Fixing control device, fixing control method, and image forming apparatus

A fixing control device which controls a fixing device including a plurality of heaters to fix an image based on image data to a recording material, the fixing control device comprising:

• an image detection unit configured to determine presence or absence of the image in each of a plurality of areas obtained by division of an image formation region in which the image is formed;
• a heater selection unit configured to select, from the plurality of heaters, heaters at positions corresponding to areas in which the presence of the image is determined;
• a heating amount computation unit configured to compute a heating amount of a heating area heated by each of the selected heaters in a fixing region corresponding to the image formation region in which the image is formed;
• a change amount computation unit configured to compute an amount of change of the heating amount between adjoining ones of the heating areas;
• a heater drive unit configured to supply a drive signal of a predetermined period to each of the plurality of heaters and turn ON and OFF power supply to each of the plurality of heaters by the drive signal;
• a threshold checking unit configured to determine whether the amount of change of the heating amount between the adjoining heating areas is greater than or equal to a predetermined threshold;
• and
• a capacitor unit configured to store electric energy temporarily,
• wherein, when the amount of change of the heating amount is determined as being greater than or equal to the predetermined threshold and an area in which the absence of the image is determined is detected before and after the areas in which the presence of the image is determined, the heater drive unit causes the capacitor unit to store electric energy whose amount is less than an amount of electric energy supplied to the heaters at the positions corresponding to the areas in which the presence of the image is determined.

A fixing control method performed by a fixing control device which controls a fixing device including a plurality of heaters to fix an image based on image data to a recording material, the fixing control method comprising:

• determining presence or absence of the image in each of a plurality of areas obtained by division of an image formation region in which the mage is formed;
• selecting, from the plurality of heaters, heaters at positions corresponding to the areas in which the presence of the image is determined;
• computing a heating amount of a heating area heated by each of the selected heaters in a fixing region corresponding to the image formation region;
• computing an amount of change of the heating amount between adjoining ones of the heating areas;
• and
• correcting one of the heating amounts of the adjoining heating areas so that the amount of change after the correction is less than a predetermined threshold.