Naoyasu Ikeda

12.3: A New Low-Power TFT-LCD Driver for Portable Devices

In this paper, we describe a new low-power data-line driver for TFT-LCDs for portable devices. The driver contains newly-developed output buffers with low static current in place of operational amplifiers in a conventional driver. The new driver test-IC achieves about 85 % reduction in static current dissipation with a high output-voltage-resolution and a wide dynamic-output-range.

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.

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.

20.2: A Simple Reflective TFT‐LCD Fabrication Using Four Photomask Processes

To reduce the production cost of reflective TFT-LCDs, we have developed a method of fabricating TFT-LCDS that is comprised of only four photo mask processes. Experimental black and white reflective LCDs fabricated with this method exhibit a lightness (L*) of 83, and no image parallax.

A 28-cm-diagonal UXGA TFT-LCD for Legible A4-size Document Viewers

□A 28-cm-diagonal UXGA TFT-LCD with 177 dpi resolution has been developed. With this LCD, the images of documents located within printable areas on A4-size papers can be legibly displayed. Using this high-resolution LCD, subjective psychological experiments have been carried out. We have found that TFT-LCD legibility was much better than that of CRT, and that minimum resolution of about 175 dpi dots per inch was needed for use in legible document viewers.