| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve control, without being affected by accuracy in the estimation of toner consumption, such that the toner concentration of two-component developer stored in a developing container used for image development falls in an appropriate range without directly detecting the toner concentration. <P>SOLUTION: When a developer cartridge is replaced, toner is supplied to a developing unit for a fixed length of time, and then the formation and detection of a reference patch image, the calculation of a detection value Rtc, and the calculation of a deviation ΔRtc from a target value are carried out in that order (252 to 260), thereby calculating the amount Rtc_upr of a detection value increased before and after the supply of toner (266). If the increased amount Rtc_upr is smaller than a specific value A (Yes in 268), a determination is made that the development performance of the developer is lower than a standard, and the target value Rtc_tgt of the detection value Rtc is altered to a low concentration level (270). If the increased amount Rtc_upr is greater than the specific value B (Yes in 272), a determination is made that the development performance of the developer is higher than the standard, and the target value Rtc_tgt of the detection value Rtc is altered to a higher concentration level (274). <P>COPYRIGHT: (C)2011,JPO&INPIT |
