DOCSLIB.ORG

Liquid Crystal Display

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Liquid Crystal Display 2 3 LIQUID CRYSTAL DISPLAY SUBMITTED BY- SHRUTI KAUSHIK SECTION- 260 ROLL NO- 07 4 TABLE OF CONTENTS SNO TOPIC PAGE NO 1 what is lcd 8 2 Technology 9 behind lcd monitor 3 Working of lcd 10 monitor 4 Features of lcd 11 television 5 Diff between lcd 12 and plasma 6 Texas 14 instrument’s test 7 High 16 transmissive tft lcd technology 8 Challenging 19 technologies for lcd 9 Conclusion 10 Refrences FIGURES 5 FIG 1………………………………PAGE 8 FIG 2………………………………PAGE 9 FIG3………………………………PAGE 10 FIG4………………………………PAGE 11 FIG5………………………………PAGE 14 FIG6………………………………PAGE 15 FIG 7………………………………PAGE18 ABSTRACT FIG 8………………………………PAGE15 A liquid crystal display (LCD) is an electro optical amplitude modulator realized as a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. 6 There are 2 types of LCD that is PASSIVE get stretched and block the light and the MATRIX and ACTIVE MATRIX darkening of the pixels depends on the LCD.LC’s can be aligned by electric and electric current. Pixels are completely magnetic fields .one electro optical affects darkened when there is no electricity. with LCs requires a current through the LCs cell; all other practiced electro optical As for colour LCD display, it will have three affects only require an electric field(without sub-pixels (green, blue and red) and current) for the alignment of LC. depending on the pixels that get light, the LCD will produce the final image on the LCD television now uses liquid crystals screen. captivated between two polarized glass sheets and a matrix of TFT (thin film WHAT IS LCD……….??????? transistor) transistors that control the electric flow through the crystals .The glass sheet A liquid crystal display (LCD) is an electro contains thousands of tiny cells or pixels and optical amplitude modulator realized as a each one is colored with green blue or red. thin, flat display device made up of any The performance of LCD can be improved number of color or monochrome pixels what is llcd(RGB) light emitting diodes arrayed in front of a light source or reflector. instead of cold cathode fluorescent lamps in edge lit LCD backlights brightness and color It is often utilized in battery-powered performance (gamut) of LCD displays. electronic devices because it uses very small amounts of electric power. In present daily life some other technologies have entered this feild which have better features than LCD technology like DLP (Digital liquid processing) and CRT (cathode ray tube).Presently it is being . challenged by PLASMA television. The main difference between LCD and DLP is being presented in the project .Texas Instruments experiment clearly describes the difference between LCD and DLP technology. INTODUCTION In the following project a detail explanation about what is LCD and what are the features of LCD are being depicted.LCD is a display device that uses thin, flat sheet made up of liquid crystals and this thin sheet is placed in front of a light source. The molecules of Figure 1 liquid crystal are twisted in their natural state and allow the light to pass through. However, when certain amount electricity passes through liquid crystals, the molecules 7 Above picture represents us Reflective Twisted Nematic liquid crystal display. The main features of this particular liquid crystal display are as follows:- Glass substrate with ITOelectrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is turned ON. Vertical ridges etched on the Figure 2 surface are smooth. 1. Twisted nematic liquid crystal. 2. Glass substrate with common Liquid Crystal display or LCD monitor is a electrode film (ITO) with horizontal thin and flat device for display. It is made by ridges to line up with the horizontal large number of color or monochromatic filter. pixels which are arrayed in way of a light 3. Polarizing filter film with a source or a reflector. It uses very small horizontal axis to block/pass light. amount of electric power and hence is used 4. Reflective surface to send light back often in battery powered electronic devices. to viewer. The technology used is very much dissimilar to CRT technology which is used by many desktop monitors. It was used only on notebook computers for a very long time. Only recently they have been offered as an alternative to CRT monitors. They take up An example of LCD:- very less desk space and are much lighter than the CRT monitors. But they are also quite expensive. LCD monitor Each pixel of LCD monitor display has a layer of aligned molecules between two Liquid Crystal display or LCD monitor is a electrodes which are transparent and two thin and flat device for display. It is made by polarizing filters. Because there is no liquid large number of color or monochromatic crystal between the aligned polarizing pixels which are arrayed in way of a light filters, light which has passed through the source or a reflector. first filter will be blocked by the second polarizer. The surface which is in contact with the crystal is treated to align it in particular direction. The direction of TECHNOLOGY BEHIND LCD alignment is defined by direction of rubbing. MONITOR Resolution, in terms of horizontal and vertical size expressed in pixels, is native supported for the best display effects. This is 8 one of the things that sets LCD monitor apart. Dot Pitch is defined as the distance LCD technology has some critical between two adjacent pixels. It is the drawbacks too. Resolution of a CRT minimum for sharper image. Each pixel is monitor can be changed without divided into three cells, or sub pixels. These introduction of any new artifact. But LCDs are colored