| 摘要 |
PURPOSE: To stably carry developer by a developer supply roller and a developing roller and to improve image quality by forming the developer supply roller of a nearly regular triangle pole and projecting it to be circular arc shape so that its each side surface may be the internal envelope of cross section trochoid. CONSTITUTION: The developing roller 22, a toner supply roller 23 and a toner stirring roller 26 are provided in the developing tank 49 of the cartridge main body 21 of a developing cartridge 20. The toner supply roller 23 is formed of the nearly regular triangle pole, and it is formed to be projected so that its each side surface may be the internal envelope of the cross section trochoid. In the case of assuming that the rotational radius of the roller 23 is (r), the curvature of the circular arc of each projected side surface 1/rb (rb is the radius of curvature) desirably satisfies the relation of (1/ra )×0.2<=1./rb <=(1/r2b )×0/9. When it is assumed that the radius of the developing roller 2 is (r), it is desirable that the relation of (1/5)×rc <=ra <=rc holds. |
