| 摘要 |
PURPOSE:To eliminate the erroneous operation of a photosensitive drum by a paper sheet winding detection device to increase the service life of the photosensitive drum by providing a means to identify the damage part on an OPC film and a blank sheet of paper. CONSTITUTION:A detector 11 is close to a photosensitive drum 15, mounted opposedly to each other, and comprises a light emitting element 25 and light receiving elements 26 and 27. The rediation beam from the light emitting element 25 enters the photosensitive drum 15 at a specified angle, and the diffused reflection light is detected by the light receiving element 26 positioned at a specified angle relative to the photosensitive drum 15, and the direct reflection light is detected by the light receiving element 27. Then set-solid blank sheet winding is detected by the fact that a direct reflection beam output DIRECT-P signal reduced below the set value of a slice level 1. Also blank sheet winding is detected by the fact that a direct reflection beam output DIRECT-P signal is reduced below the set value of a slide level 3 and a diffused reflection beam output DIFFUSE-P signal is increased over a specified value of a slice level. |