red, green and blue. Each sub can produce only their native resolution and pixel can be controlled independently for non native resolutions are achieved by millions of combinations and hence colors. scaling. The blacks of LCDs are actually Older CRT monitors use phosphors for sub grey because of presence of a light source. pixel structure. The analog electron beam This results in lower contrast ratio when though does not hit the exact sub pixel. compared to CRTs. LCDs with cheaper parts cannot display as many colors plasma Color components can be arrayed in various or CRT counterparts. geometries, depending on how the monitor is to be used. If the software being used Also, LCD display has longer response time knows the geometry, it can be used to when compared to Plasma or CRT increase the apparent number of pixels using counterparts. Input lag is also present and sub pixel rendering. This kind of technique the viewing angle is limited. In spite of these is often used in text anti-aliasing. LCDs drawbacks, LCD display is quickly gaining which are used in digital watches and prominence. calculators have separate contact for each segment. Thus an external dedicated circuit charges each segment individually. This is not possible if the number of elements increases. Small monochrome displays like the ones used in Personal Organizers or in older laptops have passive matrix like structure WORKING OF A LCD and employ super twisted nematic or double TELEVISION layer STN technology. Here, each row or each column has a single electrical circuit and the pixels are hence addressed according to rows and columns. But as the number of pixels increases, the response time decreases and the technique no longer remains feasible. Color displays used in modern LCD monitors and televisions use active matrix structure. An array of thin film transistors (TFT) is added. Each pixel has a dedicated transistor. Active Matrix display looks brighter and sharper than passive matrix display of similar size and has better response time. 9 Figure 3 HOW DOES A LCD TELEVISION WORK?? LCD television uses liquid crystals captivated between two polarized, glass Figure 4 sheets and a matrix of TFT (thin-film The screen resolution of LCD TV starts transistor) transistors that control the electric from 720p and higher (1080i and 1080p). flow through the crystals. The glass sheet This means its higher native resolution contains thousands of tiny cells or pixels and ensures that picture looks sharper, more each one is coloured with green or blue or detailed and clearer. red. LCD Screen and profile There is a florescent bulb which sits right behind the glass pixels and illuminates these Typically, LCD TV screen size varies cells. Each pixel has a TFT transistor next to between 26" and 40" although larger screen it that determines how much it should be sizes are available at expensive price tags. electrically charged. Less the pixel is Currently, the largest LCD TV available in electrically charged, more light beams it commercial market has about 52" screen allows and greater the intensity of respective size and the models will be very few. colour on the LCD screen. Thus, the light beams are either blocked off or shown in different amounts so the combination of all pixels produce the image on the screen, FEATURES OF LCD TELEVISION:- Screen resolution The native or screen resolution determines how much sharp the picture will look on the screen. CRT type TVs work well with standard definition and can show pictures of 330 lines resolution. LCD TV is a bit thinner (less than 3" thickness) and also weighs much lesser than FIGURE 4 represents the LCD resolution plasma TV so it can be hung on the wall. Wide Aspect Ratio 10 LCD TV looks typically rectangular as its screen supports 16:9 aspect ratio, which is the standard screen format of high definition videos.
Load more

Recommended publications
  • Tvs Final Report
    Revising the Ecolabel Criteria for Televisions – Final Report April 2008 Executive Summary Background The existing EU Ecolabel criteria for Televisions (Commission Decision 2002/255/EC, March 2002) were developed at a time when the EU TV market was dominated by Cathode Ray Tube (CRT) technology. Today however, the market has changed markedly such that new technologies including Liquid Crystal Display (LCD) and Plasma Display Panel (PDP) technologies account for an increasing market share driven by consumer preference for larger screen sizes. Other developments are important drivers for change too including the development of High Definition and Digital television. These developments mean that the existing criteria’s applicability in the rapidly changing market place is becoming increasingly marginalised. Indeed the existing criteria’s relevance to non-CRT technology is questionable. Consequently, the TV criteria are in urgent need of an update if they are to keep pace with the market. AEA was pleased to work with the Commission in undertaking the revision exercise over the period Spring 2006 to Spring 2008. We were assisted by the ad-hoc working group (AHWG) that met twice during the period to discuss and inform the revision. AHWG members and others also lent advice to the project via email and individual meetings that were immensely helpful. In parallel with our work, other important work in support of product policy was underway that helped inform the ecolabel revision, namely: 1 The revision of the TV energy testing methodology. The importance of this work is that it is being undertaken in recognition of the fact that the TV products have changed markedly and that as a result the existing test method is inadequate for non-CRT technology.
