| 摘要 |
PURPOSE:To detect principally a band-shape defect which can not be detected before by employing an image pickup camera as a camera which has such a linear image sensor whose longitudinal-lateral shape ratio of one unit element is >=(1:50) and providing a swing and tilt mechanism to its sensor fitting part. CONSTITUTION:The image pickup camera is used as the camera which has the linear array image sensor 1a whose longitudinal-lateral shape ratio of one unit element 6a is >=(1:50). The swing and tilt mechanism is provided to the fitting part of the sensor 1a. The image of an element 6a of the sensor 1a corresponds to a unit equivalent visual field 7 on a running sheet 3 to be scanned. 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. When the position of the sensor 1a is FF, a focusing position is E'F' because of the swing and tilt mechanism and the focus is obtained on the sheet 3. Consequently, the detection of principally the band-shaped defect which can not be detected before is enabled. |
