| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming device that forms a high-quality image even if screen ruling changes. <P>SOLUTION: An optical scanner forms an electrostatic latent image on a photoreceptor drum 4 under control of a control part based on image data. The developing roller 78 carries developer containing toner, and applies the toner to the photoreceptor drum 4 to develop the electrostatic latent image. A voltage application part 32 applies developing bias formed by superimposing a DC voltage on an AC voltage, to the developing roller 78. A control part selects screen ruling on the basis of the image data, and selects frequency of the AC voltage. The control part selects 9 kHz as frequency when 190lpi is selected as screen ruling, and selects 5 kHz as frequency when 210lpi is selected as screen ruling. <P>COPYRIGHT: (C)2013,JPO&INPIT |
