| 摘要 |
PURPOSE:To attain the simplification of structure, reduction in cost, the suppress of the density fluctuation of an image, the improvement of image quality, and high-precision for detecting the exhausting of toner by turning the toner fetching magnetic pole of a developing magnet installed inside a developer carrier toward a toner fetching port, and providing an electrostatic capacity detecting type residual toner quantity detecting means nearby the developer carrier inside a developing part. CONSTITUTION:A small-capacity developing part B for installing a developing sleeve 2 is provided, and a space is made small in the vicinity of the developing sleeve 2. Simultaneously, while the toner fetching port 4a of a film 4 is blocked with toner 3 by the action of the toner fetching pole N1 of a developing magnet 7, the toner 3 is fetched in the developing part B. Therefore, the massiveness of the toner 3 in the space in the vicinity of the developing sleeve 2 is almost constant. When fresh toner 3 is replenished from a hopper part A, the mass of the toner 3 is rapidly destroyed and changed, so that the exhausting of the toner can be detected by the electrostatic capacity detecting type residual toner quantity detecting means 18 closely installed on the developer carrier inside the developing part B. Thus, the simplification of the structure, the reduction in cost, the suppressing of fluctuation of an image density, the improvement of the image quality, and the high-precision for detecting the exhausting of the toner are attained. |
