FIXING DEVICE, IMAGE FORMING APPARATUS, AND METHOD FOR EVALUATING SURFACE STATE OF FIXING MEMBER

摘要

PROBLEM TO BE SOLVED: To realize a fixing device capable of performing scratch detection in which the state of a scratch changed in a sub direction is considered.;SOLUTION: The fixing device includes a reflection type optical detector 200 radiating a light spot on the surface 61A of a fixing member 61 and receiving light reflected by the surface and a surface state evaluation device 300 evaluating the surface state of the fixing member, on the basis of the output of the reflection type optical detector 200. Large output fluctuations periodically occurring in the output of the reflection type optical detector 200 are detected, output is detected from the detected output fluctuations, whenever a predetermined time of K(n) (n=1, 2, ..) elapses, a characteristic value is calculated from n (≥2) pieces of the detected detection values, and the surface state of the fixing member is evaluated based on the calculated characteristic value.;COPYRIGHT: (C)2014,JPO&INPIT