| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress occurrence of abnormal image such as nonuniform image density while saving occupancy space and making high in operating speed in a two-component developing device which includes a developing roller 51 with a magnetic field generating means, a stir conveying means for stirring and conveying developer in a developing container storing two-component developer, and a case member enclosing the developing roller, and which conveys the developer by the rotation of the developing roller 51 and develops an electrostatic latent image on the photoreceptor drum 20 with a magnetic brush. <P>SOLUTION: In the area where a repulsive magnetic field generated between magnetic poles P3 and P4 of the same polarity which are disposed adjacent to each other in order of upstream side in the direction of the rotation of the developing roller 51, the normal reflection vector B which is formed such that a normal vector drawn on the peripheral face of the developing roller is reflected against the internal wall of a case member 55 enclosing the developing roller 51 has an angle α of 0° to 70° to a horizontal line LL1 in the direction of the normal vector. In addition, of the two magnetic poles of the same polarity, the magnetic pole P4 situated downstream in the direction of the rotation of the developing roller has a peak magnetic force of 35mT to 55mT inclusive in the normal direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
