Visual inspection method of detecting flaws on optical glasses surface

A computer visual inspection method for detecting flaws on optical glasses surface was introduced. This method mainly aimed at detecting flaws such as pockmark, scratch, burr, edge damage and so on. According to the principle that bright spots and bright bands generated by the diffuse reflection of flaws under the action of side light, the flaws detection device based on reflection detection method was developed, and the work cycle of the device was less than 5 s per piece. The blackbody was creatively used to form the dark background and enhance the contrast. In the visual inspection, the total area detection method was used to detect the pockmark and scratch of glasses surface, and the edge burr detection method was used to detect the burr and edge damage of glasses edge. In the experiment, 53 pieces of 10mm diameter optical glasses were tested and the accuracy reached 100%. In the end, the detection result based on the 310 000 pixel CCD was given. According to the result, the total number of flaws on OK glasses is ≤100 (pixel), and the maximum gray value is ≤80. The total number of flaws on pockmark and scratch glasses is between 200 and 600 (pixel), and the maximum gray value is ≤210. The total number of flaws on burr/edge damage glasses is ≤100 (pixel), and the maximum gray value is between 200~255. Thus it can be seen that, the total number of flaws on pockmark and scratch glasses is obviously higher than that of flaws on burr/edge damage and OK glasses.