| 摘要 |
PROBLEM TO BE SOLVED: To enable the highly accurate detection of toner remaining in a toner cartridge by minimum structure. SOLUTION: The output of a magnetic sensor 160 when the toner cartridge 150 has not been attached yet is prestored in a part 133 which stores a voltage value obtained when the toner cartridge is absent, and the stored output value and the present output value of the magnetic sensor 160 are compared in a sequence control part 131. Thus, the device judges whether the toner cartridge 150 has been attached or not. |
