| 摘要 |
PURPOSE:To prevent a detecting malfunction caused by adhesion of a toner, etc., to detect exactly running of a photosensitive body, and also to simplify a constitution by providing a detecting sensor for detecting the running of the photosensitive body, on the inside circumferential surface part of a belt-shaped photosensitive body. CONSTITUTION:A belt-shaped photosensitive body 20 is endlessly constituted, and is extended between rollers 21, 22, and a developing process is executed on its outside circumferential surface. In about the center of the inside circumferential surface of the photosensitive body, for instance, marks (a), (b) and (c), etc. by black painting are provided, and a photosensitive body position sensor 24 for detecting them is provided by using a reflection type opitcal sensor which has constituted, for instance, a light emitting device and a photodetecting device as one body in the inside. Accordingly, comparing with a detection of running of the photosensitive body by utilizing the surface of the photosensitive body, a detecting malfunction caused by contamination, etc. by a toner can be prevented, and also the constitution is simplified. |
