| 摘要 |
PURPOSE:To shorten an initial picture forming period and to prevent unnecessary developer from attaching to a picture carrier by electrifying the picture carrier for a prescribed period before the operation of an optical polarizing means is stabilized after it has started and performing pre-electrification. CONSTITUTION:When the operation starts, a sleeve 21, a photosensitive drum 11 and a rotary polygon mirror 27 rotate, and an electrifying charge 15 pre- electrifies the drum 11. When the leading edge of the electrified photosensitive body reaches a developing position at time T2, a developing voltage is applied to the sleeve 21, which makes just one turn and reaches an electrifying position. Then pre-electrification ends. At time T1 a laser diode oscillator 25 starts, at the time T2 the application of the developing voltage is stopped, and the charger 15 resumes electrification. The oscillator 25 whose operation is stabilized and the polygon mirror 27 form an electrostatic latent image on the photosensitive body. When the body reaches the developing position, the developing voltage is again applied to the sleeve 21 to supply the developer. Compared with a conventional method, the pre-electrifying period To can be shortened, and moreover the developer can be reduced. |
