Patent ID: 7487522

Claim:
A disk cartridge comprising: a case having a housing portion for housing a disk medium formed in a disc shape so as to be rotatable, and a head opening which is provided on a recording face side of the disk medium in said housing portion and through which a head of a drive device accesses the recording face; and a shutter mechanism having a first shutter rotatably provided at the case so as to be coaxial with the disk medium and a second shutter swingable around an axis different from that of the first shutter, closing the head opening by contact ends of the first and second shutters coming into contact with each other, and opening the head opening by the first and second shutters rotating in directions opposite to each other with respect to the head opening, wherein the contact end of the first shutter includes a first arc portion and the contact end of the second shutter includes a second arc portion and wherein in a state where the head opening is closed a radius of curvature of the first arc portion and a radius of curvature of the second arc portion are coincident with each other.