Patent ID: 7457554

Claim:
An image forming apparatus comprising: a rotatable image bearing member on which an electrostatic latent image is formed; a charging member for being supplied with a charging voltage which is a DC voltage not having an AC voltage component and for contacting said image bearing member to electrically charge a surface of said image bearing member using an electric discharge; and a transfer member for transferring onto a transfer material a toner image formed on the surface of said image bearing member by developing the electrostatic latent image, at a transfer position, wherein the charging potential of said charging member is different between, when said charging member provides a first region with a potential and when said charging member provides a second region with a potential, thus providing a predetermined potential difference between said first region and said second region, wherein said transfer member is not supplied with a voltage when said second region after being charged by said charging member is at the transfer position, wherein said first region is a region on said image bearing member which has been charged by said charging member and which is to be an image forming region, said second region is a region of said image bearing member which is a non-image-forming region in a rotation of said image bearing member immediately preceding said first region, and a third region proceeds said second region, wherein said charging member or said transfer member is supplied with the voltage to provide the predetermined potential difference between said second region and said third region, wherein said third region is a region of said image bearing member which is a non-image-forming region in a rotation of said image bearing member immediately previous to said second region and which corresponds to said second region on said image bearing member, and wherein when a length of said third region measured along a peripheral movement of the surface of said image bearing member is larger than one full-circumferential length of said image bearing member, said transfer member is supplied with the voltage to provide said predetermined potential difference between a potential of said third region before being charged by said charging member and a potential of said third region after being charged by said charging member.