Method and device for measuring space speckle contrast ratio of laser projector

Abstract

The invention discloses a laser projector space speckle contrast ratio measuring method and device. The device comprises a laser projector, a screen, a diaphragm, an optical lens, a photoelectric sensor, a base body and a mobile station. The laser projector is used for projecting laser onto a screen; the screen is used for changing a laser light path; the diaphragm is used for adjusting the size of light; the optical lens is used for focusing the light on the photoelectric sensor, so that the light forms a speckle image on the surface of the photoelectric sensor; the photoelectric sensor is used for receiving light, converting a formed speckle image into an electric signal with corresponding image data, and calculating the contrast RS of the speckle image; and the mobile station is used for driving the photoelectric sensor to move along the optical axis direction so as to adjust the distance between the photoelectric sensor and the optical lens, so that virtual image light on a plane with a certain distance S in front of and behind the screen is focused on a light detection surface of the photoelectric sensor through the optical lens, and an object-image conjugate relationship is formed between the photoelectric sensor and a virtual image.

Description

technical field [0001] The invention relates to the technical field of speckle measurement, in particular to a method and device for measuring spatial speckle contrast of a laser projector. Background technique [0002] With the development of display technology, laser display has become the most promising new-generation display technology with many advantages such as high color gamut coverage, high brightness, and high contrast. Its main advantages mainly come from the adoption of laser light sources. The laser light source has good coherence, monochromaticity, and high color purity, but there are also problems that the surface of the projection optics is often rough due to the matching of the laser wavelength, and the laser will interfere with the rough surface, and then appear in the projection screen. "Speckle" phenomenon, the existence of speckle will not only seriously affect the uniformity of illumination spot and image quality, but also cause visual fatigue, so in or...

AI Technical Summary

Problems solved by technology

The laser light source has good coherence, monochromaticity, and high color purity, but there is also a problem that the surface of the projection optics is often rough due to the matching of the laser wavelength, and the laser will interfere with the rough surface, and then appear in the projection screen. "Speckle" phenomenon, the existence of speckle will not only seriously affect the uniformity of illumination spot and image quality, but also cause visual fatigue, so in order to better eliminate the adverse effects of speckle, for laser speckle The accurate measurement of laser speckle is particularly important, and the evaluation of laser speckle degree by collecting speckle contrast data is an important part of verifying the effect of speckle technology

[0003] However, the commonly used speckle contrast detection methods today are based on the ideal situation where the light is completely focused on the screen or a point away from the screen, etc., but the actual In daily life, the human eye often zooms out or narrows the field of view habitually for reasons such as ensuring the integrity of the viewing screen when watching the screen, and this makes the focus of the human eye often not exactly right. Focusing on the screen, but focusing on the front and back of the screen, at the same time, this viewing method will cause the interference speckle received by the retina of the human eye to be different from the ideal state, making the interference speckle compared to the ideal state have a certain degree of enhancement or weakening

As a result, the products produced after the detection cannot achieve the expected effect.

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