| 摘要 |
PURPOSE:To accurately detect the remaining quantity of developer regardless of the kind of developer by providing a means for detecting the remaining quantity of the developer, which can detect the inside of a developing means from the outside of a cartridge, and a means for identifying the kind of the developer. CONSTITUTION:An incident transmission window 117 is provided near a light transmission window 8 and a developer kind identification means 116 is provided on a part corresponding to the window 117. By detecting the quantity of light reflected from the developer 11, the means 116 outputs a signal corresponding to the transmissivity and the reflectance of the light from the developer 11 to a CPU 13. The CPU 13 specifies the kind of the developer based on the signal from the means 116 and the data on the kind of the developer 11 stored in a ROM. The CPU 13 compares and arithmetically operates the data on the detection quantity of the remaining quantity of the developer outputted from a photodetector 9 and the data on the threshold of the developer 11. When it is judged based on the compared and operated results that the developer does not remain, an LED is lighted so as to inform that the developer does not remain. Thus, the remaining quantity of the developer can be accurately detected. |
