Digital grating and physical grating combined tiny object surface three-dimensional measurement system

Abstract

The invention provides a digital grating and physical grating combined tiny object surface three-dimensional measurement system which is composed of a computer, collimated laser beams, a digital micromirror device (DMD), digital gratings, physical gratings, three lens groups, an object to be measured, an object table and a CCD image detector. The computer generates light and dark graphs to be transmitted to the DMD. The collimated laser beams irradiate the DMD to be reflected and then generate the digital gratings through the first lens group, and then the digital gratings reach the surface of the object to be measured on the object table through the second lens group. The digital gratings modulated by the object to be measured are imaged on the surface of the physical gratings through the second and third lens groups. The digital grating and the physical gratings are superposed at a certain gap, and multiple times of diffraction occurs so that the amplified Moire interference fringes are formed and then imaged on the CCD image detector, and image acquisition and processing are performed through the computer so that three-dimensional information of the object to be measured can be acquired. The system is high in precision, easy to operate and high in anti-interference capacity and has high application value.

Description

technical field [0001] The invention relates to a three-dimensional measurement system for the surface of a tiny object combined with a digital grating and a physical grating, and belongs to the field of measurement technology. Background technique [0002] In the field of industrial design inspection and micro-nano processing, we can only obtain two-dimensional information of the measured object through traditional optical microscopes or scanning electron microscopes. However, in some specific occasions that require quantitative analysis, such as real-time detection of electronic components, three-dimensional size acquisition of micro-nano devices, etc., the traditional two-dimensional information measurement cannot meet the measurement requirements, and the height beyond two-dimensional information Or depth information measurement is particularly important. [0003] In recent years, non-contact measurement has been widely used for its advantages of fast measurement speed,...

AI Technical Summary

Problems solved by technology

However, in the measurement of tiny objects, its light field projection and imaging system structure are likely to have a certain impact on the measurement accuracy

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