TVs, 3-D, and Holograms at Display Week 2014
Advanced technologies at this year’s show included very large curved TVs, light-field displays, and more.
by Steve Sechrist
DISPLAY WEEK 2014 attracted some of the biggest and brightest by way of new TV displays. Flat-screen-TV market leaders Samsung and LG both brought their latest
technology to the show as did others, including Sharp and BOE. For its efforts, LG took home SID’s Display of the Year Silver Award, which recognized its 55-in. curved FHD OLED TV set, first announced earlier this year as a shipping product.
LG apparently has made significant progress in moving its big-screen OLED technology to mass production, with independent reports coming from the Korean press earlier this spring that the company has reached yields in the 70% range using its white OLED approach with color filters. When asked at the show about these reports, LG’s Chief Research Engineer, Dr. Hong Jae Shin, told Information Display that the company could not confirm them but, smiling, added that they would not deny the report.
LG is expanding its OLED TV line-up and showed 65- and 77-in. curved UHD sets and non-curved OLED sets in its large booth at Display Week (Fig. 1). At the show, LG said two larger sets were slated for commercial shipment later in 2014. After the show, LG announced it was planning shipment of its 65- and 77-in. OLED TV sets in Europe, starting in October. This, perhaps more than any yield report, speaks volumes on just how the company is doing vis-à-vis production efficiencies in the OLED-TV category. The company also said it was moving to a more efficient curved AMOLED 55-in. TV with a new FHD model (55EB9600) that incorporates a low-power approach LG calls “Adaptive SVDD.” This technology is designed to reduce the number of TFTs and capacitors needed in the set. Power gains include 30% reduction with a voltage drop of 25% and a boost in gray scale by 25.8%, according to LG reports. Tae-Gyung Kim and a team from LG’s OLED development group outlined the adaptive SVDD method in a Display Week technical paper entitled “A Novel Power-Saving Technology for OLED TVs with External TFT Compensation.”
Fig. 1: In terms of OLED TVs, LG is moving full steam ahead, with plans to sell a high-end AMOLED set in a variety of size ranges, including 55, 65, and 77 in.
For its part, Samsung has moved on from its earlier focus on AMOLED TVs and, instead, this year introduced AMLCD curved sets that it plans to use in head-to-head competition with the LG OLED-TV technology. The Samsung booth included an impressive display of large curved TVs, including a 105-in. panoramic curved UHD model with a whopping 5120 × 2160 pixels (yes, a 5K set) that the company showed as a prototype at CES in January (Fig. 2). Samsung also showed a 65-in. curved LCD that recently received honors in the EU from the VDE (Verband der Elektrotechnik) for its ability to create an immersive viewing experience.
Fig. 2: Samsung showed curved AMLCD TVs rather than OLED TVs this year, including this visually arresting 105-in. panoramic TV.
Samsung also showed new curved monitors in 27-in. sizes that it stacked side-by-side for an immersive desktop experience. This is the first time we have seen the curved display move from TVs to desktop monitors, and this product may be a strong candidate for a SID award next year if the product ships this year. (If you think this attention to monitors is long overdue, read this issue’s opinion piece, “Gazing at the Future of Monitors,” by analyst Bob Raikes.)
Clearly, the curved large-screen display is making waves in the consumer-TV space, as evidenced by a move to this technology in LCD format by Samsung. Ray Soneira’s research at DisplayMate.com documents the visual benefits (the curvature can cut down on reflection, reduce geometric distortion, etc.), making a case for curving the set that goes beyond a mere marketing gimmick. Sony and Samsung are using this innovation to differentiate high-end LCD-based TVs. We expect this to be just the beginning and that more of these curved displays from other TV makers will appear at the Consumer Electronics Show in Las Vegas in 2015. Curved screens combined with UHD resolution (in either LCD or OLED format) make it more likely that consumers will be motivated to upgrade that living-room TV yet again.
Combined, the above innovations make a strong case for the further viability of the long-lived LCD technology. Many big-screen alternatives to LCD TVs have come and gone (remember SED TVs?), but LCDs historically have thus far risen to each challenge, closing the window on their rivals.
