| 摘要 |
PROBLEM TO BE SOLVED: To constantly maintain the concentration of a toner for two-component developer within the tolerance of an initialized value by providing a second developer concentration controller, which directly detects the concentration of the toner of a developer, and actuating the controller with the prescribed timing in order to correct the error produced at the time of the supply of the toner. SOLUTION: When the copying work corresponding to the number of copies set by an operator is completed, a second developer concentration controller is actuated, so that a reference image is formed on a photosensitive material drum 40 in order to measure the actual concentation of the toner of a developer 43 within the developing machine 44. Next, the concentration of the toner thus measured is compared with the standard value, and the defference between both is calculated, so that the value of this difference is converted into a toner-resupply-time for the excessive or insufficient toner per one sheet (of the copy), using a table of CPU 67. Since the concentration of the toner of the developer is detected directly and the resupply time (quantity) of the excessive or insufficient toner is calculated in order to correct the toner supply time (quantity), which is calculated at the time of formation of the subsequent image, the error in the supplying system, which is caused by the change of the environment or the change with the lapse of time, can be corrected constantly. |
