is of surface color, is depicted in Fig. 4. (Do not reflectance at each wavelength multiplied by often a good approximation and is sufficient worry if you find Figs. 4 and 5 too complex to the source intensity at that wavelength, and the for the purposes of this article.) easily follow in detail – just getting the gist of color of that reflected light is then assessed, The process of effectively referencing the them will enable you to easily follow the resulting in the listed L, M, and S values. That color of a surface to the color of the illumi- remainder of this article.) is, on the left we have L, M, and S values for nant is called chromatic adaptation, and it is The main point in Fig. 4 is that surface color the surface of interest and on the right side the very important because it provides reliable perception involves two separate assessments of larger L, M, and S values for the white surface. determination of surface color, somewhat light color that happen at the same time. The The last two rows of Fig. 4 show the unique independent of the color of the illumination. left half of Fig. 4 is concerned with light and important characteristic of surface color For example, people can accurately judge the reflecting toward the eye from a surface of perception: The L, M, and S values for the ripeness of a banana, based on its color, when interest, and the right half is concerned with surface of interest are divided by, respectively, it is illuminated by daylight or by incandes- light reflecting toward the eye from a white the L, M, and S values for the white surface, cent light. Even though the color of the incan- surface. Importantly, both surfaces are illumi- yielding effective reflectance values weighted descent light is pale orange in comparison to nated by the same light source, depicted as by the L, M, and S sensitivity functions. daylight, the perceived subtle shades associ- the SPD shown at the top center of the figure. (It should be pointed out that, in general, the ated with a ripening banana are not substan- On both sides of the figure, the SPD of the processing is not nearly as simple as depicted tially changed. Without the sophistication of

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chromatic adaptation, the accuracy and relia- that a special SPD has been selected for the color. As real life examples, some popular bility of our perception of surface color would light source, and also a different special energy-efficient lamps make tomatoes seem be severely diminished. function has been selected for the spectral pale, while purple petunias appear blue. In turn, diminished color-perception accu- reflectance function of the object of interest. Overall, there are two desirable features of racy would be problematic because accurate In both cases, the function alternates from natural illumination that we would like to assessment of surface color is useful – it gives high to low as a function of wavelength, preserve indoors. First, surface colors indoors us information about spectral reflectance which is unusual but possible. should appear similar to their natural color function of the surfaces around us. That is, The light source shown in the top row outdoors. Second, if two objects have match- over large portions of the visible spectrum, we appears white (because it stimulates the L, M, ing surface color under natural illumination, can estimate roughly what fraction of the inci- and S cones approximately equally), and the they should also have matching surface color dent illumination is reflected by an object, and surface represented here, when illuminated by indoors. This reliability gives meaning to the this can then tell us about the materials that daylight, would appear gray (because in that idea of surface color; it enables people to con- are present within the object’s surface. For case its reflected light stimulates the L, M, sider the precise shade of surface color to be a example, the spectral reflectance function of and S cones equally). However, the simple property of a surface. Therefore, we should human skin is affected by degree of oxygena- arrangement in Fig. 5 has a perplexing out- try to minimize surface color distortion. Light tion of hemoglobin molecules, which relates come: When this particular white light shines sources that fulfill this requirement are said to to health.11 Similarly, such information can on this particular gray surface, it appears have high color rendering.13 This idea is quan- help us know if various foods are fresh.12 orange! (This can be seen in Fig. 5, where tified by the CIE Color Rendering Index.14 The reason for distinguishing between the the bottom-row ratios RS, RM, and RL So, how do LEDs impact color rendering? assessment of light color and surface color is correspond to those normally found for an Well, on the positive side, the spectral design that they depend in very different ways on the orange surface color.) This is because both freedom provided by solid-state lighting SPD of light, which, in turn, places different the source SPD and the surface spectral makes it fairly easy to produce smoothly vary- constraints on color excellence in displays and reflectance function have narrow features in ing SPDs that do not distort color, and so it in illumination. Let’s now consider these rela- the wavelength dimension that interact, via would seem reasonable, going forward, to tionships, first for the case of illumination and the reflection process, in a way that distorts expect no further problems with color render- then for displays. surface color. This is an extreme case, but ing. Ironically, the opposite is the case, as a many common electric lamps cause smaller, result of a simplistic response to a fundamental Color-Perception Quality Issues with but still unpleasant, distortions of surface trade-off between color quality and luminous Illumination Since color perception evolved with daylight as the dominant source of illumination, and daylight remains unchanged and universally available today, it makes sense that people prefer to have artificial lighting provide the same color appearances that we see under daylight. This requirement is not terribly constraining because daylight itself comes in a wide variety of SPDs. Generally, all of these different daylight SPDs have the common characteristic of a fairly smoothly varying SPD. In some cases, there is a relatively smaller intensity at longer wavelengths (as with illumination from blue sky) and in others relatively more (as with sunlight near sunrise or sunset), yet in both cases white objects look white and the appearance of other objects appear consistent and natural, largely as a result of the chromatic adaptation taking place within the visual system. Let us now consider a very important concept known as color rendering. To help understand it, we’ll consider an example of a source SPD under which colors can appear extremely distorted. Consider Fig. 5, which is almost identical to Fig. 4, showing the obser- vation of a surface color. The only change is Fig. 6: Depicted is the the photopic luminous-efficacy function.

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efficacy. To help explain this, consider Fig. 6, Lastly, for completeness, it is important to spectral sensitivity function has a similar shape which shows the overall light sensitivity of bear in mind another quality factor that is not to that of cone cells, with a peak response the human color-vision system, showing a directly color related but that does influence located between those of the M and S cones. peak response at 555 nm and a smooth fall-off the best choices for LED lamp design. This is Given these important effects, it would seem to either side. the topic of the photo-biological impact of wise to ensure that the relative amount of The average luminous efficacy of a lamp light. In the human retina, there is an impor- IPRGC stimulation approximately match what will be greater if its SPD has more of its energy tant recently discovered class of photoreceptors is normally found in daylight during the day close to the peak of Fig. 6. Put the other way known as intrinsically photosensitive retinal and what is found in dim incandescent sources around, an SPD will have less average lumi- ganglion cells (IPRGCs). They have been during the evening. Generally, this will be the nous efficacy if a significant portion of its shown to send signals to the brain that do not case for fairly uniform spectral distributions, intensity lies near the ends of the distribution. directly cause visible sensation but which but it will require careful design consideration Unfortunately, that is what is needed for high influence the diameter of the eye’s pupil18 and when working with narrow-band LEDs. color-rendering quality. In other words, in have also been linked to reduction of seasonal designing a lamp’s SPD, we are forced to affective disorder and synchronization of Color-Perception Quality Issues with choose between producing more visible light circadian rhythm.19 Recently, significant circa- Information Displays or higher color quality; we cannot maximize dian rhythm disturbances have been observed Let us now consider how the principles of both at the same time. Fortunately, this turns to result from late-night use of e-Readers20 color vision influence the design of displays. out to be a very mild tradeoff – in most practi- with backlighting. The IPRGC relative Color reproduction has been practical for a cal cases only a 10% reduction in luminous efficacy is needed to maintain reasonably high color quality. And, importantly, this requires no power increase; the power can be kept con- stant while reducing the illuminance by 10% – a decrease that is essentially imperceptible – while providing an improvement in color quality that is very noticeable. Once this trade-off is properly understood, it is clear that color rendering can take priority without any negative consequences. High-color-rendering light is simply better for people, overall. Nev- ertheless lighting color quality is currently threatened by the widespread misunderstand- ing of the relative importance of luminous efficacy and color rendering.15 A related issue is that the current method for assessing color rendering (the aforemen- tioned CIE Color Rendering Index) has certain inaccuracies when rating narrow-band light sources.16 Fortunately, a new improvement for that metric is under development by the CIE17 and is expected to overcome that diffi- culty. This will be helpful because phosphor- free narrow-band LEDs have the potential to be the most efficient light sources, and achieving high color rendering with them will require accurate design. Another critical requirement for high-color- quality lighting is the avoidance of undesir- able color variations between the various sources illuminating a room. Between rooms, people are comfortable with a range of lighting conditions (just as daylight comes in a range of colors), but within a given room even small color differences can distort the color appear- ance of objects, so such variations should be Fig. 7: This CIEx,y chromaticity diagram also shows the maximum possible luminous efficacy avoided. of radiation at selected x, y coordinates.

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long time because of a key simplification second in the green region, and the third in the Another difficulty with wide-gamut displays arising from the fact that we only have three blue. This is the standard well-known concept is that they intensify natural differences types of cone cells. Two SPDs that cause the of additive color mixing as used in most elec- between human observers. The L, M, and S same level of stimulation of the three cone tronic image displays.23 cone response functions shown in Fig. 2 result cell types will have the same color appear- Less well-known are some key color-vision mainly from special light-sensitive molecules ance, even though they may have very differ- issues associated with the choice of additive that differ in the three cone types but are the ent intensities at various wavelengths. (In this primaries. One of these relates to the tradeoff same in the great majority of people with case, the SPDs are described as metameric.) between gamut and efficacy. The numbers normal color vision, which is why three Generally, the overall shapes of metameric shown within the colored region of Fig. 7 depict primary systems work fairly well for most SPDs are somewhat similar, but at a detailed the maximum possible luminous efficacy of people. However, the eye has light transmis- level they may be very different. Because SPDs with that chromaticity coordinate, shown sion losses that modify the cone response there are only three cone cell types, it follows in lm/W. (These values were obtained by functions to some degree, and these losses are that for most SPDs, an SPD of matching color numerically optimizing a source SPD subject more variable from one person to another and appearance can be generated by adding to the constraint that it have the specified x,y even over a person’s life.23 As a result, the together a selected amount of three so-called coordinate.) The maximum possible efficacy accuracy with which a blend of primaries will “primary” SPDs. Typically in information is 683 lm/W, which occurs with monochro- match the appearance of a real scene varies displays, the three primaries used appear red, matic light with a wavelength of 555 nm and somewhat from person to person, an effect green, and blue. appears yellow. All other chromaticity coor- sometimes called metameric error. It is not a From this perspective, a convenient way to dinates have lower values, tending toward zero large problem, but it can be bothersome, and, characterize any given SPD is by the relative at the extreme red and blue ends of the spectrum. unfortunately, the severity of this problem degree to which they excite the three cones. The net result is that there is a fundamental grows with the gamut area of a display. Generally, these can be described by a pair of trade-off when selecting primary stimuli for Finally, from a practical point of view, it is numbers that are determined from the ratios of color displays. On the one hand, we would more difficult to accurately reproduce subtle the cone excitations, and there are many like them to be as far as possible into the pastel colors if the underlying primaries are different ways to do that. Here, we will use “corners,” so as to encompass the largest extremely vivid – greater control precision is the most common one – the familiar CIEx,y triangle of possible colors. (This is called the then required. For these reasons, there has chromaticity coordinates,21 as shown in Fig. 7. “gamut” of the display and generally it is felt always been a tug of war involved in design- The curved envelope shown in Fig. 7 that a larger “gamut area” is better because it ing primary-color stimuli for information depicts the x,y chromaticity coordinates of all allows a wider range of colors to be repro- displays. of the individual spectral wavelengths, rang- duced.) This forces us to use primaries that Finally, there is a new concern that relates ing from about 400 nm at the bottom left to have low efficacy, thus wasting energy or to the image content that a wide-gamut display about 700 nm at the bottom right. Connecting sacrificing brightness, or both. can show. In recent decades, researchers have the two ends of the spectral points is the so- called purple line segment, coordinates that can only be achieved by blending monochro- matic blue light from one end with monochro- matic red light from the other. The primary significance of this diagram is as follows: Consider a first SPD that corre- sponds to a first point in the diagram and a second SPD that corresponds to a second point. Any mixture of the two distributions will correspond to a point in the diagram lying somewhere on the straight-line segment con- necting the first point with the second point. Furthermore, if there is a third distribution corresponding to a third point, all mixtures of these three distributions will correspond to points located within the triangle formed by the three points. There are two key practical implications – first, the only possible coordi- nates are those lying in the colored region within Fig. 7. Second, most chromaticity coordinates can be made through mixtures of three primary stimuli, the first of which has Fig. 8: In Times Square in New York City, most of the night-time light comes from displays. chromaticity coordinates in the red region, the The chart at right shows the SPD and the CRI of the resulting ambient lighting.

