Patent ID: 8081912

Claim:
An image forming apparatus, comprising: a transfer material feeding member for feeding a transfer material; a first image bearing member for carrying a first toner image; a second image bearing member, provided downstream of said first image bearing member with respect to a feeding direction of said transfer material feeding member, for carrying a second toner image; a first transfer member for transferring the first toner image carried on said first image bearing member onto a transfer material; and a second transfer member, provided downstream of said first transfer member with respect to the feeding direction, for transferring the second toner image carried on said second image bearing member onto the transfer material, wherein said apparatus is operable in a marginless print mode in which the first toner image is formed on a first region on said first image bearing member corresponding to a size of the transfer material and a second region on said first image bearing member outside said first region, and wherein a reverse-transfer efficiency TR 1 =(P 2 /P 1 )×100(%) and a reverse-transfer efficiency TR 2 =(E 2 /E 1 )×100(%) satisfy: TR 1 <TR 2 where the reverse-transfer efficiency TR 1 is a percentage of a mass P 2 (g/cm 2 ), per unit area, of toner back-transferred from the transfer material onto said second image bearing member by said second transfer member to a mass P 1 (g/cm 2 ), per unit area, of toner transferred from said first region onto the transfer material by said first transfer member, and where the reverse-transfer efficiency TR 2 is a percentage of a mass E 2 (g/cm 2 ), per unit area, of toner back-transferred from said transfer material feeding member onto said second image bearing member by said second transferring means to a mass E 1 (g/cm 2 ), per unit area, of toner transferred from said second region onto said transfer material feeding member by said first transfer member.