Process method for accurately detecting micro-defects on surface of large-diameter element

• Main Authors: LIAO WEI, YUAN XIAODONG, ZHANG CHUANCHAO, WANG HAIJUN, ZHAO LINJIE, CHENG JIAN, YIN CHAOYANG, CHEN MINGJUN, ZHENG WANGUO
• Format: Patent
• Language: Chinese; English
• Published: 01.03.2022
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

The invention discloses a process method for accurately detecting surface micro-defects of a large-aperture element, relates to the technical field of engineering optics, and aims to solve the problem of low positioning accuracy of surface defect detection of the large-aperture element in the prior art. According to the technical key points, the method comprises the following steps: carrying out line-by-line and column-by-column mobile scanning on a preset scanning area on the surface of an element in a dark field environment, and acquiring a plurality of sub-aperture images at a plurality of preset photographing positions; and processing the plurality of sub-aperture images to obtain positions and actual sizes of a plurality of defect areas on the surface of the element. According to the method, the dark field image of the surface of the large-aperture element is acquired in a scanning and photographing mode, and surface defects are accurately extracted through image processing. The method provided by the in