Speed ratio between an image holding member and a developer carrier varies according to an image ratio

摘要

An image forming apparatus is capable of improving throughput, preventing deterioration of developer and preventing shortening of the life of a developing apparatus. In the image forming apparatus, an image holding member holds an electrostatic latent image and a developer carrier carries developer to a developing portion, and a speed ratio between the image holding member and the developer carrier varies according to an image ratio.