    [Show full text]
  • New Display Technologies (Crts), Displays Have Become Ubiquitous and Have Taken Many Different Forms
    1.0 Introduction Mini Briefing Electronic displays are one of the fastest-growing worldwide technologies. Once reserved for televisions and computers, and composed of large cathode-ray tubes New Display Technologies (CRTs), displays have become ubiquitous and have taken many different forms. Flat-panel displays are overtaking the CRT and are being used in larger quantities for Steve Statham portable computers, a variety of handheld devices, desktop computers and televisions, as well as tiny microdisplays, which are being used in projection televisions, for near-eye applications, where a virtual screen is presented to the viewer. The world of displays is Advances in new display technologies are rapidly changing to meet the evolving needs of the beginning to open up many new possibilities to electronic-device user. consumers and manufacturers. Unfortunately there is always a large time lag between the discoveries made, and the time when practical applications 2.0 Applications finally appear. Even once they have been incorporated into everyday items, they are The electronic-display device industry caters mainly for the sometimes expensive. automation and electronics appliance industries. Characteristic of OEM products, the growth of the display However, major developments are now taking industry is directly linked to the demand trends in end-user place in a variety of display materials with the markets. Display manufacturers, mainly concentrated in potential to enable handheld computers and mobile Japan and East Asian countries, account for over 80% of phones to be more functional and user-friendly, total display production. which could greatly aid in the convergence of functionality and convenience that these products The end-user market (which includes televisions, are intended to deliver.
    [Show full text]
  • Microdisplays - Market, Industry and Technology Trends 2020 Market and Technology Report 2020
    From Technologies to Markets Microdisplays - Market, Industry and Technology Trends 2020 Market and Technology Report 2020 Sample © 2020 TABLE OF CONTENTS • Glossary and definition • Industry trends 154 • Table of contents o Established technologies players 156 • Report objectives o Emerging technologies players 158 • Report scope o Ecosystem analysis 160 • Report methodology o Noticeable collaborations and partnerships 170 • About the authors o Company profiles 174 • Companies cited in this report • Who should be interested by this report • Yole Group related reports • Technology trends 187 o Competition benchmarking 189 • Executive Summary 009 o Technology description 191 o Technology roadmaps 209 • Context 048 o Examples of products and future launches 225 • Market forecasts 063 • Outlooks 236 o End-systems 088 o AR headsets 104 • About Yole Group of Companies 238 o Automotive HUDs 110 o Others 127 • Market trends 077 o Focus on AR headsets 088 o A word about VR 104 o Focus on Auto HUDs 110 o Focus on 3D Displays 127 o Summary of other small SLM applications 139 Microdisplays - Market, Industry and Technology Trends 2020 | Sample | www.yole.fr | ©2020 2 ACRONYMS AMOLED: Active Matrix OLED HMD: Head mounted Device/Display PPI: Pixel Per Inch AR: Augmented Reality HOE: Holographic Optical Element PWM: Pulse Width Modulation BLU: Back Lighting Unit HRI: High Refractive Index QD: Quantum Dot CF LCOS: Color Filter LCOS HVS: Human Vision System RGB: Red-Green-Blue CG: Computer Generated IMU: Inertial measurement Unit RMLCM: Reactive Monomer
    [Show full text]
  • Digital Light Processing™: a New MEMS-Based Display Technology
    Digital Light Processing™: A New MEMS-Based Display Technology Larry J. Hornbeck Texas Instruments 1.0 Introduction Sights and sounds in our world are analog, yet when we electronically acquire, store, and communicate these analog phenomena, there are significant advantages in using digital technology. This was first evident with audio as it was transformed from a technology of analog tape and vinyl records to digital audio CDs. Video is now making the same conversion to digital technology for acquisition, storage, and communication. Witness the development of digital CCD cameras for image acquisition, digital transmission of TV signals (DBS), and video compression techniques for more efficient transmission, higher density storage on a video CD, or for video conference calls. The natural interface to digital video would be a digital display. But until recently, this possibility seemed as remote as developing a digital loudspeaker to interface with digital audio. Now there is a new MEMS-based projection display technology called Digital Light Processing (DLP) that accepts digital video and transmits to the eye a burst of digital light pulses that the eye interprets as a color analog image(Figure 1). Figure 1 DLP Processing System DLP is based on a microelectromechanical systems (MEMS) device known as the Digital Micromirror Device (DMD). Invented in 1987 at Texas Instruments, the DMD microchip[1,2] is a fast, reflective digital light switch. It can be combined with image processing, memory, a light source, and optics to form a DLP system capable of projecting large, bright, seamless, high- contrast color images with better color fidelity and consistency than current displays[3-24].
