| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image formation device, images formed by which are hardly susceptible to defects even in a case where a frequency modulation (FM) screen using a threshold matrix is applied. <P>SOLUTION: An image formation device comprises: image processing means provided with a screen processing unit that subjects image information to screen processing with an FM screen having predetermined threshold arrays in the horizontal scanning direction and the vertical scanning direction; a photosensitive drum 11; a charging roll 12 that electrically charges the photosensitive drum 11; an exposing unit 13 having a plurality of light ray sources for forming an electrostatic latent image by exposing to light the photosensitive drum 11 charged by the charging roll 12 by scanning the drum with a plurality of light rays on the basis of image information subjected to the screen processing; and a developer 14 that develops the electrostatic latent image to form a toner image. Neither the number of thresholds in the vertical scanning direction of the FM screen or the number of light ray sources exposing to light in the vertical scanning direction per scan by the exposing unit 13 is any multiple or larger or smaller by two or less of any multiple of the other. <P>COPYRIGHT: (C)2013,JPO&INPIT |
