Hideki Asada

A new patterning process concept for large-area transistor circuit fabrication without using an optical mask aligner

A new concept to produce large thin film transistor liquid crystal displays (TFT-LCDs) without using an optical mask aligner is proposed which emphasizes patterning technology. Some experimental thin film transistors (TFTs) are fabricated according to the concept and operated like conventional transistors fabricated by using an optical mask aligner. The concept includes improvement of printing technology and development of a double-layer resist method. The latter method employs a printed ink pattern and a photoresist. This prevents contamination of thin films by metal impurities which affect electrical characteristics of the TFTs. A special gravure offset printing technology is proposed, composed of a large thixotropy valued UV ink, and a fine, precision etched glass intaglio. The experimental TFTs, with a designed minimum gate length of 10 /spl mu/m, have comparable electric characteristics to those of conventional poly-Si TFTs. >

6.3: Field-Sequential Smectic LCD with TFT Pixel Amplifier

A field-sequential color smectic LCD has been developed using low-temperature poly-Si TFTs. An active-load type TFT pixel amplifier is used to drive a V-shaped-switching smectic LC without voltage fluctuation. The optical response time is 300 μs for a field frequency of 180 Hz. This LCD is capable of displaying high-quality motion-picture images.

54.1: A Low-Power SOG LCD with Integrated DACs and a DC-DC Converter for Mobile Applications

A low-power 262k-color SOG (System-On-Glass) LCD has been developed for mobile applications. It is integrated with a DC-DC converter and driver circuits that contain 6- bit DACs, and it consumes less than 5 mW in operations with a single voltage power supply of 2.5 V.

1-inch diagonal transflective 2D and 3D LCD with HDDP arrangement

We have developed a 1-inch diagonal transflective 2D/3D-LCD with a novel pixel arrangement, called HDDP (Horizontally Double-Density Pixels). In the HDDP arrangement, both horizontal and vertical resolutions are equal, which not only results in high 3D image quality, but also means that 2D images, such as characters, can be displayed perfectly. With this design, both 3D and 2D images can be displayed simultaneously in the same picture with no need for 2D/3D mode-conversion. In order to avoid increasing power consumption, we chose to use a lenticular lens and a transflective mode which employs ambient light. In transflective mode, so as not to reduce the 3D visible zone, we use a horizontal stripe reflector, which divides each dot into a transmissive region and a reflective region vertically, without dividing the 3D visible zone into transmissive or reflective zones. As a result, a wide 3D visible zone has been achieved. In addition, in order to avoid image degradation caused by a combination of a micro structure on the reflector and a lenticular lens, we optimized the micro structure and defocused the lenticular lens. Its small size, high visibility and lowpower consumption can broaden the applications of 3D displays.

Self-referenced poly-Si TFT amplifier readout for a linear image sensor

A readout scheme with thin film transistor (TFT) amplifier is proposed for a linear image sensor. Each pixel is provided with a TFT amplifier and additional TFT circuits which allow self-calibration of the amplifier. Prototype sensors were successfully fabricated by the low-temperature poly-Si process utilizing excimer laser annealing.<<ETX>>

Ferroelectric liquid-crystal shutter array with poly-Si TFT driver

A novel ferroelectric liquid-crystal (FE-LC) shutter array with a poly-Si thin-film-transistor (TFT) driver has been fabricated which has 256 dots (300 dots/in. resolution) and is 21.7 mm long. The TFT driver is capable of driving the FE-LC in the static mode and reduces the number of outlet electrodes. This results in a device with the advantages of high contrast ratio (over 20 to 1), compact device size, and low cost.<<ETX>>

16.2: A Parallel Digital‐Data‐Driver Architecture for Low‐Power Poly‐Si TFT‐LCDs

A parallel digital-data-driver architecture has been developed to reduce power consumption in low-temperature poly-Si TFT-LCDs. It features low-power 3V-interface level shifters and 198 serial/parallel converters driven in parallel at a clock frequency of 62.5 kHz. Total power consumption in a 2.4-in., 41K(176 × 234)-pixel TFT-LCD with integrated 6b DACs is 12 mW at a 30-Hz frame frequency.

31.3: Reduction and Measurement of 3D Moiré Caused by Lenticular Sheet and Backlight

We found that interference between a 3D displays lenticular sheet and backlight prism sheet causes 3D moire. This previously unknown phenomenon affects image quality. Its mechanism, reduction methods and their implementation results are described. An appropriate measurement method for 3D moire is also proposed.

A 470 × 235-ppi poly-Si TFT-LCD for high-resolution 2-D and 3-D autostereoscopic displays

— We have developed a 470 × 235-ppi poly-Si TFT-LCD with a novel pixel arrangement, called HDDP (horizontally double-density pixels), for high-resolution 2-D and 3-D autostereoscopic displays. 3-D image quality is especially high in a lenticular-lens-equipped 3-D mode because both the horizontal and vertical resolutions are high, and because these resolutions are equal. 3-D and 2-D images can be displayed simultaneously in the same picture. In addition, 3-D images can be displayed anywhere and 2-D characters can be made to appear at different depths with perfect legibility. No switching of 2-D/3-D modes is necessary, and the designs thin and uncomplicated structure makes it especially suitable for mobile terminals.

51.1: A DC-DC Converter Circuit Integrated into a Poly-Si TFT LCD Containing a 6-bit DAC

A DC-DC converter composed of charge pumps and regulators has been integrated into a poly-Si TFT LCD that also contains a 6-bit DAC. It has the ability to supply regulated voltages to the 6-bit DAC and to the LCDs gate driver circuit.