Plan Ahead for the 2013 Symposium
Make the most of Display Week 2013 with an advance look at this year’s technology sessions.
by Jenny Donelan
THE Society for Information Display’s annual symposium is the foundation of Display Week. Each year, hundreds of papers are presented that convey vital research and development information, both forward-looking and immediately practical, in numerous areas of display technology. The information you will obtain at this year’s Symposium in Vancouver, Canada, is not available at any other venue or from any other industry organizations.
As in previous years, sessions are organized by subcommittees, whose members have chosen the most exciting and informative papers in their focus areas of display technology. Those areas include active-matrix devices, applications, applied vision, display electronics, display manufacturing, display measurement, display systems, emissive displays, e-paper and flexible displays, liquid-crystal technology, OLEDs, and projection.
In addition to these regular topics, SID has designated special display topics of interest that are especially timely and important to our industry: OLED TV, oxide TFTs, 3-D, lighting, and touch and interactivity. Attendees at Display Week 2013 have the opportunity to gain comprehensive knowledge of each of these special topics not only by attending the presentations during the four-day technical symposium, but also through the special Sunday Short Courses and Monday Seminars. SID also offers a display-centric business perspective with the Business and Investors Conferences and the Market Focus Conferences. In addition, be sure to catch this year’s stellar line-up of keynote speakers (highlighted throughout this article) on Tuesday morning immediately before the exhibition opens.
The following session highlights are but a small portion of what awaits attendees at Display Week 2013. Come join us to find out what’s happened in our industry over the past year – and what’s going to happen in the years to come. See you in Vancouver!
Active-Matrix Devices: Oxide TFT Starts to Hit Its Stride
Last year’s Active-Matrix Devices (AND) sessions covered topics such as IGZO and 8K × 4K LCDs – providing advance notice of technology later shown in products at CES this year. The 2013 AMD papers will continue representing some of the most interesting and important news at the Symposium, according to subcommittee chair Tohru Nishibe. Among the most newsworthy, he says, are two invited presentations on oxide semiconductors. The first is “Electronic Structure, Carrier Transport, Defects, and Impurities in Amorphous Oxide Semiconductors,” by Toshio Kamiya of the Tokyo Institute of Technology. “This is a good tutorial and basic analysis that includes new findings,” says Nishibe. The second is “Development of IGZO-TFT and Creation of New Devices Using IGZO-TFTs,” by Hajime Imai of Sharp Corp, in collaboration with SEL (Semiconductor Energy Laboratory Co.). “This look at the world’s first IGZO product [shown at CES] will attract a huge audience,” says Nishibe. “Moreover, we’ll have intriguing invited papers from LG Display, Samsung Display, and others.”
Other papers of interest are “A 55-in. AMOLED TV Using InGaZnO TFTs Using WRGB Pixel Design,” by Woo-Jin Nam of LG Display Co. and “Negative-Bias Photodegradation Mechanism in SnO TFTs,” by Masashi Tsubuku of the Semiconductor Energy Laboratory Co., Ltd. According to Nishibe, both these papers will address key factors for improving IGZO reliability.
Applications: Expanded Interaction, Emerging Displays
As is often the case in the applications sessions at Display Week, this year’s papers cover an extremely wide range of topics. Of particular note are two invited papers on “auditory” displays in the session titled Human Enhancement and Diagnostics. “Sonification: Multimodal and Auditory Display of Data,” by Bruce Walker of the Georgia Institute of Technology, and “Development of Auditory and Cross-Modal Displays for Assistive Technology,” by Tony Stockman of Queen Mary University of London, describe displays that both speak and listen (as well as display visual imagery). They may thus prove useful to vision-impaired users, in addition to other applications, notes subcommittee chair Adi Abileah. “The idea is that there is more than one way to interact with displays,” says Abileah. “We think this is a direction that SID will head toward in the future.”
