| 摘要 |
PURPOSE: To accurately inspect a bearing ball by relying upon the diameter of the ball by detecting the defect of the convex surface of the ball which regularly reflects light in a normal state as the contrast pattern of the defect in response to the reflected light when the surface has the defect. CONSTITUTION: The spheric convex surface of a bearing ball is irradiated with diffused light 102 from a diffused-light source and the scattered light shown by the arrow 104 reflects the incident light 104 of the ball being tested. When the ball has a defect 132, the light 102 is scattered or absorbed by the defect 132 and a contrast pattern which is different in brightness from that displayed when the ball has no defect is displayed on a monitor which displays pictures stored in a means 118. When a picture element signal level is generated or changes, a detector 124 responds to the signal of an allowable/unallowable defect deciding means 126. Then a separating means 128 separates allowable defects from unallowable defects. Therefore, the bearing ball can be inspected accurately by only relying upon the diameter of the ball. |
