Device and projection display system for eliminating laser speckle and filtering

Abstract

The invention relates to a device and a projection display system used for eliminating laser speckles and filtering waves. The device comprises a combination light source, a diffusing and filtering part and a driving device, wherein the combination light source at least comprises three kinds of red light, green light and blue light laser light sources; the diffusing and filtering part is arranged on a transmitting path of emitted light of the combination light source; the diffusing and filtering part comprises a diffusing structure, a filtering structure and a fixed device; the filtering structure comprises a substrate and at least three filtering films arranged on the surface of the substrate, laser of each color in the combination light source is provided with a corresponding filtering film at the surface of the substrate, and the thickness of the diffusing structure changes along the circumferential direction of a central shaft of the diffusing and filtering part; and the driving device is used for driving the diffusing and filtering part to rotate around the central shaft, thereby enabling all of the filtering films to be arranged on the transmitting path of the emitted light of the combination light source alternatively so as to generate sequential light having alternating colors. Through the mode provided by the invention, the driving device is utilized to rotate the diffusing and filtering part, wave filtering can be realized while eliminating speckles, and the structure is compact.

Description

technical field [0001] The invention relates to the field of laser display, in particular to a device for eliminating laser speckle and filtering and a projection display system. Background technique [0002] At present, the application of laser light sources is more and more extensive, and has become a hot spot in research and development. The laser light source has the characteristics of bright color, high color purity, high brightness, wide color gamut, long life, and small size. However, due to the narrow laser line width, long coherence length and coherence time, the use of laser light source for projection shows serious speckle. There are still many difficulties in this issue. [0003] The root cause of laser speckle is that the energy of light waves is redistributed due to the phenomenon of laser interference, which leads to the enhancement of coherence in some areas to become bright spots, and the cancellation of coherence in some areas to dark spots, and the phenom...

AI Technical Summary

Problems solved by technology

[0006] The present invention mainly aims to solve the technical problem of speckle existing in the existing laser light source system, and provides a device for eliminating laser speckle and filtering and a projection display system with a compact structure and capable of effectively eliminating laser speckle

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