METHOD AND APPARATUS FOR APPEARANCE INSPECTION

摘要

PROBLEM TO BE SOLVED: To provide a low-cost and practical appearance inspection apparatus which can quickly inspect the presence/absence of defects of objects to be inspected in a simple constitution without analyzing images. SOLUTION: While an object W to be inspected having a circular or nearly circular outline such as a polygon or the like is let to roll by its weight with an outer circumferential face pressed in contact with an inclined face 1a, a light from an illumination lamp 2 is cast and a light reflected or scattered by the object W is detected by an optical sensor 3. At the same time, an output of the optical sensor 3 is compared by a comparing means 5 with a reference voltage, whereby scattering or absorption of the light due to defects present in the object W is detected to inspect the presence/absence of the defects. Since the defects move up and down while being translated by rolling the object W, the scattering or absorption of the light due to the defects can be surely detected even with the use of the optical sensor of a narrow view field.