| 摘要 |
PROBLEM TO BE SOLVED: To detect the residual amount of the developer free from incorrect detection using a permeability sensor by providing a slidably rubbing means to slidably rub an inner wall of a developer container in the vicinity of the detecting position of the permeability sensor to detect the residual amount of the developer. SOLUTION: Presence/absence of the toner stored in a toner chamber 10a is detected by a magnetic bridge sensor 20. A magnetic bridge sensor 20 is provided in a body so that a detection head 20a is opposite to a recessed part of a developing wall member 12b in the vicinity of a bottom part of the toner chamber 10a. A slidably rubbing means to slidably rub an inner wall of a developer container in the vicinity of the detecting position of the sensor is provided. The inner wall of the developer container is slidably rubbed preferably using a resin sheet as a slidably rubbing means. In addition, either of the conditions that the resin sheet is 20-100μm in thickness, the tip length is 2-10mm, the contact pressure is 5×10-5-1×10-3N/mm, and the slidably rubbing direction of the resin sheet is the forward direction, is satisfied. The condition of the developer can be changed less. |