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learned that long-term adaptation mechanisms take place in the human-visual-perception system in response to exposure to extreme stimuli. For example, exposure to significant amounts of intense red light can distort the balance of red-green response of an observer, and this effect can persist for days or weeks.24 It is possible that similar adaptation could occur to exposure to extremely high-color- contrast stimuli, which would normally be extremely rare in ordinary life. The adapta- tion could take the form of reduced contrast sensitivity, meaning that day-to-day colors could appear less colorful after such exposure. In this sense, high-color-contrast displays could be habit forming. There could be troubling psychological consequences of such exposures, and we should be particularly wary of exposing children to excessive amounts of such stimuli. Now we can take Fig. 9: Chromaticity coordinates and SPDs for a hypothetical six-primary-color display a look at how these factors will become more system are shown. important as the anticipated blending of infor- mation display and illumination proceeds. Emotional and photo-biological effects: It been less well appreciated, but is now becom- is important to understand that color vision is ing a strong driving force for this improvement, Human-Factor Trade-Offs As Information one of the most sophisticated human senses is the way in which this design overcomes the Displays and Illumination Blend and that our visual experiences, both con- other key concerns that have been mentioned As a concrete example, consider Fig. 8, show- scious and unconscious, have a profound above. Unlike wide-gamut three-primary sys- ing a recent night-time photo of New York’s impact on our sense of well being. We do not tems, the six-primary system ameliorates the Times Square and a graph of the SPD of the yet have a good understanding of these issues, following previously mentioned problems: 25 ambient lighting. and this calls for caution. Pending greater Efficacy: The inefficient deep-red and deep- That ambient lighting comes almost entirely understanding, we should at least minimize blue primaries are responsible for a small por- from the surrounding LED video displays, and exposure to stimuli that differ dramatically tion of the light, so overall efficacy is excellent. its Color Rendering Index is only 52, which is from the sorts of visual conditions under Metamerism: The deviations from viewer unacceptable for conventional lighting. Ironi- which our eyes evolved. It is possible to to viewer are very significantly reduced with cally, while the people shown on those screens produce impressive and dramatic color experi- this system because the typical SPDs are appear in their natural color, the people illu- ences with solid-state lighting, but their exces- smoother, so more people will see better color minated by the screens may not. sive use is unlikely to be good for people. most of the time. It is apparent that the challenges of the exist- Color rendering: The smooth spectral ing lighting design trade-offs will worsen as Conclusion and a Look to the Future: characteristics can yield excellent color- displays become providers of light as well as Six-Primary Displays? rendering properties without significantly imagery. The problems fall into three categories: When faced with difficult trade-offs, it is reducing efficiency or gamut. Gamut: The display industry push toward natural to ask if there can be a breakthrough Looking toward the future, we now have higher gamut will cause further problems as that lets us have our cake and eat it too. much greater motivation to achieve all of displays provide illumination because three- Indeed, for some time an idea has been float- these desirable outcomes simultaneously. primary wide-gamut lighting has very poor ing around the display industry that could be a Fortunately, it seems likely that color excel- color rendering, thus distorting the color major step forward – the use of a larger lence, from all perspectives, can be practically appearance of familiar illuminated objects. number of primaries.26 Figure 9 depicts this maintained as the fields of illumination and Color balance: Typically, the average chro- idea conceptually within the x,y chromaticity image display gradually overlap. maticity of the light produced by televisions is diagram and through graphing the SPDs for a bluer than the usual values for indoor illumi- theoretical six-primary display system. References nation. Unless handled well, this can cause The primary reason that such displays have 1R. Shapley and C. Enroth-Cugell, “Visual color-appearance distortion even if the screen been proposed in the past is to achieve even adaptation and retinal gain controls,” Progress output light is intrinsically of high color quality. greater gamut than can be achieved with any in retinal research (Elsevier, 1994). There will need to be reasonable limits on the three-primary system. Any color can be pro- 2http://www.pantone.com/pages/products/ size of the color difference between the light duced that lies within the six-sided polygon product.aspx?pid=1351&ca=92, retrieved output of displays and ambient lighting. defined by their six x,y coordinates. What has January 29, 2015.

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3Wyszecki and Stiles, Color Science, 2nd E. Gerner, and M. Rollag, “Sensitivity of the Networking Events edition (Wiley Classic Library Edition, 2000), Human Circadian System to Short-Wave- p. 306. length (420-nm) Light,” J. Biol Rhythms 23, May 31–June 5, 2015 4D. Endeman and M. Kamermans, “Cones 5, 379–386 (October 2008). perform a non-linear transformation on natu- 20A. Changa, D. Aeschbacha, J. Duffy, and Looking to meet up with ral stimuli,” Journal of Physiology 588, C. Czeisler, “Evening use of light-emitting your colleagues in the display 435–446 (February 1, 2010). e-readers negatively affects sleep, circadian industry to discuss 5M. D. Fairchild, Color Appearance Models, timing, and next-morning alertness,” PNAS technology, business, or 2nd edition (John Wiley and Sons), p. 15. 112, 4, 1232–1237; doi:10.1073/pnas. just socialize? The events 6M. A. Webster and J. D. Mollon, “Change in 1418490112 21 below present just that type colour and appearance following post-recep- J. Schanda, Colorimetry: Understanding the of opportunity: toral adaptation,” Nature 349, 235–238 (1991). CIE System (John Wiley and Sons, 2007), 7L. Silverstein, personal communications p. 34. 22 Annual Awards Dinner, Monday: (December 7, 2011). http://www.huevaluechroma.com/044.php. 8S. E. Palmer and K. B. Schloss, “An ecologi- D. Briggs, “The Dimensions of Color,” cal valence theory of human color prefer- retrieved January 29, 2015. ence,” Proceedings of the National Academy 23G. Johnson and M. Fairchild, “Full-Spectral of Science 107, 19, 8877–8882 (2010). Color Calculations in Realistic Image Synthe- Each year, SID recognizes individuals 9M. D. Fairchild, Color Appearance Models, sis,” IEEE Computer Society 19, 04, 47–53 that have played a critical role in 2nd edition (John Wiley and Sons), p. 55. (July/August 1999). improving the display industry. 10M. D. Fairchild, Color Appearance Models, 24J. Neitz, J. Carroll, Y. Yamauchi, M. Neitz, This year’s winners will be honored Business Conference Reception, 2nd edition (John Wiley and Sons), p. 183. and D. Williams, “Color Perception Is Medi- at an awards banquet taking place 11 A.Th. Schäfer, “Colour measurements of ated by a Plastic Neural Mechanism that Is Monday:the evening of June 1 at the San Jose Convention Center. pallor mortis,” International Journal of Legal Adjustable in Adults,” Neuron 35, 4, 783–792 Medicine 113, 2, 81–83 (February 2000). (15 August 2002). 12C. R. Chen and H. S. Ramaswamy, “Color 25Spectroradiometer measurements recorded and Texture Change Kinetics in Ripening by Starr Davis, ARUP, New York, NY, AnnualFollows Award the Business Luncheon, Conference, Wednesday: Bananas,” LWT – Food Science and Technol- personal correspondence (May 2, 2013). please note conference attendance is ogy 35, 5, 415–419 (August 2002). 26T. Ajito, T. Obi, M. Yamaguchi, and required for admission. 13K. Houser, M. Mossman, K. Smet, and N. Ohyama, “Expanded color gamut repro- L. Whitehead, “Tutorial: Color Rendering and duced by six-primary projection display,” Its Applications in Lighting,” LEUKOS, Proc. SPIE 3954, Projection Displays 2000: The annual Best in Show and Display DOI:10.1080/15502724.2014.989802; Sixth in a Series, 130 (April 25, 2000). n Industry Awards Luncheon will take published online: 21 Jan 2015. place at noon on Wednesday, June 3. 14Commission Internationale de l’Eclairage Both awards are peer-reviewed, (CIE), “Method of measuring and specifying such that the luncheon is well- colour rendering properties of light sources,” attended by captains of industry for 1995, Vienna (Austria): CIE. Publication No. Investorshigh-level Conference:networking and recogni- CIE 13.3-1995, p. 16. tion of the best in the industry over 15 the last year. K. Papamichael, M. Siminovitch, J. Veitch, and L. Whitehead, “High Color Rendering VISIT Provides Better Color Without Requiring The IC will feature presentations More Power,” LEUKOS (in press) (2015). from leading public and private com- 16K. Smet, J. Schanda, L. Whitehead, and INFORMATION panies in the display technology sup- R. Luo, “ CRI2012: A proposal for updating ply chain and encourage questions the CIE colour rendering index,” Lighting and discussion between presenters Res. Technol. 45(6), 689–709 (2013). DISPLAY ON-LINE and participants. Concludes with 17 MarketDrinks &Focus Displays: Conference Networking Commission Internationale de l’Eclairage Reception,Reception with Wednesday: Presenters and Technical Committee 1–90. 18 For daily display Investors M. Spitschan, S. Jain, D. Brainard, and G. Aguirre, “Opponent melanopsin and S-cone signals in the human pupillary light industry news response,” www.pnas.org/cgi/doi/10.1073/ Follows the Wednesday Market pnas.1400942111 www.informationdisplay.org Focus Conference, title and program 19 www.displayweek.orgTBD, please note conference atten- G. Brainard D. Sliney, J. Hanifin, dance is required for admission. G. Glickman, B. Byrne, J. Greeson, S. Jasse,

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Why People Should Care About Light-Field Displays

Light-field displays have a wide range of potential applications, including 3-D television and projection systems, technologies for vision assessment and correction, and small form factors with support for focus cues in head-mounted displays.

by Gordon Wetzstein

ANY PEOPLE believe that the recent displays and recent trends toward compressive back to the beginning of the last century. Mhype about stereoscopic 3-D displays is over, light-field displays, followed by a discussion In 1908, Gabriel Lipmann built the first inte- at least for the moment. Part of the reason why of applications in projection systems, vision grated light-field camera and display using 3-D television, in particular, has not been assessment and correction, wearable displays, integral imaging.1 He mounted microlens widely adopted by consumers may be the lack and a brief comparison to holography. arrays on photographic plates, then exposed of a truly unique or useful enhancement of the and developed these plates with the lens 2-D viewing experience. At the same time, From Integral Imaging to Compressive arrays in place such that they could be viewed light-field displays are expected to be “the Light-Field Displays as a light field or glasses-free 3-D image future of 3-D displays.” So what makes The invention of light-field displays dates after the fact. Over the course of more than people believe that a new technology deliver- ing an experience that consumers have not adopted in the past will work in the future? This article does not attempt to outline possible future scenarios for 3-D television applications. Instead, we discuss a range of unconventional display applications that are facilitated by light-field technology that per- haps would benefit much more than conven- tional television from emerging capabilities. Whereas glasses-based stereoscopic displays present two different views of a scene to the eyes of an observer, light-field displays aim for a multiview solution that usually removes the need for additional glasses. Conceptually, a light-field display emits a set of all possible light rays (over some field of view) such that the observer can move anywhere in front of the display and his eyes sample the appropri- ate viewing zones (Fig. 1). The next section outlines a short historical review of light-field Fig. 1: In this conceptual sketch of a light-field display, several people enjoy glasses-free 3-D Gordon Wetzstein is an assistant professor at television. The emitted light field (top right) is a collection of images depicting the same scene Stanford University. He can be reached at from slightly different horizontal and vertical perspectives. These images are all very similar, [email protected]. hence compressible. Image courtesy Wetzstein et al. (Ref. 10).

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100 years, many alternative technologies have optical systems that have the capability to two of its characteristics are particularly emerged that deliver a glasses-free 3-D expe- synthesize a compressed target light field. In important for 3-D display design: visual rience;2 for example, holography, volumetric effect, each pixel emits a superposition of acuity and the critical flicker fusion threshold displays,3,4 multi-focal-plane displays,5–7 and light rays; through compression and tailored (CFF). Usually, 3-D display capabilities are multi-projector arrays.8,9 However, extreme optical designs, fewer display pixels are created by reducing either the resolution of requirements in feature sizes, cumbersome necessary to emit a given light field (i.e., a set the screen or multiplexing information in form factors, and high cost are some of the of light rays with a specific target set of radi- time. These are fundamental tradeoffs that reasons why none of these technologies has ances) than would be demanded with a direct cannot be easily overcome; basically, “there is found widespread use in consumer electronics. optical solution. no free lunch.” With an ever-increasing demand on image Implementations of compressive light-field The most reasonable thing to do would be resolution, one of the major bottlenecks in the displays include multiple stacked layers of to make tradeoffs where an observer would light-field-display pipeline is the computation. liquid-crystal displays (LCDs) (see Fig. 2), a not perceive them. Resolutions available in Consider the example of a high-quality light- thin “sandwich” of two LCDs enclosing a commercial panels are now at, or at least close field display with 100 × 100 views, each having microlens array, or, in general, any combina- to, the “retina” level. Adding 3-D capabilities HD resolution streamed at 60 Hz. More than tion of stacked programmable light modula- through spatial multiplexing, as is the case for 1 trillion light rays have to be rendered per tors and refractive optical elements.10 The integral imaging, reduces the resolution by a second, requiring more than 100 terabytes of main difference between stacked LCDs and factor that is equal to the number of light-field floating-point RGB ray data to be stored and conventional volumetric displays is the non- views. If only a few views are desired, this processed. Furthermore, with conventional linear image formation. Cascading LCDs may be a reasonable approach, but for wide integral imaging, one would need a display have a multiplicative effect on the incident field-of-field multiview displays, the loss in panel that has a resolution 10,000× higher light,10-13 with the polarizers between panels in resolution is unacceptable for an observer. than available HD panels. place or a polarization-rotating effect without With currently available panel resolutions, To tackle the big data problem and relax the polarizers.14 Volumetric displays, such as adding 3-D capabilities through spatial multi- requirements on display hardware, compressive spinning disks or multi-focal-plane displays, plexing may actually decrease the overall light-field displays have recently been intro- are inherently additive, and hence provide a viewing experience because the gain in 3-D duced as a modern take on Lippmann’s vision. linear image formation. By using a 4-D capabilities may not be justified by the loss of They exploit two simple insights: (1) light frequency analysis,10,11 one can show that resolution. However, the critical flicker fields are highly redundant high-dimensional multiplicative non-linear displays, at least in fusion threshold of the human visual system is visual signals and (2) the human visual system theory, support high-resolution virtual content much lower than display refresh rates offered has limitations that can be exploited for visual to be displayed outside and in between the by consumer displays. LCDs can achieve signal compression. physical layers with high resolution. This is about 240 Hz, and MEMS devices run in the Rather than pursuing a direct optical solution not the case for additive multi-focal-plane kHz range. This is already widely exploited (e.g., adding one more pixel or voxel to displays. in active shutter-glasses-based 3-D displays, support the emission of one additional light The human visual system is a complex field-sequential-color displays (e.g., in projec- ray), compressive displays aim to create flexible mechanism. In addition to all the depth cues, tors), and also in time-sequential volumetric

Fig. 2: This compressive light-field prototype uses three stacked layers of LCDs (left) that are rear-illuminated by a single backlight. A non-negative light-field tensor factorization algorithm computes time-multiplexed patterns for all LCD layers (bottom right), which are then displayed at a speed exceeding the critical flicker fusion threshold of the human visual system. Perceptually, these patterns fuse into a consistent high-resolution light field that supports binocular disparity and motion parallax without the need for glasses (right). Image courtesy Wetzstein et al. (Ref. 10).

