Laser projection optical path design and speckle suppression

In order to improve the imaging quality of the existing projector and simplify the optical path structure of the projection system, this paper involves a new type of optical system of projection system, using three-color LD light source as illumination source of projection system, using tapered light guide tube as the light guide. This article studies the principle of diffusers to suppress speckles, and derives the influence of diffuser number, divergence angle and gap between diffuser on speckle contrast. Using the Tracepro to build a three-dimensional model. The optical path structure was simulated and the results of simulation were analyzed. It shows that the speckle contrast of the projection system is 5% and the spot uniformity is up to 95.8%. Compared with the traditional laser projection light path, reduce the color wheel、Color-combination prism, dichroic mirror, mirrors and other components, simplifies the light path structure.