Abstract: A disk cartridge comprises a disk-like information recording medium and a containing portion containing the recording medium in the cartridge. The containing portion is shaped complementary to the configuration of the medium, and formed with a stepped portion inside the outer periphery of the containing portion and formed with a wall portion near the central portion of the containing portion, with the wall portion being higher than the stepped portion.

Abstract: A disc cleaning device for cleaning the surface of a disc-type recording medium comprises a belt type cleaning device which is adapted to be operated in the radial direction of the recording medium so as to clean the surface of the recording medium and a pressurizing device which presses the cleaning member against the surface of the recording medium at a region to be cleaned while keeping a cleaning surface of the cleaning device in contact with the surface of the recording medium.

Abstract: A magnetic field generator includes: a first coil group, including at least one coil, for generating a magnetic field upon energization; a second coil group, including at least one coil, and arranged such that a magnetic field is generated in substantially the same space as that of the magnetic field generated by the first coil group, a self-inductance of the second coil group being smaller than that of the first coil group; and a driving means for selectively energizing the first and second coil groups. The driving means energizes the second coil group first, and after the magnetic field is caused to rise by the second coil group, energizes the first coil group, thereby holding a constant magnetic field.