Novel semiconductor laser light source speckle removing technology

Abstract

The invention relates to a novel semiconductor laser light source speckle removing technology. In a projection display illuminating light path which takes a semiconductor laser array as a light source, a diffusion sheet in the parallel light path is moved to a convergence light path at the inlet of a glass rod, only one diffusion sheet is arranged in the whole light path, and the divergence angleof the diffusion sheet is 5-6 degrees. According to the technology, the wide color gamut display of laser can be ensured, while the coherence of the light source can be effectively reduced, speckle can be inhibited, and the display quality can be improved.

Description

technical field [0001] The invention relates to a speckle elimination technology, in particular to a speckle elimination method for a laser light source. Background technique [0002] Traditional projectors using high-pressure mercury lamps as light sources have short light source life, small color gamut and low saturation of projected images, which gradually cannot meet people's needs for color. Laser light sources have the advantages of long life, extreme color performance, high-definition projection images, high contrast, etc., and are more and more widely used in the projection display industry. [0003] Compared with other solid-state lasers, semiconductor lasers are smaller in size and have higher photoelectric efficiency, making them ideal light sources for laser displays. At present, both red and blue laser diodes can be mass-produced, and the power of a single tube has reached the watt level; green lasers have also made great progress. These developments have laid ...

AI Technical Summary

Problems solved by technology

However, laser light has high coherence, which leads to an obvious shortcoming of laser projection display: speckle phenomenon

In this system, multiple optical fibers are used to couple the array laser together. Although the speckle can be suppressed to a certain extent, to achieve a better effect, the number of subs is required to be large, which will result in an increase in volume and light energy utilization. reduction in rate

These factors limit the large-scale application of laser display

[0005] At present, the more common method is to embed a diffuser in the parallel optical path. Although this method can dilute the speckle and improve the uniformity of the picture, it also has a big disadvantage that the diameter of the exit spot increases due to the increase of the laser divergence angle. However, the diameter of the entrance of the optical machine is fixed, and the output of light energy increases the loss at the interface between the light source and the optical machine.