Looking Forward to the 2018 Display Week Technical Symposium

Looking Forward to the 2018 Display Week Technical Symposium

This year’s technical program shines a spotlight on AR/VR, microLEDs, and wearables – the hottest topics in the display industry right now. But there is so much more to discover – amazingly efficient OLEDs, state-of-the-art automotive displays, ultra-high resolutions.  Read this handy preview to find out which papers belong to that absolutely can’t-miss category. But first, a note from this year’s technical program chair, Yi-Pai Huang.

Compiled by Jenny Donelan

Dear Friends and Colleagues,

On behalf of the Society for Information Display’s program committee, I am pleased to invite you to participate in Display Week 2018, which will be held from May 20 to May 25 at the Los Angeles Convention Center.

The technical program begins on Sunday with the Short Courses and is followed by the Monday Seminars. The Display Week Symposium, the main event, takes place from Tuesday to Friday. This year’s symposium features 83 technical sessions consisting of nearly 450 oral and poster presentations, including about 85 invited talks.

Augmented reality/virtual reality (AR/VR), microLEDs, and wearables are the three special hot topics this year. In AR/VR, the technical tracks will cover systems, optical design, human factors, and even artificial-intelligence applications. For microLEDs, manufacturing and materials are the two major issues under discussion. In the wearables area, presentations will focus not only on displays, but on stretchable electronics and devices.

Of course, active-matrix thin-film transistors (TFTs), liquid-crystal (LC) technology, and organic-light-emitting diodes (OLEDs) are still the most important fields, and most of the paper submissions belong to these categories. But there are papers of interest in all areas. In addition to the above three, there are sessions based on Emerging Applications, Applied Vision, Display Electronics, Display Manufacturing, Display Measurement, Display Systems, Emissive Displays, e-Paper and Flexible Technology, Lighting, Touch and Interactive Displays, and Automotive/Vehicular Displays.

Additionally, SID will celebrate LCD’s 50th anniversary during Display Week. This once-in-a-lifetime event honors the technology that opened a new era of small-to-large display-related products and helped shape today’s industry. This celebration will feature LCD pioneers sharing their experiences from earlier days in both R&D and commercialization and marketing sectors. Don’t miss it! (For more information about the 50th Anniversary LCD Celebration, see this issue’s SID News.)

In light of past successful events, we expect 7,500 or more participants from all over the world to attend Display Week this year. Your participation has always been vital to the success of SID’s Display Week. We sincerely look forward to seeing you in Los Angeles this May!

Respectfully yours,

Yi-Pai Huang, Ph.D.
SID Display Week 2018 Program Chair

Display Week 2018 Symposium at a Glance

Display Week 2018 Overview

The New Reality

Augmented reality and virtual reality are the biggest story for the 2018 program. “I see a clear trend in AR/VR,” says Wei Yao, chair of the Display Electronics subcommittee. “There are lots of papers in this area.” His observation was echoed by many of the chairs, with AR/VR-related papers appearing in almost every segment of the symposium – from head-up products to manufacturing solutions to metrology for near-to-eye displays. There are so many great AR/VR papers (approximately 60), says Technical Program Chair Yi-Pai Huang, that they appear on all four days of the symposium in multiple sessions.

What this boom in AR/VR research portends for the consumer market is only partially clear. “I think a lot of companies are trying to replace the mobile phone with Google-type glasses,” says Huang. Yet consumers aren’t on the whole clamoring for augmented-reality glasses to wear full time, or for virtual-reality headsets to take them out of the here and now. So this push toward AR/VR could be a case of the tail wagging the dog. On the other hand, consumers don’t always know what they want before they get it. Twenty years ago, few of us knew we’d depend on our smartphones to the point of looking at them before we go to bed at night and when we wake up in the morning.

One thing is clear: For AR/VR technology to get to that smartphone-level of ubiquity, it has to get better. And that’s something that the researchers delivering papers at Display Week are working toward. “For consumer applications in AR/VR, there’s a very big technology gap,” says Huang. “And there is also a price vs. quality gap. AR/VR systems are very complex in terms of integration.” So the industry still needs solutions in terms of hardware – comfortable headsets, immersive displays that are comfortable to use – and in terms of software – applications that are useful, accessible, and compelling enough that people turn to AR/VR devices on a regular basis, not just for niche uses or entertainment.