    [Show full text]
  • Digital Display Circuits This Worksheet and All Related Files Are Licensed Under the Creative Commons Attribution License, Versi
    Digital display circuits This worksheet and all related files are licensed under the Creative Commons Attribution License, version 1.0. To view a copy of this license, visit http://creativecommons.org/licenses/by/1.0/, or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. The terms and conditions of this license allow for free copying, distribution, and/or modification of all licensed works by the general public. Resources and methods for learning about these subjects (list a few here, in preparation for your research): 1 Questions Question 1 What is the purpose of a seven-segment decoder circuit? What is a ”seven-segment” display, and why do we need a decoder circuit to drive it? Research the part number for a typical seven-segment decoder circuit (either CMOS or TTL). file 01417 Question 2 A seven segment decoder is a digital circuit designed to drive a very common type of digital display device: a set of LED (or LCD) segments that render numerals 0 through 9 at the command of a four-bit code: Display driver IC Seven-segment display VDD a a . A b . f b c . g Inputs B d . C e . f . D g . e c d The behavior of the display driver IC may be represented by a truth table with seven outputs: one for each segment of the seven-segment display (a through g). In the following table, a ”1” output represents an active display segment, while a ”0” output represents an inactive segment: D C B A a b c d e f g Display 0 0 0 0 1 1 1 1 1 1 0 ”0” 0 0 0 1 0 1 1 0 0 0 0 ”1” 0 0 1 0 1 1 0 1 1 0 1 ”2” 0 0 1 1 1 1 1 1 0 0 1 ”3” 0 1 0 0 0 1 1 0 0 1 1 ”4” 0 1 0 1 1 0 1 1 0 1 1 ”5” 0 1 1 0 1 0 1 1 1 1 1 ”6” 0 1 1 1 1 1 1 0 0 0 0 ”7” 1 0 0 0 1 1 1 1 1 1 1 ”8” 1 0 0 1 1 1 1 1 0 1 1 ”9” Write the unsimplified SOP or POS expressions (choose the most appropriate form) for outputs a, b, c, and e.
    [Show full text]
  • Epson Projector Fact Sheet
    EPSON PROJECTOR FACT SHEET 3LCD – A CLEAR DIFFERENCE As the number one projector manufacturer globally1, Epson leads the market in the development of projector technology. Epson projectors use a 3LCD projection engine to deliver bright, clear images that are rich in detail and colour. 2 Many of Epson’s competitors use 1-chip DLP™ projector systems, which create thousands of pulses of coloured light per second. They do this by shining lamp light 3 through red, green, blue and white parts of a rotating colour wheel. These light pulses are 4 then reflected by a DMD™ device, which is on a hinge and has a tiny mirror for each pixel of the image. The series of rapid colour bursts is then projected onto the screen. The viewer’s brain can’t pick out the individual flickers - it mixes the basic colours that appear in succession in each pixel to come up with the final colour the viewer sees. Epson’s 3LCD system works differently, using a combination of dichroic mirrors to separate the white light from the projector lamp into red, green and blue light. Each of the three light colours is then passed through its own LCD panel and recombined using a prism before being projected onto the screen. With 1-chip DLP technology, colour break-up or the ‘rainbow effect’ can sometimes be seen. This occurs when the eye perceives the individual colours, and is a result of the colours being projected sequentially by the colour wheel. Epson’s 3LCD technology avoids this by including all three basic colours in each pixel of the projection, delivering superior Colour Light Output that’s easier on the eyes.
