Patent ID: 7724394

Claim:
An image forming apparatus, comprising: a pseudo half tone processing unit that performs a pseudo half tone process on input image data to generate output image data; and a writing unit that performs writing by executing light modulation of a plurality of light emitting sources based on the output image data, wherein the writing unit performs writing with fewer light emitting sources among the plurality of light emitting sources for a picture image or a graphics image than for a character/line image, and by scanning an emitting light from each of the fewer light emitting sources in a main scanning direction in such a way as to satisfy a relationship of Ds>L, where L is a length per pixel based on a resolution of the character/line image and Ds is a beam spot size in a sub scanning direction in writing, and the pseudo half tone processing unit performs the pseudo half tone process with a lower resolution in the sub scanning direction for the picture image or the graphics image than for the character/line image, based on the number of the light emitting sources to be used for the writing by the writing unit.