Image forming apparatus with positioning mechanism for detection unit and for contact unit

An image forming apparatus comprising:

• an apparatus body provided with an opening portion;
• and
• an attachable/detachable unit configured to be attached to and detached from the apparatus body through the opening portion,
• wherein the apparatus body includes
• (i) an opening/closing member configured to move between a closed position in which the opening/closing member closes the opening portion and an opened position in which the opening/closing member opens the opening portion,
• (ii) a detection unit configured to detect a state of the attachable/detachable unit, the detection unit being disposed to face an end face of the attachable/detachable unit in a first direction in a state where the attachable/detachable unit is attached to the apparatus body, the first direction being a direction intersecting an attachment direction of the attachable/detachable unit to the apparatus body,
• (iii) a movement member configured to move the detection unit between a first position and a second position in the first direction and to allow a movement of the detection unit with respect to the movement member,
• (iv) a restricting member configured to restrict, to a first range, a movement of the detection unit with respect to the movement member in a second direction intersecting the first direction, and
• (v) an interlocking mechanism configured to move the movement member in an interlocked manner with a movement of the opening/closing member,
• wherein the attachable/detachable unit includes a positioning portion disposed on the end face,
• wherein the detection unit includes a positioned portion configured to be engaged with the positioning portion such that a position of the detection unit with respect to the attachable/detachable unit on a plane perpendicular to the first direction is determined,
• wherein one of the positioned portion and the positioning portion is a projecting portion that projects in the first direction, and the other of the positioned portion and the positioning portion is a first hole portion configured to be engaged with the projecting portion,
• wherein the first position is a position in which the positioned portion is engaged with the positioning portion, and the second position is a position in which the positioned portion is disengaged from the positioning portion,
• wherein the interlocking mechanism is configured such that the movement member moves the detection unit from the first position to the second position in a case where the opening/closing member is moved from the closed position to the opened position, and such that the movement member moves the detection unit from the second position to the first position in a case where the opening/closing member is moved from the opened position to the closed position, and
• wherein the restricting member is configured such that the first range in a state where the detection unit is positioned at the second position is narrower than the first range in a state where the detection unit is positioned at the first position.