Lens defect detection method based on stripe deflection

Abstract

The invention relates to a lens defect detection method based on stripe deflection. The method comprises the steps that a lens is placed above a screen, and a camera performs shooting above the lens;a shot image is utilized to make the screen display all white, and extraction of a region of interest in the lens is extracted through threshold segmentation; the screen is utilized to project sine stripes, and the camera takes a picture of the stripes refracted by a tested lens by aid of a telecentric lens; and defect recognition is performed in the region of interest, phase calculation is performed through a three-step phase shift method to acquire phase information, whether a phase jump exists or not is judged through calculation, and defect recognition and positioning are realized.

Description

Technical field [0001] The invention relates to a method for detecting micro lens defects Background technique [0002] Lens, as the most commonly used optical device, is widely used in industrial production and life. With the continuous expansion of demand, the lens has achieved mass production and automated production. However, in the processing process, processing defects such as water lines and bubbles are inevitable. Therefore, before the lens is officially put into use, it is necessary to introduce a detection process to avoid it affecting the final working performance of the equipment and causing irreparable losses. However, the problem is that, first of all, the lens is a transparent material, and it is often difficult to directly capture defects. Secondly, lens defects are often extremely small in size, and it is difficult to detect them by normal means. [0003] In the past, detection was often achieved through manual detection. However, manual detection has the foll...

AI Technical Summary

Problems solved by technology

However, in the process of processing, there are inevitably processing defects such as water marks and air bubbles.

Therefore, before the lens is officially put into use, it is necessary to introduce a testing process to avoid affecting the final performance of the device and causing irreparable losses

But the problem is that, first of all, the lens is a transparent material, and it is often difficult to directly photograph the defects

[0004] (1) From the perspective of production process and cost, manual inspection will introduce unnecessary additional links to production assembly, which is not conducive to the realization of fully automatic production assembly, and will also increase labor costs

[0005](2) From the perspective of production efficiency, the speed of manual inspection is relatively slow, and online inspection cannot be realized

[0006](3) From the perspective of testing results, the reliability of manual testing cannot be guaranteed, and it is easy to introduce human error

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