Patent ID: 7233748

Claim:
An image forming apparatus that forms a color image by overlapping toners of a plurality of colors, on the basis of a plurality of image data corresponding to the plurality of colors, the apparatus comprising: setting means for setting a thick paper mode in which an image is to be formed on thick paper, in contrast to an ordinary paper mode in which an image is to be formed on ordinary paper, on the basis of the plurality of image data corresponding to the plurality of colors; and control means for executing, when the thick paper mode is set by the setting means, a control to reduce a maximum toner attachment amount, compared to the ordinary paper mode, and to set the same fixation temperature condition as in the ordinary paper mode, wherein the control means executes, when γ correction is performed for the image data of each color, a control to change a γ correction value for the ordinary paper mode to a γ correction value for the thick paper mode, thereby reducing the maximum toner attachment amount of each color, and wherein the control means executes a control to change a transfer bias for the ordinary paper mode to a transfer bias for the thick paper mode, thereby reducing the maximum toner attachment amount.