| 摘要 |
PURPOSE:To supply properly each toner into a developer to develop always images well, by measuring the density of the image and the ratio of two kinds of toner after development when the mixture of two kinds of toner different in magnetic characteristic is used to perform development. CONSTITUTION:The developer consisting of a mixture between a magnetic toner A and a nonmagnetic toner B is stored in a developing device 9, and the electrostatic latent image on a photosensitive drum 1 is developed by a magnetic roll. The density and the quantity of the magnetic toner of the toner image of the developed standard pattern for measurement are detected by an optical sensor 22 and a magnetic sensor 23. These detected values are processed in an operating circuit 24 to obtain the mixture ratio of the toner B. It is discriminated in the circuit 24 whether this obtained value is within a proper range of mixture ration 76<=R<=98 for obtaining a good copy or not, and the toner A is supplied from a tank 25 if the toner A is deficient, and the toner B is supplied from the tank 27 if the toner B is deficient. |
