DISPLAY Smartphone using Smart AMOLED and Retina Display

Smartphone display market shows highest demand for touch screen technology. As per market study, there is a critical change in key specification like resolution, size and display technology. Demand for high resolution displays drives the growth of display technology such as AMOLED (Active-matrix Organic Light Emitting Diode) and also “retina” displays for the next generation of smartphones and tablets.

PRIYA PATHAK

ver since smartphones came into images on the screen. This display is possible with existence, there has been a constant chemically treated glass of the screen and LED improvement in their display systems. backlighting that improves the resolution of the EDisplay of a smartphone has been made images. a parameter to judge or rate its performance against other smartphones. Two of AMOLED Technology the latest display technologies in smartphones are The emergence of active-matrix organic light retina display (adopted by Apple in its iPhone 4) emitting diode (AMOLED) displays has whetted and AMOLED and super AMOLED (used by consumers’ appetites for improved display Samsung in its Galaxy series smartphones). performance, especially in the highly competitive AMOLED Display is a technology also referred to smartphone field. The Korea Herald reports that as active matrix organic light emitting diodes, one manufacturer, Samsung Mobile Display(SMD), mainly used in smartphones and televisions. Active controls 98% of the global AMOLED display matrix is the system of addressing the pixels market. SMD parent company Samsung is the whereas OLED is a thin film technology that world’s second largest mobile phone manufacturer contains compounds that help in producing after Nokia. Samsung is leveraging its controlling display. This display technology uses less power position in AMOLED display supply while it aims to and is a cost effective means of display in large double its smartphone market share. Demand for televisions. AMOLED displays, which consume less AMOLED displays for smartphone handsets has power and have higher refresh rates have become spiked sharply and AMOLED display panels in the very popular as any power saved is critical in the 3–4-inch diagonal size range are currently in short context of mobile phones. However, it is difficult to supply. While Samsung can source AMOLED view properly in AMOLED display under direct sunlight. Also, the compounds used for display are displays from SMD, other smartphone developers prone to degradation in a short period of time than LCD display. Retina Display, this is the name given to the technology used by Apple in its latest smartphone iPhone 4, and is a very high resolution display technology. This display is able to pack considerably larger pixels in a screen of a mobile phone than is possible with any other display technologies. As a result, retina display boasts of 326 pixels per inch that produces high definition Fig.1. Nexus One Smartphone Source: Google

DISPLAY , AMOLED manufacturing technology and investing in the manufacturing capacity required to bring In all applications, AMOLED displays to market in high volumes. Prior and ongoing investment by display manufacturers in LCD manufacturing capacity complicates AMOLED displays investment decisions for AMOLED displays, which are essentially replacements for LCDs. compete directly With the recent emergence of the smartphone as a popular consumer electronics product, with more mature smartphone developers have sought to differentiate their phones using high-performance thin-film transistor AMOLED displays. While smartphone developers including HTC and Pantech have shipped (TFT) LCDs AMOLED display smartphones, Samsung with its captive AMOLED display capability has been , particularly aggressive in rolling out a wide range of portable products with AMOLED displays, including Nokia, LG, RIM, Motorola, Apple, HTC, including digital cameras and mp3 players, as well Pantech and others are having to rely on more as smartphones. readily available liquid crystal displays (LCDs) for Current status some or all oftheir products, or rely on limited AMOLEDs are now perceived by smartphone supplies of AMOLED displays coming from SMD. consumers as offering higher display performance Other display manufacturers, including LG, Sony, and longer battery life compared to competing AU Optronics and Chimei Innolux, have AMOLED LCDs. Whether these consumer perceptions are display capability, but SMD has been the most realised in a commercial product depends on the aggressive in building manufacturing capacity for implementation of the display. AMOLED display panels for portable products. One determining factor in the performance of Background smartphone displays is the touchscreen. Current Before looking further at the current status of the smartphone models typically incorporate a AMOLED industry and how it will evolve in future, it touchscreen display user interface and may or may is useful to examine how we arrived at this point, not include a physical keyboard. Integration of the where AMOLED display demand is outstripping touchscreen with the display is a key determinant of supply. AMOLEDs have been under development display performance, since the added layers for several years with many impressive required may lead to reflections that lower display demonstrations (from Sony, Samsung, LG, Chi Mei, contrast. Kodak and others) of high contrast levels, good Innovations in touchscreen technology and black levels and highly saturated colours. AMOLED integration are being pursued by developers. displays in sizes ranging from mobile phone size to Samsung has again been aggressive by launching 40-inch high-definition (HD) televisions have been AMOLED displays with improved touchscreens. demonstrated, but until recently AMOLED displays have reached the market in only a few products at relatively high price points. Retina Display To date, AMOLED displays have been used in Based on retina display, Apple introduced iPhone4 mobile phones, digital cameras, portable media which promises excellent sharp quality. As per (mp3) players, and a few smaller screen (11–15- Apple it is the most vibrant, highest resolution inch) televisions. In all applications, AMOLED phone screen ever. Put basically, Apples version of a displays compete directly with more mature thin- Retina Display is an ultra high-resolution screen. film transistor (TFT) LCDs. The iPhone 4 features an eye watering 960 x 640 Reaction pixels, which is four times as many on-screen pixels The reviews and reactions garnered by these early compared with Apples earlier iPhone models. AMOLED products have been very positive The iPhone 4 Retina display uses technology called concerning display performance. As with many new IPS (in-plane switching) — the same technology technologies however, display manufacturers have used in the Apple LED Cinema Display and iPad — had to make tough decisions about developing to achieve a wider viewing angle than on typical

