| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device by which the life of developer is maintained for a long time by consuming the toner of a small particle size in two-component developer at the inside of a developing unit, whose running cost is suppressed by eliminating the frequent exchange of developer and by which the image of an excellent quality is obtained. SOLUTION: Blank pulse obtained by intermittently superposing AC voltage to DC voltage is used as developing bias applied to a developing sleeve 3 so as to obtain the image of the excellent quality when an electrostatic latent image on a photoreceptive drum 4M is developed by the developing unit 9M by using the two-component developer at the image forming time of a normal output image. The image for the forcible consumption o the toner is formed at an operation time other than the forming time of the normal output image so as to bring back the toner particle size distribution of the developer biased on a small particle size side by development by the blank pulse to a proper state, and the latent image of the image is developed by using rectangular bias obtained by successively superposing an AC component to a DC component so that the small-sized toner is consumed in a large quantity. |
