Non-contact conoscopic holography measurement system

Abstract

The invention discloses a non-contact conoscopic holography measurement system. The non-contact conoscopic holography measurement system comprises a laser system, a light reflection system, a light receiving system and a polarization splitting prism, wherein the laser system emits laser beams, the light reflection system collects the laser beams passing through an beam expanding and collimating system to one point of a measured object, and the light receiving system collects returned light. The light reflection system comprises a diaphragm, a lamda / 4 slide and an objective lens, wherein the diaphragm, the lamda / 4 slide and the objective lens are arrayed along a forwarding link of the laser beams. The light receiving system comprises a birefringent crystal, a polarizing film and an optical picture taking device in a light propagation path, wherein the optical picture taking device is connected with a computer. The laser system comprises a laser source and a lamda / 2 slide, and the beam expanding and collimating system below the laser source comprises a beam expander and a collimating lens. The non-contact conoscopic holography measurement system is reasonable in design, simple in structure and suitable for acquiring surface height information of common industrial parts 101 mm-102 mm in size; the digital image processing technology and the optical hologram technology can be comprehensively utilized, and the product measurement precision is further improved.

Description

technical field [0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to a non-contact conoscopic holographic measurement system based on a phase-height method. Background technique [0002] At present, with the continuous expansion of the industrial measurement field and the continuous improvement of the requirements for measurement accuracy and measurement speed, the traditional contact measurement has been unable to meet the needs of the industry. Non-contact measurement has become a hot spot in the field of measurement due to its good accuracy and real-time performance. In terms of optics, non-contact measurement methods mainly include binocular, multi-eye vision measurement, triangulation measurement, laser scanning measurement and digital holographic measurement, etc. Conoscopic holography is one of the digital holographic measurement methods. It is a polarized light interferometry method based on crystal optics. Its...

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Problems solved by technology

However, the current measurement methods for conoscopic holographic systems at home and abroad are almost all using the light intensity information of the hologram to obtain the measured object, such as the international patent No. The angle between the polarization axis of the wave plate and the optical axis of the wave plate realizes the phase shift, and then changes the light intensity transfer function of the system, and then obtains the height information of the measured surface according to the light intensity information of multiple phase-shifted holograms; but this light intensity - The disadvantage of the height method is that it is more sensitive to the fluctuation of the light source, and there is a phase shift error

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