Display Week 2007: Innovation on Display

Display Week 2007, SID's annual display extravaganza, offers the most comprehensive look at the current and future technologies shaping the display industry.

by Michael Morgenthal and Jessica Quandt

"THE BEST WAY to predict the future is to invent it," stated the American computer scientist Alan Kay in 1971. For generations, science-fiction writers have foreseen a world where information is displayed and updated instantaneously via any number of electronic devices. From mega-sized paper-thin screens in shopping malls, airports, or on the streets that change according to the profile of the viewer, to small flexible hand-held gizmos with crystal-clear images broadcast from the other side of the world, to 3-D images that perfectly replicate the real thing, the world of the future was supposed to be one dominated by an infinite number of information displays.

Today, that world is closer than ever before, thanks to the vision of display engineers who have been bold enough to predict the future by inventing it. Their latest breakthroughs will be unveiled at Display Week 2007: The Society for Information Display (SID) International Symposium, Seminar & Exhibition, which will take place May 20–25 at the Long Beach Convention Center in Long Beach, California, U.S.A. (Fig. 1).

More than 8000 attendees are expected to flock to Long Beach for Display Week 2007. Display Week has evolved into a comprehensive event that has elements that appeal to people from all sectors of the display industry, from novices to experts, to engineers and marketers. These include:

• Symposium (May 22–25): The heart and soul of Display Week, the four-day Symposium kicks off with the Keynote Addresses and comprises 68 technical sessions featuring 279 presentations and a poster session with 210 papers. A more extensive preview of the Symposium follows these descriptions.

• Exhibition (May 22–24): Display Week features the largest exhibition in North America exclusively devoted to electronic information displays (Fig. 2). Companies ranging from the largest Fortune 500 corporations to start-ups with promising technologies will showcase the latest in displays, applications, components, manufacturing and test equipment, and materials in more than 58,000 square feet of exhibition space.

• Business Conference (May 21–22): The Business Conference will feature talks from leading executives from around the world, exploring the key business issues, problems, and solutions affecting the electronic-display industry, both now and in the future. For a preview of the Business Conference, see page 20.

• Investors Conference (May 22–23): Co-sponsored by Cowen & Co. LLC, a securities and investment banking firm, this conference will feature company presentations from leading public and private display companies, intended to appeal primarily to securities analysts, portfolio managers, investors, M&A specialists, and display company executives.

• Sunday Short Courses (May 20): These four-hour tutorial-style classes covering the fundamentals of information displays serve as great introductions to the technologies behind electronic information displays. This year's topics will be Vision and Color, Display Optics, Video for the 21st Century, and Microdisplays.

• Display Technology Seminars (May 21): These 90-minute seminars offer over-views of 12 topics, ranging from organic-light-emitting-diode (OLED) displays to liquid-crystal displays (LCDs) to flexible displays. The technical foundations, advances, and future trends for each technology are explored in a manner that will be educational and enlightening to display novices and experts alike.

• Application Tutorials (May 23–25): These six tutorials are practical and interactive 90-minute tutorials focused on the application and evaluation of displays. The topics this year include Active-Matrix Addressing Technologies for Flat-Panel Displays, Flat-Panel Display Measurements, Mobile Displays, Liquid-Crystal Electro-Optical Modes for Active-Matrix Displays, Optimizing Color Calibration and Characterization of Active-Matrix LCDs, and Thin-Film-Transistor LCD Product Trends.

• Display Week Luncheon (May 23): The Luncheon is always one of the most popular events at Display Week. This year,Professor Charles Falco (Fig. 3) of the University of Arizona will deliver the Luncheon address, entitled "The Science of Optics: The History of Art," in which he will discuss his work with renowned artist David Hockney, who recently observed that certain drawings and paintings from as early as the Renaissance seemed almost "photographic" in detail. Following an extensive visual investigation of western art of the past 1000 years, Hockney made the revolutionary claim that artists even of the prominence of van Eyck and Bellini must have used optical aids. However, many art historians insisted there was no supporting evidence for such a remarkable assertion. In this talk, Falco will show a wealth of optical evidence supporting Hockney's claim. In addition, the 2007 Display of the Year Awards will be presented during the Luncheon.

