US Patent 7210156 Disk cartridge

A disk cartridge storing an optical disk includes a cartridge main body including a lower shell formed with a first opening and an upper shell abutted against the lower shell, a rotation wheel rotatably stored in the cartridge main body and storing the optical disk and formed with a second opening to cause the stored optical disk to face outside, and a pair of shutter plates positioned between the lower shell and the rotation wheel so that when the first and second openings coincide with each other in operative association with the rotation of the rotation wheel, these openings are opened. The rotation wheel is formed with an engagement groove adapted to engage the peripheral edge of one shutter plate.