| 摘要 |
PURPOSE:To detect a defect of a pattern at a high speed and with high accuracy by providing >=2 optical pattern detection systems and only one pattern comparing and inspecting means. CONSTITUTION:An object 2 of inspection is scanned in a Y or an X direction at a constant speed by a table driving part 13 through a driving table 1 and pattern detection signals corresponding to cells are obtained from linear image sensors 9 and 10 in order and stored 14 and 16 as multi-value digital signals through A/D converters 22 and 23. Multi-value digital signals corresponding to cells which are one scan before are transferred to and stored in memories 15 and 17 from the memories 14 and 16 prior to said storage, so pattern defect detection processing between adjacent cells is possible at the point of the stores 14 and 16. Then, this defect detection processing is performed, positioning 19 on a detected image is performed, but a multi-value image signal is outputted from a positioning processing part 19 to a comparison processing part 20 based on the quantity of position shifting and the processing part 20 finds the difference between two many-valued image signals and makes a decision 21 on the difference by using a proper threshold value, thereby outputting the difference as a defect when the difference is larger than the threshold value. |