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displays. Although not perfect, it appears to form factors can be reduced, requirements for systems that provide an impressive image be the most reasonable choice if making display refresh rate and resolution can be quality and extreme depth of field have tradeoffs cannot be avoided. Compressive relaxed, and visual discomfort introduced by emerged.8,9 For horizontal-only parallax light-field displays usually are also time- the vergence-accommodation conflict can be systems, a one-dimensional array of projectors multiplex visual signals, but some incarna- mitigated. The design and implementation is mounted in front of or behind a vertical- tions10,15 are designed such that the same of such displays is at the convergence of only diffusing screen. The diffuser ensures hardware configuration allows for dynamic applied mathematics, optics, electronics, that the generated image is independent of tradeoffs in resolution, image brightness, 3-D high-performance computing, and human the vertical viewing position, whereas the quality, etc., to be made in software in a perception. horizontal directionality of individual projector content-adaptive manner. rays is preserved by the screen. As a viewer And although compressive light-field 3-D Projection: Toward the Holodeck moves in front of the displays, his eyes sample displays have so far only been demonstrated Large-scale glasses-free 3-D displays have a the emitted light field. As with any 3-D in the form of academic prototypes (Fig. 2), wide range of applications in collaborative display, there are tradeoffs. The number of the promised benefits make further research learning, planning and training, advertisement, required projectors directly scales with the and development worthwhile: traditional scientific visualization, and entertainment. desired field of view and angular density of resolution tradeoffs can be overcome, device Over the last decade, light-field projection emitted rays. In practical applications, dozens

Fig. 3: At left is a schematic of a compressive light-field projection system comprised of a passive angle-expanding screen and a light-field projector. On the right is a photograph of a prototype system demonstrating a field of view and viewing zone separation suitable for a 3-D display. Image courtesy Hirsch et al. (Ref. 16).

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of projectors are often employed, which screen pixels is a beam expander (or tiny two different views have to enter the same makes multi-projector light-field displays Keplerian telescope), which expands the field pupil to produce a retinal blur that triggers expensive, difficult to calibrate, power hungry, of view but inherently shrinks the pixel area accommodative responses.19 Although and sometimes bulky. These limitations may on the other side. The tradeoff is now researchers have attempted to produce faithful not be restrictive for some applications – for between pixel fill factor and desired angle focus cues – accommodation and retinal blur example, military training – but it could be amplification. A prototype system providing a – in addition to binocular disparity and motion argued that they make consumer applications field of view 5° for a monochromatic light parallax,13 it is very challenging to achieve currently unfeasible. field was recently demonstrated by Hirsch et high image quality, and diffraction places an The compressive light-field methodology al.16 This is a promising direction that may upper boundary on the achieved resolution. also applies to projection systems.16 In this lead to practical and low-cost 3-D projection The diffraction limit is critical in this context case, the goal is to “compress” the number of systems, but high-quality manufacturing tech- because transparent LCDs are high-frequency required devices, thereby increasing power niques for angle-expanding screens providing pixel grids that filter visual signals (or addi- efficiency, form factor, and cost of the system. a significantly higher angle expansion factor tional LCDs) physically located behind the The basic idea behind compressive light-field have yet to be developed. former LCDs such that those are optically projection is intuitive: ideally, one would only blurred via diffraction. The smaller the pixel use a single projector that generates a light Assessing and Enhancing Human Vision structures, the more blurred the spatial content field inside the device and emits it on a screen Perhaps one of the most unconventional appli- of farther display planes becomes. Hence, that preserves the angular variation of the cations of light-field displays is the assess- there is a type of uncertainty principle at light field. Diffusers would not be suitable for ment17 and correction18 of visual aberrations work: adding more and higher-resolution that task. Furthermore, the field of view of in a human observer (see Fig. 4). In essence, LCDs to the stack ought to increase the 3-D the emitted light field would only be as large the light-field display presents a distorted light capabilities of the device, yet it comes at the as the projector aperture, so at first glance this field to the eyes of the viewer such that her cost of reduced spatial resolution of other does not seem like a feasible option. aberrations undistort the light-field imagery, device components. A possible solution to this problem was resulting in the desired image. The idea is Ignoring stereo cues and motion parallax, recently presented16: a light-field projector very similar to wavefront correction with however, allows for practical light-field that employs two cascading spatial light coherent optics. The requirements on the displays to be built that support only focus modulators (SLMs) and a rear-illuminated light-field display are extreme in this case. cues.17,18 To assess visual aberrations, a passive screen that not only preserves angular For conventional 3-D displays, as discussed light field containing a pair of lines can be light variation but actually expands it such above, stereoscopic depth cues and motion presented to an observer such that the retinal that the perceived field of view is much parallax are usually sufficient. Hence, the projections exactly overlap when the viewer larger than the projector aperture. This angle emitted light field has to provide views that has normal or corrected vision but appear at expansion can be achieved by a screen that is are densely packed such that each of the eyes spatially distinct locations when that is not the composed of two microlens arrays with of the observer always sees a different image. case. By interactively aligning the lines, one different focal lengths, mounted back-to-back. For vision assessing and correcting displays, can manually pre-distort the light field until Each of the microlenses covers the area of a one not only needs to emit two different the pre-distortions are canceled out by the single pixel, thereby not compromising image images into the observer’s eyes, but multiple refractive errors of the eye. The amount of resolution. As illustrated in Fig. 3, each of the different images into the same pupil. At least manually induced pre-distortion then gives

Fig. 4: At left is a comparison between a conventional display and a vision-correcting light-field display. On the right are some application scenarios. Vision correcting displays could be integrated into existing displays and used in laptops, cellphones, watches, e-Readers, and cars to provide a comfortable eyeglasses-free experience. Image courtesy Huang et al. (Ref. 18).

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frontline technology

insights into the distortions in the eye. The idea but lifts the deconvolution problem into experiences. For immersive VR, this lack of procedure can be repeated for lines at varying the 4-D light-field domain, where it becomes support results in the well-known vergence- rotation angles, allowing for astigmatism to be mathematically well-posed. Current vision- accommodation conflict,21 which can lead to estimated as well as defocus. correcting displays require the prescription of visual discomfort and fatigue, eyestrain, Assuming that the refractive errors in the the viewer to be known (no changes to the diplopic vision, headaches, nausea, compro- eye are known, either from an eye exam or hardware are necessary; different prescrip- mised image quality, and even pathologies in through self-diagnosis, one can also emit tions can be corrected in software) and the developing visual systems. Only a few arbitrary light fields that are pre-distorted for pupil positions and diameters to be tracked. display solutions exist that support correct or a particular viewer. This approach creates a The latter is an engineering challenge that nearly correct focus cues;5,6 i.e., accommoda- vision-correcting display. Instead of correct- would have to be implemented to make tion and retinal blur. These are multi-focal- ing vision with eyeglasses or contact lenses, vision-correcting light-field displays robust plane displays that closely approximate the same can be done directly in the screen, enough for consumer devices. volumetric displays.3,4 Volumetric displays allowing for myopia, hyperoptia, astigmatism, can be interpreted as one special type of light- and even higher-order aberrations to be Near-to-Eye Displays field display that is capable of producing light corrected. One application of light-field displays that has distributions that are a subset of the full 4-D The main technical insight of recent work received a lot of attention recently are wearable light-field space. on vision-correcting displays is this: the image displays. With the emergence of Google Lanman et al.22 have recently shown that a presented on a conventional display appears Glass, the Oculus Rift, and, more recently, different implementation of a near-to-eye blurred for a viewer with refractive errors. Microsoft’s HoloLens near-to-eye displays for light-field display (i.e., integral imaging) is One could attempt to deconvolve the presented virtual reality (VR) and augmented-reality also suitable for supporting focus cues within image with the point-spread function of the (AR) applications in the consumer space have some range and at a reduced image resolution observer, such that the image and the become one of the most anticipated emerging (see Fig. 5). The focus of their paper was the observer’s visual defects together optically technologies. design of a very thin device form factor rather cancel out,20 but it turns out that this is usually Unfortunately, no existing near-to-eye than an in-depth evaluation of the range in an ill-posed mathematical problem. Employing display supports correct focus cues, which are which focus cues are actually supported. light-field displays, however, uses the same crucial for comfortable and natural viewing This idea is very similar to vision-correcting

Fig. 5: The shown near-to-eye light-field display provides a very thin form factor and correct or nearly correct focus cues within a limited depth range. Image courtesy Lanman et al. (Ref. 22).

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light-field displays: a virtual image is shown for vision assessment and correction, and one 6B. T. Schowengerdt and E. J. Seibel, “True outside the physical device enclosure. In of the “hottest” areas at the moment are appli- 3-D scanned voxel displays using single and principle, both could be combined into a cations to small form factors and the support multiple light sources, J. Soc. Info. Display single, slim near-to-eye display that supports for focus cues in head-mounted displays. 14(2), 135-143 (2006). focus cues and simultaneously corrects Even if public interest in any of these applica- 7G. Love, D. Hoffman, P. Hands, J. Gao, A. myopia, hyperopia, astigmatism, and higher- tions may diminish in the long term, light Kirby, and M. Banks, “High-speed switchable order aberrations in the eye. However, such a fields provide a fundamental framework that lens enables the development of a volumetric device has not been demonstrated yet. The allows almost all existing display technologies stereoscopic display,” Opt. Express 17, requirements for focus-supporting near-to-eye to be analyzed and compared in a unifying 15716–15725 (2009). light-field displays are the same as for vision- mathematical framework. The same frame- 8T. Baloght, “The HoloVizio System,” Proc. correcting displays: at least two different work also makes it intuitive to leverage SPIE 6055, 60550U (2006). views have to enter the same pupil.19 In modern signal processing and optimization 9A. Jones, K. Nagano, J. Liu, J. Busch, X. Yu, display applications, the algorithms doing algorithms, which has led to the emergence of M. Bolas, and P. Debevec, “Interpolating digital refocus in light-field cameras (“shift compressive light-field displays. Finally, very vertical parallax for an autostereoscopic 3-D and add light-field views”) are optically similar strategies can be employed to design projector array,” J. Electron. Imaging 23, performed in the eye. Overall, near-to-eye and build 2-D super-resolution and high- 011005 (2014). light-field displays hold great promise in dynamic-range displays.15,16,23 10G. Wetzstein, D. Lanman, M. Hirsch, and R. overcoming some of the most challenging Thus far, all of the recent advances in Raskar, “Tensor Displays: Compressive Light limitations of head-mounted displays today computational and compressive display tech- Field Synthesis using Multilayer Displays and helping to create more-comfortable and nology have been made using standard optical with Directional Backlighting,” ACM Trans. natural viewing experiences. Perhaps this is and electronics components, including LCDs, Graph. (SIGGRAPH) 31, 1–11 (2012). one of the most promising and at the same liquid-crystal–on–silicon (LCoS) microlens 11G. Wetzstein, D. Lanman, W. Heidrich, and time unexplored areas of light-field displays arrays, etc. Future designs, however, may R. Raskar, “Layered 3-D: Tomographic Image in general. incorporate completely new optical designs Synthesis for Attenuation-based Light Field that are not only tailored to a particular appli- and High Dynamic Range Displays,” ACM Light Fields and Holography cation (wearable, mobile, television) but also Trans. Graph. (SIGGRAPH) (2011). The difference between light fields and to specific algorithms driving these devices. 12D. Lanman, M. Hirsch, Y. Kim, and R. holograms is a subject for evening-filling We have entered an area in which advanced Raskar, “Content-Adaptive Parallax Barriers: philosophical discussions and cannot easily be computation has become an integral part of Optimizing Dual-Layer 3-D Displays Using answered. The author’s take on it is this that the image formation in many emerging Low-Rank Light Field Factorization,” ACM both effectively create similar viewing experi- display technologies. The synergy between Trans. Graph. (SIGGRAPH Asia) 28, 5, 1–10 ences, but a fundamental difference is that computation, optics, electronics, and human (2010). light fields usually work with incoherent light perception is expected to become even more 13A. Maimone, G. Wetzstein, D. Lanman, M. and holograms are based on coherent illumi- important in the future. Hirsch, R. Raskar, and H. Fuchs, “Focus 3-D: nation. However, partially coherent or Compressive Accommodation Display,” ACM incoherent holograms exist as well and light- References Trans. Graph. (TOG) 32, 5, 153:1–153:13 field displays can also account for diffractive 1G. Lippmann, La Photographie Int´egrale. (2013). phenomena.24 The boundaries between these Academie des Sciences 146, 446–451 (1908). 14D. Lanman, G. Wetzstein, M. Hirsch, W. fields are fluid, but traditionally holograms 2H. Urey, K. V. Chellappan, E. Erden, and Heidrich, and R. Raskar, “Polarization Fields: are modeled using wave optics, whereas light P, Surman, “State of the Art in Stereoscopic Dynamic Light Field Display Using Multi- fields are modeled as rays or geometric optics. and Autostereoscopic Displays,” Proc. IEEE Layer LCDs,” ACM Trans. Graph. (SIGGRAPH As pixels get smaller, the image formation of 99, 4, 540–555 (2011). Asia) 30, 6, 186 (2011). light-field displays will have to incorporate 3O. S. Cossairt, J. Napoli, S. L. Hill, R. K. 15F. Heide, J. Gregson, G. Wetzstein, R. Raskar, diffractive effects, so the areas are expected to Dorval, and G. E. Favalora, “Occlusion-Capa- and W. Heidrich, “Compressive multi-mode merge eventually. Nevertheless, it is advanta- ble Multiview Volumetric Three-Dimensional superresolution display,” Opt. Express 22, geous to think about light fields in the ray- Display,” Applied Optics 46, 8, 1244–1250 14981–14992 (2014). space because it makes connections to (2007). 16M. Hirsch, G. Wetzstein, and R. Raskar, “A advanced signal processing and optimization 4A. Jones, I. McDowall, H. Yamada, M. Compressive Light Field Projection System,” algorithms, such as computed tomography11 Bolas, and P. Debevec, “Rendering for an ACM Trans. Graph. (ACM SIGGRAPH) (2014). and a non-negative matrix12 and tensor factor- Interactive 360° Light Field Display,” ACM 17V. Pamplona, A. Mohan, M. Oliveira, and ization,10 very intuitive. Trans. Graph. (SIGGRAPH) 26, 40:1-40:10 R. Raskar, 2010, “NETRA: Interactive Display (2007). for Estimating Refractive Errors and Focal A Potential As Yet Unrealized 5K. Akeley, S. J. Watt, A. R. Girshik, and Range,” ACM Trans. Graph. (SIGGRAPH) In summary, light-field displays have a wide M. S. Banks, “A Stereo Display Prototype (2010). range of applications in 3-D television and with Multiple Focal Distances,” ACM Trans. 18F. C. Huang, G. Wetzstein, B. Barsky, and projection systems; they enable technologies Graph. (SIGGRAPH) 23, 804–813 (2004). R. Raskar, “Eyeglasses-free Display: Towards

