| 摘要 |
PURPOSE:To detect the residual of toner precisely by forming an exciting means and a switch member having variable electrodes and moving the switch member to turn on and off the electrode by the compressing work of the tone. CONSTITUTION:A toner detecting device 14 is fitted to a developing device. An electromagnet 15 is arranged on the detector 14 and a switch 16 is arranged in the exciting direction of the electromagnet 15. The switch 16 is constituted by fitting a plate electrode 16 and a flexible electrode 21 to a holder 17 through a spring 18. A space 20 is arranged on the fitting part of the switch 16 to enter toner into the holder 17. The switch 16 is magnetically attracted by the electromagnet 15, and at the existence of toner, the electrode 21 is deformed by the toner and the switch 16 is turned on. When there exists no toner in the holder 17, the electrode 21 is not deformed and the switch 16 is turned off. The switch 16 is moved and turned on/off by the compressing work of the toner, the residual of toner can be stably detected. |
