Patent ID: 7287265

Claim:
A disk cartridge, comprising: a cartridge body including a lower shell having formed therein a first opening for write and/or read and an upper shell butt-joined to the lower shell; a rotation wheel housed rotatably in the cartridge body and which houses a disk and has formed therein a second opening corresponding to the first opening and through which the housed disk is exposed to outside; and a shutter mechanism provided between the lower shell and rotation wheel and including a pair of shutter plates which are pivoted in conjunction with the rotation of the rotation wheel to uncover the first and second openings when the latter coincide with each other, the rotation wheel having formed at the front side thereof, at which the disk cartridge is first inserted into a disk recorder and/or player, a to-be-operated portion in which a shutter releasing portion of the disk recorder and/or player is engaged; and the to-be-operated portion being formed from a concavity opening the front side of the disk cartridge at which the latter is first inserted into the disk recorder and/or player.