| 摘要 |
PROBLEM TO BE SOLVED: To stabilize an amount of the supply of developer to developing rolls and to obtain a high quality image by putting the intersection between a line including the polarity inverting position of the one developing roll and the axis of the developing roll and a line connecting the polarity inverting position of the other developing roll and the axis of the developing roll into the position that is further upstream than a doctor blade in the directions of the rotations of the developing rolls. SOLUTION: In magnetic-polarity inverting positions (polarity inverting positions E1 and E2) between magnetic poles of different polarities situated upstream and downstream from a doctor blade 3, developer is supplied to a pair of developing rolls 1 and 2. That is, an inverting-position crossing part F where a line connecting the axis of the one developing roll 1 and the polarity inverting position E1 of the developing roll 1 and a line connecting the axis of the other developing roll 2 and the polarity inverting position E2 of the developing roll 2 cross is disposed further upstream than the doctor blade 3 in the directions of the rotations of the pair of developing rolls. Thus, an amount of the supply of the developer to the developing rolls 1 and 2 is stabilized, and a high quality image can be obtained. |
