| 摘要 |
PURPOSE:To suppress the probability of misjudgment to a low level at the time of judging a defect by limiting the necessity of indicating the existence of an object to be detected over the whole range of picture data only to an inside tolerance limit area and limiting the necessity of indicating the absence of the object to be detected only to an outside telerance limit area. CONSTITUTION:A CPU 22 being a judging means compares picture data store in the 1st memory 18 with position data stored in the 2nd memory 20. Only when the picture data indicates the existence of an inner-read over the whole inside tolerance limit area and the absence of the inner-read over the whole outside tolerance limit area, the coincidence of the shape of the inner-read with the shape of a virtual inner-read having an ideal shape is judged and the other case is judged as discrepancy. Even when a null part or an image caused by noise or dust is generated in a position other than the inside and outside telerance limit areas, no influence is exerted upon the judgement of pattern coincidence. |