    [Show full text]
  • Review of Display Technologies Focusing on Power Consumption
    Sustainability 2015, 7, 10854-10875; doi:10.3390/su70810854 OPEN ACCESS sustainability ISSN 2071-1050 www.mdpi.com/journal/sustainability Review Review of Display Technologies Focusing on Power Consumption María Rodríguez Fernández 1,†, Eduardo Zalama Casanova 2,* and Ignacio González Alonso 3,† 1 Department of Systems Engineering and Automatic Control, University of Valladolid, Paseo del Cauce S/N, 47011 Valladolid, Spain; E-Mail: [email protected] 2 Instituto de las Tecnologías Avanzadas de la Producción, University of Valladolid, Paseo del Cauce S/N, 47011 Valladolid, Spain 3 Department of Computer Science, University of Oviedo, C/González Gutiérrez Quirós, 33600 Mieres, Spain; E-Mail: [email protected] † These authors contributed equally to this work. * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +34-659-782-534. Academic Editor: Marc A. Rosen Received: 16 June 2015 / Accepted: 4 August 2015 / Published: 11 August 2015 Abstract: This paper provides an overview of the main manufacturing technologies of displays, focusing on those with low and ultra-low levels of power consumption, which make them suitable for current societal needs. Considering the typified value obtained from the manufacturer’s specifications, four technologies—Liquid Crystal Displays, electronic paper, Organic Light-Emitting Display and Electroluminescent Displays—were selected in a first iteration. For each of them, several features, including size and brightness, were assessed in order to ascertain possible proportional relationships with the rate of consumption. To normalize the comparison between different display types, relative units such as the surface power density and the display frontal intensity efficiency were proposed.
    [Show full text]
  • Life Cycle Assessment Study of a Field Emission Display Television Device
    Int J Life Cycle Assess (2015) 20:61–73 DOI 10.1007/s11367-014-0806-2 LCI METHODOLOGY AND DATABASES Life cycle assessment study of a field emission display television device Roland Hischier Received: 2 April 2013 /Accepted: 24 September 2014 /Published online: 8 October 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract printed wiring boards) shows the highest contribution—while, Purpose An life cycle assessment (LCA) study of a field even when focussing on the glass and its various coating emission display (FED) television device was established. layers only, the carbon nanotubes (CNTs) production has a The first objective of this study was to get an up-to-date and very minor influence. The releases of CNTs during the End- comprehensive picture by applying the latest developments in of-Life treatment do not contribute in a relevant manner to the the area of LCA, especially concerning the use of nanoparti- overall impact neither—even when focussing on the cles. In its second part, the study shows a comparison with “ecotoxicity potential” by using conservative CFs reported today’s display technologies (i.e. CRT, LCD, plasma) and the for this type of releases. Last but not least, the comparison timely development of the assessment of a FED television with the existing television display technologies shows that an device. FED device has an environmental advantage over all three Methods This LCA study covers the complete life cycle of a other technologies using the above stated functional unit of FED television device in accordance with the ISO 14040 “one square-inch of display during 1 h of active use”.
    [Show full text]
  • Flat Panel Displays: End of Life Management Report
    Literature Review Flat Panel Displays: End of Life Management Report Final Report Prepared By: King County Solid Waste Division 201 South Jackson Street, Suite 701 Seattle, WA 98104 Updated April 24, 2008 Original Report Date August 20, 2007 Table of Contents Acronyms …….............................................................................................................................iv Acknowledgements...................................................................................................................... vi Executive Summary .................................................................................................................... vii Section 1: Introduction............................................................................................................1 1.1 Goals and Objectives.................................................................................3 1.2 Scope and Limitations ...............................................................................4 Section 2: Types of Flat Panel Displays.................................................................................5 2.1 Liquid Crystal Displays (LCDs)..................................................................5 2.1.1 History............................................................................................5 2.1.2 Technology ....................................................................................5 2.1.3 Manufacturing ................................................................................7 2.1.4
    [Show full text]
  • Class-Action Lawsuit
    Case3:14-cv-00801 Document1 Filed02/21/14 Page1 of 36 1 Francis O. Scarpulla (41059) Judith A. Zahid (215418) 2 Patrick B. Clayton (240191) Zelle Hofmann Voelbel & Mason LLP 3 44 Montgomery Street, Suite 3400 San Francisco, CA 94104 4 Telephone: 415-693-0700 Facsimile: 415-693-0770 5 Email: [email protected] [email protected] 6 [email protected] 7 Jonathan Shub (237708) Scott A. George (Pro Hac Vice Appl. To Be Filed) 8 Seeger Weiss LLP 1515 Market Street, Suite 1380 9 Philadelphia, PA 19102 Telephone: 215-564-2300 10 Facsimile: 215-851-8029 Email: [email protected] 11 [email protected] 12 Attorneys for Plaintiff and the proposed class 13 [Additional counsel listed on signature page] 14 UNITED STATES DISTRICT COURT 15 NORTHERN DISTRICT OF CALIFORNIA 16 17 Shahla Rabinowitz, on behalf of herself and all Case No. __________ 18 others similarly situated, COMPLAINT 19 Plaintiff, 20 v. Demand for Jury Trial 21 Samsung Electronics America, Inc., 22 Defendant. 23 24 25 26 27 28 CASE NO. __________ 5803987.5 COMPLAINT Case3:14-cv-00801 Document1 Filed02/21/14 Page2 of 36 1 Shahla Rabinowitz (“Plaintiff”), by and through Plaintiff’s undersigned attorneys, on 2 behalf of herself as well as the proposed class (defined infra ), demanding trial by jury of all claims 3 properly triable thereby, makes the following allegations and claims against Samsung Electronics 4 America, Inc. (“Samsung” or “Defendant”). 5 JURISDICTION 6 1. This Court has jurisdiction over all causes of action asserted herein pursuant to the 7 Class Action Fairness Act. 28 U.S.C.
