Experi Mental Study On The Optical Engine Of Laser Projection Display

The light source of laser projection display is based on red, green, and blue laser, the tricolor laser beam send out to the corresponding image display module after beam shaping and reducing speckle, The tricolor laser which is modulated by image signal by X prisms incident to projection lens and screen with rich colors, colorful images finally. The technology makes full use of the laser’s characteristics,directional, monochromatic, high brightness, and the characteristics of wide color gamut range, high color purity and saturation, it also has other characteristics such as high solar energy utilization, energy consumption low and long life. The laser display has further development of space and broad market prospects in the field of public information multimedia large-screen, laser TV, digital cinema, and it will become a next generation of new display technology.This paper based on the laser projection display applications and study as a starting point, through the laser projection display optical engine experimental research, eventually developed a laser projection display prototype. Outline:(1)This paper introduces several images of the display module (LCD, DLP and LCOS) in projection display, analysis their principles, structure and characteristics, and compare them.(2) After analyzing and comparing different kinds of traditional projection display optical engine structures (such as the monolithic structure and the three-chip structure) and their characteristics, and their advantages and disadvantages, determined the structure of the optical engine suitable for the laser projection display.(3) According to the compound principle of three primary colors, paper analysis the color gamut characteristics of the laser display, combined with the requirements of the projection display of the light source and discuss the basic principles of the laser light source’s selection, according to the laboratory device, we selected laser as the light source.(4)Analysis laser beam shaping and reducing speckle technique and devices currently, propose the integrated device that can realize laser beam shaping and reducing speckle, and it achieved by using diffractive optical elements.(5)Based on the above analysis,combined with laboratory devices conditions, we use the LCOS as image display module and three-chip LCOS optical engine and choose laser source, then according to the system’s requirements of the design and the laser beam parameters, we build an optical engine system, developed the laser projection display principle prototype and tested its performance.Prototype for rear screen projection,the screen size is65inches,screen aspect ratio of16:9,a picture resolution of1920×1080, color domain coverage ratio reached63.9%(of NTSC168%190%PAL),luminous flux of2774lumens, contrast ratio of1004:1,light uniformity of77.2%, color temperature of6923K, horizontal and vertical visual angle of108°and34°, respectively.