On the 3-D front, we found some compelling developments at Display Week. In its booth at the exhibition, display maker Tianma (now partnered with electronics component maker NLT) announced a 3-D display system with eye tracking that it calls TR3i-2 or “Truly Realistic 3-D imaging.” (Tianma NLT America, Inc., was established in November 2013 as a joint venture between Shanghai AVIC Optoelectronics Co., Ltd., and NLT Technologies, Ltd.)
This autostereoscopic eye-tracking system achieves smooth and realistic 3-D images without the use of glasses. It has its roots in NLT’s proprietary 3-D image-processing engine that uses H×DP (or horizontally × density pixels) technology, now married to an eye-tracking device that helps localize the 3-D effect by detecting exact eye location. The system is designed to optimize parallax from any view, which will diminish or eliminate problems of motion parallax and 3-D crosstalk (Fig. 3). Takefumi Hasegawa of NLT Technologies provided information on the TR3i-2 system in a Display Week paper entitled “Optimized Parallax Control of Arbitrary Viewpoint Images with Motion Parallax on Autostereoscopic Displays.”
Fig. 2: This diagram shows the 3-D cross-talk space of a proposed autostereoscopic display using TR3i-2 technology from NLT-Tianma. Image source: NLT Technology/T.Hasegawa.
NLT’s approach is to convert stereo images and place them in the observer’s field of view using the eye-position data, and it can even vary the binocular
parallax based on the viewing angle of the observer to the display. The company said it is focusing on active-matrix LCD modules for now.
In the abstract for his Display Week technical paper, “Wide-Field-of-View Compressive Light-Field Display Using a Multilayered Architecture and Viewer Tracking,” Andrew Miamone of UNC Chapel Hill wrote: “Over the last few years, a new generation of displays has started to emerge: compressive light-field displays. By combining unconventional optical setups, such as multilayer LCDs or directional backlights with compressive computation, these types of displays support unprecedented image resolution and 3-D capabilities using commodity hardware. The key idea behind all of these displays is to directly exploit the compressibility of the presented light-field image content. However, as opposed to conventional 2-D image compression, compressive light-field displays employ a joint optical and computational approach to presenting compressed content that allows the human visual system to act as a decoder.”
Work in the area of light fields was discussed in Miamone’s presentation, delivered with contributions from his group at UNC and by Ramesh Raskar and Andrew Wetzstein of the MIT Media Lab. This presentation demonstrated a real-time glasses-free 3-D display with a 110 × 45° field of view using efficient optimization and commodity tracking hardware and software. The authors’ off-the-shelf prototype included a compressive light-field display created from
two stacked LCDs and a Microsoft Kinect sensor that was used to estimate the position of the observer’s eyes (Fig. 4). The software is said to be capable of real-time multilayer optimization, allowing the display to be observed over a wide field of view by an eye-tracked user.
Fig. 4: This off-the-shelf prototype from UNC and MIT Media Lab’s presentation on light-field displays shows the components used to extend the apparent field of view with eye tracking.
The authors included a description of how a wide “apparent” field of view is created by using an extension of these light-field displays, where the narrow-view cones follow the viewer, thus moving autostereoscopic viewing beyond a single viewer experience, creating true parallax for one or multiple observers. This exploratory work using a combination of compressive light-field displays and head tracking to dynamically steer a small instantaneous field of view into the direction of a single tracked observer illustrates one way the perceived field of view of a display could be significantly improved.
In the Innovation Zone at Display Week, a company named PolarScreens was also making use of this compressive approach, but rather than light-field imaging, used two different images and a common mode image. PolarScreens calls it a tri-phase patterned light generator. It operates at 180 Hz and produces an artifact-free autostereoscopic 3-D image.