As is also usual for applications, there are too many interesting papers to cite here, but one of note in the Emerging Displays session is the invited paper “Optical and System Considerations for Mobile Touch-Screen Applications,” by Steven Bathiche of Microsoft, which Abileah describes as an excellent review presentation that will cover different considerations for mobile-display parameters including pixel density, optical effects, ambient-lighting influence, touch-screen weight, and power. The paper analyzes the significance of these parameters based on the human eye’s acuity, contrast sensitivity, and focusing ability in different lighting conditions. The paper “Semi-Transparent Inverted Quantum-Dot Light-Emitting Diodes,” by Jin Jang of Kyung Hee University, will describe a new display technology, a semi-transparent inverted quantum-dot light-emitting diode (QLED) that uses tri-layered quantum dots. “Blur-Free Transparent LCD with Hybrid Transparency,” by Chia-Wei Kuo of AU Optronics Corp., outlines a 65-in transparent LCD in which the author controlled LC orientation to suppress image blurring behind the transparent LCD.
Applied Vision: Night-time TV Watching
“This year there are a lot of Applied Vision papers related to 3-D and lighting,” says subcommittee chair Yi-Pai Huang. “These are the trends.” Two interesting invited papers from the joint session with lighting that address real practical marketplace issues are “Displays as Light Sources: Resolving the Conflict between Gamut and Color Rendering,” by Lorne Whitehead of the University of British Columbia, and “Opportunities with LEDs for Increasing the Visual Benefits of Lighting,” by Mark Rea of the Rensselaer Polytechnic Institute.
One slightly different paper that Huang recommends is “The Impact of Watching Television on Evening Melatonin Levels,” by Mariana Figueiro of Rensselaer Polytechnic Institute. For at least a decade, some researchers (and the media) have suggested that night-time TV viewing suppresses human melatonin levels and thus interferes with sleep. Figueiro’s paper investigated whether the blue light from television does in fact suppress melatonin. Readers will have to attend the session to find out the answer, as well as the author’s recommendation.
Display Electronics: OLED Drivers Lead the Pack
The scope of papers in Display Electronics this year is diverse but very relevant, according to subcommittee chair Seung Woo Lee. “We do have many OLED-driving papers, but except for this area, the topics are widespread,” he says. One trend that Lee did note for 2013 is a larger number of papers from academia rather than private industry.
There is a full session focused on OLED Pixel and Driving as well as interesting papers in other areas include “Capacitively Coupled 13.56-MHz Resonance-Controlled Wireless Power Transfer System for e-Paper Modules,” by Reiji Hattori of Kyushu University, and “ESD and EOS Impact During Module Assembly Processes of Display Panels,” by Ming-Dou Ker of the National Chiao-Tung University, both from the advanced LCD Electronics session. Hattori’s paper describes a development that could enable electronic paper that works without batteries. Ker’s presentation will address the phenomena of electrostatic discharge (ESD) and electrical overstress (EOS) as they occur in production processes, as well as their effect on product reliability. He will suggest ways to control ESD and EOS so as to improve overall yield.
Dr. Kinam Kim President & CEO, Samsung Display Co., will give a keynote address on “Displays and Innovation: An Exciting Future”
Display Manufacturing: Timely Problem Solving
Manufacturing is an exciting R&D focus topic these days. We are witnessing doubled-down efforts for solving manufacturing process and materials challenges to enable the long-held promise of OLED use in TVs, as well as to accelerate the adoption of oxide-semiconductor TFTs for high-performance display applications. With that in mind, the Display Manufacturing subcommittee is highlighting three papers from this year’s impressive selection. The first, “Ink-Jet-Printed 17-in. AMOLED Display with Amorphous-IGZO TFT Backplane,” by Ze Liu of BOE Technology Group Co., is an invited paper that reports on the successful integration of ink-jet processed OLEDs with amorphous-oxide TFTs as a path to cost-effective manufacturing of large-sized panels. “It is very exciting to see this technology at the manufacturing stage,” says Subcommittee Chair Ion Bita. “BOE is a relative newcomer,” he says, “but their rapid advances in technology development and manufacturing are very impressive.”
