| 摘要 |
PROBLEM TO BE SOLVED: To provide a concentration controller by which the replenishment of toner in the midst of printing can be extremely reduced at the time of intermittent printing. SOLUTION: This concentration controller for controlling toner concentration in a developing device for sticking the toner to a photoreceptor on which an electrostatic latent image is formed by storing developer consisting of several kinds of components including the toner is equipped with a toner concentration detecting sensor 14 detecting toner concentration, a CPU 21 realizing a replenishment judging means for judging whether or not the developing device should be replenished with the toner based on detection output from the sensor 14, and a motor 34 replenishing the developing device with the toner according to the judged result by the replenishment judging means. The replenishment judging means judges that the replenishment of the toner must be performed with thicker concentration in the midst of non-printing than in the midst of printing by making the toner concentration for judging the propriety of the replenishment of the toner different between in the midst of printing and in the midst of non-printing. |