PolarScreens showed how an autostereoscopic image can be enhanced using a third image. The company says it can deliver full HD (FHD) to each eye and offer “complete freedom of movement” using this approach. The novel 3-D image-processing method includes adding the additional image (what is simply a normal 2-D image) to a left- and right-eye image sequence. According to the company, this central image goes a long way toward reducing flicker that can occur, especially when the viewer is blinking. This technology leverages the similarity between right- and left-eye images in a normal stereoscopic display by creating this third or central view. This common field is displayed during full backlight and during the change (delta fields). It essentially decomposes the video into three fields: (1) common field, (2) left-right delta, (3) right-left delta; this delivers a more fluid transition between images, resulting in a comfortable viewer experience with minimal flickering.
Another example of 3-D in the I-Zone was a novel display device, the Quantum Photonic Imager (QPI), from Ostendo Technologies, which earned SID’s Best I-Zone Prototype award. The QPI is a 3-D integrated circuit with what the company calls “micro-pixelated LED layers.” The layers are stacked on top of a custom graphics processor and every pixel directly emits multi-color (RGB) light. According to the company, the display offers a density of about 25 million
pixels/sq. in. and enables power-efficient and ultra-compact displays and projectors with applications in mobile (wearable) and potentially light-field displays (Fig. 5). Ostendo says it is looking at commercial, defense, air-traffic control, oil and
gas, and similar industries with a potential to be operational with a commercial display as early as Q3 2015.
Fig. 5: Ostendo Technologies showed its 3-D integrated circuit, the Quantum Photonic Imager (QPI), in Display Week’s I-Zone.
Researchers at Princeton University were also showing 3-D in the I-Zone – a capacitive 3-D gesture-sensing system. The team developed this by extending the sensing range of a capacitive touch screen further into the Z-space. Its sensing system consists of a gesture-sensing sheet that includes a readout IC (up to the 30-cm range) at a resolution of <1 cm or at a distance of 20 cm as developed on a 23-in. display. Princeton researchers said the 23-in.-diagonal display can sense gestures from the 3-D position of the user’s hand (or other object) over the entire display area.
Of additional interest at Display Week was a paper covering holographic displays by Xiao Li and others from Shanghai Jiao Tong University entitled “Real-Time Holographic Display Using Quantum-Dot Doped Liquid Crystal.” The group reported on creating a real-time holographic display with a refresh rate of 25 Hz from a quantum-dot doped liquid crystal. Other characteristics of the real-time hologram prototype included an applied voltage of around 30 V, a rise time on the order of several to tens of milliseconds, diffraction efficiency up to 20%, and diffraction efficiency controlled by applying the external DC voltage.
The group also said they have successfully shown RGB real-time videos and verified the feasibility as a color holographic display with improvements up to two orders of magnitude (in diffraction efficiency over previous work) (Fig. 6).
Fig. 6: Photos from Shanghai Jiao Tong University of an RGB diffracted video image illustrate real-time holographic video from the holographic display.
Last, but not least, was the second-generation holographic display from Scotland-based Holoxica, Ltd., demonstrated at the I-Zone. The company developed what it calls a holographic optical element (HOA) that uses a laser-based DLP projector subsystem. Its technology is based on the same principles of free-space optics used in creating HUD systems that push the image to display in mid-air beyond the windscreen in a car. To this, the company added an element of interactivity using a Kinect motion sensor and developed a series of applications that engage the user with interactive icons, buttons, and the ability to draw in mid-air. I-Zone demos included a holo-based pong-style game, keypad, and free-form drawing in space and image sequences. This can all be seen in a Vimeo video from the company Web site at www.holoxica.com (Fig. 7).
Fig. 7: This still image from Holoxica’s Interactive Holographic Video Display on Vimeo.com shows how the technology enables a user to draw in “mid air.” Source: Holoxica.
Display Week delivered on its annual promise of bringing the best and brightest together in the display industry, from the slick new curved TVs now available in both AMLCD and OLED varieties to the migration of the curved screen to the desktop. (Samsung was first with this here at the show.) Pioneering autostereoscopic and holographic display work was also showcased at Display Week. The recent work in light-field displays, now merging with sensor technology such as eye- and head-tracking devices, is particularly inspiring. These demonstrations, both in the new I-Zone prototype area and in the long-standing SID Symposium with its strict peer-review process, show great promise for the future of the display industry. •