The paper “Advanced Glass Substrate for the Enhancement of OLED Lighting Out-Coupling Efficiency,” by Nobuhiro Nakamura of Asahi Glass Co., reports on a substrate designed to improve efficiency in lighting and with potential for display applications. This substrate incorporates a glass-scattering layer that greatly improves efficiency, as demonstrated by the paper’s author using OLED lighting panels. “Roll-to-Roll Process on Ultra-Thin Flexible Glass for Manufacturing a Multi-Touch Sensor Panel,” by Chia-Sheng Huang of ITRI, demonstrates the advantages of roll-to-roll manufacturing on thin-glass substrates, in which the set of processes and equipment developed by the authors enabled fabrication of ITO-pattern-based touch-sensor panels from 0.1-mm rollable thin glass.
Display Measurement: IDMS Gains Traction
As was the case for the last several years, 3-D is a hot topic for Display Measurement in 2013. This is because 2-D measurement just doesn’t cover all of what needs to be measured in 3-D, explains subcommittee chair Frank Rochow. What is new in measurement papers this year is that authors have begun adopting the IDMS, the display measurement standard released in 2012 by the ICDM (International Committee for Display Metrology). “The IDMS methods are definitely being implemented in the papers being presented,” says Rochow. “The IDMS is being seen as a success and is widely respected.”
A good paper to check out for the latest in 3-D measurements is the invited “Techniques and Challenges in the Measurement of Stereoscopic Displays,” by Adi Abileah of Planar Systems. Another interesting paper that takes on the newest types of displays is “Viewing-Angle Measurements on Flexible Reflective e-Paper Displays,” by Dirk Hertel of E Ink Corp. Displays that are curved and reflective make it difficult for researchers to obtain repeatable, consistent measurements, explains Rochow.
Display Systems: Deep Views
With nine separate sessions, Display Systems has a lot going on this year. 3-D continues to be a popular topic, but within 3-D the types of displays have grown increasingly diverse. This year’s 3-D sessions include Autostereoscopic and Multiview I and II, Holographic and Volumetric Displays, Lightfield Display, and 3-D Algorithms and Driving.
Other Display Systems sessions include Augmented Reality and Near-to-Eye Displays, Novel Backlighting Systems, Automotive and Head-Up Displays, and Energy-Efficient Displays. Of special interest is the invited paper, “Augmented-Reality Head-Up Display for Car Navigation System,” by Toshiki Kaneko of Japan Display, Inc., which uses a laser projector and microlens array to create what the authors say is the first such display that creates augmented reality beyond the windshield. Another invited paper, “Extending Battery Life of Ultrabook through Use of Panel Self-Refresh Technology,” by Kamal Shah of Intel Corp., describes an interesting new power-management technique for mobile devices.
Emissive Displays: Lots of Late-News for Quantum Dots and Phosphors
Probably the most intriguing aspect of the Emissive Display sessions this year are the number of late-news papers in the Phosphors and Quantum-Dot session – three out of a total of six. These are “Development of Stable Alkaline-Earth-Sulfide LED Phosphors for LCD Backlights,” by Ravi Rao of Specialty Phosphors, Inc.; “High-Efficiency and Long-Lifetime Quantum-Dot Light-Emitting Diodes for Flat-Panel-Display Application,” by Paul Holloway of the University of Florida; and “How to Fabricate Much Brighter AC Electroluminescent Lamps: Optimizing the Alignment of the Emitting ZnS:Cu Phosphor Particles to the AC Field,” by Jack Silver of Brunel University. According to the committee, an exceptional paper in this session is “Characterization of Electron–Hole-Pair Migration and Trapping in Rare-Earth-Doped YBO3 under Vacuum-Ultraviolet Excitation,” by Anthony Diaz of Central Washington University, in which the author’s analysis suggests a correlation between electron-hole trapping efficiency and the energy of activator electronic states relative to the host conduction band.
