DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of faint printing at the rear end and a reduction in density of an image even when vertical band images or total solid images are continuously printed over a long period.SOLUTION: A developing device calculates an image area ratio for each of a plurality of long and narrow areas extending in a sub scanning direction of an image carrier on the basis of image data, and changes the linear speed ratio between a developer carrier and a developer supply body and a supply bias voltage during development.SELECTED DRAWING: Figure 7a