Patent ID: 8205875

Claim:
An apparatus comprising an apparatus body, a functional unit detachably attached to the apparatus body, and a functional unit positioning device for positioning the functional unit detachably attachable to the apparatus body, comprising: a biasing device that biases the functional unit in a unit-out direction, the biasing device including an actuator; and a stopper mechanism having a first stopper and a second stopper, the stopper mechanism exerting and releasing control over release of the functional unit, wherein the biasing device biases the functional unit so that the second stopper comes in contact with the first stopper to set the functional unit in a locked position in a unit in-out direction, and the biasing device is configured to change, using the actuator, the magnitude of a bias force on the functional unit from low to high when the functional unit is inserted and advanced up to a predetermined position into the apparatus body.