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SOCIETYSID FOR INFORMATION DISPLAY Correcting Visual Aberrations with Computa- tional Light Field Displays,” ACM Trans. Graph. (SIGGRAPH) (2014). Information 19Y. Takaki, “High-Density Directional Display for Generating Natural Three-Dimensional Images,” Proc. IEEE 94, 3 (2006). DISPLAY 20J. I. Yellott and J. W. Yellott, “Correcting spurious resolution in defocused images,” Proc. SPIE 6492 (2007). 21D. Hoffman, A. Girshick, K. Akeley, and M. ADVANCED TELEVISION TECHNOLOGY ISSUE Information Display welcomes Banks, “Vergence-accommodation conflict Nov./Dec. 2014 Vol. 30, No. 6 www.informationdisplay.org hinders visual performance and causes visual • Official Monthly Publication of the Society for Information Display contributions that contain fatigue,” Journal of Vision 8(3) (2008). 22D. Lanman and D. Luebke, “Near-to-Eye unique technical, manufactur- Light Field Displays,” ACM Trans. Graph. (SIGGRAPH Asia), 32(6) (2013). ing, or market research content 23F. Heide, D. Lanman, D. Reddy, J. Kautz, K. Pulli, and D. Luebke, “Cascaded displays: that will interest and/or assist spatiotemporal superresolution using offset our readers – individuals pixel layers,” ACM Trans. Graph. (SIGGRAPH), 33(4) (2014). involved in the business or research of displays. 24G. Ye, S. Jolly, M. Bove, Q. Dai, R. Raskar, and G. Wetzstein, “Toward DxDF Display using Multilayer Diffraction,” ACM Trans. n Please contact Jenny Donelan, Managing Editor, Graph. (SIGGRAPH Asia), 33(6) (2014). at [email protected] with questions or proposals.

Turn to page 35 for a list of 2015 editorial themes, with approximate dates for submitting article proposals.

SID International Symposium, Seminar & Exhibition May 31–June 5, 2015 PleaseSubmit send all press Your releases and News new product Releases announcements to: Jenny Donelan San Jose Convention Center Information Display Magazine San Jose, California, USA 411 Lafayette Street, Suite 201 New York, NY 10003 Fax: 212.460.5460 e-mail: [email protected] www.displayweek.org

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symposium preview

Inspiration and Innovation Abound at Display Week’s Annual Technical Symposium

This year’s technical program at Display Week features more than 450 papers on topics ranging from quantum dots to light-field displays.

by Jenny Donelan

HE display industry is never static, and OLEDs, Projection, and Touch and Interac- Amazon’s Kindle Fire tablets and in LCD theT annual SID International Symposium at tivity – then assigned to sessions designated TVs shown at CES last January. “It’s nice to Display Week both reflects and informs that by topic, such as Wearable Display Systems. see this technology moving from the experi- state of constant change. Last year, backplane Each session consists of three to five 20- mental phase to the lab and now to product technology took center stage at the symposium, minute paper presentations. This year, four fruition,” says Qun “Frank” Yan, co-chair of with 12 papers devoted to the topic of Oxide special focus areas – Oxide and LTPS TFTs, the Emissive Displays subcommittee. vs. LTPS TFTs alone. This year, backplanes Wearable Displays, Disruptive Display Mate- Quantum dots have many potential uses, as remain an essential focus, but other topics, rials, and Curved and High-Resolution Dis- will be discovered in this year’s symposium, including materials that promise to disruptive plays – and three Mini-Symposia on Lighting again offering three dedicated sessions on the industry as we know it, are strongly repre- [in cooperation with the Illuminating Engi- QDs. “Quantum dots have the potential to sented. Program Chair Seonki Kim also points neering Society (IES)], Vehicle Displays and disrupt the display industry,” says Seth Coe- to an increased number of papers on vehicle Trends, and Imaging Technologies and Appli- Sullivan of QD Vision, Vice-Chair of the displays and also displays being produced in cations were also included. Disruptive Display Materials special topic. curved and non-rectangular form factors. The peer-reviewed papers chosen for pres- Despite the aforementioned commercial forays, This year, the technical symposium features entation at Display Week represent the best of many of the improvements to the technology 75 sessions and more than 460 papers. That’s the best. Here are just some of the highlights are still at the research stage, he says, adding: more than any one person can take in during from this year’s sessions. “The next question is: Can we reduce that the four days (June 2–5) of the program, but science to practical innovations that lead to you can take in a lot if you plan ahead by Quantum Dots and Other Disruptive improved products?” accessing the preliminary program online at Materials There is a great deal of interest in how QDs http://displayweek.org/2015/Program/ Even if you can’t see quantum dots (QDs) – can help achieve Rec. 2020, the new ITU color Symposium.aspx and also by reading this these tiny nanocrystals range from 2 to 10 nm specification for UHD broadcasting, says article, in which we point out some of the (10–50 atoms) in diameter – they have been Coe-Sullivan. Jame Thielen of 3M will be highlights. hard to miss lately. QDs are not new to the presenting an overview of that effort in the paper Each year, the papers presented are organ- symposium or the exhibit hall at Display “Optimizing Quantum-Dot LCD Systems to ized by their major technical focus – Active- Week – companies such as 3M, Nanosys, and Achieve Rec. 2020 Color Performance.” Matrix Devices, Applications, Applied Vision/ QD Vision have been named by SID’s awards Another recommended paper is “Next-Gener- Human Factors, Display Electronics, Display committee several times since 2012 for their ation Display Technology: Quantum-Dot Manufacturing, Display Measurement, Display quantum-dot technology. Last year’s techni- LEDs” from Jesse Manders of NanoPhotonica. Systems, Emissive Displays, e-Paper and cal program featured three sessions dedicated The NanoPhotonica team achieved extremely Flexible Displays, Liquid-Crystal Technology, to quantum dots, and, at the time, this maga- high external quantum efficiency for green zine noted that the technology was gaining and blue quantum-dot LEDs, as well as high Jenny Donelan is the Managing Editor of momentum. What’s new this year is that performance for red QD-LEDs. Information Display magazine. She can be quantum dots are rapidly showing up in a Quantum dots are but one technology clas- reached at [email protected]. whole range of LCD-based products, such as sified as disruptive by this year’s technical

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Display Week 2015 Symposium at a Glance

2015 SID Display Week Symposium at a Glance – San Jose Convention Center Times Ballroom 220B Ballroom 220C Room LL20A Room LL20BC Room LL20D Room LL21EF Room LL21D

8:00 – 10:20 am SID Business Meeting and Keynote Session (Ballroom 220A) 3 8 Wearable Display 4 6 7 Imaging Technologies 5 Quantum-Dot Materials Systems Flexible Display Novel Display OLED Driving and 10:50 am – 12:10 pm Image Quality of Displays (Joint with (Joint with Display Manufacturing Applications I Techniques Applications I Disruptive Materials) Systems and Projection)

Tuesday, June 2 June Tuesday, 9 Wearable Displays: 10 11 12 13 14 Imaging Technologies 2:00 – 3:20 pm Direct View OLED Encapsulation Hunan Factors Novel Display Advanced Displays Photoluminescent and (Joint with and Reliability and Applications Applications II and Imaging Quantum Dots Applications II e-Paper/Flexible)

Tuesday, June 2 15 18 20 Applied Vision and 16 17 Applications of Flexible 19 Electroluminescent Imaging Technologies 3:40 – 5:00 pm Applications of OLED Deposition Color Appearance Display Technology Image Processing for Quantum Dots and Wearable Displays and Patterning of Displays (Joint with Display Enhancement (Joint with Applications III (Joint with Applications) e-Paper/Flexible) Disruptive Materials)

5:00 – 6:00 pm Author Interviews

Designated Exhibit Time (Exhibit Hall) 24 25 26 21 22 23 3D Light-Field Laser-Phosphor Light Micro LED Displays and 9:00 – 10:20 am Oxide-TFT Manufacturing OLED Materials I e-Paper Displays and Imaging Sources for Projectors Electroluminescence

9:00 – 10:20 am 3 June Wednesday, 29 32 27 31 TFTs and Circuits for Front Lighting and Advanced 28 30 Disruptive LCD Materials Flexible Devices Reflective Displays 10:40 am – 12:00 pm Manufacturing OLED Materials II 3D Applications (Joint with (Joint with e-Paper (Joint with e-Paper/ Technologies Disruptive Materials) and Flexible Displays) Flexible and Lighting)

2:00 – 3:30 pm Designated Exhibit Time (Exhibit Hall)

Wednesday, June 3 34 38 33 Disruptive OLED Materials 35 36 37 OLED Lighting 3:30 – 4:50 pm Novel Devices (Joint with Disruptive Projetion Optics Holographic 3D Displays Blue-Phase LCDs 3:30 – 4:50 pm (Joint with Lighting) Materials)

5:00 – 6:00 pm Author Interviews (Ballroom 210)

Vehicular Displays 8:30 – 9:00 am and Trends Morning Plenary Talk

42 41 Curved and High- 44

39 40 Automotive Display Resolution Display 43 Advanced Light 9:00 – 10:20 am Advanced TFTs OLED Devices I Applications Metrology FFS/IPS I Sources, Components, and Systems (Joint with Curved and and Systems I High-Resolution Displays)

47

Next-Generation 48 45 50 46 Automotive Display Display Standards and 49 10:40 am – 12:00 High-Performance Effect of Lighting on pm OLED Devices II Technologies I: HUDs Their Application to FFS/IPS II Oxide TFTs I Health and Perception (Joint with Transparent Displays Display Systems) Thursday, June 4 June Thursday,

Vehicular Displays

1:00 – 1:30 pm and Trends 9:00 – 10:20 am Afternoon Plenary Talk

53

Thursday, June 4 51 Touch, Interactivity, and 54 56 52 55 High-Performance Human-Machine Interface Transparent Advanced 1:30 – 2:50 pm OLED Devices III LC Beyond Displays Oxide TFTs II (Joint wiith Touch Display Systems Lighting Applications

and Interactivity)

59 62 57 Next-Generation 58 60 61 Advanced Light Oxide and LTPS TFTs Automotive Display A 3:10 – 4:30 pm OLED Displays I Capacitive Touch Liquid-Crystal Lenses Sources, Components, Technologies II: Flexible, and Systems II Curved, Coatings

4:30 – 5:30 pm Author Interviews (Ballroom 210) 5:00 – 8:00 pm Poster Session (Ballroom 220A)

64 68 63 OLED Displays II: Curved 65 66 Touch Systems 67 9:00 – 10:20 am High-Resolution Displays and High-Resolution Flexible Stereoscopic 3D Displays and Materials

Photo Alignment 5 June Friday, (Joint with Curved and Display Technology (Joint with Projection) (Joint with Manufacturing High-Resolution Displays) and Vehicular) 9:00 – 10:20 am 72

Curved and 69 70 71 High-Resolution 73 74 10:40 am – 12:00 pm Friday, June 5 Oxide-TFT Reliability OLED Displays III Flexible Encapsulation Large Displays Ultra-Low-Power LCDs Touch Applications (Joint with Curved and High-Resolution Displays) A

TECHNOLOGY TRACKS KEY Active-Matrix Devices Applications Applied Vision Curved and High-Resolution Displays Display Electronics Display Measurement Display Systems Disruptive Materials Emissive Displays e-Paper/Flexible IES Lighting Imaging Liquid-Crystal Technology Manufacturing OLEDs Oxide and LTPS TFTs Projection Touch and Interactivity Vehicular Wearable Displays

