| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a developing device of a cartridge system made small in size and light in weight and capable of reducing an image defect. <P>SOLUTION: The developing device is equipped with a developing roll 20 having an elastic layer 22 on the periphery of a core bar 21, and a toner supply roll 30 and a developing blade 40 which are made to abut on the developing roll 20, and is also attachably/detachably provided in an electrophotographic image forming apparatus. The elastic layer 22 of the developing roll 20 has a reverse crown shape whose diameter gets larger and larger toward the ends from the center part in a longitudinal direction, and the developing roll 20 is held in such a state that the core bar is bent by pressing force of the toner supply roll 30 and the developing blade 40. The surface position in a radial direction of the center part with reference at the surface positions in the radial direction of both ends in the longitudinal direction of a contact area where the developing roll comes in contact with the photoreceptor is within 0 to +50μm when a protrusive direction is expressed by +. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
