| 摘要 |
PURPOSE:To generate an approximately even concentration and to stabilize an image quality by changing the shape of a developer circulation restricting member in the lengthwise direction central part of a developing sleeve. CONSTITUTION:For a carrier return 5, the bottom surface is crowned in a concave shape, and a circulating space surrounded with the developing sleeve faced surface of the carrier return 5, a thin plate member 12 which are arranged to the carrier return 5, a magnetic force line concentrating member 6 and the developing sleeve is formed to be wider than an edge 5a in a central part 5b of the carrier return 5 by a degree to be crowned from the viewpoint of the lengthwise direction of the developing sleeve. Thus, even a toner is taken in a prescribed quantity, the developer maintains prescribed toner contents, and even the image is made even in the lengthwise direction and of a good quality. |
