Patent ID: 7769321

Claim:
A functional unit that is detachably attached to a main body of an image forming apparatus by inserting into a hollow portion of the main body, comprising: a casing; a first locking member that is pivotally supported by the casing; and a second locking member that is supported by the casing to be movable in a direction of approaching or separating from the first locking member and is pressed in a direction of approaching to the first locking member by a restricting member provided on the main body when the functional unit is inserted into the hollow portion, wherein the first locking member and the second locking member are arranged in the casing such that, when the functional unit is drawn out of the main body, and the second locking member and the restricting member are disengaged from each other, the first locking member can freely pivot within a predetermined angular range, and when the first locking member is pivoted at a locking position where the first locking member engages with the second locking member pressed by the restricting member while the functional unit is inserted into the hollow portion, the first locking member frictionally engages with the second locking member where the first locking member is engaged at the locking position, and the second locking member and the restricting member come in pressure contact with each other, so that the functional unit is locked to the image forming apparatus main body, and wherein the restricting member includes a tongue portion having an inclination face inclined obliquely downwardly from a top portion toward an inner side of the image forming apparatus main body, and the second locking member is pressed in the direction of approaching the first locking member by running on the inclination face of the restricting member.