Abstract: An optical disk drive comprises a spindle motor (5) and an optical pickup (9) provided with an objective lens (10) for focusing a light beam on an optical recording disk (1) held on a disk table which is driven for rotation by the spindle motor (5). The spindle motor (5) is disposed with its center axis (P2) of vibration inclined at an angle (&Dgr;&thgr;) to a reference scanning line (P1) intersecting the center axis of the spindle motor (5) and the optical axis of the objective lens (10). Since the center axis (P2) of vibration is inclined at an angle (&Dgr;&thgr;) to the reference scanning line (P1), the adverse effect of the resonant vibrations of the spindle motor (5) on the operation of the optical disk drive for focusing a light beam on the optical recording disk (1) and positioning the objective lens (10) for tracking is reduced.

Abstract: A disk cartridge has an overwritable magneto-optical disk rotably mounted therein. The overwritable magneto-optical disk cartridge is usable in compatible type disk drives which also accept conventional, non-overwritable, magneto-optical disks. A magnetic initializing device is provided within the cartridge casing such that a sufficient magnetic field may be generated within the cartridge for effecting overwrite operations. Accordingly, no such magnetic initializing device need be provided in a disk drive and a size, weight and cost of such disk drives may be reduced, while cartridge performance may be reliably improved.

Abstract: A support mechanism for an optical block provided with an optical head, wherein provision is made of a reference shaft and a support shaft attached in parallel to the reference shaft, the optical block being supported between the reference shaft and the support shaft in a movable manner by positioning rotational members which are provided at one side of the optical block and which are for positioning and guiding at two locations along the axial direction of the reference shaft and by supporting rotational members which are provided at the other side of the optical block and which are for supporting and guiding the optical block at two locations of the support shaft corresponding to the two locations along the axial direction of the reference shaft.

Abstract: A rotation control for a magnet used in a magneto-optical recording system having a first coil that rotates a permanent magnet to invert the polarity of its magnetic field applied to an optical recording type disc and a second coil provided at the position displaced from the central line of the first coil and for applying a driving force to the permanent magnet when the permanent magnet begins to rotate, wherein the permanent magnet can be settled in quite a short time after it is inverted in polarity by controlling a drive current applied to the second coil.