The other two emissive sessions are devoted to plasma. An invited plasma paper of special interest is “Progress in Luminous Array Film with Plasma-Tube Technology for Seamless-Tiling Super-Large-Area Display,” by Terukazu Kosako of Shinoda Plasma Co., which discusses a new flat-sealing process that can enable extra-large curved displays. The late-news paper “New, Thinner Phosphor Layer Fabrication Process for ACPDPs,” by Ryuichi Murai of Panasonic AVC Networks Company, describes a process for achieving a 3-µm-thick phosphor layer in the PDP cells.
Mr. Bill Buxton, Principal Researcher, Microsoft Research, Microsoft Corp., will give a keynote address on “The Social Life of Devices”
e-Paper and Flexible Displays
The six e-Paper and Flexible Displays sessions this year include one composed entirely of late-news papers on the topic of Flexible OLEDs and Printed Electronics. These five papers, covering topics such as barrier films, ink-jet printing, and plastic substrates, will obviously provide an exciting look at the state of the art.
A notable paper from AU Optronics is “A 9-in. Flexible Color Electrophoretic Display with Projected-Capacitive Touch Panel and Integrated a-Si Gate Driver,” by Yen Lai. This paper, highly recommended by the subcommitee, describes how the authors developed a prototype and concept design for what they describe as the next-stage e-reader: combining a flexible color electrophoretic display (EPD), flexible projected-capacitive touch panel (TP), and amorphous-silicon gate driver circuit on array (GOA) technologies.
Liquid-Crystal Technology: Meeting the Challenges of a Changing Landscape
The LCT subcommittee made a point of inviting what chair Philip Chen describes as the major Asian companies to submit papers this year: Samsung, AUO, LG Display, Japan Display, China Star, BOE, and others. The idea, says Chen, was to get these companies to come to Display Week to share their latest developments and plans for the future, thus providing symposium goers with a complete view of the LC landscape.
Another subcommittee initiative was to organize a session specifically on the topic of OLEDs and LCDs. The three invited papers in the session titled LCDs or OLEDs? include “TFT-LCDs as the Future Leading Role in FPDs,” by Yasuhiro Ukai of Ukai Display Device Institute;”AH-IPS, Superb Display for Mobile Devices,” by Joun Ho Lee of LG Display Co.; and “LCD or OLED: Who Wins?,” by David Barnes of BizWitz. This last, possibly provocative paper will discuss historical trends that point toward a future of increasing technical performance and decreasing financial performance for LCD producers, as well as the feasibility of creating an OLED infrastructure. “This will be a very attractive session,” says Chen, “for students and for anyone else in the industry who wants to know about the future direction of these technologies.”
Four more notable papers from the LC sessions are “High-Transmission VA-LCD with a Three Dimensionally Shaped Pixel Electrode for 4K × 2K Displays,” by Masashi Miyakawa of Sony Corp.;” “LC GRIN Lens Mode with Wide Viewing Angle for Rotatable 2D/3D Tablet,” by Masako Kashiwagi of Toshiba Corp.; “Driving Method of FFS-Mode Oxide LCD for Reducing Eye Strain,” by Ryo Hatsumi of the Semiconductor Energy Laboratory Co.; and “A Nematic LCD with Submillisecond Gray-to-Gray Response Time,” by Daming Xu of the University of Central Florida.
OLEDs: Big TVs and Better Materials
One trend is certain: OLED TVs, at least OLED TV prototypes, keep getting larger. The most exciting OLED paper this year, according to subcommittee chair Sven Murano, will be “Large-Sized Amorphous-Oxide-TFT AMOLED-TV Using Side-by-Side and Fine-Metal-Mask Technology” by Jen-Yu Lee of AU Optronics Corp. This paper describes a 65-in. panel with a long-range threshold voltage uniformity of 0.34 V. The dam and fill encapsulation process is simple and highly stable, according to the author. The AUO paper is part of a special all OLED-TV session (jointly offered through the OLEDs and Active-Matrix Devices committees) that Murano says may be among the hottest at the symposium.
