SHEET DETECTOR FOR ROTATING BODY

摘要

PURPOSE:To detect both a transparent sheet and a black sheet and to prevent a flaw on the surface of the sheet by detecting the presence of electric conductivity between the 1st and 2nd electrodes. CONSTITUTION:A groove 1c is formed at a position of each projection of claws 5a-5j on the surface of a drum 1 and an electrode plate 4 is imbedded in the slot 1c. The electrode plate 4 is arranged in parallel along the axis of the drum 1 and the surface is aligned to be continuous to the surface of the drum 1. A printed board 4a is fixed onto the surface of the electrode plate 4. In total 150 electrode patterns 19n (n=1-150; only a part of them is shown) are printed on the printed board 4a at positions corresponding to projections of the claws 5a-5j. The conduction among the claws 5a-5j and the electrode patterns 19n (n=1-150) is checked to detect whether or not any sheet exists among them. The presence of the sheet is detected respectively at 150 divisions in the axial direction on the drum 1.