| 摘要 |
PURPOSE:To automatically and surely detect an irregular reflection part without generating misdetection by detecting whether light having an oscillation direction different from that of incident light is contained in reflected light or not. CONSTITUTION:A sheet of laver 1 carried by upstream side conveyers 2a, 3a is exposed to light from the upper part by the 1st halogen lamp 7 and a reflec tion pattern concretized by the reflected light from the exposed part is read out by the 1st camera 5. The read reflection pattern is converted into an electric signal and processed by a camera controller. The pattern is compared with a prescribed pattern, and when both the patterns are identical, foreign substances such as seeweed, the feather of a sea bird and paper having high brightness are not included. If a foreign substance having high brightness is stuck to the surface of the laver 1, the reflection pattern is made irregular, detecting the adhesion of the foreign substance to the laver 1. |
