Light Engine Design For Laser Rear Projection TV Based On LCoS

Tricolor laser display has a wider color gamut, higher color purity and saturation, and the images' color shown by it is more plentiful, more vibrant, and closer to the natural colors because the laser's better monochromeaticity, better directivity, and higher brightness. That tricolor laser with small size, high power, and stable performance is developing rapidly, and its prices is also becoming lower and lower advanced the research and application process of laser display technology. Laser display technology has widespread applications fields and huge market.The main topic of this paper is the structure and experimental research about the optical engine of laser projection display based on LCoS. Specifically, include the following five sections:(1) The influence of tricolor laser wavelengths on the size of display color gamut is analyzed, the selecting principles of tricolor laser wavelengths is given with the help of color Principles and photometry theory, and the power ratio the specific power of tricolor laser is calculated according to the tricolor laser wavelength selected, display screen size, and the light loss of the optical system is also taken into account. (2) After analyzing and comparing different kinds of traditional projection display optical engine structures, three-chip LCoS optical engine structure is finally determined, combing many considerations such as the characteristics of laser source and the Tricolor laser's performance parameters, the light use efficiency and the contrast, and other considerations. The use methods, and impact of the polarized optics devices (for example polarizing beam splitter, a quarter wave plate, etc.) used in systems on contrast are also analyzed. (3) This paper analysis the principle of the phase-type diffraction beam shaping devices suitable for laser beam shaping according the scalar diffraction theory, introduces various design algorithms of it and its evaluation functions, gives computer simulation results of some algorithms, three using methods of it and its experimental validation are also given. (4) This paper gives the theoretical analysis about laser speckle and background stripes that comes out only in the laser display, proposes three new programs to reduce laser speckle and two programs of integrated device that can realize laser beam shaping and speckle removing simultaneously after describing existing different programs to reduce laser speckle. (5) This paper gives a preliminary modeling analysis of the whole optical system of the laser projection display engine. Some elements are designed and simulated by computer. The parameters of each component and the whole system are determined. The experimental system using three-chip LCoS for laser projection display is constructed, and many experimental researches have also been done. At last, this paper gives a preliminary experimental measurement about the brightness and color parameter index of the image shown, the experimental results verified the feasibility of the overall program.