| 摘要 |
PURPOSE:To improve the image forming speed of a monochromatic image forming mode by switching the image forming process speed at the time of a full-color image forming and at the time of the monochromatic image forming and switching the number of scanning lines of laser beam. CONSTITUTION:When a full-color copy mode, etc., or a monochromatic copy mode is designated by an operation part selection switch 13, a number of scanning lines switching means 12 reads corresponded image forming process speed information (the rotation speed of a drum driving motor 16, a charging device, a developing bias, the voltage of a transferring device) from a reference table and it is given to a DC controller 11. The DC controller 11 gives the process speed information to a motor driver 15, a developing bias power supply 20 and a high voltage power supply 21. Namely, the signal for changing the rotation speed of a photosensitive drum is transmitted to the motor driver 15. Thus, the image forming process speed is switched between at the time of full-color image forming and at the time of monochromatic image forming and the number of scanning lines of laser beam is switched. |
