IMAGE FORMING DEVICE

• Main Authors: HATANAKA EISAKU, NAGAYAMA KATSUHIRO, NAOI HIROO, TOKUYAMA MITSURU, ITOYAMA MOTOYUKI, TAKEI YUICHIRO
• Format: Patent
• Language: English
• Published: 10.01.1997
• Edition: 6
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PURPOSE: To obtain an image excellent in halftone reproducibility by obtaining grid bias correction amount in accordance with developing bias correction amount and correcting grid bias so that the change of halftone potential on the surface of a photoreceptor at the time of correcting the grid bias is restrained. CONSTITUTION: In the case of correcting the grid bias of an electrifier 19, the grid bias correction amount is obtained based on a correction table previously stored, whereby the grid bias is corrected. The correction table stores a correction coefficient(<1) by which the developing bias correction amount set in accordance with the developing bias correction amount is multiplied en bloc so that the increase of the halftone potential on the surface of the photoreceptor 18 at the time of correcting the grid bias may be restrained. The larger the developing bias amount becomes, the larger the correction coefficient is made. Therefore, the correction coefficient is selected in accordance with the developing bias correction amount and the grid bias correction amount is obtained by multiplying the developing bias correction amount by the correction coefficient.