Method of and apparatus for detecting external defects of a circular sealing member

摘要

A method and apparatus for detecting external defects of a circular sealing member by means of irradiation of detecting rays. A laser detecting ray for scanning is irradiated to a surface of the circular member which is rotated at the detecting section, and reflected light from the surface is received to be converted into electric signals so that the surface defects can be optically inspected. In case there is a defective surface, an irregularly reflected light can be received and based on an extracted signal a defective surface can be easily discriminated from the normal surface. The circular member is delivered one after another to the detecting section wherein discrimination is automatically made whether the circular member is non-defective or defective by means of rotation, irradiation of detecting rays and defect detecting action.