Patent ID: 7171675

Claim:
A disc player comprising: a turntable; a disc stopper movable to a first position where a first disc is concentrically positioned with the turntable and to a first retracted position where the disc stopper is spaced from the first disc; a sensor arm that moves the disc stopper from the first position to the first retracted position, wherein the disc stopper is further movable to a second position to position a second disc concentrically with the turntable and to a second retracted position where the disc stopper is spaced from the second disc, and wherein the first disc has a larger diameter than the second disc; a rotatable G plate on which the disc stopper is mounted; a loading roller that feeds a disc in a feeding direction, wherein the sensor arm comprises a boss engaging an opening in the rotatable G plate, wherein the disc player further comprises a spring that rotatably biases the boss toward a first position in the opening in the rotatable G plate, wherein the loading roller feeds the disc into contact with the disc stopper, wherein the loading roller further feeds the disc to force the disc stopper in the feeding direction to rotate the G plate, and wherein the disc player further comprises a damper unit that clamps a disc to the turntable; and a lock mechanism that comprises: a key-shaped hole in a drive plate; an elongated hole of a driving piece of a first cam plate; a trigger groove in a trigger rack; and a lock pin of a sensor arm stopper that engages the key-shaped hole, the elongated hole and the trigger groove.