| 摘要 |
PURPOSE:To raise accuracy of defect detection to a large extent by providing a first optical system that scans spot light on the surface along the axis of an object to be inspected and a second optical system that makes an image of said object to be inspected and at the same time changes the luminous intensity into electric signal. CONSTITUTION:A defect detecting device is provided with a first optical system (luminous optical system) that scans light on the surface along the axis of an object 11 to be inspected and a second optical system (light receiving system) that makes an image of said object 11 to be inspected and at the same time changes its luminous intensity into electric signal. Here the luminous optical system that comprises a rotating multi-face mirror 3 and the light receiving optical system that is constituted by a lens 4, photo-electric converter 5 and slit 6 are provided on a plane that includes the object 11 such as a welding rod. With this arrangement, difference in the diameters of welding rod and the range of light reflection that varies in relation to the difference in diameters of welding rod that are the objects of inspection or accuracy of the rotation can be held narrow, and thereby the accuracy of defect detection can be raised to a large extent. |
