| 摘要 |
PURPOSE:To eliminate the waste of change of a photosensitive body, which can be still usable, by detecting malfunction of a current value flowing in a charged roller to judge a lifetime of the photosensitive body. CONSTITUTION:A charged roller 2, a developing unit 3, a copying and peeling unit 4, a cleaner 5, and an electricity removing lamp 6 are arranged in this order in the periphery of a photosensitive body 1 so as to face to each other. The charged roller 2 is arranged so as to contact to the photosensitive body 1, and the constant voltage is supplied. The photosensitive body 1 is grounded, and a circuit is formed between the charged roller 2 and the photosensitive body 1. When the photosensitive body 1 is deviated and the charged potential of the surface of the photosensitive body 1 is raised, a current value flowing in the charged roller 2 is raised. Lifetime of the photosensitive body 1 is judged by measuring the current value of the charged roller to be used practically. The end of lifetime of the photosensitive body can be thereby judged at the time when the condition of the photosensitive body l becomes the condition that the image quality itself is influenced badly, and the waste of change of the photosensitive body 1, which can be still used, is eliminated. |
