| 摘要 |
PURPOSE:To enable to detect all faults on the object to be inspected with high accuracy by a method wherein a multilevel fixed level binary circuit is added by a floating level binary system circuit. CONSTITUTION:In case faults exist on an object to be inspected, an image pickup signal from an image pickup system 7 becomes a signal a in an amplifier 9, enters a delay unit 13 and is output from the unit 13 as an b signal. An attenuator 15 outputs a C signal and an attenuator 17 outputs a d signal. On this account, a comparator 19, a binary signal f is obtained. The NAND conditional signals j, k of the aforementioned binary signals e, f and the output signals h, i of flipflop 21, 23 are as shown in (H), and (I) and further, the output j of a NAND circuit 25 contains two pulses corresponding to faulty signals S5, S7 and the output k of a NAND circuit 27 contains two pulses corresponding to faulty signals S5, S6. Whereas, faulty signals are not detected in a multilevel fixed level system inspection circuit 31 and the NAND conditional signal of the output m of a NOT circuit 33 and the output j, k of NAND circuits 25, 26 is an n. In this way, discrimination of fault is performed. |
