Patent ID: 8063341
Filing Date: 2011-11-22
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a heating device, including: a heating member drive control part for controlling electrical power supplied to said first and second heat generating members in accordance with a temperature detected by said first temperature detecting means; and a feeding device which feeds the material to be heated to said heating device, wherein in a case where a print signal for an image on a first sheet material is input in a condition where said moving member and said pressing member are stopped, said moving member and said pressing member start rotating, and said heating member drive control part starts controlling electrification to said first and second heat generating members so that a turn-on time ratio between said first heat generating member and said second heat generating member becomes a first turn-on time ratio defined irrespectively of a size of the material to be heated, wherein in a condition under electrification in the first turn-on time ratio when the temperature detected by said first temperature detecting means reaches a predetermined target temperature, said heating member drive control part switches the turn-on time ratio to a second turn-on time ratio that is defined according to a size of the material to be heated, that is equal to or less than the first turn-on time ratio, and that is a ratio in which a temperature of an area of said heating member through which the material does not pass is less than a temperature of the area in the first turn-on time ratio, to continue controlling the electrification, and wherein after the turn-on time ratio is switched from the first turn-on time ratio to the second turn-on time ratio, when the difference between a temperature detected by said first temperature detecting means and a temperature detected by said second temperature detecting means exceeds a predetermined threshold value set according to a size of the material to be heated, said feeding device starts feeding the first sheet material to be heated.