Patent ID: 6948179

Claim:
A disk cartridge provided with a disk-shaped recording medium, wherein, the disk cartridge is configured with a disk space therein in which the recording medium can rotate; a disk-movement-restricting portion is integrally formed in the disk cartridge, defines a periphery of the disk space, and is configured to restrict movement of the recording medium in a direction parallel with a surface of the recording medium; and if: i) a width of the disk cartridge is W 1 , ii) an outside diameter of the recording medium is D 1 , and iii) the shortest distance between a rotation axis around which the recording medium rotates in the disk cartridge and the disk movement restricting portion is R 1 , then the following relationship is made to hold true: 2 ×R 1 > W 1 ≧ D 1 ; and an aperture formed on a side of the disk cartridge extends into the disk space.