David Hoffman, chair of the Applied Vision subcommittee, says, “We’re seeing lots of interest in image manipulation and color processing, as well as in studying human factors with AR/VR. One of the recurring issues is how to balance quality with bandwidth.”

Each of the following three papers provides an example of how AR/VR developers are taking on the challenge of making the headgear more usable – balancing image quality against bandwidth, providing higher resolution OLEDs, and reducing motion blur.

•  “Visually Lossless Compression of High-Dynamic Range Images: A Large-Scale Evaluation” by Aishwarya Sudhama of York University in Canada tackles the quality/bandwidth issue. The author writes: “High-dynamic-range (HDR) displays provide impressive image quality but require markedly higher bandwidth. Here, we report results from the first large-scale subjective assessment of HDR image compression.”

•  “An AMOLED Pixel Circuit for 1,000 ppi and 5.87-in. Mobile Displays with AR and VR Applications” by Oh-Kyong Kwon of Hanyang University describes the creation of a prototype AMOLED pixel circuit consisting of three TFTs and two capacitors, designed for 1,000-ppi AR/VR mobile displays, simulating emission current and crosstalk errors.

•  “Fast Motion-Picture Response Color-Filter LCOS for Wearable Applications” by Yuet Wing Li of Himax Display, Inc., proposes an image-blur-free color-filter LCOS equipped with 1.9-ms liquid-crystal response time; analog frame buffer; and a 480-frame-per-second refresh rate. The author explains, “The display system for AR applications has to update images promptly in order to cope with the user’s head movement or any environmental change. This requires both low latency of the image data and fast image response on the display itself. Image blur becomes noticeable if the motion-picture response time (MPRT) of the AR display is longer than 1.5ms.” The MPRT of the Himax device is reported as <1.5ms.

Measuring AR/VR

In addition to addressing image artifact problems such as sparkle and image retention, this year’s metrology papers cover a range of display technology that indicates what’s cutting edge in the industry. “The measurement papers we see each year tend to reflect the new display problems that people are trying to solve,” says Display Measurement Subcommittee Chair Stephen Atwood. “In order to know if you have made a significant performance improvement, you need robust optical metrology methods, and the papers in this year’s lineup reflect the most pressing needs for developers now and in the future.” Measurement topics therefore include reflective e-paper, light-field displays, high-dynamic-range (HDR) displays, and of course, near-to-eye displays for AR/VR, as in the Sustar-Optics paper below:

•  “Requirements for Lenses in Measuring Systems Evaluating Near-to-Eye Displays” by Norbert Schuster of Sustar-Optics proposes that imaging luminance and color measuring devices (also called array detectors), combined with adapted measuring lenses, provide effective one-shot solutions for evaluating near-to-eye displays.

A Higher Plane

According to Huang, the most surprising, exciting thing you will see this year at Display Week and nowhere else is a profound increase in resolutions across all types of displays. “Everyone keeps pushing the boundaries of resolution,” he says. “LG and Google have an OLED that’s more than 1,400 ppi. It’s very hard to imagine that!” That paper is:

•  “An 18 Megapixel 4.3-in. 1,443-ppi 120Hz OLED Display for Wide-Field-of-View High-Acuity Head-Mounted Displays” by Carlin Vieri of Google LLC. According to the author, this is the world’s highest resolution (18-megapixel, 1,443-ppi) OLED-on-glass display yet developed. A white OLED with a color filter structure was used for high-density pixelization, and an n-type LTPS backplane was chosen for higher electron mobility compared to mobile phone displays. A custom high bandwidth driver IC was fabricated, and foveated driving logic for VR and AR applications was implemented.

Two technical sessions are entirely devoted to ultra-high resolution this year, and every paper should be highly informative. Two samples:

•  “Large-Area Ultra-High-Density 5.36-in. 10K 2,250-ppi Display” by Hyun Sup Lee of Samsung Display Co. describes a new pixel architecture that integrates TFTs, contact holes, and data/gate lines in the smallest pixel pitch yet reported on glass. A new driver system including a new IC design has also been developed for this 10K resolution display, which the author sees as ideal for VR/AR and holo-graphic displays.

