| 摘要 |
PROBLEM TO BE SOLVED: To accurately achieve the target number of sheets as toner yields without requiring a special means by controlling image forming conditions, based on the detection result of a quantitative toner-consumption-detection means, thereby reducing an amount of toner consumption. SOLUTION: When a copy button is turned on, a copying operation is repeated continuously on the set number of sheets, the cumulative number of copies (the number of sheets subjected to image formation) are counted up by an ejected-sheet counter 22 and it is stored in the memory of a control part 23. Also, when the copying operation is carried out, the control part 23 make a cumulative toner-replenishing-time counter, as a time measuring means, measure the time in such a manner that the driving time of a toner replenishment part 9a obtained this time is added to the cumulative driving-time of the toner replenishment part 9a obtained from the previous copying operation. The cumulative driving-time of the toner replenishment part 9a is stored in the memory. Then, from the cumulative number of copies and the cumulative toner- replenishing-time the control part 23 judges an amount of toner consumption per prescribed number of sheets. Based on the result of the judgment, it controls the image forming conditions for reducing the amount of toner consumption. |
