Patent ID: 6961526

Claim:
An image forming apparatus comprising: image forming means for forming a toner image on an image carrier; transfer means for transferring the toner image formed by said image forming means onto a transfer material in a transfer position; fusing means for fusing the toner image transferred by said transfer means on the transfer material; reversing means for reversing the transfer material having the toner image fused by said fusing means; duplex feed means for feeding the transfer material reversed by said reversing means to the transfer position; detecting means for detecting, in a predetermined detecting position, at least one of density and chromaticity of the toner image fused on the transfer material by said fusing means, the predetermined detecting position being a certain position in the middle of a feed path within a region after the transfer material has passed said duplex feed means but until reaching the transfer position; and control means for controlling said image forming means based on a result detected by said detecting means.