| 摘要 |
PROBLEM TO BE SOLVED: To stably maintain the level of the image quality of developed image from the start of the use of a developing device to the end of its life by detecting a quantity of toner remaining in a toner holding chamber, and controlling the speed of revolution of a developing roller or the number of sheets, of recording media, on which printing is carried out. SOLUTION: The initial speed R of revolution of a toner carrier is set, and the toner carrier 31 is rotated to print. Then, according to the number of printed sheets, a quantity of toner remaining in a holding chamber 42, that is, the output of the detection of the quantity of toner from a photo-sensor 38 is measured. In the case the level of the output of the detection of the measured quantity of toner is above a CorBor A level, the speed of revolution of the toner carrier is increased according to each level, and a fresh speed R+r of revolution of the toner carrier is reset, again and the toner carrier 31 is rotated to continue printing. When the level of the output of the detection of the quantity of toner is equal to or below A, a user is informed of the state of being nearly empty that means the toner is running out, the allowable number of sheets on which printing is carried out is set, and the number of the sheets is decreased after each printing. At a point of time that the number of the sheets reaches zero, the user is informed of the state of being empty that means the toner has run out. |
