A Method for Generating Programmable Analog Grating with Large Depth of Field

Abstract

The invention discloses a method for generating a programmable analog grating with a large depth of field. The laser beam emitted by a laser is focused and collimated by a collimator lens to obtain a collimated Gaussian laser beam that meets the requirements; The laser beam is incident on the MEMS vibrating mirror through the circular aperture; the beam is reflected to the surface of the object to be measured through the MEMS vibrating mirror; under the control of the sinusoidal current signal generated by the drive board, the laser performs sinusoidal modulation on the brightness of the laser beam; the MEMS vibrating mirror is driven Under the excitation of the driving signal generated by the board, it makes a two-dimensional rotation, thereby driving the laser beam to scan and generate a raster image. Change the period and phase of the laser driving signal to obtain grating patterns with different periods and phases. The grating produced by the invention has the advantages of programmable digital grating and high resolution of physical grating. In addition, the depth of field of the resulting grating has been expanded by more than 10 times, and the measurement range has been greatly improved.

Description

Technical field: [0001] The invention belongs to the field of optical detection, and relates to a method for generating a grating, in particular to a method for generating a programmable analog grating with a large depth of field. Background technique: [0002] As a bridge between the real world and the virtual digital world, 3D measurement technology plays an increasingly important role. It is widely used in many industries such as industrial inspection, medical health, digital entertainment, e-commerce, cultural relics protection, etc. Due to the advantages of non-contact, high precision and fast speed, optical three-dimensional measurement has developed into the most important technology in the field of three-dimensional inspection. Optical three-dimensional measurement can be divided into two types: active and passive. Passive measurement methods are represented by stereo vision. However, the stereoscopic vision technology system is simple in structure and low in cost...

AI Technical Summary

Problems solved by technology

But the disadvantage of physical grating is that the projection pattern is fixed and the use is not flexible

In addition, no matter the analog pattern of digital light projection technology or physical grating projection, it is an image of the film, which is an imaging relationship, so there is a limitation of depth of field

Greatly limits the range of 3D measurements

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