Patent ID: 7237248

Claim:
In a disk cartridge comprising: an outer shell having a first shell, second shell, and an opening portion through which a disk table of a disk drive apparatus is inserted; an inner shell supported to slidably rotate in an inside of the outer shell; shutter members supported to slidably rotate at the inner shell; and a disk-shaped recording medium rotatably housed in a housing space formed between the inner shell and the first shell of the outer shell, wherein slidable rotation of the inner shell to the outer shell causes slidable rotation of the shutter members to open or close the opening portion of the outer shell, and the disk cartridge is inserted into an insertion opening of the disk drive apparatus so that the disk-shaped recording medium is mounted on the disk table to be used; wherein said disk cartridge further comprising; an discrimination groove formed on the outer shell and opened to an insertion direction side to the insertion opening of the disk drive apparatus for performing discrimination from another type of the disk cartridge.