Patent ID: 7873291
Filing Date: 2011-01-18
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: an image bearing member including a travelling moving surface; a charging device comprising a charging member facing the moving surface of the image bearing member, the charging device uniformly charging the moving surface of the image bearing member to form a latent electrostatic image thereon by applying a charging bias in which an AC voltage is overlapped with a DC voltage to the charging member; a developing device that develops the latent electrostatic image with toner to form a toner image on the moving surface of the image bearing member; a transfer device that transfers the toner image on the moving surface of the image bearing member to a recording medium; a fixing device that fixes the toner image on the recording medium; an image formation speed switching device that switches from one image formation speed to another image formation speed among multiple image formation speeds by changing a surface traveling speed of the image bearing member according to a particular switching condition; a storage device that stores a charging current target of the charging bias applied to the charging member for each of the multiple image formation speeds; an electric current detection device that detects an electric current flown through the charging member; and an AC voltage adjustment device that adjusts an AC voltage of the charging bias applied to the charging member such that the electric current detected by the electric current detection device corresponds to the charging current target of the image formation speed, wherein with regard to at least two image formation speeds among the multiple image formation speeds, the charging current target is set for each of the at least two image formation speeds such that each AC voltage adjusted by the AC voltage adjustment device is substantially the same.