Image forming apparatus and method of controlling commercial power supply to fusing means

An image forming apparatus comprising:

• a fusing unit having a heating element to which a commercial power source is supplied and fusing a toner image formed on a transfer material;
• a rechargeable battery capable of supplying power to a load other than the heating element;
• a power supply controller which controls power supplied from the commercial power source and said rechargeable battery to the load other than the heating element;
• a fusing controller which limits power from the commercial power source to a limit level corresponding to a control state by said power supply controller;
• a temperature detector which detects a temperature of said fusing unit;
• a first adjusting circuit which causes said power supply controller to supply power from said rechargeable battery to the load and causes said fusing controller to increase the limit level, when the temperature of said fusing unit which is detected by said temperature detector at turn-on or upon returning from an energy saving mode is less than a predetermined temperature;
• and
• a second adjustment circuit which monitors the temperature of said fusing unit which is detected by said temperature detector while power from said rechargeable battery is supplied to the load, and when the temperature of said fusing unit is not less than the predetermined temperature, causes said power supply controller to supply power from the commercial power source to the load, and causes said fusing controller to decrease the limit level.

A control method for an image forming apparatus including a fusing unit having a heating element to which a commercial power source is supplied and fusing a toner image formed on a transfer material, and a rechargeable battery capable of supplying power to a load other than the heating element, comprising:

• a temperature detection step of detecting a temperature of the fusing unit;
• a power supply control step of controlling supply of power from the commercial power source and the rechargeable battery to the load other than the heating element in accordance with a detection result obtained in the temperature detection step;
• and
• a fusing control step of limiting power from the commercial power source to a limit level corresponding to a control state in the power supply control step, and supplying the power to the heating element.

An image forming apparatus comprising:

• a fusing unit having a heating element to which a commercial power source is supplied and fusing a toner image formed on a transfer material;
• a rechargeable battery capable of supplying power to a load other than the heating element;
• a temperature detector for detecting a temperature of said fusing unit;
• a power supply controller for controlling supply of power from the commercial power source and said rechargeable battery to the load other than the heating element in accordance with a detection result obtained by said temperature detector;
• and
• a fusing controller for limiting power from the commercial power source to a limit level corresponding to a control state by said power supply controller, and supplying the power to said heating element.