Heater controller, image forming apparatus, method for controlling heater

A heater controller that performs on/off control of a plurality of heaters, the heater controller comprising:

• a storage unit that stores therein a plurality of pattern sets, wherein each of the pattern sets includes a plurality of heater-on/off patterns for respectively controlling the heaters, and each of the heater-on/off patterns is set in terms of a predetermined control period;
• a reference-value calculating unit that calculates a reference value representing an average of values of electric power supplied to the heater controller over a predetermined period of time;
• an output-value calculating unit that calculates, for each of the pattern sets, an output power value to be supplied to the heaters when the heaters are turned-on according to the heater-on/off patterns included in the pattern set;
• a difference calculating unit that calculates, for each of the pattern sets, a difference between the reference value and the output power value;
• a selecting unit that selects, from the pattern sets, one pattern set having a smallest difference;
• and
• an on/off control unit that performs on/off control of the heaters according to the heater-on/off patterns included in the pattern set selected by the selecting unit, respectively.