Patent ID: 9235180
Filing Date: 2016-01-12
CPC Classification: G03G

Claim Text:
1. A fixing device for thermally fixing an unfixed toner image onto a recording sheet, the fixing device comprising: a heating belt that is endless and includes a resistive heating layer configured to generate heat to fuse the unfixed toner image onto the recording sheet; an electrifier that applies voltage across the resistive heating layer in a circumferential direction of the heating belt, to heat the resistive heating layer; a detector that measures a value of electric current flowing through the resistive heating layer along the direction of voltage application for heating the resistive heating layer; and a determiner that determines whether or not the resistive heating layer has a scratch by monitoring an amount of change between a reference value predetermined for an electric current flowing through the resistive heating layer having no scratch and an actual value of the electric current measured by the detector, wherein the resistive heating layer exhibits resistivity anisotropy satisfying R1<R2, where R1 denotes a volume resistivity of the resistive heating layer in the direction of voltage application, and R2 denotes a volume resistivity of the resistive heating layer in a direction perpendicular to the direction of voltage application.