Patent ID: 8731424
Filing Date: 2014-05-20
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image forming unit configured to form an image on a recording sheet; a fixing unit configured to fix the image on the recording sheet, the fixing unit including a heater having a first resistance heating element and a second resistance heating element that are formed on a substrate and that generate heat with electric power supplied from a commercial power supply, a film having a first surface adapted to slide over the heater and a second surface in contact with the recording sheet bearing an unfixed image, a pressing member forming a fixing nip together with the heater via the film to convey the recording sheet while nipping it, and a temperature detecting device configured to detect the temperature of the heater, the fixing unit being configured such that a connection of the first resistance heating element and the second resistance heating element can be switched between a series connection mode in which they are connected in series and a parallel connection mode in which they are connected in parallel, depending on a voltage of the commercial power supply; and a control unit that controls electric power supplied to the first resistance heating element and the second resistance heating element from the commercial power supply depending on the temperature detected by the temperature detecting device, wherein the control unit changes a fixing condition employed by the fixing unit in the fixing of the image depending on whether the first resistance heating element and the second resistance heating element are connected in parallel or in series, wherein the fixing condition is a target control temperature of the heater, and wherein the control unit sets the target control temperature to be higher in the parallel connection mode than in the series connection mode.