| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus preventing soiled printing occurring due to causes such as decrease of charging ability by deterioration of an charging unit or attachment of toner, deterioration of an image carrier and abnormally charged toner. <P>SOLUTION: An electrophotographic type image forming apparatus includes a conveying part holding a transfer medium with the image carrier to convey it, a detection part detecting density of developer attached to a surface of the conveying part and a voltage control part controlling charging voltage supplied to the charging unit. The voltage control part determines the charging voltage supplied to the charging unit based on the detected density of the developer detected by the detecting part when the developer is attached to the surface of the conveying part from the image carrier when a second charging voltage with a prescribed potential difference from a first charging voltage which is to be a reference is applied. <P>COPYRIGHT: (C)2008,JPO&INPIT |
