System and method for detecting surface defect on glass panel

Abstract

The invention provides a system and a method for detecting a surface defect of a glass panel. According to the system and the method, a single lens and a telecentric light path are combined with phase measurement deflectometry. Through setting positions of coding surface structural light display equipment, a beam splitter mirror, a to-be-detected surface of the glass panel and an image acquisition device in a space, a reflection law is satisfied. A lens is arranged between the coding surface structural light display equipment and the beam splitter mirror. Furthermore the coding surface structural light display equipment is arranged above an object space focal plane of the lens. Through computer controlling, standard N-step phase shift surface structural light which is perpendicular with each other is generated and transmitted to the to-be-detected surface of the glass panel. After image acquisition, back-end image processing equipment performs processing for obtaining modulation degree distribution, optimal gradient distribution and optimal height distribution of deformation surface structural light. The system and the method settle a problem of phase and height information inaccuracy caused by system ambiguity in defect detection by a traditional system based on the phase measurement deflectometry, and furthermore improving precision and accuracy in performing surface defect detection on the glass panel.

Description

technical field [0001] The invention specifically relates to a system and method for detecting surface defects of a glass panel. Background technique [0002] With the rapid development of information technology in recent years, glass panels are widely used in LCD liquid crystal displays, mobile phone screens, tablet computers, household appliances and other fields due to their high strength, high hardness, compression resistance, and collision resistance. The requirements have also become more stringent. [0003] The production process of glass panels includes: material cutting, CNC, grinding, polishing, ion exchange, ultrasonic cleaning, silk screen printing, baking, coating, etc. Defects may occur in all links of the production process. Therefore, defect detection of glass panels is crucial. Traditional detection methods are based on the principle of reflected light or transmitted light intensity detection, mainly including manual detection and machine vision detection....

AI Technical Summary

Problems solved by technology

However, the phase measured by the phase measurement deflection technique is not only modulated by the gradient of the object to be measured, but also by the height of the object to be measured. In the phase data obtained by demodulation, the gradient and height cannot be distinguished, that is, the so-called system multiple ambiguity, and system ambiguity can lead to errors in phase measurements

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