METHOD FOR POSITIONING CAMERA AND SURFACE IMAGE FORMING DEVICE FOR OBJECT OF SCRATCH INSPECTION

摘要

PROBLEM TO BE SOLVED: To eliminate the adjustment of a camera, which forms surface images of an object of scratch inspection, to an angle of little brightness variation affected by conditions of the object as well as to acquire good surface images. SOLUTION: A lighting device 13 to illuminate an object of scratch inspection 11 is placed at any position. Brightness of the illuminated object having mirror surface is measured from various directions to form an envelope 15 of the first brightness vector. Brightness of the illuminated object having rough surface is measured from various directions to form an envelope 16 of the second brightness vector. The direction of the line connecting the intersection 18 of these two envelopes with the illuminating position 10 of the lighting device 13 is determined as the direction of the position of the camera.