| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of maintaining high image quality by detecting change in a surface state of a fixing device with high accuracy.SOLUTION: The image forming apparatus comprises: photoreceptor drums 101Y, 101C, 101M and 101K; charging units 301Y, 301C, 301M and 301K; an exposure device 200; developing units 102Y, 102C, 102M and 102K; first transfer units 106Y, 106C, 106M and 106K; photoreceptor cleaning units 308Y, 308C, 308M and 308K; a fixing unit 111 having a fixing belt 67; reflective optical sensors 68a and 68b; a body control unit 400 or the like. The body control unit 400 calculates a quotient by dividing a detected value in a worn area AW which is detected by the reflective optical sensors 68a and 68b by a detected value in a non worn area NW and determines the wear state of the fixing belt 67 from the quotient. |