DISPLAY While, AMOLED consumes less power, retina display is known for packing a high number of pixels on the screen of the mobile, LCDs. Which means you can hold iPhone 4 almost any way you want and still get a brilliant picture. That’s perfect when you’re sharing photos with a friend or moving your iPhone around while playing a driving or flying game. In addition, the Retina display offers four times the contrast ratio of previous models, so whites are brighter, blacks are market. VRD shows strong potential to replace LCD darker, and everything is more beautiful. screens in cell phones, handheld computers, What is Retina Display? handheld gaming systems, and eventually even Retina display is also called Virtual retina display larger computers such as laptops. VRD. It is an “IPS” (In-plane switching) technology As the components of VRD displays decrease in cost and is “better than OLED technology for smaller and the manufacturing processes used to create products like the iPhone. them improve, distribution of the product will surely A VRD unit consists of 4 modules; drive electronics expand to a very large market. to break down an incoming source image into an Retina Display Acuity information stream, a light source made up of “Retina Display” is a great marketing name, and laser(s) or LED(s), a scanner bank made up of it’s the sharpest smartphone display available, 23 horizontal and vertical scanners, and a lens to percent sharper than the nearest competitor, but expand the image that projects through the scanners. As in a television, the scanners rapidly objectively it does not meet the quantitative criteria oscillate left-to-right or down-to-up, selectively for being a true Retina Display – it’s about a factor permitting colors through in precise configurations of two lower than the acuity of the human Retina. that produce a high-resolution 2mm x 2mm field of Rather, the iPhone 4 has a “20/20 Vision Display” pixels. Then a lens acting as an expander boosts the because when it is held more than 10.5 inches size of the image to something like 18mm x 18mm, away, a person with 20/20 Vision will not be able to allowing for a larger and more natural image. The resolve the iPhone 4 screen pixels, which are at 326 pixel field is then projected onto the eye, where the ppi (1 arc-minute resolution). But 20/20 Vision is eye's lens focuses the image onto the retina. Aside the legal definition of “Normal Vision,” which is at from tapping into the optic nerve itself, there may the lower end of true normal vision. There are in be no more effective way to display an image. fact lots of people with much better than 20/20 The virtual retinal display is highly efficient with Vision, and for most people visual acuity is limited respect to power consumption, requiring far less by blurring from the lens in the eye. The best human power than the postage-stamp LCD screens used vision is about 20/10 Vision, twice as good as commonly in today's mobile devices. A VRD display 20/20 Vision, and that is what corresponds to the uses about a microwatt of power. Since VRD acuity of the Retina. So to be a “True Retina displays project images directly onto the retina, they Display” a screen needs about 652 ppi at 10.5 provide a sharp, clear image regardless of external inches, or 572 ppi at 12 inches. Unfortunately, a lighting conditions. VRD displays require a fraction “20/20 Vision Display” doesn’t sound anywhere of the hardware of conventional display devices, near as enticing as a “Retina Display” so marketing allowing for lighter and more elegant mobile and science don’t see eye-to-eye on this… devices, in high demand for today's electronics