| 摘要 |
PURPOSE:To prevent the sticking of a toner to the window of a sensor and to control the concn. of the toner in a developer to a correct value by using the developer contg. a specific nonmagnetic toner and a resin coated carrier. CONSTITUTION:A screw 7 which transports the fresh toner and the toner and carrier recovered from the surface of a sleeve 2b to a transporting pipe 31 while uniformly mixing the toners and the carrier is provided in the lower part of a developer container 2. The sensor window for a toner concn. detector 20 is provided in the transporting pipe 31. The carrier of the developer is pro vided with the coating layer consisting of a resin on the surface of magnetic material particles. The toner is constituted of the binder resin as well as a perylene pigment, and 'C.I. Pigment Yellow 81R'. The rise of the electrostatic charge of the toner is, therefore, fast and the replenished toner is immediately provided with the correct electrostatic charge quantity by the agitating and mixing with the carrier. The sticking of the toner to the sensor window is obviated in this way and the stable control of the concn of the toner in the developer to the correct value is possible. |