Keynote Preview

The close ties between the display world and the entertainment and automotive industries will take center stage during the Display Week 2007 Keynote Addresses, which will be delivered on Tuesday, May 22, as the kickoff to the Symposium segment of Display Week. This year's keynote speakers are Jerry Pierce, former Senior Vice President of Technology for Universal Pictures; Robert Isele, Manager of Driver Information Concepts – Display Technologies for BMW Group and Chair of FPD Technologies for the German Flat-Panel Display Forum (DFF); and In Doo Kang, General Manager and President of applied materials company AKT's Display Business Group (Fig. 4).

Display Week 2007's setting in Long Beach – in close proximity to Hollywood, the entertainment capital of the world – inspired Pierce's keynote, entitled "Technologies in the Cinema Industry and Their Impact on the Display Industry." Pierce will explore how to better develop large-sized displays for home entertainment in order to meet the growing demands of the movie-buff consumer. He will also decipher what the transition in movie making and distribution from film to digital formats will mean to the display industry.

Isele's keynote will focus on the growing automotive-display market. Displays are being used in today's vehicles for everything from global-positioning-system (GPS) devices, to entertainment systems, to instrumentation, and the market for automotive displays such as these is projected to reach 50 million units by 2010 and more than 100 million by 2015. However, suppliers of these displays face myriad commercial and technical challenges, including temperature range, sunlight readability, and attaining life cycles of 20 years. Isele will explore these challenges and present his predictions for this market for the next decade in his keynote, "Displays in Automobile Applications."

"All of the OEM (original equipment manufacturer) industry and all of the supplier industry are available at this conference, and I want to address the display industry and give it a look at the future of automotive displays," Isele said of his interest in speaking at this year's Symposium. "I would like attendees to take away a feeling of where the automotive display market is going, and for them to have an idea what are the real requirements for automotive applications, to know about increasing the number of displays for the future, to know about the targets for pricing for the future. There's a big potential market behind that and this is related to some key requirements."

In "Are We There Yet: The End Game of Generations," Kang will seek to answer the question of just how much bigger information displays will get and what will come after the industry's current Gen 8 factories, which produce the largest displays available today. Kang became head of AKT's marketing and global sales in 2001, has been corporate vice president of the Display Group since 2005, and was recently promoted to president. Before joining AKT, Kang held marketing and engineering positions at Sun Microsystems and Fairchild Semiconductor.

Symposium Preview: OLEDs, LCDs Predominate

The technology behind LCDs and OLEDs will be the most prominent features of the Symposium program at Display Week 2007. LCDs will be the sole focus of 16 sessions, while OLEDs will be the focus of 14 sessions, not counting a late-news session on Thursday that comprises papers solely covering these two technologies.

"The 2007 Symposium sees the continuing trends of improving LCD TV's visual performance by employing various techniques such as 120-Hz-driving dynamic control using LED (light-emitting-diode) local dimming, and motion-compensated impulsive driving to reduce the blurring effect on LCD TV," said Fan Luo of AU Optronics Corp., General Chair of Display Week 2007. "Also, OLED devices have kept their fast pace of progress. This year, there are two sessions on white OLEDs (sessions 19 and 25) with improved efficiency, longer life, and better match with color filters, and two sessions on the improvements of OLED life (sessions 30 and 36)."

The sessions on white OLEDs will take place back to back on Wednesday morning, and each features an Invited Paper worth noting. Paper 19.1 by Tomoyuki Nakayama, Konica Minolta Technology Center, Inc., is entitled "Development of Phosphorescent White OLED with Extremely High Power Efficiency and Long Lifetime," a critical issue for the future development of OLED displays. Paper 25.1 is entitled "Challenges of Using Organic Light Emitting Devices as White Light Sources" and will be presented by Stephen Forrest, University of Michigan, who was awarded SID's Jan Rajchman Prize in 2006 for his work in OLED development.

