| 摘要 |
PURPOSE:To enable easy distinction of a pseudo-defect by executing position alignment of optical reading devices again only when the number of discriminated defects is a set number or above. CONSTITUTION:In an image 41 out of read images 41 and 42, an image of a defect 45 is read. In a comparison image 5 showing a difference between the images 41 and 42, patterns 43 and 44 read at the same positions on the images are canceled and the defect 45 read only in the image 41 is made to be alone. Accordingly, the defect 45 can be discriminated on the basis of the image 5. Information of the coordinates of the discriminated defect 45 on the image 5 is discriminated on the basis of images of light-sensing areas read sequentially and is displayed 6. In the case when the number of the discriminated defects 45 is a number set beforehand or above, the display 8 makes judgement as to whether it is above or below, and when the number is above the preset number, relative position alignment of two optical reading devices 10 and 20 is executed again. Then the display 6 is made free from that the defects 45 in a larger number than a set value are shown on one horizontal line. |
