L‐9: Late‐News Paper: Laser Projection Display with Low Electric Consumption and Wide Color Gamut by Using Efficient Green SHG Laser and New Illumination Optics

air-cooled RGB lasers including a compact and efficient green SHG laser and new illumination optics for speckle noise reduction, we developed advanced laser projection engine. A prototype of laser rear projection display with low electric consumption (about 50W) for light sources and wide color gamut (137%NTSC) was realized. 1. Introduction the last decade, several different micro-display technologies (LCD, DMD and LCOS) have been developed and projection displays captured the large screen market for business and home theater. Most projection displays are now using lamps as light sources, such as high-pressure mercury lamps and metal halide lamps. Laser light sources are attractive for projection displays. Projection displays based on RGB lasers can provide extremely wide color expression with the narrow spectrum of lasers. Due to small etendue, laser lights are projected with high efficiency. Lasers have longer life time and faster response time than lamps. As high brightness and high power efficiency of lasers contribute to downsizing systems and improving electric efficiency, laser projection displays will find wide applications (1-3). However, for realizing laser displays there are two problems. The one is a suitable green laser with high efficiency, high power and compact size. As there are no green diode lasers and conventional green lasers for high output power need big mechanisms such as water-cooling devices, it is difficult to downsize and to decrease electric consumption. The other problem is an interference phenomenon called speckle. As lasers have high coherency, speckle noises are superposed on projected images (4). We overcome these problems and demonstrate a laser rear projection display with low electric consumption.