| 摘要 |
PURPOSE:To stably perform recording to the extent of high density by measuring the electrostatically charged quantity of developer and consequently controlling the electrostatically charged quantity so that it may be a prescribed value. CONSTITUTION:In the flow of the developer, a measuring mechanism 1 and a control mechanism 30 are provided on the upstream side of an electrostatic charger 2. As to the developer, the electrostatically charged quantity is controlled by the electrostatic charging mechanism 2 based on the measured results to obtain the prescribed electrostatically charged quantity. The prescribed electrostatically charged quantity means the always fixed quantity of charges which should be given to the developer and also means the quantity of charges necessary to maintain the recording with the initial density of electrophotography or the high density. The developer having prescribed electrostatically charged quantity is conveyed to a developing brush 3 and development is performed by allowing toner to adhere to the photosensitive body. Thus, the change of the electrostatically charged quantity of the developer caused by the fatigue of developer, the change of toner concentration and the change of temperature and humidity, etc., can be prevented and also the stable recording density can be accomplished. |
