Kazuhiro Arai

High‐efficiency optical system for ultra‐short‐throw‐distance projector based on multi‐laser light source

— A novel laser-light-source projector having the three outstanding features of high brightness, ultra-short throw distance, and high color reproduction has been developed.These features have recently come to be required in the high-end projector market. The technologies for the laser-light-source projectors fully utilize the advantages of lasers, such as high luminance, small etendue, and high color purity. By integrating a triple-rod illumination system with a multi-laser light source and an ultra-wide-angle projection system, the developed high-efficiency optical system has achieved a brightness of 7000 lm and a throw ratio of 0.28 with an image size of 100–150 in. Another new technology, laser color processing (LCP), has offered vivid color reproduction which has a color gamut that is up to 180% wider than the BT.709 standard without appearing unnaturally colored. Furthermore, a speckle suppression effect produced by the multi-laser light source has been demonstrated. In this paper, an overview of these newly developed technologies that are used in the novel laser-light-source projector is presented, and solutions to the issues of speckle noise and safety are presented.

16.4: A New Projection System with Scrolling Illumination for Motion Picture

A projection system was developed to reduce blurred images caused by fast motion pictures on hold-type display such as LCD panels. The system incorporates an optical scrolling system using a spiral aperture wheel (SAW) made of glass and aluminum to transmit and reflect light.

8.2: Color Tuning Projection System for Adaptive Combination of High Brightness and Wide Color Gamut

We have developed a new projector with a fourth liquid crystal panel that controls yellow light separately from RGB lights of UHP lamp. This additional panel system enables projector to achieve adaptive control of both high brightness and 120% wide color gamut. In this paper, we propose the innovative design concept and the technical development of the Color Tuning Projection System and represent the characteristics of the prototype.

65.3: Distinguished Paper: High Efficiency Optical System for Ultra-Short Throw Distance Projector Based on Multi-laser Light Source

We have developed a high-efficiency optical system that uses multiple lasers as a light source. This optical system enables us to produce a novel laser projector with a high brightness and an ultra-short throw distance. By utilizing the advantages of a laser, we have achieved a brightness of 7,000 lm and a throw ratio of 0.28 with an image size of 100–150 inches.

Color‐tuning projection system for adaptive combination of high brightness and wide color gamut

— The demand for projectors with high brightness and wide color gamut has been increasing; however, UHP lamp projectors cannot deliver those two qualities efficiently and simultaneously because of its color-separation system. The newly developed projection system — “Color-Tuning Projection System” — realizes the adaptive combination of high brightness and wide color gamut with one projector. This projector features a fourth liquid-crystal panel — “Color Tuner” — with a 3LCD optical engine, which controls yellow light separately from the RGB light of a UHP lamp. This color-tuner-based optical engine — “Color-Tuning Optical Engine” — and a new color-conversion signal-processing algorithm — “Adaptive Color Conversion Algorithm” — controls the yellow-light volume and corrects color-shifted pixels according to the brightness and chromaticity analysis of the input image, key technologies of the Color-Tuning Projection System. This additional panel system enables the projector to ach ieve up to 115% higher brightness and 120% wider color gamut according to the input image. This paper presents an innovative design concept, a novel technology regarding brightness and a color-gamut conversion projection system, and the characteristics of the prototype.

Color Tuner based optical engine for high brightness and wide color gamut

We have developed the new projector with the fourth new liquid crystal panel (Color Tuner) that controls the yellow light independently in an ultra-high-pressure mercury lamp. This system enables both high brightness and 120% wide color gamut compared with the conventional models.

Development of a new LC rear-projection display with an aspherical mirror projection system

We have developed a new projection system that consists of an aspherical mirror projection system. This system realizes the small depth that cannot be achieved with the conventional rear projection lens. Furthermore, we have developed a new screen that realizes high brightness, good uniformity within the whole image area, a wide viewing angle, and reduction of the ghost image by obtaining the ideal conditions between each blaze angle of the Fresnel screen and the projected rays onto the screen.