•  “4,032-ppi High-Resolution OLED Microdisplay” by Takuma Fujii of Sony Semiconductor Solutions Corp. covers the development of a 0.5-in. UXGA OLED microdisplay with 6.3µm pixel pitch that is described as suited to near-to-eye display applications, especially viewfinders.

Smaller Is Better: Quantum Dots and MicroLEDs

Quantum dots and microLEDs are potentially disruptive display materials that everyone in the industry should learn more about, and there’s no better place than Display Week’s technical symposium to do so. Quantum dots are already in widescale commercial use as a complementary material in LCDs, whereas microLEDs are viewed by many people as “the next big thing” in display materials. In order for microLEDs to live up to their promise, however, many manufacturing issues need to be addressed.

“There are no commercial display devices built on microLEDs at this time,” says Display Manufacturing Subcommittee Chair Chi Woo Kim. “We don’t know the right answers about how to manufacture them yet.” You can find out about the state of the art, though, in the following paper from Veeco:

•  “MicroLED Displays: Key Manufacturing Challenges and Solutions” by Christopher Morath of Veeco explains that while microLED displays offer potential advantages such as high brightness and low energy consumption, mass adoption requires that higher manufacturing yield and lower cost targets be met. In this presentation, the author explores key manufacturing requirements and presents solutions for epitaxy and mass transfer to enable microLED display adoption for consumer applications.

Emissive Displays Subcommittee Chair Seth Coe-Sullivan notes that microLED papers of all kinds have proliferated at Display Week. “We have four sessions on microLEDs,” he says, “which is twice as many as last year, which was twice as many as the year before that.” The quality of the papers is also quite high, with approaches like the aforementioned manufacturing paper from Veeco that seem likely to lead to breakthroughs.

In other emissive topics, progress is being made on true quantum-dot LEDs (QLEDs). Instead of using quantum dots (QDs) to enhance LCDs, this approach would make the QDs, or rather QLEDs, the primary display material.

“What’s exciting about this paper,” says Coe-Sullivan, “is that it’s a 14-in. QLED display that is entirely ink-jet printed. And it’s easily scalable to bigger sizes.”

•  “Developing AMQLED Technology for Display Applications” by Yanzhao Li of BOE describes the current state of the active-matrix (AM) QLED display technology and analyzes the ways this technology can be developed for mass production, with a discussion of material requirements, device structures, and the electrical and optical properties of quantum-dot light-emitting diodes (QLEDs). The author makes the argument that QLEDs can provide a compelling alternative to OLED- and LCD-based panels in the near future.

Stretchable (Inspirational) Sensors

This year’s special focus area of Wearable Displays, Sensors, and Devices features several papers on biometric sensors that retrieve data via an interface with human skin. The committee invited these authors in the hopes of inspiring the wider display community. “We believe this topic is going to open the minds of future display engineers,” says Wearables Subcommittee Chair Bo Ru Yang. One example is:

•  “Stretchable Electronics for Wearable Microvolt Biosignal Monitoring Systems” by Tsuyoshi Sekitani of Osaka University, in which the author discusses sensors for patch-type biosignal monitoring sheets with high measurement accuracy and wireless sheet-type electroencephalogram (EEG) and fetal electrocardiogram (ECG) monitoring systems for next-generation telemedicine.

If the technology development at this year’s technical symposium is any indication, products like the Vuzix Blade, a pair of augmented-reality smart glasses with proprietary waveguide optics and built-in Alexa, will be appearing more frequently in our future. Source: Vuzix

Light Shaping and Tunable Lighting

Tunable lighting can produce a range of correlated color temperatures – from cool to warm illumination as well as a change in intensity of light. Many of this year’s lighting papers focus on OLEDs and LED tunability, according to Lighting Subcommittee Chair Marina Kondakova. One paper from the Light-Emitting and eXcitonic Organic Semiconductors Group at the University of Dresden describes a new OLED structure with controllable angular emission (light shaping). “The manipulation of emission profile is important. With it, the OLED light can be directed where it has the most functionality while maintaining high light quality,” says Kondakova. “We haven’t seen much on this topic before, especially for OLED. Its further development can create new applications for OLED displays and lighting.”

