| 摘要 |
PROBLEM TO BE SOLVED: To solve such a defect that image density fluctuates in accordance with a rapid change of the electrostatically charged quantity of developer, as for an image forming device for controlling toner concentration. SOLUTION: The image forming device is provided with a latent image forming means 3 for forming a latent image on an image carrier, a developing device 5 for developing the latent image by the developer constituted of toner and carrier, a toner replenishing device 12 for replenishing the toner to the developing device, a toner concentration detecting means 13 for detecting the mixture ratio of the toner to the carrier in the developer in the developing device, a reference image density detecting means 15 for detecting the density of the reference image formed on the image carrier, and a correcting means for correcting the target value of the toner concentration detecting means based on the detection value of the reference image density detecting means so that the detection value may become a prescribed target value, and in the case a fixing temperature set when a power is supplied is equal to or below a prescribed temperature, besides, in the case the integrated number of image-formed sheets counted after the power is supplied is equal to or below a prescribed value, the target value of the toner concentration detecting means is varied at prescribed intervals at the time of continuously forming the images. |
