Kazuo Sekiya

Speckle reduction mechanism in laser rear projection displays using a small moving diffuser.

Recently, a practical method of speckle reduction in laser rear projection displays that uses an optical system with a small moving diffuser has attracted much attention. In this paper, a model of the speckle generation and reduction mechanism in the system is presented. We investigated the speckle, focusing on the physical aspects of its generation, rather than treating it statistically. We found that the granularity of the speckle patterns generated by the small diffuser corresponded to the size of the coherent regions on the projection screen. This determined the efficiency of the speckle reduction when the small diffuser was rotated.

L-4: Late-News Paper: A Simple and Practical Way to Cope With Color Breakup on Field Sequential Color LCDs

In-depth theoretical analysis is performed on several methods that have been proposed for the reduction of color breakup on field sequential color LCDs. Among them, our newly proposed method, RGBKKK, gives the best practical result. The results were verified on our field sequential OCB-mode LCD of 36.9cm-diagonal XGA size.

High-performance OCB-mode field-sequential-color LCD

— Optically compensated bend (OCB) mode is a promising technology for future high-quality display devices due to its wide viewing angle without gray-scale inversion and color shift, fast response time, high contrast ratio, and wide temperature range. This paper summarizes the developments of the OCB mode and the optical performance of OCB-mode field-sequential-color LCD.

Spatio‐temporal scanning backlight mode for field‐sequential‐color optically‐compensated‐bend liquid‐crystal display

— A spatially and temporally scanning backlight consisting of ten isolated micro-structured light guides has been developed to be combined with a fast-response optically-compensated-bend-mode field-sequential-color LCD in which the liquid-crystal cell does not contain color filters. The sequential fields of three primary colors are generated by illumination of the red-, green-, and blue-light-emitting diodes, each illuminating for one-half of the field, resulting in a luminance of 200 cd/m2 for the LCD. The effect of light leakage between the blocks in the scanning backlight in field-sequential-color applications was measured and will be described.

36.3: Late-News Paper: Spatio-Temporal Scanning Backlight for Color-Field Sequential Optically Compensated Bend Liquid-Crystal Display

A spatio-temporally scanning backlight consisting of ten distinct micro-structured light-guides has been developed for the use in the newly developed OCB-mode field sequential color LCD in which the liquid crystal cell has no color filters. The sequential fields of three primary colors are generated by illumination of the red, green and blue light emitting diodes each flashing for a half of the field, which results in a luminance of 200cd/m2 on the top of the LCD.

Analysis of speckle‐reduction performance in a laser rear‐projection display using a small moving diffuser

— Recently, a practical method of speckle reduction in laser rear-projection displays that uses an optical system with a small moving diffuser has attracted much attention. In this paper, a model of the speckle generation and reduction mechanism in the system is presented. Speckle in the system was investigated, focusing on the physical aspects of its generation rather than treating it statistically, and it was found that the granularity of the speckle patterns generated by the small diffuser corresponded to the size of the coherent regions on the projection screen. This determined the efficiency of the speckle reduction when the small diffuser was rotated. By using these results, a method to estimate the performance of speckle reduction on the system was developed.

Improvement of Transmittance and Viewing Angle of Optically Compensated Bend Mode Liquid Crystal Display Using Wide-Viewing-Angle Circular Polarizer

A field sequential color liquid crystal display (LCD) has been developed using an optically compensated bend (OCB) mode liquid crystal cell and a light-emitting diode backlight. Application of a wide-viewing-angle- and wide-band-type circular polarizer realized a wide-viewing-angle and high-transmittance OCB-mode LC cell. In this paper, we describe the principle of the optical compensation and the fundamental characteristics of an advanced OCB-mode LCD.

LP‐4: Late‐News Poster: Overdrive for Compensating Color‐Shift on Field Sequential Color TFT‐LCDs

This paper points out that field sequential color method causes color-shift artifact on TFT-LCDs in its nature, and that overdrive scheme can work for the purpose of eliminating the artifact. It also reports the effect of overdrive measured on our prototyped OCB-mode field sequential color TFT-LCD of 6-inch VGA-size.

17.1: Invited Paper: High Performance OCB-mode for Field Sequential Color LCDs

Optically compensated bend (OCB) mode is a promising technology for future high quality display devices due to its wide viewing angle without gray scale inversion and color shift, fast response speed, high contrast ratio and wide temperature range. This paper summarizes the developments of the OCB mode and the optical performance of OCB mode field sequential color LCD.

Development of high definition liquid crystal display with excellent moving image

It is easy for the liquid crystal to save the electric power for non-emissive display essentially in various flat panel displays, and to improve the electro-optical property by function separation of a light source and an optical control, etc. However, the utilizing efficiency of light in liquid crystal displays is about several %. One of the low efficiency factors is a color filter. We adopted the FS method to switch the light source color using OCB mode with excellent switching speed. This method is a technology that displays full colors by switching a red, green, blue image at high speed sequentially. The merit of this method is high efficiency without using the color filter that absorbs 67.1% of the backlight, and it is a useful skill to the power consumption reduction of the liquid crystal panel. In addition, there is an advantage that clear motion image can be displayed for this method to blink the source of the backlight at high speed. The 6-inch LCD panel with the FS OCB mode was manufactured. The clear motion image, high utilizing efficiency of light, and large color gamut were achieved.