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symposium preview

program organizers. Other technologies Chen of AU Optronics Corp., in which the Touch, Liquid Crystals, and Projection include new material innovations in LCDs and author and his team describe the architecture Touch technology has been an integral part of in OLEDs, according to Coe-Sullivan. and fabrication of a high-performance 65-in. the display industry and Display Week for “OLED is very materials-innovation heavy ultra-HD OLED TV with excellent visual several years. Subcommittee chair Jeff Han right now,” he says. One example is the quality that utilizes stable arrays and cutting- notes that even though there may not seem to invited paper, “Combinatorial Design of edge OLED processes. be as much touch news as there has been in OLED-Emitting Materials,” by Alán Aspuru- the past: “Touch is still hot. People just don’t Guzik of Harvard University, which looks at a Flexible, Foldable, Wearable want to talk about it because companies inte- particular example of recent developments in Flexible technology continues to be a hall- grating touch would have to describe their thermally assisted delayed fluorescence mark of Display Week, and the most outstand- own stacks, etc.” In terms of trends: “In-cell (TADF) emitters that are enabling novel ing trend here is that flexible displays are is what it’s all about,” says Han. “I feel like classes of OLEDs using technology that may entering a more mature phase, according to the tide is turning in this regard [in the direc- be better for the environment and, possibly, subcommittee chair Kevin Gahagan of tion of vertical integration].” There are still longer lasting than OLEDs using phosphor Corning, who cites commercial examples that plenty of touch papers at the symposium, with emitters. A representative paper on poten- contain flexible displays, such as LG’s G Flex four separate sessions. The invited paper tially disruptive LCD developments is phone. Flexible papers this year reflect that “Panel-Structure Evolution of In-Cell Capaci- “Evolution of Cellulose Triacetate (TAC) relative maturity, he says, in that issues like tive Touch Sensor” by Qijun Yao of Shanghai Films for LCDs: Novel Technologies for High scaling are more of a focus, as well as encap- Tianma Microelectronics Co. will look at Hardness, Durability, and Dimensional Stabil- sulation and the integration of features such as various integration schemes for in-cell capaci- ity” by Ryo Suzuki of Fujifilm Corp., which touch and transparency. “The [whole] system tive touch panels and review ongoing efforts describes the development of different films has to be flexible,” he says. being made to eliminate the interference that could solve stability problems caused by Looking farther ahead, Gahagan thinks between display and touch-sensor structure. reductions in the thickness of polarizers and that foldable is the next frontier for flexible That paper will also present an in-cell LCD reduce warping in IPS-LCD TV panels. devices. “We’re seeing demos of foldable module with an integrated self-capacitance An even more disruptive technology, notes displays that are high resolution, with many touch sensor. Yan, are micro-sized LEDs, which he says bend cycles.” One example is “Foldable In terms of liquid crystals, besides the could be the display industry’s “next big AMOLED Displays with a Touch Panel” from disruptive materials papers mentioned earlier, thing.” These LEDs integrate light source and Jia-Chong Ho of ITRI. “There is a growing fringe-field switching (FFS) and in-plane optics, enabling high-pixel density and may consensus that foldable is the ultimate form switching (IPS) are current trends in the be well-suited to 3-D displays, he says. factor,” says Gahagan. “It’s easy to interact industry, according to subcommittee chair Ostendo, last year’s Innovation Zone winner with.” Although the flexible display that can Philip Chen, as are suggested breakthroughs at Display Week, has a very interesting paper be rolled up and popped into a purse or brief- for blue phase involving a new structure. on this technology: “Quantum Photonic case has been the form factor most people Look for the papers “A High-Transmittance Imager (QPI): A Novel Display Technology imagine for the ultimate flexible display, the IPS LC Mode Using a New Self-Aligned that Enables more than 3D Applications,” by scroll can be problematic because when you Structure” by Sun-Hwa Lee, of LG Display Hussein S. El-Ghoroury, which describes the write on it, it’s unsupported in the middle, Co., “A Fast-Response A-film-Enhanced FFS QPI, a 3D-IC semiconductor device compris- explains Gahagan. “This might be specula- LCD from AU Optronics Corp., and “A Blue- ing a high-density array of digitally address- tion,” he says, “but foldable is where I think Phase LCD with Wall Electrode and High- able micro-LED pixels. we’re headed.” Driving-Voltage Circuit” by Cheng-Yeh Tsai, The category of flexible often meshes with also of AUO. OLEDs wearable, and a case in point is the paper The biggest trend in projection this year is The biggest trend in OLEDs, according to “Stretchable 45 × 80 RGB-LED Display that solid-state light sources are replacing subcommittee chair Sven Zimmermann, are Using Meander Wiring Technology” by lamps, according to projection co-chair Dave the TADF emitters mentioned in the disrup- Hideki Ohmae of Panasonic Corp. This paper Eccles. LEDs were much vaunted for projec- tive materials section above. He believes describes a foldable and stretchable (up to tors a few years ago, but are not really bright these may soon be competitive with normal 10%) fabric-like display that incorporates enough for most applications beyond pico phosphorescent emitters (which contain heavy LEDs. Another wearable paper to look for is projectors, explains Eccles. Laser phosphors, metals and have lifespan issues). TADF “High-Image-Quality Wearable Displays with which have been described in papers at OLEDs also have a more uniform spectral dis- Fast-Response Liquid Crystal” by Zhenyue Display Week for some years, are now being tribution, which could make them strong can- Luo at the University of Central Florida. used in commercial products. They can be didates for lighting applications in particular. Luo reports on two ultra-low-viscosity liquid employed for everything from pico projectors Zimmermann notes that there are also crystals with a field-sequential-color LCOS. to digital-cinema projectors, says Eccles, several symposium papers on OLED TV. The The LC’s fast response time offers vivid color, though in digital-cinema applications, laser current state of the art can be found in the a high ambient contrast ratio, low power con- phosphor projectors are referred to as “non- paper “High-Performance Large-Sized OLED sumption, and mitigated color breakup even in coherent light” for public-relations purposes. TV with UHD Resolution” from Yu-Hung extremely low temperatures. A particularly educational and interesting

32 Information Display 2/15 ID DonelanPreviewp30-34_Layout13/18/20157:52PMPage33

Display Week 2015 Overview San Jose Convention Center, San Jose, California, USA May 31–June 5, 2015

Sunday Monday Tuesday Wednesday Thursday Friday May 31 June 1 June 2 June 3 June 4 June 5 Exhibits Exhibits Exhibits TIMES Exhibitors Exhibitors Market Market Short Business Mini- Investors Mini- Exhibitors Seminars Symposium Forum Symposium Forum Focus Symposium Focus Symposium Courses Conf. Symposium Conf. Symposia Forum Sessions / Sessions / Conf. Conf. Sessions I-Zone I-Zone

7:45 AM Session 1: SID Business Meeting 8:30 AM Seminars Session 2: 9:00 AM Oral Oral Oral M1 - M3 Welcome / 9:30 AM Sessions Sessions Sessions Keynote Addresses 10:00 AM 21-26 39-44 63-68 Short 10:30 AM Business Oral Oral Oral Courses Seminars Conference Oral 11:00 AM Sessions Sessions Sessions S-1 & S-2 M4 - M6 Sessions 11:30 AM 27-32 45-50 69-74 3-8 12:00 PM Exhibits / Author DIA & Lunch 12:30 PM Best-in-Show Interviews Exhibitors Forum Forum Exhibitors Bus. Conf. Conf. 1:00 PM Lunch Lunch Awards Touch Seminars Luncheon I-Zone Oral 1:30 PM

M7- M9 Sessions Lighting SID/IES 2:00 PM Oral Sessions 41, 47, 53, 58 53, 47, 41, Sessions

Designated 51-56 Flexible - Wearable Applications I-Zone 2:30 PM Sessions 62 56, 50, 44, Sessions Sessions I, II, III II, I, Sessions

Exhibit Time Trends and Displays Vehicular

3:00 PM 9-14 Conference: Focus Market Oral Conference: Focus Market

Seminars Conference Investors

3:30 PM Oral Oral / Forum Exhibitors / Exhibits Sessions Business M10 - M12 and Technologies Imaging 4:00 PM Conference Sessions Sessions 57-62 Short 4:30 PM 15-20 33-38 Author Courses / Forum Exhibitors / Exhibits 5:00 PM Bus. Author Author Interviews S-3 & S-4 Seminars Inv. Conf.

Information Display 2/1533 5:30 PM Conf. Interviews Interviews M13 - M15 Recept. 6:00 PM Recept. Poster 6:30 PM Session 7:00 PM 7:30 PM Special Networking Event 8:00 PM Honors San Jose Museum of Art 8:30 PM and 9:00 PM Awards 9:30 PM Banquet ID DonelanPreview p30-34_Layout 1 3/18/2015 7:52 PM Page 34

symposium preview

paper to catch is “The Progress in Interna- as a stand-alone event to our guests from Sensing Technology” tional Safety Standards for Laser-Illuminated IESNA. For further registration information, Achin Bhowmik, Intel Corp. Projection Systems” by Greg Niven of LIPA. go to www.displayweek.org/2015/Attendee/ Access to this 1-day Mini-Symposium is “This is a good one for people to hear because Registration.aspx. included for those attending the Display Week it will explain current standards for both the Vehicle Displays and Trends: This pro- Symposium. For further registration informa- U.S. and the rest of world,” says Eccles. gram will bring together scientists, engineers, tion, go to www.displayweek.org/2015/Attendee/ market analysts, and industry leaders from the Registration.aspx. Light-Field Displays display, touch, photonics, and vehicle systems Yet another key technology not to be missed communities for a unique one of a kind event Keep Up the Pace at Display Week is light-field displays. This exploring the recent developments and trends As always, there is more to see and hear at the is an area that is growing, says displays of vehicle displays. This Mini-Symposium is Display Week Symposium than one person systems chair Kalil Käläntär. “Everyone is also scheduled for Thursday, June 4, and will can see and hear, and we’ve only been able to being challenged to ‘solve’ light-field displays, consist of a morning and afternoon plenary mention a few examples here. Other recom- including 3D displays,” he says. “Light field talk and the following four sessions: mended presentations include the special would be a great candidate for next-generation • Next-Generation Automotive Display lighting sessions, vehicle display sessions, displays.” To find out more, catch the invited Technologies I: HUDs display measurement papers that look at paper “Design Principles for Light-Field Image • Automotive Display Applications and metrics for curved displays and transparent Capture and Display” by Kathrin Berkner of Systems displays, near-to-eye display presentations – Ricoh Innovations Corp., in which the author • Touch, Interactivity, and Human- the list is nearly endless. Whatever you do, and her team discuss design principles for Machine Interface don’t miss the technical symposium at task-specific light-field camera systems and • Next-Generation Automotive Display Display Week. It’s the best way to keep up outline how such principles can be applied to Technologies II: Flexible, Curved, with the pace of the display industry. n the design of personal light-field displays. Coatings Access to this 1-day Mini-Symposium is Special Mini-Symposia included for those attending the Display Week New to Display Week in 2015 is the addition Symposium. It is also available as a stand- of three Mini-Symposia in the form of Special alone event. For further registration informa- E XHIBIT N OW AT Technology Tracks on Lighting, Vehicle tion, go to www.displayweek.org/2015/ Displays and Trends, and Imaging Technolo- Attendee/Registration.aspx. gies and Applications. Imaging Technologies and Applications: SID/IES Lighting: There has always been The Mini-Symposium on Imaging Technolo- a great deal of overlap in the technology gies and Applications will feature invited behind lighting and displays. In recognition papers covering the areas of imaging tech- of the newly signed Friendship Agreement nologies, products, applications, advanced between SID and the Illuminating Engineer- EXHIBITION DATES: developments, and emerging trends. This ing Society of North America (IESNA), the focused track will bring together scientists, SID/IES Lighting Track aims to deliver in- engineers, business professionals, market depth coverage in a diverse range of topics of analysts, academic, and industry leaders common interest to both lighting and display pioneering the end-to-end chain of imaging to professionals. This Mini-Symposium is XHIBITION OURS display technologies and applications. Sched- E June 2–4, 2015H : scheduled for Thursday, June 4, and will uled for Tuesday, June 2, it will consist of San Jose Convention Center consist of the following four sessions: three sessions of invited papers that include: San Jose, CA, USA • Advanced Light Sources, Components, • “On the Duality of Compressive Imaging and Systems I and Display” Tuesday, June 2 • Advanced Light Sources, Components, Gordon Wetzstein, Stanford University 10:30 am – 6:00 pm and Systems II • “Image Systems Simulation” Wednesday, June 3 • Effects of Lighting on Health and Joyce Farrell, Stanford University CONTACTS FOR9:00 EXHIBITS am – 5:00 pm Perception • “The Importance of Focus Cues in 3D Thursday,AND June SPONSORSHIPS 4 : • Advanced Lighting Applications Displays” Jim Buckley9:00 am – 2:00 pm There will be additional OLED lighting Martin Banks, University of California at sessions outside of this 1-day event for more Berkeley, Berkeley, CA, USA in-depth discussions on OLED device physics • “Light-Field Imaging” and materials. Access to this 1-day Mini- Kurt Akeley, Lytro Exhibition and Sponsorship Sales, Sue Chung Symposium is included for those attending the • “Interactive Systems and Applications Europe and Americas Display Week Symposium. It is also available Based on Depth-Imaging and 3D- [email protected] Phone +1 (203) 502-8283 34 Information Display 2/15 Exhibition and Sponsorship Sales, Asia [email protected] Phone +1 (408) 489-9596 Editorial Calendar_Layout 1 11/9/2014 1:20 PM Page 50

MATERIALS AND FLEXIBLE TECHNOLOGY ISSUE Jan./Feb. 2014 Vol. 30, No. 1 TABLETS AND TOUCH ISSUE

• www.informationdisplay.org

Official Monthly Publication of the Society for Information Display

Official Monthly Publication of the Society for Information Display

• www.informationdisplay.org July/August 2014 Vol. 30, No. 4

Official Monthly Publication of the Society for Information Display

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show review

CES 2015: The Show of Everything (SoE)

For a consumer-electronics show, CES 2015 was noticeably shorter on traditional consumer- electronic products than in previous years. Enterprise solutions – such as automotive electronics and displays – received as much attention as TVs.

by Ken Werner

ITH 170,000 registered attendees, the time of 5 sec and a very large center-stack products), company executives removed it by InternationalW Consumer Electronics Show in display (Fig. 1). saying, “You will increasingly see Panasonic Las Vegas this year was once again the Panasonic certainly was not hiding the create enterprise solutions as our B2B busi- biggest in history, but the show feels increas- industrial thrust of its exhibits. At the com- ness grows.” ingly strange. For an event that is nominally pany’s big press event at the beginning of the Consider the energy with which TCL, about consumer-electronic products, a surpris- week, the company proudly announced it is Hisense, and other Chinese TV set-makers are ing number of the products shown were not the “Number 1 supplier of Li-ion batteries for entering the North American market with sets for consumers – and many were not primarily automobiles” and “the Number 1 supplier of carrying their own brands, the retreat of electronic. automotive infotainment systems worldwide.” Toshiba from the North American market, Cars, batteries, and electric appliances, both If there was any doubt about the direction Sharp’s licensing of its brand to Best Buy for small (as in personal-grooming products) and Panasonic is pursuing (outside of grooming the 2K part of its TV business, and JVC’s large (as in home appliances), were just some of the products on exhibit that did not fall under the traditional “CES” umbrella. Some of these products (cars, appliances) had displays; some did not. A significant portion of Panasonic’s booth was devoted to a men’s grooming salon where male attendees were being barbered for free, with Panasonic grooming devices. Not far away was a beauty salon, where female attendees were being beautified, again with Panasonic products. Samsung, LG, and others showed stoves, refrigerators, washing machines, and dryers. Panasonic also emphasized batteries, promoting the huge battery plant it is building near Reno with Tesla Motors, which Panasonic called “the largest investment in electric automotive technology anywhere.” Also in Panasonic’s booth was the new Tesla Model X crossover SUV, which has a 0–60 acceleration

Ken Werner is the Founder and Principal of Nutmeg Consultants, which specializes in the display industry, display technology, and display applications. He can be reached at Fig. 1: Tesla’s new Model X, shown in Panasonic’s booth, contains an impressively large [email protected]. center-stack display. Photo courtesy Ken Werner.

