| 摘要 |
PURPOSE:To use a developer having high developing efficiency and comparatively high density, by providing a temperature detecting means and a viscosity detecting means of a developer, and providing a means for detecting and controlling the toner density in the developer. CONSTITUTION:When a rotating member 11 is rotated at a constant speed by a motor 13, rotation torque increases as the viscosity of a developer increases, a current flowing to the motor 13 also increases, and the viscosity of the developer can also be measured by measuring the current. When the viscosity of a developer is measured by a viscosimeter 6 and temperature is measured by a thermister 5, its detected signal is inputted to a controller 14, and is compared with a reference value. When the viscosity at a temperature of the developer in that case is smaller than the reference value, a solenoid valve 15 is opened for a constant interval of time, and a toner 17 is supplied into a developer tank 1 by a fixed quantity. On the contrary, when the measured viscosity is larger than the reference value, a solenoid valve 18 is opened for a constant interval of time, and a diluting solution, namely, a liquid 20 having the same quality as a solvent in the developer is supplied into the developer tank 1 by a fixed quantity. |
