| 摘要 |
PROBLEM TO BE SOLVED: To expand a range for the selection of printing density by equipping both of an exposure value change device connected to an exposure device, and a printing density selector mechanism connected to the exposure value change device and a developing high-voltage power supply. SOLUTION: A photosensitive member 3 is electrified with an electrifier 2 connected to an electrification high-voltage power supply 1, and a static latent image is formed on the surface of the electrified photosensitive member 3 through an exposure device 4. Also, a developing roller 5 adsorbs and carries a developer 8 as a mixture of toner 6 and carrier 7 with a magnetic force. In addition, a printing density selector mechanism 10 connected to the electrification high-voltage power supply 1 and a developing high-voltage power supply 9 makes variable output therefrom, and the quantity of the toner 6 to be developed is thereby changed for changing printing density. Furthermore, an exposure value change device 11 is connected to the printing density selector mechanism 10, so as to change luminous energy emitted from the exposure device 4 concurrently with the operation of the printing density selector mechanism 10. |
