Patent ID: 8396379

Claim:
An image forming apparatus comprising: a plurality of doors capable of selectively opening and closing each of a plurality of openings into which a plurality of cartridges each containing a respective toner can be respectively inserted; a lock mechanism to allow each of the plurality of doors to be selectively locked; a drive mechanism to automatically open an unlocked door when the door is released from a locking by the lock mechanism; a detecting unit capable of detecting information concerning the remaining amount of toner in each of the plurality of cartridges; an output unit configured to output a signal that carries information concerning the remaining amount of toner in a cartridge, among the plurality of cartridges, when that remaining amount is equal to or smaller than a predetermined amount; an input unit configured to receive an input signal for unlocking a door being locked by the lock mechanism; and a control unit configured to control the lock mechanism to selectively unlock the plurality of doors based on information detected by the detecting unit and the input signal received by the input unit, wherein, in a case where an input signal input in the input unit by a user is a signal for unlocking a locking of a door corresponding to the cartridge in which the remaining amount of the toner is equal to or smaller than the predetermined amount, the control unit controls the lock mechanism to immediately unlock the locking of the door corresponding to the input signal input in the input unit while, in a case where an input signal input in the input unit by the user is not a signal for unlocking a locking of a door corresponding to the cartridge in which the remaining amount of the toner is equal to or smaller than the predetermined amount, the control unit outputs information for confirming that the input signal input in the input unit is not the signal for unlocking the locking of the door corresponding to the cartridge in which the remaining amount of the toner is equal to or smaller than the predetermined amount and controls the lock mechanism to unlock or not to unlock the door in response to a signal input in the input unit by the user, based on whether the input signal is a signal of acceptance of unlocking or a signal of rejection of unlocking.