| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of suppressing an abrupt density variation and a waste of developer, while increasing a drive speed of a developer carrier in the mid-way.SOLUTION: An image forming device has a photoreceptor drum moved by carrying an electrostatic image and a developer sleeve relatively moving opposing to the photoreceptor drum by carrying a developer, and includes: a developing unit for developing an electrostatic image formed on the photoreceptor drum; and a control part capable of executing a density adjustment control for adjusting the developed density of the electrostatic image formed on the photoreceptor drum. The control part can switch a speed ratio R for a photoreceptor drum of the developer sleeve to a first speed ratio R1 and a second speed ratio R2 larger than the first speed ratio R1, and a frequency of executing the density adjustment control for the number of image forming sheets Np is increased (Steps S7, S8) as compared with the case of the first speed ratio R1 when the speed ratio R is the second speed ratio R2 (Step S5).SELECTED DRAWING: Figure 3 |
