Color filter for 10.4-in.-diagonal 4096-color thin-film-transistor liquid crystal displays

Color filters with a wide color reproduction gamut and high transmittance were developed for 10.4-in.-diagonal 4096-color thin-film-transistor liquid crystal displays using pigment-dispersed photosensitive polymers. The transmission spectrum of each color pixel was designed in conjunction with other components such as backlight and polarizers in order to meet front-of-screen quality requirements. To improve screen quality, a low-resistivity common electrode was used, eliminating the top coating. A repair technique utilizing back-exposure was also developed to improve production yield. This pigment-dispersed-type color filter has the merits of a simple process, low fabrication cost, good uniformity, high reliability, and applicability to high-resolution displays. There is a problem involving deterioration of contrast ratio caused by the depolarization effect of the color filter. We measured depolarization factors for several pigments and showed that the yellow pigment was the major contributor. This depolarization effect has been minimized.