| 摘要 |
PURPOSE:To prevent the generation of an overshoot phenomenon at the time of controlling a toner concentration, by measuring the toner concentration in a developer at a prescribed time interval, and replenishing the toner quantity of a prescribed quantity required for reaching a reference concentration value, to the developer quantity which is divided by a measurement interval. CONSTITUTION:By a toner concentration detector 25, the toner concentration in a developer is measured at a prescribed time interval, and when its measured value is below a reference concentration value which is determined in advance, the toner quantity of a prescribed quantity required for reaching said reference concentration is replenished to the developer quantity which is divided by a measurement interval. That is, the developer quantity in a developing device is divided into very small quantities, the toner concentration of its divided developer is measured in a real time and a toner is replenished. In such a way, a toner concentration control being free from an overshoot and having a high definition can be executed, and an image having no fog can be obtained. |
