| 摘要 |
PURPOSE:To perform foreign matter detection based upon variation in electric conductivity due to local compression of a pressure conductive rubber sheet caused by foreign matter sticking on a surface to be inspected by pressing the pressure conductive rubber sheet uniformly against the surface to be inspected. CONSTITUTION:An inspection plate constituted by sticking a comb tupe detection electrode 3 on a parallel plane pressure plate 2 and adhering the pressure conductive rubber sheet 4 to the detection electrode 3 is pressed uniformly against the smooth surface 1 to be inspected. If foreign matter 6 sticks on the surface 1 to be inspected as shown in a figure (C), the rubber sheet 4 abuts on the foreign matter 6 strongly at the part and the rubber sheet 4 is compressed locally, so the compressed part 7 becomes conductive to short-circuit part of the comb type electrode 3. A proper potential is applied between both terminals of the lead wire 5 of the comb type electrode 3 and variation of a current of voltage due to the short circuiting is detected to detect the presence of the foreign matter. |
