Image writing apparatus for controlling transfer of image data

An image writing apparatus comprising:

• a light-emitting-element array unit that includes a plurality of light-emitting-element arrays in which a plurality of light-emitting elements that are controlled based on binary image data are arranged in a row;
• and
• an image-data-transfer control unit that divides image data corresponding to one line in a main scanning direction for each of the light-emitting-element arrays, and when transferring the image data divided to each of the light-emitting-element arrays, controls the transfer of the image data such that,
• in a first output mode, by repeating a process of alternately transferring even pixel data and odd pixel data in one cycle of the one line in the main scanning direction, and
• in a second output mode, by performing once a process of alternately transferring even pixel data and odd pixel data in one cycle of the one line in the main scanning direction,
• wherein, in the first output mode, the image-data-transfer control unit further controls a ratio of a lighting time of first even pixel data to a lighting time of second even pixel data such that a total lighting time of the first even pixel data and the second even pixel data in the one cycle of the one line in the main scanning direction becomes same for each cycle.