| 摘要 |
PURPOSE:To provided an optical defect detector which automatically detects a defect included in a pattern, by a method wherein an optical axis of a receiving system is inclined so that it approaches a direction of a stripe more than a direction extending perpendicularly to a pattern surface. CONSTITUTION:Output signals of light receivers A1 9-1, and A2 9-2 and A3 9-3 are inputted to an angle signal circuit 16, a positive or a negative angle signal is produced by the output signals, and a computer 17 issues a command to drivers 21 and 22 via a control circuit 20 according to a previously determined program to perform a scanning in an X-direction and a Y-direction of a laser projecting light. If a spot of the laser projecting light so scanned passes through a defect spot of a stripe pattern, a scattered light enters a photomultiplier tube 15, and the detecting signal of the photomultiplier 15 is inputted to a signal processing part 24 via a preamplifier 23. After the signal processing part 24 conducts a processing such as a schematic classification of a defect degree by means of a crest value of a defect signal, it is inputted to the microcomputer 17, which, in turn, detects a defect of a stripe forming a stripe pattern. |