There is more to OLEDs than big TVs, though. This year has brought many improvements to OLED lighting technology (see the Lighting section below), and also progress in OLED R&D in general. One of the hurdles that OLED technology needs to clear in order to realize its full commercial potential is efficiency in both materials and devices. Two very interesting papers that address this aspect are “Highly Efficient OLED Device with Device Architecture for Reducing Drive Voltage,” by Yoshiharu Hirakata of Semiconductor Energy Laboratory, which describes how the author’s team developed phosphorescent OLEDs with high efficiency, a long lifetime, and low drive voltage using energy transfer from an exciplex to an emitter; and “Efficiency Improvement of Fluorescent Blue Device by Molecular Orientation of Blue Dopant,” by Hitoshi Kuma of Idemitsu Kosan Co., Ltd. Kuma’s research suggests how phosphorescent blue devices, which have lagged behind their red and green counterparts in terms of efficiency, can be made to catch up.
Projection: Lasers Loom Larger
Last year, subcommittee co-chair Alan Sobel predicted that 2012 would be the year of the pico projector, in terms of commercial availability. That seems to be true, based on a quick online search for the products, which are numerous and available in some cases for less than $200. In terms of the symposium, however, the technology is mature. “Surprisingly, there are no [LED-based] pico-projector papers this year,” says Sobel. Instead, laser-light engines for projection are the focus of several papers.
A standout invited paper in the Projection sessions that Sobel recommends is “High-Efficiency Polarization Preserving Cinema Projection Screen,” by Dave Coleman of RealD. This paper describes a polarization-preserving projection screen that addresses issues of conventional silver screens through substantially increased efficiency (brightness), increased stereo contrast, larger viewing angle, and matte appearance. In addition, the screen enables vastly improved laser-speckle reduction. Says Sobel, “This is potentially a game changer, a big curved screen for digital cinema, with better performance, wider angles, [reduced] ghosting. It will be more expensive than conventional screens.”
Professor John F. Wager, The Michael and Judith Gaulke Endowed Chair Professor of Electrical Engineering, School of EECS, Oregon State University, will give a keynote address on “Exciting Developments in Oxide-TFT Technology”
Special Topics: OLED TV, Oxide TFTs, 3-D, Lighting, and Touch & Interactivity
Each year, the Society for Information Display designates special sessions to explore important and timely display topics. This year’s sessions are OLED TV, oxide TFTs, 3-D, lighting, and touch & interactivity. Here are highlights from each:
OLED TV: The four papers in this one session, jointly sponsored by the Active-Matrix Devices and OLEDs subcommittees, will no doubt be among the most popular at the symposium. AUO’s 65-in TV (described in the OLEDs section above) will certainly be an attention-getter, but the other three papers will be fascinating as well. Certainly, no one will want to miss “Technological Progress and Commercialization of AMOLED TV,” in which author Chang-Ho Oh of LG Display Co. talks about the art and science behind getting the first mass-produced large-area OLED TVs off the factory floor and into people’s living rooms.
Oxide TFTs: A mere four years ago, the idea that oxide TFT could take the place of silicon in display devices was “very new and promising,”according to Hyun Jae Kim, the 2009 Active-Matrix subcommittee chair. In 2013, oxide TFT is now a special topic with five sessions devoted to it alone. Those are:
• Oxide TFT I and II • Oxide TFT Reliability • OLED and Oxide TFT Manufacturing • Oxide TFT Manufacturing
Several of the outstanding oxide-TFT papers have been described above in conjunction with other technology topics such as Active-Matrix Devices and Display Manufacturing. An additional paper to take note of is “Electrical Properties of Amorphous InGaZnO TFTs Prepared by Magnetron Sputtering Using Kr and Xe Gas,” by Tetsuya Goto of Tohoku University. Goto’s work explains how the use of certain noble gases in the magnetron-sputtering part of the manufacturing process can reduce film damage caused by ion-bombardment, and thus improve overall thin-film quality.
