Patent ID: 8212852

Claim:
An image writing device comprising: a light-emitting element array unit including a light-emitting element array formed with a plurality of light-emitting elements arranged in one direction, a light emission of the light-emitting elements being controlled based on binary image data; and an image forming unit that forms an image of lights emitted by the light-emitting element array on a photo-sensitive element; an image-data transfer controller that transfers image data corresponding to one line in a main scanning direction of the photo-sensitive element by two transferring operations to the light-emitting element array unit, to drive each of the light-emitting elements in the light-emitting element array unit for an exposure of the photo-sensitive element in the main-scanning direction; and a plurality of storing units that store at least three lines of image data transferred by the image-data transfer controller, wherein the image-data transfer controller reads out a data matrix made of at least three pixels in the main scanning direction and at least three pixels in a sub scanning direction around a target pixel from the storing units, converts the binary data to multi-valued data with respect to the target pixel on the basis of a pattern of the matrix, determines whether the multi-valued target data is to be converted from black data to white data, and transfers the multi-valued target data by the two transfer operations depending on a result of the determination.