Optical dot matrix projection module and depth camera

Abstract

The invention discloses an optical dot matrix projection module and a depth camera. The optical dot matrix projection module comprises: a light source configured to supply a preset first spot pattern;a collimating lens arranged at a light-emitting side of the light source to receive the first spot pattern and modulate the first spot pattern to a collimation first spot pattern; a Dammann grating arranged at the light-emitting side of the collimating lens to receive the collimation first spot pattern and perform copy and extension on the collimation first spot pattern to obtain a second spot pattern; and a projection lens arranged at the light-emitting side of the Dammann grating to receive the second spot pattern and project the second spot pattern to a target scene to be measured according to a predetermined ratio. The Dammann grating is employed to perform copy and extension on a dot matrix to make the diffraction intensity uniformity of the optical dot matrix projection module better, and therefore, the depth camera has a relatively uniform depth measurement index so as to provide a basic parameter value with a higher freedom degree and more accuracy for the subsequent application development.

Description

technical field [0001] The invention relates to the technical field of three-dimensional depth measurement, in particular to an optical lattice projection module and a depth camera. Background technique [0002] The 3D depth measurement technology can collect the depth coordinate information of the scene target, providing additional data processing freedom for the back-end development. With the popularization of mobile terminal devices and intelligent interactive devices, three-dimensional depth measurement technology has increasingly become the core technology of the new generation of human-computer interaction, and has a wide range of applications in industrial inspection, security retail, somatosensory games, mobile payment and biomedicine. Application prospect. [0003] Speckle structured light technology is a widely used 3D depth measurement solution. It uses coded random, pseudo-random or regularly arranged spot light clusters to project to a specific space scene, an...

AI Technical Summary

Problems solved by technology

However, the intensity uniformity between DOE diffraction orders in the current commonly used projection modules is still insufficient. The projected light spots often have a large difference in intensity between the central area and the edge area, which affects the overall depth acquisition accuracy of the scene, especially in measurement. When objects are far or close, the influence of intensity non-uniformity is more prominent, which greatly restricts the development of 3D depth measurement technology

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