IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To maintain the quality of a final output image by: comprehending the adverse effects of a paper transfer (secondary transfer) step and a fixing step on the final output image on recording paper; and performing a feedback control to these steps if necessary. SOLUTION: The image forming apparatus includes: a toner image detection sensor 30 for detecting a toner image not transferred to the surface of recording paper 20 in a position P1 or P2; and a fixed image detection sensor 31 for detecting a toner image secondarily transferred to the surface of the recording paper 20. The toner image detection sensor 30 and the fixed image detection sensor 31 are aligned in a direction corresponding to main scan which intersects the direction of conveyance of the recording paper 20 at right angle. To compare the output values of both the sensors, measurement data of sensor heads in the same position in the direction corresponding to the main scan are compared. Thus, if nonuniform image density is caused as a result of the second transfer step to the fixing step, the adverse effects of them are correctly comprehended. COPYRIGHT: (C)2010,JPO&INPIT