Patent ID: 7991303

Claim:
An image forming apparatus that is operable in a state in which a power supply unit is switched on, the image forming apparatus comprising; an apparatus main body; a detachable member that is detachably provided in the apparatus main body; a cover that is provided so as to be openable and closable to the apparatus main body, the cover being opened and closed for an attachment and detachment operation of the detachable member; a displacement member that is provided so as to be movable between a preventing position where the displacement member prevents the attachment and detachment operation of the detachable member and a permitting position where the displacement member permits the attachment and detachment operation of the detachable member; a one-way link mechanism that is provided in the apparatus main body for displacing the displacement member from the preventing position to the permitting position when the cover is opened from a state in which the cover is closed and the displacement member is disposed in the preventing position, the one-way link mechanism being provided for keeping the displacement member in the permitting position when the cover is closed from a state in which the cover is opened; a position detection unit for detecting a position of the displacement member right after the power supply unit has been switched on; and a history determination unit for determining an existence of a history showing an opening and closure of the cover while the power supply unit is left off based on the position of the displacement member detected by the position detection unit.