Image forming apparatus and its control method

摘要

There are provided an image forming apparatus which can implement on-demand fusing with quick rise in temperature by using the upper current (power) limit of a commercial power supply more effectively and a control method for the apparatus. The image forming apparatus includes a rechargeable battery device capable of charging and discharging. A load other than the heating element of a fusing device is designed to be capable of receiving power from the commercial power supply and/or the rechargeable battery device. At turn-on or upon returning from the energy saving mode, the supply of power from the commercial power supply and rechargeable battery device to the load is controlled. The power supplied from the commercial power supply to the fusing device is limited to a limit level corresponding to the above control result.