Patent ID: 7730504

Claim:
A disc cartridge comprising: a disc; a main cartridge body unit having said disc rotatably housed therein and including a recording and/or reproducing aperture for exposing a portion of said disc to outside across inner and outer rims of said disc, the recording and/or reproducing aperture defining a first side and a second side of the main cartridge body unit; and an entrance part for a head unit of a recording and/or reproducing apparatus, said entrance part being a recess which is formed in the first side of the main cartridge body unit and extending to said recording and/or reproducing aperture, for entrance of at least a portion of said head unit below an outer surface of the main cartridge body unit; wherein the portion of said recording and/or reproducing aperture along the outer rim of said main cartridge body unit is opened by being formed with a cut-out formed in a wall of the main cartridge body unit and extending in a direction along the thickness of said disc, and a depth of said entrance part is less than a thickness of a wall of the first side of said main cartridge body unit so as to not expose another portion of the disc located adjacent to the recess to the outside.