| 摘要 |
PROBLEM TO BE SOLVED: To form images with stable density regardless of a charge amount of toner and reduce an amount of excessive density caused by correcting, to high-density side, an output target value Vtref that functions as a target value of toner density.SOLUTION: An image forming apparatus performs: detecting, with an optical sensor unit 103, a toner attachment amount of a test toner image for each of YMCK colors, and, based on the result, calculating a correction amount of an output target value Vtref of a toner density sensor (each of 10Y, M, C, and K); correcting the Vtref on the basis of the calculation result, and, before replenishing toner on the basis of the difference between an output value Vt of the toner density sensor and a post-correction output target value Vtref, calculating a correction-corresponding drive amount that is On-time of replenishing clutch (each of 83Y, M, C, and K) for changing the toner density of a developer by an amount corresponding to the correction amount; and executing a correction-corresponding replenishing process of turning on the replenishing clutch by the amount of the calculated amount to replenish the toner. |
