Bent glass subsurface defect detection method based on dark-field illumination

Abstract

The invention discloses a bent glass subsurface defect detection method based on dark-field illumination. The method comprises the following steps: vertically irradiating a polarizing prism via the laser generated by a laser light source to obtain a P wave and a S wave, in which emitting directions thereof are vertical to each other; shielding the S wave, irradiating the bent glass to be tested via the P wave after beam expansion, wherein the light of the P wave generating total internal reflection in the bent glass to be tested forms a standing wave with the P wave to perform first time dark-field illumination on the bent glass to be tested; focusing a subsurface of the bent glass to be tested under the first time illumination, adjusting the incidence direction of the P wave according toa focused image, and fixing the P wave; shielding the P wave, making the light path of the S wave coincide with that of the P wave, irradiating the bent glass to be tested via the S wave after beam expansion, wherein the light of the S wave generating total internal reflection in the bent glass to be tested forms a standing wave with the S wave to perform second time dark-field illumination on thebent glass to be tested; and collecting an image containing a bent glass surface defect under the second time illumination. According to the bent glass subsurface defect detection method disclosed bythe invention, twice illumination is performed to perform non-destructive detection on defects in the bent glass, and the detection efficiency and the detection contrast are improved.

Description

technical field [0001] The invention belongs to the technical field of visual inspection, and more specifically relates to a detection method for subsurface defects of curved glass based on dark field illumination. Background technique [0002] As a non-metallic material with high smoothness, glass has a wide range of applications, but it is very easy to cause damage during production and processing, not only surface damage, but also internal damage has a great impact on the service life of the material . [0003] The detection methods of internal damage are usually divided into destructive measurement and non-destructive measurement. In recent years, due to the rapid development of computer technology, non-destructive measurement has been widely used due to its non-contact, non-destructive, repeatable and many other advantages. At present, the existing non-destructive measurement technology is mostly used in the internal defect detection of planar objects, and there is les...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to provide a detection method for subsurface defects of curved glass based on dark-field illumination, aiming to solve the problem of low efficiency caused by the prior detection technology relying on manual experience and subjective observation

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