| 摘要 |
PURPOSE:To accurately detect residual developer without requiring an independent detecting conductor. CONSTITUTION:A blade supporting member 4 supporting an elastic blade 3 regulating the layer thickness of the developer 5 is used as the detecting conductor for the residual developer, so that a voltage induced to the blade supporting member 4 is detected with an AC bias voltage impressed to a developing sleeve 2, and converted into a DC voltage Va through a rectrifying circuit 8 and a voltage converting circuit 9. The DC voltage Va is compared with a DC voltage Vs detected when the residual toner is, for instance, 50g, on a comparing circuit 11, and when the residual toner is less than 50g, toner run-out display circuit 12 is operated, to drive toner run-out display unit 13, and the toner run-out is warned outside. The developer 5 does not stick to the blade supporting member 4, so that the residual of the developer can be accurately detected, and the flowability of the developer 5 does not have an adverse effect, as well. |
