Everything You Need to Know About Displays (in Four Days)
The annual technical symposium at Display Week features a mix of breaking news, developments, and predictions from hundreds of key companies and academic institutions that can be found nowhere else.
by Jenny Donelan
IN SAN DIEGO this June, scientists and researchers from all over the world will reveal the year’s most important display-industry developments. To anyone who works in displays, or even in an industry touched by displays, the annual International Symposium at Display Week is for a short time the center of the technical universe. It’s a one-of-a-kind clearinghouse for all the information that will be essential for carrying on the business of the following year. From the very immediate concerns of which backplane technology to use – oxide TFT or LTPS, for example – to more forward-looking topics such as holographic display systems – they will all be featured in San Diego this spring from June 3–6.
For the purposes of peer review, the papers that will be presented are evaluated by display discipline – Active-Matrix Devices, Applications, Applied Vision/Human Factors, Display Electronics, Display Manufacturing, Display Measurement, Display Systems, Emissive Displays, e-Paper and Flexible Displays, Liquid-Crystal Technology, OLEDs, Projection, Touch and Interactivity – then assigned to sessions designated by topic, such as Electro-luminescent Quantum Dots. (This year, five special focus areas were also determined: OLED TV, Wearable Displays, Oxide TFT vs. LTPS, 3D, and Lighting.) Each session consists of 3–5 20-minute paper presentations. The papers chosen to appear at Display Week represent the best of the best. Here are just some of the highlights from this year’s sessions:
The Back Story on Backplanes
If there is one dominant theme going into this year’s symposium, it is backplanes. Determining which backplane technology is best for a display is not a trivial exercise. Among other considerations, it depends on the display material itself – LCD vs. OLED, for example; and the size – mobile to massive TV. Finding the best one makes a great deal of difference – not only to consumers, in terms of device performance and price, but to companies that make the devices. There are three sessions and 12 papers devoted to the subject of Oxide TFTs vs. LTPS alone this year. Papers that look especially exciting include a late-news paper (one with extremely recent information) from Samsung, entitled “An Advanced ELA for Large-Sized AMOLED Displays.” It describes an Advanced Excimer Laser Annealing process used to make displays such as the 55-in. OLED TV that Samsung introduced last summer. LG also has an interesting late-news paper, on “Roll-to-Roll Processed and Top-Gate Structured a-InGaZnO TFTs with Large Source/Drain Offsets,” which describes a future manufacturing technique for rollable displays.
Another backplane-related topic of interest is quantum dots. This year, there are an unprecedented three sessions with 13 papers devoted to this subject, from companies including QD Vision, Pacific Light Technologies, 3M, and Sony. QD Vision has recently asserted that quantum dots will enable LCDs to compete with OLED displays to such a degree as to push OLED TVs out of the picture. See if that’s possible by checking out QD Vision’s paper, “Quantum Dots: The Ultimate Down-Conversion Material for LCDs,” in which the authors, in their words, “make the case that QDs are the ultimate light-generating material for the future of displays.”
Onward for OLEDs
OLEDs are of course an ongoing source of interest for most of the display community. It is a technology whose time has almost come – over and over again. Yet, while the focus has been on TVs all the while, OLEDs have quietly become the foundation for many best-selling mobile devices. This year, both Samsung and LG finally released commercial versions of large OLED TVs (in a curved 55-in. format), which represented a major breakthrough, even though manufacturing challenges remain for large-area OLEDs, and solving those is a point of much of the aforementioned backplane development.
This year’s symposium features OLED sessions on devices, flexible OLEDs, materials, OLED driving, lighting, and, of course, TVs. The emphasis for contributed papers of late has been on flexible and TV technology, notes OLED subcommittee chair Sven Murano. With 51 presentations on OLEDs alone, this year’s symposium is the place to find out what’s going on with OLEDs. There are many papers of practical significance, including “Advancements in Ink-Jet Printing for OLED Mass Production” from Kateeva, which describes how to overcome challenges in achieving uniform, mura-free panels, a procedure that is highly dependent on the deposition of uniform ink volumes into each subpixel.
