Tetsuo Urabe

24.4L: Late-News Paper: A 13.0-inch AM-OLED Display with Top Emitting Structure and Adaptive Current Mode Programmed Pixel Circuit (TAC)

A device structure and a driving method were developed to design large-scale active matrix organic light-emitting diode (AM-OLED) display with good gray scale uniformity and high aperture ratio. With these technologies, we developed a full color 13.0-inch SVGA AM-OLED display, the largest OLED display ever reported to date. These technologies will open up the OLED applications to larger size displays such as desktop monitors and TVs.

A flexible full‐color AMOLED display driven by OTFTs

Abstract— Organic thin-film-transistor (OTFT) technologies have been developed to achieve a flexible backplane for driving full-color organic light-emitting diodes (OLEDs) with a resolution of 80 ppi. The full-color pixel structure can be attained by using a combination of top-emission OLEDs and fine-patterned OTFTs. The fine-patterned OTFTs are integrated by utilizing an organic semiconductor (OSC) separator, which is an insulating wall structure made of an organic insulator. Organic insulators are actively used for the OTFT integration, as well as for the separator, in order to enhance the mechanical flexibility of the OTFT backplane. By using these technologies, active-matrix OLED (AMOLED) displays can be driven by the developed OTFT backplane even when they are mechanically flexed.

29.5L: Late‐News Paper: Advanced AM‐OLED Display Based on White Emitter with Microcavity Structure

We developed an AM-OLED display having saturated RGB, high efficiency and good contrast ratio. These properties, which outperform those of a conventional White OLED and color filter (WOLED+CF) system, were achieved with a unique combination of white emitter, microcavity structure and color filter array (WOLED+MC+CF).

An OTFT-driven rollable OLED display

Abstract— An 80-μm-thick rollable AMOLED display driven by an OTFT is reported. The display was developed so as to be rollable in one direction with an integrated OTFT gate driver circuit. It was successfully operated by an originally developed organic semiconductor, a peri-xanthenoxanthene derivative. The display retained its initial electrical properties and picture quality even after being subjected to 1000 cycles of a roll-up-and-release test with a radius of 4 mm.

13.1: Invited Paper: Technological Evolution for Large Screen Size Active Matrix OLED Display

Vacuum evaporation process with metal mask using LTPS (Low Temperature Poly Silicon TFT) backplane is well established OLED production process. However this technology is not applicable for large sized display like TV. Various technologies to break through this constraint have been proposed so far. In this paper pros and cons of these proposed technologies are discussed and new approach, micro silicon TFT with unique anneal technology and laser transfer OLED process, is presented.

47.3: A Rollable AM-OLED Display Driven by OTFTs

We have developed an 80-μm-thick rollable AM-OLED display. The display is driven by an organic TFT backplane for which we have used originally developed semiconductor, a perixanthenoxanthene derivative. The display shows no degradation in a 4 mm-radius roll-up-and-release cycle of 1000 times.

63.2: Distinguished Paper: A Full-Color, Top-Emission AM-OLED Display Driven by OTFTs

We have developed an integration architecture for high-resolution organic-TFT (OTFT) arrays with top pixel electrodes on a plastic film. In this architecture, no damage isolation method of organic semiconductor (OSC) in a photolithographically defined resolution is employed. All the insulators in the backplane consist of organic polymers, enhancing both the mechanical flexibility of the backplane and the manufacturing throughput. These technologies have been successfully applied to produce a flexible, full-color and top-emission active-matrix organic light-emitting diode (AM-OLED) display on a plastic substrate with a resolution of 80 ppi.

A flexible OLED display with an OTFT backplane made by scalable manufacturing process

— A full-color top-emission AMOLED display driven by an organic TFT backplane manufactured using a scalable, lift-off-free, and shadow-mask-free process has been developed. It was shown that cost-efficient copper can be used for S/D electrodes. The display has shown no significant degradation over a storage life of more than 10 months and operation over 25 hours during which the display is bent over 10,000 times.

54.5L: Late-News Paper: A 24-inch AM-OLED Display with XGA Resolution by Novel Seamless Tiling Technology

We developed a novel seamless tiling technology for full color AM-OLED display. This technology is based on three items: 1) TAC-based tiling structure, 2) High precision tiling process, 3) Brightness and color matching system. As a result, a 24-inch panel, the largest OLED display ever reported, has been fabricated using 2×2 tiles with no apparent seams.

44.2: New Driving Method with Current Subtraction Pixel Circuit for AM-OLED Displays

A new current programmed driving method with current subtraction pixel circuit has been developed for LTPS AM-OLED displays. The new driving method enables to program low brightness signal current for larger sized panel and compensate electrical characteristic variations of LTPS TFT. Consequently, we can achieve high contrast ratio and good pixel-to-pixel luminance uniformity for LTPS AM-OLED displays.