Image forming apparatus and temperature control method in fixing device thereof for controlling temperature of fixing device to be at target temperature after execution of non-image formation device

摘要

Image forming apparatus including: first executing unit executing image formation mode of forming image by transferring toner image from image holder onto recording sheet, and then, in fixing device, causing fixing member, heated to fixable temperature by heater, to thermally fix toner image; second executing unit executing non-image-formation mode not involving thermal fixing performed by fixing device; instructing unit selectively instructing to execute image formation mode or non-image-formation mode; and controller controlling power supply to heater of fixing device in accordance with execution state of image formation and non-image-formation modes, the controller performing first control of decreasing temperature of fixing member by stopping or reducing power supply to heater when non-image-formation mode starts, and second control of stopping first control at predetermined timing during execution of non-image-formation mode and increasing temperature of fixing member so as to reach predetermined target temperature at end of execution of non-image-formation mode.

主权项

1. An image forming apparatus comprising:
a first executing unit that executes an image formation mode which includes a printing process of forming an image by transferring a toner image from an image holder onto a recording sheet, and then, in a fixing device, causing a fixing member heated to a fixable temperature by a heater to thermally fix the toner image on the recording sheet; a second executing unit that executes a non-image-formation mode process that is different from a wait state and that does not include a thermal fixing performed by the fixing device; an instructing unit that selectively instructs the first executing unit to execute the image formation mode or the second executing unit to execute the non-image-formation mode process; a controller that controls a power supply to the heater of the fixing device in accordance with an execution state of the image formation mode and the non-image-formation mode process, wherein the controller performs: (i) a first control of decreasing a temperature of the fixing member by stopping or reducing the power supply to the heater when the non-image-formation mode process starts to be executed, and (ii) a second control of stopping the first control at a predetermined timing in a middle of the execution of the non-image-formation mode process and then increasing the temperature of the fixing member so that the temperature reaches a predetermined target temperature at an end of the execution of the non-image-formation mode process; an obtaining unit that obtains a process time of the non-image-formation mode process to be executed; and a prohibiting unit that prohibits the controller from executing the first control and the second control if the process time is equal to or smaller than a predetermined time.