| 摘要 |
PROBLEM TO BE SOLVED: To restrain secular density fluctuation and irregular density at the time of recording a solid image by setting the rotational circumferential speed of a developing roll higher than the surface speed of a photoreceptor and setting the rotating speed of the developing roll so that toner amount supplied to the photoreceptor may be larger than the toner amount by which sufficient image density is obtained. SOLUTION: The rotational circumferential speed of the developing roll 1 is set to be higher than the surface speed of the photoreceptor 10, and the rotating speed of the roll 1 is set so that the toner amount supplied to the photoreceptor 10 by the roll 1 may be larger than the toner amount by which the sufficient image density is obtained. Furthermore, developing bias is set so that the toner amount at the time of developing may be smaller than the toner amount supplied to the photoreceptor 10 by the roll 1. Thus, when the toner adhesive amount of a toner thin film on the roll 1 is reduced with time, the rate of the shifting of the toner on the roll 1 to the photoreceptor 10 is increased because of the lowering of the electrification amount, so that the toner amount by which an electrostatic latent image on the photoreceptor 10 is developed becomes stable in substance. |