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licensing of its direct-view North American TV business to AmTRAN; and then consider Panasonic’s statements. It is reasonable to speculate that Panasonic will be the next company to drop out of the consumer TV business.

Automobiles, and Some Electronics Not many years ago, the North Hall at CES looked like a compact version of the annual show put on by the Specialty Equipment Market Association (SEMA). The hall bris- tled with garish but beautifully executed custom vehicles, and the air pounded with powerful custom audio systems exquisitely integrated into those vehicles. Some of the SEMA aesthetic could still be seen in North Hall this year, but the show’s vibe was more like a toned-down New York (or Detroit or Los Angeles) auto show, with the center of gravity shifted heavily toward vehicle manu- facturers instead of after-market customizers. A JVC Kenwood rep stated his company commanded 50% of the U.S. market for Fig. 2: How many displays can you fit in the cockpit of a two-seat car? If you’re McLaren, the in-deck navigation systems. The Model answer is five. Photo courtesy Ken Werner. DDX9702S, in addition to sophisticated audio features such as time alignment and nuggets of information, such as oil level, able presence at CES this year is likely to grow. crossover adjustments, provides touch control, battery-charge level, or remaining electric Although other manufacturers may not have phone mirroring and control, optional wireless range, and you can code a central button to do made that statement explicitly, several traditional HDMI, Android Auto, and Apple CarPlay. something useful, such as flashing the head- makers of consumer electronics, Panasonic Android Auto supplies Google Maps, music lights. It will also tell you if you forgot to among them, implied that they were emphasiz- streaming, “Ok Google” speech recognition, lock a door. You can check the battery status ing their automotive electronic products. and auto-optimized apps on the Android Auto of your i3 on your smart TV and plan your The logic behind this is clear. As consumer site. The DNN992 “connected DVD receiver route before you leave your bed – if you electronics continues to be a difficult business with navigation” incorporates a 6.95-in. hi-res ignore your sleep therapist and keep a TV in with low margins and many competitors, capacitive touch screen, built-in WiFi, a wire- your bedroom. automotive electronics is a rapidly growing less link for in-car content sharing, and a In its large press conference on Press Day “route collector” trip planner. In the Kenwood and in its booth in Central Hall, Sharp showed booth was a McLaren 650S with its (presum- its IGZO-driven free-form displays, which ably) Kenwood-based five-display digital feed both column- and row-driving signals in cockpit system (Fig. 2). from the bottom edge of the display, so the FCA (Fiat Chrysler Automobiles) showed rest of the display can be curved in various its RAM 1500 Eco-Diesel light truck. Its ways to fit the design for an automobile’s large infotainment screen is approximately instrument cluster, or a designer’s whim for square and well-integrated into the center other locations (Fig. 3). Sharp has shown the stack, but FCA’s main interest seemed to be concept at display-oriented shows, including its new U-Connect infotainment system that SID’s Display Week last year, but presenting will present a nearly uniform interface across it at CES implies that Sharp is ready to roll the all of FCA’s global markets. FCA’s primary innovative displays out in volume. Given interest seems to be the cost savings it can typical automotive design cycles, it is unlikely obtain from a (nearly) universal platform. we will see these displays in cars for at least BMW was emphasizing its electric i3 and 3 years, but see them we will. stunningly designed i8, along with inductive Ford stated explicitly that CES is very charging and a key fob for the i8 with multi- important to them, and the company wanted Fig. 3: This “free-form” automotive display ple control and information capabilities via a to be accepted as part of the CES community. from Sharp was shown at CES. Photo cour- small display. The display can provide A Ford executive suggested that Ford’s size- tesy Ken Werner.

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show review

market with significant opportunities for credibility for Samsung’s claim. The QD TV calling it “Sharp’s version of quantum dots.” innovation and profit. using QD Vision’s Color IQ optical element I would guess that Sharp will be moving to a exhibited greater luminance and color gamut true quantum-dot solution in the relatively Displays at CES than the OLED TV next to it. The QD TV near future. Despite the automotive distractions, there could not match the OLED’s inky blacks, but This year QD will be for premium sets, were still a lot of consumer-electronic prod- one could make a credible case that the QD with TCL saying it will have a UHD 65-in. ucts at CES. A major trend in TV this year is TV had a better image overall. Not everybody set with QD for $3000 later in the year. the increasing commoditization of UHD (4K) will agree with that case, but it is defendable. Next year, these sets will enter the pricing TV. The speed with which 4K has gone from When LG announced its line of QD- mainstream. expensive to cheap continues to surprise many enhanced TVs, its marketing people were As usual, LG had a very large exhibit for people in the industry. forced to walk a very tricky tightrope. On the customers, analysts, and the press in a hotel Quantum-dot-enhanced TVs are at the same one hand, the company said its new QD- suite. Of course, LG was featuring its mid-to- stage this year as 4K was last year. Many enhanced TVs offer a huge improvement over very-large-sized curved UHD OLED-TV major manufacturers announced QD- conventional LCDs, that the new sets are panels, but I was taken by the flat 55-in. UHD enhanced TVs for release this year, including beautiful, and that everybody should buy OLED TV with its impressive pixel density Samsung, LG, and TCL. Unfortunately, they one – but they are not as good as OLED TVs, and typical OLED color saturation and con- will probably be called “QD TVs.” But we which is the technology of tomorrow. That’s a trast ratio. For those inclined to say at this survived “LED TVs,” and we can probably tightrope on which they might not be able to point that you cannot see the difference survive “QD TVs” too (Fig. 4). balance for long. between 2K and 4K on a 55-in. screen at Viewed side by side with conventional Panasonic and Sharp were using non- normal viewing distance, I can only respond LCD TVs, the increased color saturation and quantum-dot phosphor sheets to enhance color that the Snellen visual-acuity chart in your gamut produced by QDs provide an obvious gamut instead of sheets or linear elements optometrist’s office does not begin to describe improvement in image quality and allow TV containing quantum dots. Panasonic what goes on when you view moving images makers to exceed 90% of REC.2020. Com- described its approach in some detail, claim- sampled by a fixed pixel matrix. But that is bined with 4K, QDs produce really com- ing up to 98% of the DCI color space (which the subject of another article. pelling images. Samsung went so far as to say is considerable smaller than Rec.2020) and LG had some good demonstrations of high that QD enhancement provides image quality high color accuracy within the space thanks to dynamic range (HDR), which was a feature in that is superior to OLED. “professional-level 3D lookup tables” and premium sets promoted by all major set- In its suite, QD Vision had a side-by-side “six-color reproduction.” Strangely, Sharp makers. LG, of course, argued that OLED demo that went a long way toward providing was not straightforward about its approach, technology is ideal for implementing HDR, but LCDs with local-area dimming and good algorithms can do very nicely. LG also had a good 8K demo, with a 98-in. 8K set showing 2K, 4K, and 8K images on different portions of the screen. To my eye, the subjective difference between 4K and 2K was obvious and impressive, but the differ- ence between 8K and 4K was subtle. Smart TVs are no longer exclusive to premium sets, and at least one market-intelli- gence firm said the market penetration is already at 50%. Not surprisingly, LG was also promoting flexible OLEDs for mobile electronics and automotive applications. The company also showed its “M+” LCD technology for com- mercial displays, which adds a white subpixel to each conventional RGB triad, with signals converted from RGB inputs and optimized with a chip-based algorithm (Fig. 5). An unusual feature is that the white subpixel is smaller than its RGB siblings. The idea is to provide increased pixel density, lower power consumption, better color rendition, and Fig. 4: A TCL executive gleefully introduced TCL’s new quantum-dot-enhanced TV and the higher luminance at low incremental cost. company’s relationship with QD Vision. Photo courtesy Ken Werner. Side-by-side demos were impressive.

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Quantum-Dot Makers Nanosys: Jason Hartlove, CEO of Nanosys (Milpitas, California) says Samsung has licensed Nanosys’s cadmium-free quantum dots, which Nanosys has been developing under the radar. The license agreement gives Samsung access to the Nanosys technology and specifies that Samsung will be manufac- turing the dots. In addition, Nanosys is ramp- ing up its line in Milpitas. Capacity is now 25 tons/year, enough for 10-million TVs. Hartlove was understandably pleased that Samsung had a major demo in its booth com- paring quantum-dot-enhanced LCD TVs to other technologies, including plasma and OLED. Samsung’s conclusion, boldly stated in the booth, is that quantum dots are better than OLED for television. Fig. 5: LG’s M+ technology (in image at right) provides some of the benefits of QD enhance- This position represents a solid strategy for ment at relatively low incremental cost for industrial displays. Photo courtesy Ken Werner. Samsung. Samsung has abandoned OLED TV as not being a feasible high-volume tech- nology, at least for the present, leaving LG in Materials and Components estimation and motion compensation (MEMC) possession of the OLED field. But it’s a field You might not expect materials and compo- algorithms to do its work, which is also used whose value is debatable. By taking a strong nents to be a major topic at CES, and on the for TV. Loveridge said that Iris is unique in position on the outright superiority of QD- show floor, they were not. But with much of that it does MEMC without producing a halo enhanced LCD – rather than saying, as LG is, the electronic, and now automotive, world around moving images. that it is the best technology until OLED is congregating in Las Vegas in January, it is Pixelworks also claims enhanced colors and ready for the mainstream – Samsung is an excellent opportunity for materials and wider gamut through the use of a 3-D look-up attempting to reduce the value of LG’s OLED component makers to rent hotel suites and table, better contrast, better high-ambient field even more. Nanosys’s media guru Jeff meet with their customers – both current and visibility, and custom color tuning. The color Yurek added, “We’re very excited by HDR. potential. tuning, Loveridge said, can be used to make OLED has troubles.” Pixelworks introduced its “Iris” mobile sure that all displays in a production run look Nanosys supplies 3M with the quantum display co-processor, which improves mobile the same. But more than that, the OEM can dots it uses in its Quantum Dot Enhancement display quality while reducing system cost, buy displays from different manufacturers and Film (QDEF). (Although “QDEF” is consis- the company says. Graham Loveridge, Senior tune them so they all look alike. tent with the names of other 3M optical Vice-President of Strategic Marketing and What is surprising is that all of this can be enhancement products, Nanosys actually Business Development, says Iris is the world’s done with a power reduction of roughly 25%. owns the name.) Hisense is using QDEF for first mobile-display co-processor. Many of Some of the savings come from the Iris chip its ULED TVs and is fully committed to con- Iris’s functions have been performed by tele- off-loading functions from the GPU and CPU tinuing the film-based approach. Changhong vision video-processing chips and cores for and performing them more efficiently. and LG are also using the film approach, as years. But incorporating those functions and Because the Iris chip permits savings else- will Samsung when it begins manufacturing others in a chip that takes up sufficiently little where in the display electronics, it can save this year. space and consumes sufficiently little power $6 on panel cost, says Loveridge. The power Hartlove said that QDEF sets are now for a mobile device is new. Pixelworks calls savings permit a smaller battery, which can delivering 90% of Rec. 2020. Nanosys, the display performance that results from Iris save another $2. Depending on order size, working with Dolby and the chip vender, processing “True Clarity.” the chip can be had for less than $6. So, says customized the dots to do this. With a better One of the more obvious things Iris does is Loveridge, “if a manufacturer is savvy he can blue filter, they can do 97% of Rec.2020, says up-convert mobile-display video from 15 or improve system performance and simultane- Hartlove, and this has been shown in a 30 frames per second (fps) to 60 fps. In side- ously lower cost.” demonstration unit. by-side demonstrations in the suite, this TV-quality LCD cells are increasingly com- Some vendors have spoken of “QD on provided motion images with far less judder, mon in mobile devices. With the addition of chip” – putting the quantum dots directly on much smoother scrolling, and motion that had TV-quality video processing, it will be even the LED chip – as the ideal solution. Hartlove much less blur. This should not be a surprise more appealing for viewers to do more of thinks there is lots of work that needs to be since we have seen the same evolution in their movie and “TV” viewing on mobile done before this can be achieved. For large-screen television, and Iris uses motion devices. Hartlove, the ultimate solution is the emissive

