| 摘要 |
PURPOSE:To improve the detecting ability principally for a band-shaped defect, etc., by employing an image pickup camera as a camera which has such a innear array image sensor that the longitudinal-lateral shape ratio of one unit element is >=(1:50). CONSTITUTION:The image pickup camera is used as the camera which has the linear image array image sensor 1a whose longitudinal-lateral shape ratio of one unit element 6a is >=(1:50). The image of an element 6a of the sensor 1a corresponds to one unit element equivalent visual field 7 on a running sheet 3 to be inspected. Defects 4 and 5 which are long in a scanning direction are added optically. The accumulation of errors due to electronic addition and a decrease in defect deciding ability are eliminated. Consequently, the detecting ability mainly for the band-shaped defect, etc., is improved. |
