| 摘要 |
PURPOSE:To always control the electrifying quantity of a developer within a specified range by detecting the flowing pressure of the developer inside a developing unit, and controlling the action of a developer stirring means. CONSTITUTION:A stirring unit 2 and a developing roller 13 are rotated like arrows B and C, so that the developer inside the developing unit 1 flows like arrows (d), (e) and (f). In the vicinity of the bottom part of the developing unit 1, a high-polymen piezoelectric plate 3 for detecting the flowing pressure of the developer is arranged at the position near between the developing roller 13 and the stirring unit 2. The flowing pressure of the developer inside the developing unit 1 is detected by a developer flowing pressure detecting means 3. and the action of the developer stirring means 2 is controlled by a stirring control means 4, according to the detected signal. Thus, the developer is stirred according to the electrifying quantity, and the electrifying quantity of the developer can be controlled within the specified range. |