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show review

quantum-dot display, in which the QDs are micro-reactors is much more economical than roll-to-roll manufacturing facility helped a energized by an electric field instead of opti- the batch processing of other manufacturers, lot. cally. He feels this is more interesting than Squires says. “Continuous production is The company also announced that CN QD on chip. The emissive QD display is disruptive without a doubt.” Innovations (CNI), a company known for sometimes called “QLED,” a name that has Late last year, Quantum Materials VP for making touch sensors using laser technology been copyrighted by QD Vision. In the nearer R&D David Doderer said, “One continuous- with both roll-to-roll and sheet manufacturing, term, Nanosys is aiming to make QD- flow microreactor can produce 100 kg of is delivering touch panels based on ClearOhm enhanced systems cost-neutral. highly uniform tetrapod quantum dots/day, or to Tier One OEMs. LeMoncheck said that the Although Nanosys started out producing around 30,000 kg/year. Assuming a design laser patterning CNI is known for is hard to cadmium-based QDs, the company is now that coats the entire display surface with QD do with ITO, but is easy with AgNWs. developing cadmium-free materials as well. film, this is enough to create approximately He also says that the single-layer film The underlying equipment is similar for both 10-million QD-LED TVs, outpacing projected (GF1) touch sensors that can be made with products, Hartlove said. Cadmium is a bit market demand over the next few years.” At AgNWs are very interesting to cost-conscious more efficient and provides a larger color CES, Squires announced the company is Chinese manufacturers whose products are gamut, so it is needed for Rec. 2020. increasing its annual production capacity to targeted at the value end of the spectrum. Samsung’s new QD-enhanced sets will 2000 kg beginning in Q2. GF1 delivers a small amount of crosstalk, but display the DCI P3 gamut, which is used Squires thinks the QD-in-photoresist it is well suited to value-oriented products. for digital cinemas. (Although generous, approach is very interesting. In addition to Other architectures deliver higher levels of DCI P3 is not as large as Rec. 2020.) displays, Squires is attracted to applications in performance. The two-layer architecture is QD Vision: Steve Ward is the new anti-counterfeiting and lighting, and says there effective for large displays. One customer is Executive Chairman of QD Vision (Lexington, are so many interesting possibilities that the making a 65-in. touch display. Massachusetts). He was formerly with company must be disciplined and not try to Le Moncheck notes that the current ThinkPad and Lenovo (until 10 years ago), chase too many of them. “I think we are in an “Jupiter” ink produces a little haze in the was former CIO at IBM, and spent time with enviable position as a company right now,” he OFF-state in bright ambients because the E Ink. Advanced Development Manager John says. ambient light reflects from the wires. The Ho says the company finds the QD-on-chip new “Mercury” wires are thinner – only a few approach very interesting and that QD ITO Alternatives at CES atoms thick – and these provide a “jet-black Vision’s quantum dots are particularly suited There has been much development and even OFF-state in bright light.” This allows for the approach. Ho says, as the company more talk about new transparent-conductor Cambrios to go after high-end applications, has said repeatedly in the past, that QD Vision technologies to replace the brittle and not-all- Le Moncheck says. has spent significant effort to make its dots that-conductive indium tin oxide (ITO), which In addition, the touch-sensor-maker TPK more resistant to heat and luminous flux than has been the dominant display technology for has a joint venture with Cambrios. The JV is its competitors’ dots because using the dots in many years and remains so today. ramping up and could produce hundreds of the company’s Color IQ element, which sits The most commercially advanced alterna- thousands of units this year. close to the LEDs and experiences high levels tive is the ClearOhm silver nanowire (AgNW) Le Moncheck notes that the capital equip- of heat and flux, requires it. These are just the ink from Cambrios. Very-fine nanowires as ment cost for AgNW-based touch sensors is characteristics, in enhanced form, that are small as a few atoms in diameter are dispersed perhaps one-tenth that for ITO. Thus, he is required for the QD-on-chip approach. in a carrier. This ink is applied to either a hopeful that when sensor makers have to add Ho showed me a side-by-side demo of a glass or polymer substrate and can then be capacity or replace worn-out equipment, they QD-enhanced TV and an OLED TV. The patterned. will turn to AgNW. “A robust supply chain is OLED set indeed had deeper blacks, but the In the Cambrios suite, CEO John Le in place,” Le Moncheck says, “and AgNWs QD-enhanced set was brighter and had a Moncheck told us the market has expanded in are the obvious technology to use for the larger color gamut, while still having black the last half-year, as has Cambrios production. coming wave of flexible devices.” levels that were quite good. In 2013, the company could produce 22,000 QD Vision is obtaining new customers liters/year; in 2014, it was 175,000 liters. The Cima NanoTech for its Color IQ approach, says CMO John company announced that its collaboration This company takes a different approach to Volkmann. The company believes the with the chemical and electronic materials transparent conductors, using a conductive economies of this approach over the film business division of LG Electronics had nanoparticle technology that self-assembles approach will eventually result in it dominat- produced a production rate of more than a into a random mesh-like network when coated ing the market. million units of AgNW touch panels per year. onto a substrate. In addition to touch screens, Quantum Materials Corp.: Steve Squires, LG is shipping large volumes of touch Cima is targeting capacitive proximity sensors, founder and CEO of Quantum Materials panels to Tier One OEMs in the U.S., China, transparent antennas, wearables, transparent Corporation (San Marcos, Texas), and Toshi Taiwan, and Korea. Le Moncheck says that microwave and EMI shielding, OLED light- Ando, Senior Director of Asian Business the use of AgNWs had “real champions at LG, ing, and transparent heating. In its suite at Development, wanted to talk about micro- who wanted to sell [touch sensors] outside the CES, Cima planned to showcase a 58-in. reactors. The continuous production from company.” And the fact that LG already had a interactive tabletop and 42-in. interactive

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digital signage. “For large-format touch screens to become a mainstream product, we J O I N S I D knew we needed to provide a cost-effective We invite you to join SID to solution that can be easily integrated and participate in shaping the future creates an engaging user experience,” says development of: Cima CEO Jon Brodd. Back in the laboratories, other approaches – • Display technologies and display- including organic conductors and graphene – related products are being investigated, but it is technologies such as Cambrios and Cima NanoTech’s that • Materials and components for will be leading the charge against ITO for the displays and display applications foreseeable future. Display Week 2015 • Manufacturing processes and The Future of CES Innovation Zone (I-Zone) equipment So, what is CES? CES is morphing from a June 2–3, 2015 consumer-electronics show to a show of • New markets and applications everything (SoE). It’s still a place to see In every specialty you will find SID consumer-electronic products that will appear in stores very soon, as well as display technol- members as leading contributors to ogy that has found its way into real products, their profession. but the focus has definitely broadened. Given he prototypes on display in the commitment of its sponsoring organiza- the Innovation Zone at Display http://www.sid.org/ tion, the Consumer Electronics Association Week 2015 will be among the (CEA), to growth above all, we can expect most exciting things you see at this Membership.aspx this evolution to continue. Will CES evolve year’s show. These exhibits were into a brontosaurus and eventually collapse chosen by the Society for Information from its own weight? Many of us have been Display’s I-Zone Committee for their predicting that for years, but it has not novelty, quality, and potential to happened yet. n enhance and even transform the dis- play industry. Programmable shoes, interactive holograms, the latest VISIT For Industry News, New Products, head-up displays, and much more will not only fire your imagination, INFORMATION Current and Forthcoming Articles, but provide an advance look at many see www.informationdisplay.org of the commercial products you’ll be DISPLAY ON-LINE using a few years from now. For daily display SIDT created the I-Zone as a forum for live demonstrations of emerging industry news information- display technologies. Display Week 2015 This special exhibit offers researchers www.informationdisplay.org space to demonstrate their proto- SID International Symposium, types or other hardware demos dur- Seminar & Exhibition ing Display Week, and encourages participation by small companies, May 31–June 5, 2015 startups, universities, government Submit Your News Releases labs, and independent research labs. Please send all press releases and new product San Jose Convention Center announcements to: Jenny Donelan San Jose, California, USA Don’t miss the 2015 I-Zone, taking Information Display Magazine place twoI-Zone days only: 2014 Tuesday Best June 2, 411 Lafayette Street, Suite 201 and PrototypeWednesday Award June 3, Winner:on the show New York, NY 10003 www.displayweek.org floor at Display Week. Fax: 212.460.5460 Ostendo Technologies, Inc. e-mail: [email protected]

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Planar Announces Transparent Instrument Systems Intros New SID New England Chapter OLED Photometer/Colorimeter Members Brave Snow to Hear Planar Systems, Inc., a maker of display and Instrument Systems, which develops, manu- About Advanced Television digital-signage technology, announced a new factures, and markets turnkey solutions transparent OLED technology at Integrated for light measurement, has introduced the Display Technology Systems Europe (ISE) in Amsterdam last LumiCam 1300 Advanced, a new imaging by Steve Atwood February (Fig. 1). photometer and colorimeter (Fig. 2). The According to Planar, the 55-in. prototype’s LumiCam 1300 Advanced has been designed It was January 29th, just two days after a OLED technology improves on the trans- for extremely high accuracy in analyzing the record-setting storm had delivered over 3 feet parency of LCD-based see-through displays characteristics of displays and electronic- of snow to the Boston area, and no one was because OLED displays are self-emitting, thus panel graphics. sure if the roads would even be clear. Yet, eliminating the need for a backlight or enclo- The new device is based on six filters. roughly 30 hearty SID New England Chapter sure. (Planar also makes transparent LCDs.) Alongside the four optical filters used in the members made their way safely to Waltham, According to the company, transparent OLED company’s LumiCam 1300 Color, the new Massachusetts, for a lively dinner and evening technology also offers brilliant picture quality camera has been expanded by two filters. of technical discussions around the topic of and contrast and wide viewing angles. Planar The system allows very accurate adjustment advanced television displays. This annual anticipates adding the transparent OLED tech- to eye-sensitivity functions using the data event was made possible in part by the nology as a product offering in early 2016. recorded from the six channels. The Lumi- generosity of 3M Company. Cam 1300 Advanced provides excellent accu- Leading the technical bill was longtime racy for color coordinates, particularly when Information Display contributor and current taking LED color measurements. industry analyst Ken Werner, who presented a survey of a number of key innovations being utilized by the television industry to entice consumers and squeeze more value out of their products. Some new features like 4K resolu- tion, quantum dots, and OLEDs are being met with almost universal applause, while others, like curved TVs, are facing some skepticism. Ken delivered his engaging and very informa- tive analysis of all of these areas with empha- sis on which ones people should pay the most attention to in the coming years. Following Ken was a presentation from John Van Derlofske, Senior Research Scientist at 3M, who drilled into some key technical areas of LCDs, including backlighting Fig. 1: Planar’s transparent OLED display Fig. 2: The LumiCam 1300 Advanced is efficiency, color-gamut expansion, and high- expands signage possibilities because it designed for high accuracy in analyzing dynamic-range (HDR) capabilities. These doesn’t need a backlight. display metrics. subjects generated a great deal of audience discussion during the Q&A periods, with listeners asking specific questions about quantum-dot technology and video encoding www.displayweek.org and distribution for 4K and HDR platforms. It wasn’t long after this evening that the snow came again, and the shovels and plows were once more the order of the day, but everyone was glad for the chance to re-connect with old friends, make some new ones, and Display Week 2015 learn something along the way. The New England chapter will carry on with at least SID International Symposium, Seminar & Exhibition two more technical meetings this spring, and May 31–June 5, 2015 all are welcome, members or guests, to partic- ipate. Meeting announcements are posted on San Jose Convention Center San Jose, California, USA the SID NE webpage: http://www.sid.org/ chapters/americas/newengland.aspx. n

Information Display 2/15 43 ID Editorial Issue2 p2,44_Layout 1 3/15/2015 8:15 PM Page 44