Fig. 4: Display Week 2007 Keynote Speakers (from left to right): Jerry Pierce, former Senior Vice President of Technology for Universal Pictures; Robert Isele, Manager of Driver Information Concepts – Display Technologies for BMW Group and Chair of FPD Technologies for the German Flat-Panel Display Forum (DFF); and In Doo Kang, General Manager and President of applied materials company AKT's Display Business Group.

Session 53 on Thursday features two interesting papers on the use of lasers for improved OLED manufacturing. Paper 53.1, "Laser-Induced Thermal Imaging (LITI) Technology for High-Resolution and Large-Sized AMOLEDs," is an Invited Paper from Seong Taek Lee of Samsung SDI. To date, it has been difficult to achieve high-resolution patterning of OLEDs, according to Chin (Fred) Chen of National Chiao Tung University, Hsinchu, Taiwan, who chaired the 2007 Display Week OLED Program Subcommittee. However, the LITI process holds great promise because the lasers permit direct patterning of the OLEDs, which allows for VGA resolution on a 2.2.-in. display. Paper 53.2, "Novel Laser Transfer Technology for Manufacturing Large-Sized OLED Displays," by Takahshi Hirano, Sony Corp., has been designated as a Distinguished Paper and details the technology that enabled Sony to develop its 27-in. active-matrix OLED TV, which caused a stir when it was introduced earlier this year. According to Chen, Sony will show the 27-in. OLED at Display Week.

Two other OLED papers were singled out for special attention by Chen and Luo. Paper 30.1, "OLED Lifetime Issues in the Mobile-Phone Industry," by Antti Laaperi, Nokia Research Center, Espoo, Finland, will investigate the market potential for OLEDs by one of the world leaders in mobile phones. Paper 41.1, "LTPS Technology for Improving the Uniformity of AMOLEDs," by Soon-Kwang Hong, LG.Philips LCD, will evaluate various techniques such as voltage compensation, current writing, and digital driving in order to solve the problem of mura in active-matrix OLED panels caused by non-uniform low-temperature polysilicon (LTPS) characteristics.

Turning to LCDs, two papers that are worthy of special attention come from Samsung according to Luo. In "Novel TFT-LCD Technology for Motion-Blur Reduction Using 120-Hz Driving with Motion-Compensated Frame Interpolation (McFi)," Sang Soo Kim of Samsung will discuss a 70-in. thin-film-transistor LCD (TFT-LCD) with the motion blur reduced by using a motion-compensated frame-interpolation technique. Luo also singled out Paper 58.5, "14.3-in. Active-Matrix-Based Plastic Electrophoretic Display Using Low-Temperature Processes," by Seong-Sik Shin of Samsung Electronics, which details how a 14.3-in. 1280 x 900 electrophoretic flexible display using an amorphous-silicon (a-Si) TFT was fabricated below 120°C.

While several sessions throughout the program include papers on flexible displays, which continues to be a hot topic at Display Week, Session 58 is the only one completely devoted to the topic. In addition to Paper 58.5, this session features three invited papers from heavy hitters in the display industry:

Paper 58.1, "TFT Technology for Flexible Displays," by Chang-Dong Kim, LG.Philips LCD, will examine technical trends of low-temperature amorphous-silicon (a-Si) TFTs and organic TFTs, as well as recent research results in the areas of plastic AMLCDs,e-paper, and organic TFT-based AMLCDs.

Paper 58.2, "Suftla Flexible Microelectronics on Their Way to Business," by Mitsutoshi Miyasaka, Seiko-Epson Corp., will detail the "Suftla" technology, which enables poly-Si TFTs to be transferred from one substrate to another while realizing highly functional LSI circuits on plastic. Devices formed on plastic must not be damaged during the fabrication process and must be durable enough for practical uses, so plastic engineering is one of the keys to solving thermal reliability problems faced by flexible microelectronics devices.

