Patent ID: 7222351

Claim:
A shutter opening/closing mechanism for a disc cartridge comprising a disc-shaped recording medium, an inner rotor, a shutter and a housing in which an aperture is formed, said aperture opened or closed by said shutter by rotation of said inner rotor, said shutter opening/closing mechanism comprising: a base relatively movable along one lateral surface of said housing; a first engagement member provided to one end of said base for engaging with a first mating engagement section provided to an outer rim of said inner rotor facing outwards from a lateral side of said housing when said shutter is closed; a second engagement member provided to an other end of said base for engaging with a second mating engagement section provided to the outer rim of said inner rotor facing outwards from a lateral side of said housing when said shutter is opened; said first engagement member and said second engagement member being mounted to said base so that both engagement members are movable both linearly, perpendicular to a surface of said housing, and angularly, coincident with said surface of said housing; a rack member mounted between said first engagement member and said second engagement member of said base for meshing with a gear provided in a preset area of the outer rim of said inner rotor between said first mating engagement section and said second mating engagement section; and a first torsion coil spring and a second torsion coil spring each having one end of the coiled part of the wire retained by said base and an other end resiliently movable in a direction perpendicular to the surface and in contact with one of the first or second engagement members in a manner to allow the engagement members to move both linearly and angularly.