editorial

continued from page 2 A great book about this subject is The seen in our industry every day as new tech- It has been a privilege to work with our Innovators by Walter Isaacson, in which he nologies combined with new ways to enable guest editor for this month, Jim Larimer. Jim illustrates how teamwork and spirit among human–machine interaction to create stunning is a leading consultant in the field of applied truly visionary teams have consistently over- and in some cases life-changing new products. vision and has been a trusted advisor to many come the negative pressure of conventional The incredibly rapid penetration of smart- of us in SID over the years. In his guest column wisdom. Imagine how much faster the pace phones and tablets into our everyday lives for this issue, he introduces two Frontline of computer-science innovation might have over the last few years shows how a simple Technology features, the first an article writ- been if every leader had been truly “on-board” idea can become a whole new paradigm. ten by Gordon Wetzstein of Stanford Univer- from the beginning. Did any of us really foresee the impact that sity and addressing a self-imposed question, Clearly, we cannot create a simple model to an embedded digital camera in a handheld “Why Should People Care about Light-Field measure the pace of innovation any more than phone would have on the world? Similarly, I Displays?” During Jim’s introduction, he we can define the success of innovation itself do not think anyone could have predicted that takes the time to explain exactly what is in simple terms. But we all can understand a political mandate for space exploration in meant by the term “light-field Display” in a innovation as a process of inputs (efforts and the 1960s would have fueled semiconductors way that is better than any other explanations resources) producing (hopefully) productive and integrated circuits innovation for decades I have read. Gordon’s article then paints the and profitable outputs. to come, along with all that those innovations complete picture about the potential future As leaders in our own spheres of influence, then enabled. It is clear, however, that along and present day capabilities of the technology. are we providing the right inputs by effec- the trajectory from transistors to smartphones We’ve been covering light-field displays in ID tively evaluating and promoting the best in there were countless people with truly innova- for a while now but this one is one of the best creative thinking? Are each of us truly open- tive ideas and some visionary leaders who had overall views we have had to date. The next minded to the types of radical ideas and the imagination to embrace and nurture those article is a very interesting presentation on unconventional thinking that have made so ideas with whatever it took to succeed. various aspects of solid-state lighting and many great technological achievements Our own industry is proof that the pace of human-vision considerations titled “Solid- happen? If so, are we communicating that innovation continues to accelerate. Each of State Lighting for Illumination and Displays: every day to our teams and re-enforcing it us should strive to bring the same creative Opportunities and Challenges for Color with the right support? Or are we the ones open-minded cultures to our own teams in our Excellence” by Lorne Whitehead of the who shy away from risk, hold on to conven- own spheres of influence – whether business, University of British Columbia. In both tional norms, and put negative pressure on the academic, or social – as those who came cases, I urge you to read Jim’s excellent intro- pace of innovation? before us. The rewards will far outweigh the duction first and then enjoy the articles with As I learned from reading Isaacson’s book, risks. his perspective as a starting point. really great ideas will break through no matter So, with that in mind, welcome to our latest Now we come to our other major feature how much negative pressure exists. And if issue, in which we preview Display Week for this issue, the preview of the annual tech- your organization does not provide the right 2015, announce the winners of the annual nical program known as the International environment, those great ideas may spring up SID Honors and Awards, and also explore Symposium at Display Week 2015. If you are somewhere else instead. If the people in your some interesting topics in applied vision. As looking for proof that innovations are plentiful organization cannot find an avenue to explore you all know, the annual gathering of the dis- in the world of displays, this will certainly do their ideas and fuel their creative spirits, they play industry is just a few months away and it. Aside from the sheer numbers – 450+ will go elsewhere to do it. The annals of this year it’s back to Silicon Valley for us all. papers in 72 technical sessions and a poster history are full of once-great companies that We’ll get to some of those specifics shortly session – the rich array of technical focus failed to adapt and embrace innovation – for a but first we begin with our cover story areas such as disruptive display materials myriad of reasons. Many times they had it all announcing the annual SID Honors and (including quantum dots), OLEDs, flexible within their grasp – the ideas, the resources to Awards. Each year, the Society for Information and foldable Displays, and light-field technol- develop them, even the infrastructure to com- Display honors those individuals who have ogy will surely make for one of the most mercialize them – but for familiar reasons they made outstanding contributions to the field of exciting symposiums ever. Starting with the chose to ignore those ideas and play it safe. displays, and if anything symbolizes the spirit seminars on Sunday, May 31 at the San Jose In contrast, we can all probably cite of innovation, this year’s honorees certainly Convention Center, this year’s Display Week numerous examples of businesses that have do. Read about “SID’s Best and Brightest” will pack more technical and business content exceeded our wildest expectations through for 2015 (written by Jenny Donelan) and you into one week than any other display-industry innovation and great leadership. There are will see in each case examples of true creative event in the world. To start planning your many more of these examples today than ever energy combined with commitment to prob- visit, consult the Display Week Web site before. These businesses know how to take lem solving and furthering the success of our http://www.displayweek.org/2015/2015.aspx risks, provide the necessary fuel for innova- industry. These are people who lead by exam- to register, then sit back and enjoy our preview, tion, and remain open minded about what ple and continue to give so much back to help “Inspiration and Innovation Abound at Display comes out. Sometimes what you get out of fuel innovation not only today but for future Week’s Annual Technical Symposium.” the process has even more value than what generations to come. Congratulations to all Another good barometer for display inno- you originally expected. The results can be the honorees. vation each year is the Consumer Electronics

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editorial guest editorial

continued from page 44 continued from page 4 Show (CES) in Las Vegas, which features the projection; today, that is no longer the case. meaning all of the information at the location latest in actual products, including all manner The technology to do this is now becoming of an observer’s eyes that can be perceived or of TVs, portable devices, wearables, and rapidly available. These innovations would used by the observer. Gibson believed that everything else you can think of that might not be possible, however, without high-speed perception is based upon our sensory apparatus use a display. This year we asked Ken Werner powerful graphical computing and without being capable of detecting information in the to chronicle it all for us and he responded with important insights into how we perceive the immediate environment that can be acted upon a wonderful story about all the highlights world. These insights began to be clearly by the perceiver. According to Gibson, “. . . titled “CES 2015: The Show of Everything understood a little fewer than 20 years ago. what we perceive when we look at objects are (SoE).” If you have been waiting to see new Adelson and Bergen3 characterized the light their affordances, not their qualities,” and later he innovations in automotive electronics and passing through a pinhole or any arbitrary said, “ . . . what an object affords us (actions we more form factors for automotive displays, point in space as a function of the location of can take) is what we normally pay attention to.” this was your year. It makes sense, since this a point in space, the azimuth, and elevation This suggests that evolution has produced is an area where display makers can generate angles of each direction through the point and sentient mechanisms to extract information a lot of value with their capabilities and the the spectral power distribution of the light from the environment and a cognizance volumes are very attractive. I think many of coursing through the point in each direction. capable of acting on it. us have been wondering why it has taken so They called this the plenoptic function; a We use our eyes to avoid hazards such as long for electronic dashboards and truly new contraction of plenus for full or complete and spoiled food and dangerous substances and user interfaces to make it to the marketplace. optics – full optic. Their plenoptic function to judge the health and therefore the risks pre- This year may be the turning point. Of corresponds to da Vinci’s radiant pyramids. sented by people near us. These actions need course, there was also no shortage of great TV The Russian scientist Arun Gershun coined not be conscious and willful. Without think- products featuring quantum-dot backlights, the term “light field” in a classic 1936 paper4 ing, for example, we avoid stepping on some- ultra-high-definition (UHD) and many more describing the radiometric properties of light. thing that appears yucky. The color and new innovations. Clearly, CES continues to The idea is even older and was introduced by textures of surfaces are how we conceive and prove there is no finish line for the pace of Faraday in a lecture given in 1846 entitled recognize these hazards. The light imaged on innovation, at least in the display world. “Thoughts on Ray Vibrations.” The light field the retina depends upon the reflectivity of the This wraps up another issue of Information is a connected set of plenoptic functions – all surfaces of objects in the visual field and the Display. I hope to see every one of you in the points on the surface of a window or spectral content of the light illuminating them. San Jose for Display Week in just a few short within the plane of a camera’s entrance aper- What we perceive can be dramatically altered months. n ture, for example. by changes in either of these two important ______Adelson and Bergen went on to describe the variables. 1http://www.wired.com/2013/11/bill-gates-wired- many ways biological vision has evolved to A second article in this issue, by Lorne essay/ exploit the information in the light field. We Whitehead, probes the quality of light emitted sample the parallax information contained in by displays and from ordinary lighting fixtures the blurry image formed by our eye to give us as it impacts our ability to see surface colors. cues about the distance to objects.5 In a single Our color sensibilities evolved in an environ- eye’s image, this information is contained in ment in which the illuminants were skylight, the blur and sharp regions of the image. starlight, or firelight. Today, we illuminate JOIN SID When the two eyes of an animal have over- our work and home spaces with artificial light We invite you to join SID to participate in lapping visual fields, then the displacements of sources that will soon be mostly based upon objects in one eye’s image relative to the image solid-state technologies, i.e., LEDs and shaping the future development of: formed in the other eye is another cue to dis- OLEDs. Will the colors of familiar objects • Display technologies and display-related tance called disparity. Many animals, such look right in this light? Whitehead’s article products as sheep, have only a small region in which describes the engineering trade-offs that are the visual fields of their two eyes overlap. being made to produce light from displays and • Materials and components for displays These animals have eyes looking to both sides from solid-state luminaries. Some of these and display applications simultaneously. In these eyes and for the non- trade-offs will confuse our senses. His article overlapping portions of the visual field, focus describes how to fix this problem for both • Manufacturing processes and equipment yields important information about distances. ordinary room lighting and for displays. • New markets and applications Some animals, such as sheep, have apparently There is mounting evidence that information evolved different shaped pupils to use blur in the light field, i.e., the intensity and spectral In every specialty you will find SID information in one axis to estimate depth in properties of daylight over the course of the members as leading contributors to their one plane while maintaining sharpness in the day, is used to synchronize our biological profession. orthogonal plane.6 clocks or circadian rhythms.8 A recent report The psychologist J. J. Gibson7 described the finds that light emitted from backlit e-Readers http://www.sid.org/Membership.aspx light field passing through a volume in space when used in the evening can have a negative as the “. . . permanent possibilities of vision . . ,” effect on sleep and morning alertness.9 When

Information Display 2/15 45 ID Editorial Issue2 p2,44_Layout 1 3/15/2015 8:15 PM Page 46

guest editorial Display Week 2015 continued from page 45 modern electronic-imaging systems leave out 9A. Chang, D. Aeschbach, J. Duffy, and important information, distort it, or exaggerate C. A. Czeisler, “Evening use of light-emitting Networking Events naturally occurring signals embedded in the eReaders negatively affects sleep, circadian light field that we sense to relate our bodies, timing, and next-morning alertness,” PNAS May 31–June 5, 2015 the consequences can be unexpected. We now 112/4, 1232-1237 (2015). n have to consider the possibility that signals in Looking to meet up with the light may cause not only sleep loss, but Jim Larimer received a degree in experimental your colleagues in the display possibly depression and even, some speculate, psychology from Purdue University and was a industry to discuss the early onset of puberty. These are emerging postdoctoral fellow at the Human Performance technology, business, or concerns for the display and lighting industries. Center at the University of Michigan. He was just socialize? The events Not fully capturing all of the critical informa- a Professor of Psychology at Temple University below present just that type tion, i.e., affordances, in the light field, can be and conducted basic research on color vision. of opportunity: pleasing, misleading, or actually bad for us. At NASA, he was a Senior Scientist and partic- Whitehead’s article describes how solid- ipated in the ARPA-funded High Definition Annual Awards Dinner, Monday: state light emitters can be engineered to Systems program which supported many of address these problems. As new understanding the early developments in flat-panel displays. of light’s role in human vision and biology He is now retired and works occasionally as emerges, so does new technology that can a consultant on digital imaging.” Jim can be remedy problems we are just now discovering. reached at [email protected]. Each year, SID recognizes individuals Whether it is making objects look “right” or that have played a critical role in controlling the spectral content of the light to improving the display industry. get a better night’s sleep, the evolution of This year’s winners will be honored Businessat an awards Conference banquet taking Reception, place technology now allows us to manipulate light Monday:the evening of June 1 at the San Jose so that it is consistent with the evolution of Convention Center. human vision. Adhesives for Display References Annual Award Luncheon, 1 Applications Follows the Business Conference, M. Kemp, Leonardo on Painting (Yale Wednesday: University Press, New Haven, 1989). please note conference attendance is 2J. P. Richter, The Notebooks of Leonardo Epoxies, Silicones and required for admission. da Vinci, Vol. 1 (Dover, New York, 1970). 3E. H. Adelson and J. R. Bergen, The Plenoptic Light Cure Systems Function and the Elements of Early Vision: The annual Best in Show and Display Computational Models of Visual Processing, Industry Awards Luncheon will take edited by M. Landy and J. A. Movshon (MIT place at noon on Wednesday, June 3. Press, Cambridge, MA, 1991), pp. 3–20. Both awards are peer-reviewed, 4A. Gershun, "The Light Field," Journal of such that the luncheon is well- Mathematics and Physics Vol. XVIII, 51–151 attended by captains of industry for Investorshigh-level Conference:networking and recogni- (1939) (Translated by P. Moon and G. Timo- tion of the best in the industry over shenko, Moscow, 1936). the last year. 5R. T. Held, E. A. Cooper, and M. S. Banks, “Blur and Disparity Are Complementary Cues to Depth,” Current Biology 22, 1–6 (2012). The IC will feature presentations 6W. Sprague and M. S. Banks, Lecture given • Excellent light transmission properties from leading public and private com- panies in the display technology sup- at the Optometry School at the University of • Low stress • High strength ply chain and encourage questions California Berkeley with data (2013). 7 • Low outgassing • Solvent free and discussion between presenters J. J. Gibson, “The Theory of Affordances,” and participants. Concludes with in Perceiving, Acting, and Knowing, edited by MarketDrinks &Focus Displays: Conference Networking R. Shaw and J. Bransford (1977). Reception,Reception with Wednesday: Presenters and 8 M. E. Guido, E. Garbarino-Pico, M. A. Investors Contin, D. J. Valdez, P. S. Nieto, D. M. Verra, Hackensack, NJ 07601 USA V. A. Acosta-Rodriguez, N. de Zavalía, and +1.201.343.8983 • main masterbond.com R. E. Rosenstein, “Inner retinal circadian Follows the Wednesday Market clocks and non-visual photoreceptors: Novel www.masterbond.com Focus Conference, title and program players in the circadian system, Prog. Neurobio. www.displayweek.orgTBD, please note conference atten- 92, 484–504 (2010). dance is required for admission.

46 Information Display 1/13 Info Display Half-Page_Layout 1 11/8/13 8:36 AM Page 1 ID Ad Index Issue2_Layout 1 3/18/2015 6:36 PM Page 48

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Instrument Systems Germany · Phone: +49 89 45 49 43 0 · [email protected] · www.instrumentsystems.com Architects of World Class Display Enhancements

Visit usus atat BoothBooth # #934 1503

PRODUCT & CAPABILITIES: EuropTec USA is a specialist in cover glass processing and . • EagleEtch® & EagleEtch Plus™ - industry’s best performing Anti-Glare Glass fabrication for the display industry. As an expert in various finishing and ® . • EagleEtch XS - thin AG Glass processing technologies, we design . • EagleEtch® Tough - aluminosilicate AG Glass and manufacture products for . • Luxar® Anti-Reflective Glass display applications. . • Silk Screening . • Chemical Strengthening . • Heat Tempering . • Technical Processing: CNC Cutting, Edgework, Beveling, Hole Drilling

APPLICATIONS: . • Touch Panels . • Vehicle Displays . • ATMs & Kiosks 423 Tuna Street . • Military & Avionics Clarksburg, WV 26301 . • Ruggedized Displays Tel: 304-624-7461 Email: [email protected] . • Digital Signage www.europtecusa.com

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