| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of lowering of image density due to lapse of time when electrified amount of developer is increased even when a large number of image formation is carried out within a short period of time. SOLUTION: In this device, a means 15 to control a toner replenishing means 4b based on a result of an output value of a toner concentration detecting means 10 and a standard value, a means 16 to compensate a standard value based on an output value of the image density detecting means 7 are provided and the means 16 that the value that is a compensated standard value based on the output value of the image density detecting means 7 is set to be the standard value where an amount for compensation is erased at the time of image formation of the standard image is provided. Here, the compensated value of the standard value that is compensated based on the output value of the image density detecting means 7 is varied according to the number of image formations. |
