| 摘要 |
PURPOSE:To realize detection for the defect which is parallel to the traveling direction for the optical scanner by setting the angle formed by the traveling direction of the measured plate and the scanning direction of the light source to 80 deg. + or -5 deg.. CONSTITUTION:In the device consisting of projector 1 possessing the coherent light source like the laser beam and light receiver 3, the scanning is given to scanning direction f of projected light l from projector 1 so that the angle of theta may be secured to the traveling direction of measured plate 2. The angle theta is set properly to 85 deg. + or -5 deg.. As a result, the sensitivity can be obtained even to defective part d' which is parallel to the traveling direction, i.e., in the longer direction and cannot hitherto be detected by the conventional method. |
