Patent Number: 6,311,027

Title: Image-forming apparatus which forms images by using a developer

Abstract: An image-forming apparatus is provided with: a rotatable photoreceptor; a charging device for charging the surface of the photoreceptor to a predetermined electric potential. A device for corona discharging, the charging device has a control electrode for controlling the quantity of corona ions that are allowed to reach the photoreceptor. A latent image forming device for forming an electrostatic latent image on the photoreceptor that has been charged by the charging device by use of light irradiation. There is a developing device for developing the electrostatic latent image by using a developer; and a control voltage supply device for supplying a control voltage to the control electrode and for switching the control voltage to a plurality of stages from a low-voltage side to a high-voltage side until the surface electric potential of the photoreceptor has risen to a predetermined electric potential. This image-forming apparatus prevents carrier rise at the time of a rise of the photoreceptor surface electric potential.

Inventors: Sakita; Hirofumi (Tenri, JP), Fujita; Syouichi (Kashiba, JP), Saiko; Hideji (Kitakatsuragi-gun, JP), Tokuyama; Mitsuru (Soraku-gun, JP), Nakamura; Masatsugu (Kashiba, JP), Naoi; Hiroo (Nara, JP), Takenouchi; Kouichi (Nabari, JP)

Assignee: Sharp Kabushiki Kaisha

International Classification: G03G 15/02 (20060101); G03G 015/02 (); H01T 023/00 ()

Expiration Date: 10/30/2018