    [Show full text]
  • Symposium Digest Articles Listed Chronologically 1963-1988
    Preliminary Table of Contents for SID Symposium Digests 1963-1988 ( author company affiliations not listed) Notes: 1 The index covers full papers and keynote speeches for SID Symposia from 1963 through 1988; panel sessions, seminars and luncheon speakers are not listed 2 Authors' company affiliations are not shown (to be added) 3 Lead author is designated with asterisk ( * ) 4 The first ten (10) digests were designated by number as follows 5 The first ten (10 Symposia were identified by numbers, as follows: 2/1963 -#1; 9/63 - #2; 5/64-#3; 9/64 - #4; 2/65 - #5; 9/65 - #6; 10/66 - #7; 5/67 - #8; 5/68 - #9; 5/69 - #10 Session # Year Page Title Author(s) 1963-1 1 User Requirements for Display Debons, Col, Anthony * 1963-1 13 Scan Conversion and Bright Display Porter, Richard * 1963-1 21 Multicolor Projection System Smith, Fred E.* 1963-1 31 Advanced Display Techniques through the Charactron Redman, James H.* 1963-1 53 Light Valve Display Albanese, Augustine * 1963-1 63 Colordata, A Photographic Large Screen Display system Baron, Peter C.* 1963-1 77 Human Performance Engineering and Information Display Silvern, Leonard * 1963-1 83 Multiple Projection Techniques Klein, R.C.* 1963-1 93 Photochromic Dynamic Display Hines, Logan J.* 1963-1 99 Datachrome Display System Parker, Philip A.* 1963-1 117 High Ambient Light Display Systems Miller, Wendell S.* 1963-1 127 Electroluminescent Displays Hallett, Joseph L.* 1963-1 139 Pseudo 3-D Display Perdue, Joseph L.* 1963-1 155 Aims and Purposes of the S.I.D. Vlahos, Petro * 1963-2 1 Iinformation Systems,
    [Show full text]
  • Technology Brief 6: Display Technologies
    106 TECHNOLOGY BRIEF 6: DISPLAY TECHNOLOGIES Technology Brief 6: Display Technologies From cuneiform-marked clay balls to the abacus to today’s digital projection technology, advances in visual displays have accompanied almost every major leap in information technology. While the earliest “modern” computers relied on cathode ray tubes (CRT) to project interactive images, today’s computers can access a wide variety of displays ranging from plasma screens and LED arrays to digital micromirror projectors, electronic ink, and virtual reality interfaces. In this Technology Brief, we will review the major technologies currently available for two-dimensional visual displays. Cathode Ray Tube (CRT) The earliest computers relied on the same technology that made the television possible. In a CRT television or monitor (Fig. TF6-1), an electron gun is placed behind a positively charged glass screen, and a negatively charged electrode (the cathode) is mounted at the input of the electron gun. During operation, the cathode emits streams of electrons into the electron gun. The emitted electron stream is steered onto different parts of the positively charged screen by the electron gun; the direction of the electron stream is controlled by the electric field of the deflecting coils through which the beam passes. The screen is composed of thousands of tiny dots of phosphorescent material arranged in a two-dimensional array. Every time an electron hits a phosphor dot, it glows a specific color (red, blue, or green). A pixel on the screen is composed of phosphors of these three colors. In order to make an image appear to move on the screen, the electron gun constantly steers the electron stream onto different phosphors, lighting them up faster than the eye can detect the changes, and thus, the images appear to move.
    [Show full text]