Arihiro Takeda

41.1: A Super-High Image Quality Multi-Domain Vertical Alignment LCD by New Rubbing-Less Technology

An MVA-LCD (multi-domain vertical alignment LCD) that provides super-high image quality has been developed by newly introduced rubbing-less technology. A newly introduced “protrusion” designed on the TFT substrates and on the color filter substrates automatically controls the directors of the LC molecules. By this technology we have successively developed four-domain 15″ MVA-TFT units that provide extremely wide viewing angle of more than 160 degrees, a high contrast ratio of 300:1 or more and a fast response of less than 25ms.

16.5L: Late‐News Paper: A New Design to Improve Performance and Simplify the Manufacturing Process of High‐Quality MVA TFT‐LCD Panels

An MVAMulti-domain Vertical Alignment-TFT LCD panel has been redesigned to improve optical performances and to reduce process step. The optical transmittance was improved by newly introduced protrusion wings to remove undesirable disclination lines caused by edge field effect of the pixel. Also, an aperture of the black matrix on the CF substrate was extended to include whole ITO pixel since the operating mode of the liquid crystal is Normally-Black mode. The protrusions on the TFT substrate was replaced to patterned ITO slit. This results in the contrast ratio improvement, and simplifies the manufacturing process.

39.4: A New MVA‐LCD with Jagged Shaped Pixel Electrodes

We have developed a new MVA-LCD with fast gray-scale response characteristics. The newly designed jagged shaped pixel electrodes give the oblique electric field and effectively control the LC alignment not only statically but also dynamically. We have realized the response time of 30ms (1/3 of the conventional MVA) for any gray-scale switching keeping other advantageous characteristics same; CR, viewing range etc.

Vertically Aligned TFT-LCDs

Fujitsu has developed several types of vertically aligned TFT-LCD: with protrusion; with photo-alignment; and with comb-shaped electrodes. The protrusion-type TFT-LCD has the best balance of specifications and is in mass- production. It has a transmittance of 5% for a 15-inch XGA LCD, a response of 25 ms (τon + τoff), and a contrast ratio of over 400. The photo-aligned type gives highest transmittance (7.5%) with dual domains. The lamp for UV irradiation can be a tube type and non-polarized UV is possible. We think it is a good candidate for notebook-type applications. The comb-shaped electrode type has the fastest response of better than 17 ms for any gray-scale switching. We think it is a good candidate for video applications.