Paper 58.4, "Flexible Displays Made in TFT-LCD Facilities by the EPLaR^™ Process," by Ian French, Philips Research Laboratory, will describe the EPLaR process for making flexible displays, which uses an additive process in standard TFT-LCD factories. EPLaR electrophoretic displays driven by a-Si TFTs made in working factories will be described, and progress in the development of flexible poly-Si TFTs and OLEDs will be reported.

One of the other key issues with LCDs continues to be the need to constantly improve the quality and performance of backlights, with particular attention to LED backlights for LCD TVs. According to Dick McCartney of National Semiconductor, who chairs the Display Electronics Program Subcommittee for Display Week 2007, the trend in this area is toward dynamic backlighting and independent tiled colored backlighting, which would allow the backlight to provide whatever color and light needed in the region of the display, as opposed to a uniform white light. This approach saves power and yields a larger contrast ratio, two critical issues for any LCD.

One of the more interesting breakthroughs in this area has been the development of High Dynamic Range (HDR) displays, which was debuted with much fanfare by BrightSide Technologies. Consumer-electronics giant Dolby thought so much of the HDR that it recently purchased BrightSide. BrightSide is back in 2007 as part of a complete session on HDR (Session 21), with two Invited Papers providing informative overviews of the topic. In Paper 21.1, "The Hopeful Future of High-Dynamic-Range Imaging," BrightSide's Gregory Ward will provide an overview of the challenges and opportunities presented by HDR, including an examination of the imaging pipeline from creation and storage through image editing and display. How each stage is affected by a move to HDR will be discussed. Paper 21.2, "An Overview of Dynamic-Range Reduction," by Erik Reinhardt, University of Bristol, Bristol, U.K., will explore the rapid advances achieved in the past year in dynamic-range reduction algorithms, which allow HDR images to be displayed on conventional display devices.

The HDR breakthroughs unveiled last year seem to have spawned attempts by other companies to achieve similar results. This topic will be covered in Paper 39.3, "Locally Pixel-Compensated Backlight Dimming for Improving Static Contrast on LED Backlit LCDs," by Hanfeng Chen, Samsung Electronics Co., Ltd. The paper claims a static contrast in excess of 20,000:1 on a large-sized LCD using a new driving method, with no obvious artifacts observed. The backlight luminance is dimmed locally along with the image, and pixel values are compensated synchronously according to the luminance profile of the dimmed backlight. Session 66 on Friday is completely devoted to the topic of LED Backlight Driving, and Paper 66.1, "Deriving LED Driving Signal for Area-Adaptive LED Backlight in High-Dynamic-Range Displays," by Feng Li, Rochester Institute of Technology, Rochester, NY, U.S.A., has been designated as a Distinguished Student Paper. This paper evaluates two solutions – an iterative de-convolution approach and a linear optimization approach – for the issue of crosstalk in LEDs, which can be a detriment to the increase in dynamic range that these backlights provide to LCDs.

Despite the overwhelming volume of LCD and OLED papers at Display Week 2007, papers on myriad other display technologies will be presented, and perhaps the most intriguing is in the area of field-emission displays (FEDs), a technology that has long promised superior image quality with low power consumption, but has remained in the research-and-development stage for almost two decades. Now, however, encouraging results in the area of FEDs are emerging, according to Chris Curtin, who chairs the Display Week 2007 FED Program Subcommittee. Specifically, he pointed to Paper 37.1, "Development of a Field-Emission Display," by Shigeo Itoh, Futaba Corp. This paper will detail the company's full-color FED that went into pilot production in the Spring of 2006, with a 3-in. monitor for use in automobiles. According to Curtin, this is significant because it could be the first mass-produced full-color FED.

The papers that have been covered here speak to only a small segment of the interesting and important developments in the display field that will be revealed during the Display Week 2007 Symposium.

For more information on Display Week 2007, including a look at the Advance Program and how to register, visit the official Symposium Web site at www.sid2007.org. •