Patent ID: 7158733
Filing Date: 2007-01-02
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image bearing body which can bear an electrostatic image; a bias member which is disposed opposite to said image bearing body and to which a predetermined bias is applied; bias means which applies the predetermined bias to said bias member; surface potential detection means which detects a surface potential at said image bearing body, said surface potential detection means including a detector portion which generates a signal according to a potential difference between said detector portion and a surface of said image bearing body, a detection bias generation portion which applies a bias to said detector portion according to a signal from said detector portion such that a potential at said detector portion becomes equal to a surface potential at said image bearing body, and a potential detection portion which detects the bias generated by said detection bias generation portion, wherein said potential detection portion is also used for detection of a bias value which said bias means applies to said bias member; and control means which controls said bias means based on a detection result of the bias value which said bias means applies to said bias member, the detection result being obtained by said potential detection portion.