| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus, cartridge, and image forming system which output a detection signal for residual amount of developer acquired by detection of residual amount of developer, and output alarm signals that the residual amount of developer is getting smaller or replacement is required in a short time so that a user can clearly recognize the alarm signals whether output of alarm is requested by the user or not. SOLUTION: A cartridge C has a developing device 4 provided with a developer housing part 41 for housing developer, and a residual amount of developer detecting means 33 for detecting the residual amount of developer in the developer housing part. Residual amount of developer detection signal acquired by the residual amount of developer detecting means 33 and a signal indicating the state of the cartridge C are respectively independently outputted to a controller part, and the alarm signal about the state of Cartridge C is given to the user when necessary. |
