| 摘要 |
PURPOSE:To simulate an attenuation characteristic until the time required for a mainly electrified area reaches a developing part, by operating a transfer electrifier under the same condition as a main electrifier, and measuring its electrified potential. CONSTITUTION:An angle alpha at which a photosensitive drum 20 rotates before reaching a developing position B from a main electrified position A, and an angle alpha' extending from a transfer position E to a potential sensor position D are set equal to each other. A transfer electrifier 27 is operated by the same voltage as a main electrifier 22, its electrified potential is detected by a potential sensor 32, and in accordance with its detecting value, the output of the main electrifier 22 is controlled. The potential sensor 32 can control a main electrification intensity correctly without being influenced by the attenuation characteristic of the photosensitive body because the potential of a mainly electrified photosensitive surface 21 is attenuated, reaches a developing device 25, and is comparable to the measurement of the potential of a part on which a toner image is formed. |
