METHOD FOR DETECTING SCREWED STATE OF CAP

PROBLEM TO BE SOLVED: To correctly detect a screwed state of a cap by securely discriminating between a mark of a claw of a bottle holding jig, put on a lower face of a support ring, and a bottle check mark, in an inspection method for detecting a screwed state of the cap on a bottle by picking up the image of a cap check mark and the image of the bottle check mark on the upper face of a transparent support ring with a single camera. SOLUTION: A recess or projection whose maximum circumferential width is 3 to 8 mm is formed on the upper face of the peripheral edge of the transparent support ring of the bottle. A pair of edges of the recess or the projection as viewed from above the bottle cap assemblage, which extend in the direction of the center of the cap from the peripheral edge of the support ring are combined. The combination of the edges is programmed in an image processing device so as to be recognized as the check mark for a screwing angle to the bottle. COPYRIGHT: (C)2004,JPO