| 摘要 |
PURPOSE:To detect the defect of an object to be inspected which has a circular edge form, by irradiating the light beam to the object to be inspected and detecting the scattered beams of the light beam which are radiated in the directions excepting the forward reflecting direction. CONSTITUTION:An object 2 to be inspected which has a circular edge form is turned by a rotary driving device 1 toward an arrow mark and in a certain speed. A laser beam 6 given from a light source 5 is irradiated via a collimator lens 7 to the circular groove part of the object 2 on a rotary table 3. For instance, the beam 6 is irradiated with an angle 45 deg. on the tangent line at the groove part. Thus the beam 6 has a forward reflection as long as the groove part has no defect. If the groove part has some defect, the beam 6 is scattered at the defective area. These scattered beams are formed into an image at a pinhole 9 via a lens 8. The scattered beams are converted into the electric signals in accordance with the light volume through a photoelectric transducer 10 to be displayed at a display 14. |
