| 摘要 |
PURPOSE:To reduce the possibility that a bottle with a scratch flaw is detected as a defective as well as bottles with a chipping flaw and a kink flaw, by reducing a detection signal by scattered light from an inspected part which is neck of a bottle almost to zero. CONSTITUTION:Two photoelectric converting elements 2-1 and 2-2 arranged at the condensing part of an elliptic sphere mirror condenser 1 are connected to input terminals of amplifiers 5-1 and 5-2 in the opposite-polarity relation. Then, a bottle 8 is rotated and light is made incident to neck of bottle and if there is a chipping flaw, the photoelectric converting element 2-1 generates and output signal first as the bottle is rotated and then the element 2-2 generates an output with the opposite polarity; and amplifiers 5-1 and 5-2 generate out-of-phase and opposite-polarity outputs. Reflected light is scattered light in case of a scratch flaw, so the photoelectric converting elements 2-1 and 2-2 generate nearly equal in-phase output signals, which are added together by an adder 6, so its output is nearly zero to discriminate the scratch flaw from chipping and kink flaws, so that the bottle is not detected as a defective. |