3-D: This technology area continues to be extremely well-represented in terms of paper submissions – there are 10 3-D sessions in this year’s symposium – but the subjects have evolved over the past few years from discussions on passive vs. active glasses to a wide range of 3-D displays. The 3-D sessions are
• Autostereoscopic and Multi-View I and II • LC Technology for 3D I and II • Holographic and Volumetric Displays • Light-field Display • Perception in 3D Display • 3D Algorithms and Driving • 3D Application • Projection Screens
Some of the outstanding 3-D papers are outlined in the sections above, such as RealD’s curved cinema screen described under Projection. Here are some additional ones to check out: “High-Performance Autostereoscopic 2D/3D Switchable Display Using Liquid-Crystal Lens,” by Shinichiro Oka of Japan Display, Inc., describes the development of a switchable 2D/3D display with higher luminance and reduced crosstalk. Late-news paper “Real-Time Up-Converter from HDTV to 4K with Super-High Resolution,” by Seiichi Gohshi of Kogakuin University, suggests a method for obtaining high-quality 4K resolution from HDTV video, a subject that will become increasingly relevant in the months and years to come.
Lighting: There are four lighting sessions this year, two of them devoted to OLEDs:
• Human Factors on Lighting • Lighting Design • OLED Lighting I and II
OLED lighting still has far to go in terms of manufacturing costs, efficiency, and lifetime, but progress is being made. One paper that describes a good advance is the invited “80-lm/W White OLEDs for Solid-State Lighting,” by Jaemin Moon of LG Chem. These OLEDs were realized by introducing a three-stacked tandem structure in conjunction with an internal light-extraction layer. Another exciting paper in terms of getting closer to commercial viability is “Highly Efficient White OLEDs with Over 100-lm/W for General Lighting,” by Kazuyuki Yamae of Panasonic Eco Solutions. The author’s high-performance all-phosphorescent white devices on a light-outcoupling substrate showed an efficacy of 114 lm/W at 1000 cd/m2 and 102 lm/W at 3000 cd/m2.
According to Sven Murano, this year’s OLED subcommittee chair, “Now is the time when [lighting] companies are starting to invest in manufacturing lines, and I am optimistic that in the coming years OLED lighting will become cheaper and its efficacy will go up.”
Touch and Interactivity: Tighter integration and reduction of cost are two major issues surrounding touch in display design and manufacturing, according to Touch & Interactivity chair Jeff Han. (Earlier this year, Han gave the keynote address for the Bay Area SID Chapter’s one-day technical conference, Display and Touch Technologies of the Future.) “Touch is still expensive,” says Han, also noting that the touch user experience is also increasingly crucial. This year there is a session devoted just to the user experience, and three others as well:
• Touch User Experience • Touch Integration and Controller • Touch Application • Touch Sensors, Materials, and Manufacturing
A touch paper of note is “12.2-in. 1920 × RGBW × 720 IPS-LCD Integrating In-Cell Touch Panel for Automotive Use,” by Chihiro Tanaka of Japan Display, Inc., which suggests solutions to some of the special issues surrounding the design of an in-cell touch panel specifically for automotive use. An interesting paper that addresses the touch user experience is “The Need for Speed in Touch Systems,” by Albert Ng of Microsoft. The author shows the impact of touch-to-display latency, frame rate, and motion blur on the touch-user experience. He explains how by using a custom device his team was able to achieve latencies down to ~1 msec, with frame rates up to 1000 Hz.
A Wealth of Information
In sum total, there is no doubt that this collection of symposium papers represents the most important display industry information you will find all year. Please join the Display Week presenters as they share their research with their friends and colleagues in the display industry. •