| 摘要 |
PURPOSE:To prolong the life of the photosensitive body of an image forming device where a contour image forming unit is fitted by actuating a 2nd electrostatic charger which adds opposite polarity charges to a latent image for a necessary time in accordance with the acting time of a 1st electrostatic charger. CONSTITUTION:After the photosensitive drum 1 is uniformly electrified by the 1st electrostatic charger 2 which is a main electrostatic charger, the latent image is formed on the drum 1 by exposing the image. And the scorotron 11 of the 2nd electrostatic charger which is a subcharger controlled by the contour forming unit adds the opposite polarity charge to a latent image part so as to form the contour image. The electrification acting time by the scorotron 11 is set below the electrification acting time by the charger 2. And unnecessary charge is prevented by executing the electrification action for a necessary time only to a necessary part and electrified charges are reduced. As a result the life of the photosensitive body of the image forming device where the contour image forming unit is fitted can be prolonged. |
