Patent ID: 11899386
Assignee: RICOH COMPANY, LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 6:
7. An image forming method comprising:
forming a toner image on a recording medium;
fixing the toner image onto the recording medium using a fixing rotator heated by one of a first mode in which only a first heater having a uniform heat generation amount distribution in a longitudinal direction of the fixing rotator heats the fixing rotator and a second mode in which a second heater having different heat generation amounts at different positions in the longitudinal direction of fixing rotator heats the fixing rotator together with the first heater, the second heater generating larger heat amounts in each of end portions of the second heater than a center portion of the second heater, and
monitoring a temperature of the fixing rotator by only one temperature detector and one abnormal temperature detector, wherein the one temperature detector faces directly a center portion of the second heater, and the one abnormal temperature detector is disposed at a position facing one of the end portions of the second heater at which the plurality of heaters generate a total heat generation amount larger than at another position,
wherein an amount of heat generated at the center portion of the second heater is smaller than an amount of heat generated at a center portion of the first heater, and
the fixing rotator has a thickness equal to or smaller than 0.2 mm,
the heat generated by the first heater and/or the second heater is reflected by a reflector to heat an inner circumferential surface of the fixing rotator at a place other than a nip between the fixing rotator and a pressure rotator, and
total heat amount generated by both end portions of the first heater and the both end portions of the second heater is larger than total heat amount generated by the center portion of the first heater and the center portion of the second heater by 5% to 15% in a total heat amount ratio under a rated voltage.