| 摘要 |
PROBLEM TO BE SOLVED: To suppress charging noise without deteriorating image by changing a charging AC frequency during image formation and maintaining a developing AC frequency at an integral multiple of the charging AC frequency. SOLUTION: An image forming apparatus comprises: a charging means 3 which charges an image carrier 2 by bringing the image carrier 2 into contact with a charging member; an electrostatic latent image forming means 7 which forms an electrostatic latent image on the surface of the charged image carrier 2; a developing means 4 which develops the electrostatic latent image on the surface of the image carrier 2; and a control means 301 which controls image formation. While a developing bias frequency is maintained at the frequency ratio of an integral multiple of a charging bias frequency (S507), the charging bias frequency is changed during the image formation (S508) based on an amount of frequency change (S504) from a central frequency (S503), which is determined in advance as a charging bias frequency, and a time interval (S505) to change the frequency. COPYRIGHT: (C)2011,JPO&INPIT |
