| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device for thoroughly triboelectifying developer on a developer carrier and stably developing even in the case when the developer is quickly consumed in the developing device, and also, to provide an image forming device equipped with the developing device. SOLUTION: As for the developing device which is constituted so that the toner lying on a developing sleeve 4a may be triboelectrified in accordance with the rotation of the developing sleeve 4a, and the developing sleeve 4a may be used for developing after being rotary-driven as long as a previously set rotary driving time, the device is provided with a dot counter 101 for measuring image information amount, and a CPU 103 for calculating an image ratio based on the image information amount measured by the dot counter 101, and when the image ratio calculated by the CPU 103 becomes equal to or exceeding a set value, the set rotary driving time of the developing sleeve 4a is made longer. |
