Patent ID: 11934120
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus comprising:
a heating rotary member;
a pressing rotary member, wherein the pressing rotary member and the heating rotary member are configured to form a fixing nip portion, and are configured to apply heat and pressure to a toner image carried on a recording medium at the fixing nip portion, thereby fixing the toner image onto the recording medium;
a winding roller configured to wind up a web used to collect toner that is not fixed to the recording medium and is adhered to a surface of the heating rotary member;
a motor configured to rotate the winding roller to wind up the web that has been used for the collection of the toner;
a contact member configured to contact an outside surface of the web wound around the winding roller and to be movable so as to follow the outside surface of the web;
a variable resistor disposed so as to be able to change a resistance in accordance with a position of the contact member; and
a control unit configured to control an amount of rotation of the motor in response to information related to the resistance,
wherein the control unit is configured to report an abnormality when an amount of variation of the information in a predetermined time period is equal to or less than a predetermined amount,
wherein the predetermined time period is set to correspond to a period of at least one rotation of the winding roller.