FIXING DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME

摘要

A fixing device includes a fixing member, a pressing member, a heating unit, multiple sub-heaters disposed in the heating unit, a temperature sensor to detect a temperature of the heating unit, and a heating control unit. The heating control unit controls the heating unit by controlling the multiple sub-heaters individually to heat the respective heating areas, such that a temperature at a portion of the fixing member corresponding to a blank area of the recording medium is lower than a temperature of a portion of the fixing member corresponding to an imaged area of the recording medium. The heating control unit further changes a size of a preliminary heating area to preliminarily heat the respective heating areas before the imaged area enters the fixing nip according to the temperature detected by the temperature sensor.

主权项

1. A fixing device to fix an unfixed image on a recording material in a fixing nip, the fixing device comprising:
a rotatable fixing member to contact the unfixed image; a pressing member to contact the fixing member and form the fixing nip between the pressing member and the fixing member; a heating unit to heat the fixing member with electric power from a power source; multiple sub-heaters disposed in the heating unit to heat respective heating areas, arrayed in a direction perpendicular to a direction in which a recording material is conveyed; a temperature sensor to detect a temperature of the heating unit; and a heating control unit to control the heating unit by controlling the multiple sub-heaters individually to heat the respective heating areas, such that a temperature at a portion of the fixing member corresponding to a blank area of the recording medium is lower than a temperature of a portion of the fixing member corresponding to an imaged area of the recording medium, the heating control unit further changing a size of a preliminary heating area to preliminarily heat the respective heating areas before the imaged area enters the fixing nip according to the temperature detected by the temperature sensor.