Patent attributes
The present invention provides a developing apparatus that can effectively prevent generation of a ghost due to poor detachment of a developer after development, and generation of unevenness in density between a left part and a right part of an image region due to lack of an amount of the developer transported. The developing apparatus satisfies the relationshipr+R≦d≦3r+R where r denotes a rotational radius of a second developer transporting screw, R denotes a rotational radius of a development roller, and d denotes a center distance between the second developer transporting screw and the development roller. The developing apparatus also satisfies the relationshipM0≧(mg0×v×l)/0.02where mg0 (g/mm2) denotes an amount of a toner per unit area that is supplied from the development roller to an electrostatic latent image having 100% image coverage which is formed on a photosensitive drum, v (mm/s) denotes a rotational peripheral velocity of the photosensitive drum, l (mm) denotes a maximum printing width on the photosensitive drum, and M0 (g/s) denotes an amount of the developer transported per unit time by the second developer transporting screw in a second developer transport direction.
