| 摘要 |
PURPOSE:To miniaturize an image forming device and to reduce the cost of the device by detecting whether a photosensitive body is present or absent with the output signal of a density sensor when a power source switch for enabling image formation on the photosensitive body is turned on. CONSTITUTION:When the power switch 51 for enabling the image formation on the photosensitive body 1 is turned on, a photosensitive body detecting means (CPU) detects whether the photosensitive body is present or absent with the output signal of the density sensor 53. When the power source 51 is turned on, the photosensitive body detecting means (CPU) compares the level of the output signal of the density sensor 53 with a reference level to detect whether the photosensitive body is present or absent according to the comparison result. Consequently, the density sensor 53 can be used in common to detect whether the photosensitive body is present or absent, and the device is miniaturized and the cost can be reduced. |
