| 摘要 |
PURPOSE:To expose a photoreceptor with optimum beam diameter and exposure without being influenced by a toner layer by selectively driving one or plural exposing means. CONSTITUTION:A correction data arithmetic part 18 discriminates the forming circumstances of the toner layer of dots till a prestage based on a chrominance signal inputted according to toner image forming order and the density value of the image signals of plural colors repetitively inputted every time a toner image is formed, and arithmetically calculates the correction data of the exposure for selectively driving one or two or more lasers 20A in accordance with the forming circumstances of the toner layer discriminated. The laser selected in accordance with the correction data is driven by a corresponding laser driver 22A, and the optimum exposure is performed in accordance with the forming circumstances of the toner layer. In such a case, the exposure is adjusted by selectively switching the laser 20A, thereby completely coping with the circumstances even in the case of high speed writing. |
