Daisuke Kajita

28.1: Optically Compensated IPS‐LCD for TV Applications

A light leakage and a color shift along diagonal viewing angle directions in the black representation were dramatically reduced for IPS-LCDs using a newly developed biaxial film and pixel structure. We have studied the optical compensation method suitable for a newly developed panel with the higher white transmission (IPS-Pro). This new film technology has been successfully applied for the 32-inch IPS-LCD with performances of significantly wide viewing angle performance in all images and contrast ratio over 900:1.

11.2: Improved Contrast Ratio in IPS-Pro LCD TV by Using Quantitative Analysis of Depolarized Light Leakage from Component Materials

The degree of imperfection was defined as the independent intrinsic index of the degree of degraded contrast ratio for each component. The scattering index of liquid crystal layer gives an effective guideline for reducing light leakage intensity. By using this guideline, we have made an IPS-Pro LCD with a uniform contrast ratio of 1500:1 within ±16.5° of polar angle.

An IPS-LCD with a high contrast ratio of over 80:1 at all viewing angles

Abstract— A 32-in. IPS-LCD with a significantly wide-viewing-angle performance has been developed using a new optical compensation method. It provides a contrast ratio of over 80:1 at all viewing angles, which enhances its color saturation at oblique angles. According to our study, it is important to shorten the path of the optical compensation in the Poincare sphere. We have found an effective method using two retardation films, one with an Nz value larger than 0.5 and one with a value smaller than 0.5.

Wide-viewing angle in-plane switching liquid crystal displays for television applications using optical compensation technology

Viewing angle performance in in-plane switching liquid crystal displays (IPS-LCDs) has been greatly improved, using two technologies. One is optical compensation technology using a biax- ial film. The other is a newly developed IPS-Pro cell structure with higher transmission efficiency. These technologies are successfully introduced into the fabrication of 32-in. IPS-LCDs with a minimum contrast ratio over three times that of conventional IPS-LCDs and with color saturation (area ratio to NTSC at CIE1931 xy chromaticity coordinates) of more than 70% at almost all viewing angles.

21.2: IPS-LCD with High Contrast Ratio Over 80:1 at All Viewing Angles

A 32-inch IPS-LCD with a significantly wide viewing angle performance has been developed using a new optical compensation method. It provides a contrast ratio over 80: 1 at all viewing angles. According to our study, it is important to shorten the path for the optical compensation in the Poincare sphere. We have found an effective method using two retardation films, one with an Nz value larger than 0.5 and one with a value smaller than 0.5.

P-48: Guiding Principles of Gray Level Color Gamut on LCDs for FPD-TV Application

The gray level dependence of the color gamut on a LCD, PDP and CRT is evaluated in both dark and lighted rooms. The color gamut on the LCD decreases sharply with gray level, and the dark gray level color gamut on the LCD is smaller than that on the CRT or PDP in a dark room. However, in a lighted room, the gray level dependence of color gamut on the LCD is better than that on the PDP. A higher contrast ratio is effective for improving the color gamut on LCDs in the dark rooms and the value of over 10000:1 is a good guideline for LCD-TV design.

Wide-viewing angle IPS-LCD for TV applications using optical compensation technology

The viewing angle performance in IPS-LCDs has been greatly improved, by using two technologies. One is optical compensation technology using a biaxial film. The other is the newly developed IPS-Pro cell structure with its higher transmission efficiency. These technologies have been successfully introduced into the fabrication of 32-inch IPS-LCDs with a minimum contrast ratio of over three times that of the conventional and with a color saturation (area ratio to NTSC at CIE1931 xy chromaticity coordinates) of over 70 % at almost all viewing angles.