Papers from the two OLED TV sessions are bound to draw plenty of attention, especially as manufacturers AUO, LG, Panasonic, Samsung, and Shenzen China Star Optoelectronics will all be presenting. “People are looking at questions like ‘How do I measure the quality of OLED TV, or how do I compensate for motion artifacts?” says Murano. “This is something that LCD TV guys know well, and now the OLED guys are looking into these practical questions, which is a good sign – it’s all becoming more tangible.” Of particular interest is “Advanced Technologies for Large-Sized OLED TV” from LG, which discusses achieving scalability, mass production, and lifetime reliability using oxide TFT, white OLEDs, and solid-phase encapsulation. Another promising paper is “Highly Reliable InGaZnO TFT Backplane for 55-in. 4K × 2K OLED Displays” from Panasonic, which looks at InGaZnO (IGZO) TFT backplanes used to create 55-in. 4K × 2K OLED displays in a Gen 8.5 production line.
Wearing Your Displays
Wearables are a hot topic in consumer electronics right now, and the symposium features three wearable-display sessions with a total of 14 papers. The majority of these are about non-flexible displays such as near-to-eye devices, but one session focuses on flexible wearable displays and includes the papers “OLEDs on Textile Substrates with Planarization and Encapsulation Using Multilayers for Wearable Displays,” from KAIST, which suggests how OLEDs might be fabricated on textile substrates using a poly(vinyl alcohol) (PVA) multilayer for planarization and encapsulation and “Wearable Display for Dynamic Spatial and Temporal Fashion Trends” from the University of Sunderland, with examples such as a smartphone app-controlled high-heeled shoe that can be programmed to display different imagery (to match an outfit for example (Fig. 1).
Fig. 1: A paper from the UK’s University of Sunderland describes a shoe embedded with a display that can be programmed from a smartphone to change the appearance of the footwear. Patterned displays are possible as well.
Futuristic Displays: Light-Field and Holography
New this year is an entire session devoted to Light-Field and Multi-View Displays. A paper with perhaps the longest title of the symposium – “Wide-Field-of-View Compressive Light-Field Display Using a Multilayered Architecture and Viewer Tracking” – from MIT is of special interest. In it, the authors describe “a simple extension to existing compressive multilayer light-field displays that greatly extends their field of view and depth of field,” ultimately demonstrating a real-time glasses-free 3-D display with a 110 × 45° field of view. Also of interest is “Dual-Layer Three-Dimensional Display with Enhanced Resolution” from Korea’s Inha University, which describes a system consisting of two LC panels with a lenticular lens sheet between them that can present a three-dimensional image without any resolution reduction as compared to a conventional two-view display.
The Holographic Display Systems sessions are also in a “don’t miss” category. Holography used to seem futuristic and whimsical, but every year researchers make progress. All this year’s sessions are from China, and among them, of special interest is the late-news paper “Waveguide Display System with Variable Output Intensity” from the Beijing Institute of Technology, which describes a method for achieving variable output intensity for holographic images using the holographic gratings.
Plasma Pioneers
Plasma TVs are no longer as plentiful as they used to be, though many of those still on the market are considered some of the finest TVs available. Without doubt, plasma played an important role in making the flat-panel display industry the success it is today. To mark plasma’s impact, on Tuesday afternoon at Display Week, there will be a special 90-minute session following the regular plasma session. Celebration of the “50th Anniversary of the Plasma Display Panel” will feature talks by Professor Donald L. Bitzer, co-inventor of the plasma display panel; Tsutae Shinoda, inventor of color plasma display technology; and former students of Bitzer SID Past-President Larry F. Weber and SID Fellow Roger L. Johnson. Following the session there will be a sponsored reception. This celebration will be a fascinating and no doubt entertaining retrospective of a key display technology and a chance to consider the history of the industry itself. Says Weber, “It’s the story of a technology that grew and that still has considerable potential for the future. Young people especially might find it interesting.”
Wrapping It Up
As mentioned previously, it’s impossible to describe all the important presentations at Display Week, which include sessions on UHD, novel displays, “Liquid Crystals Beyond Displays,” and much more. In addition to 4 days of oral presentations, there is also a Thursday evening poster session, with a huge range of display topics viewable at the same time. ID strongly encourages you to download the preliminary program at http://displayweek.org/2014/Program/Symposium.aspx and start planning. There’s something here for everyone – some of the papers will be invaluable to your work, and some are just plain fascinating – and you will learn things you didn’t know you didn’t know. One thing is for sure, if you do not visit Display Week to find out for yourself, you’ll be missing out on what might be the most useful four days of the entire year. •
Display Week 2014 Overview San Diego Convention Center, San Diego, California, USA June 3–6, 2014
Display Week 2014 Symposium at a Glance