| 摘要 |
PURPOSE:To make the picture density uniform and make the device small-sized and low-cost, by constituting an exposure part so that the pre-exposure and the erase exposure are performed in accordance with the size of a transfer material by a light source which is divided into plural regions in the breadthwise direction of a photosensitive drum. CONSTITUTION:A split light source 3 arranged between a charging device 2 and an image exposing device 4 is a bar-shaped light source extending in the breadthwise direction of a photoreceptor 1 and is divided into 8 regions 1-8 in the longitudinal direction. In case that the size of a transfer material is B6 when the light source 3 is used as an erase light source, only the region 2 is extinguished, and other regions 1 and 3-8 are lit, and the surface of the photoreceptor 1 corresponding to lighting regions is exposed to the light and loses the electric charge, and an electrostatic latent image of size B6 corresponding to the region 2 is formed on the photoreceptor 1. Similarly, electrostatic latent images corresponding to sizes of transfer materials are formed by selective lighting. In case of the pre-exposure, regions corresponding to the drum width are lit. Thus, the image density is made uniform, and the device is made small-sized and low-cost. |
