Laser projection system with speckle elimination function

Abstract

The invention relates to a laser projection system with a speckle elimination function. The laser projection system is composed of a plurality of lasers, a beam-combining light homogenizer, a beam expander, a phase diffuser, a light homogenizer, a beam shaping device, a projection chip, a projection lens, and a series of lenses. The plurality of lasers provide light sources for the projection system; the beam-combining light homogenizer enables laser from different lasers to be combined, compressed, and mixed fully; the beam expander carries out beam expanding on the laser that has been processed by combination and light homogenization and project the processes laser to the phase diffuser by the lenses at proper angles; the phase diffuser adds random phases to the laser projected to the phase diffuser according to the spatial positions and the laser is coupled to the light homogenizer at a divergence angle, and full mixing is carried out again; and the beam shaping device integrates the light from the light homogenizer into the light beam consistent to the projection chip and the projection lens is used for projecting an image generated at the projection chip to a screen. According to the invention, the coherence of the laser beams are substantially reduced, thereby realizing the speckle elimination effect; and the projection system can be guaranteed to have the laser energy with enough brightness.

Description

technical field [0001] The invention relates to the speckle-eliminating design of a projection system using laser light as a light source, in particular to a laser projection system with the speckle-eliminating function. In this laser projection system, the speckles caused by the high coherence of laser are eliminated to achieve the high image quality that laser display should have. Background technique [0002] A laser is a light source with high brightness that emits a coherent beam of monochromatic light. These properties make lasers ideal for use as light sources for laser displays. Laser displays provide customers with high-powered lighting and saturated colors. However, the coherence of laser light can cause a phenomenon known as laser speckle. For example, the interference of coherent light scattered by laser light from different surfaces creates a speckle pattern. Thus, while lasers are expected to provide bright images with good color, image quality can be degra...

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Problems solved by technology

However, for a large projection screen, this is not practical

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