•  “Organic Light-Emitting Diode Beam Shaping: Pixel Design for Variable Angular Emission Profile Control” by Sebastian Reineke, Technische Universität Dresden. Once integrated with a certain layer architecture into the backplane layout, OLED’s emission color and angular distribution are set by the optical properties of the layered system. In this paper the author demonstrates a pixel design that allows for actively controlled variation of the angular emission profile of the individual vertical pixel.

Fingerprint Sensing

Two major trends appeared this year in the Touch and Interactivity area: fingerprint sensing and capacitive touch on a large scale. “Big is the final frontier,” says Jeff Han, chair of the Touch and Interactivity subcommittee. There are four capacitive-touch papers focused on large-scale displays. The fingerprint sensing papers point to a new direction: “They are truly integrating fingerprint sensing into the display, not just in a panel on the side,” says Han. One example:

•  “Optical Fingerprint Sensor Based on TFT Technology” by Hong Zhu of Shanghai OXi Technology Co., Ltd., reports on optical fingerprint sensors based on hydrogenated amorphous Si TFT technology, enabling ”thin optical touch,” “hidden optical touch,” and “hidden under display” sensor technologies, depending on the application.

OLEDs Get More Efficient

“Two things jump out in OLEDs,” says OLEDs Subcommittee Chair Michael Weaver. “Efficiency – how you get beyond the status quo. And dipole alignment – trying to orient the molecules in the film to make them less random [like LCs].” An efficiency paper of note:

•  “Highly Efficient Deep-Blue Fluorescent Dopant for Achieving Low-Power OLED Display Satisfying BT.2020 Chromaticity” by Yusuke Takita of Semiconductor Energy Laboratory Co., Ltd. The author has succeeded in developing a stable, deep-blue fluorescent dopant that has a shorter emission wavelength and higher emission efficiency than conventional pyrene-based dopants. A demonstration shows that the power consumption of a panel using this novel dopant is lower than that of a conventional one.

LCD Technology Never Stops Evolving

The top trends for LCDs, unsurprisingly, are AR/VR and fast-switching, and super high resolution, according to Liquid Crystal Technology Subcommittee Chair Michael Wittek. He also cites high ambient contrast in ambient light as important for displays in general and especially for digital signage. “There’s a Sharp paper on reduced reflectivity,” says Wittek, “that is very important.”

•  “Sunlight-Readable Low-Reflection FFS-LCD” by Yuichi Kawahira, Sharp Corp. The author writes: “A novel wide-view LCD with reduced reflection has been developed to enhance ambient contrast ratio. By combining a fringe-field switching (FFS)-based new LC mode with a circular polarizer, our 12.3-in. prototype has successfully shown excellent outdoor visibility without boosted backlight brightness.”

Automotive Displays: More, Better, Bigger Business

The automotive industry will do its part to keep display makers in business for at least the foreseeable future. “In-car displays will be a $25 billion business by 2025,” says Rashmi Rao, chair of the Automotive/Vehicular Displays and HMI Technologies subcommittee. “There have been huge display enhancements in cars and in HMIs. There will be more screens, and better ones. Displays are no longer reverse-engineered – most are created directly for customers.” Here are just two of the many not-able automotive display papers to check out.

•  “Active Polarizer Dimmable Lens System” by Paul Weindorf of Visteon Corp. “Deadfront” or “secret until lit” displays are desirable in vehicles for aesthetic reasons. Display units that utilize a dimmable smart lens may be utilized to reduce the required display luminance compared to a smoked neutral density lens to provide a hidden display appearance. A lens configuration that utilizes an active polarizer in conjunction with a linear polarizer is explored.

•  “Holographic Grating to Improve the Efficiency of a Windshield HUD” by Philippe Coni of THALES Avionics SAS looks at the creation of a windshield head-up display (WHUD) using an embedded transparent holographic optical element film (THOE) film to improve system efficiency.

And There’s More

While the technical symposium is the core of Display Week, make sure to save time for the other major events: the Sunday Short Courses; the Monday Seminars; the Business, Investors, and Market Focus Conferences; the new CEO Forum; the second annual Women in Tech panel; the Wednesday night Special Networking event at the California Science Center; and, of course, the exhibition and the I-Zone. Don’t wait – start building your Display Week 2018 schedule now. See our schedules at a glance in this issue and visit www.display.org for more details. •