Abstract: A small form factor disk drive having an extremely thin, high-energy product annular magnet within the spindle motor. The magnet includes twelve alternating poles disposed about the periphery and canted from the top edge to the bottom at a slight skew angle. The high-energy product magnet generates a high starting torque which obviates the use of low viscosity lithium bearing greases. A stator disposed concentrically within the magnet has three continuous coils, each coil wound around three spokes of the stator at 120 degree intervals, for a total of nine stator slots. The rotating spindle, bearings and stationary base are constructed of materials having similar coefficients of thermal expansion to reduce stresses on the bearings during periods of temperature elevation. An annular aluminum disk support sole bonds to a ledge on the spindle hub to facilitate machining and provide material compatibility. The disk drive includes various features for reducing the amount of contamination on the disk surface.

Abstract: An actuator assembly for a disk drive is presented which includes a voice coil motor having a top return plate which is held in place substantially only by the magnetic field of the voice coil motor magnet, and no extra screws or other fasteners are needed. Non-magnetic spacers position the top return plate above the voice coil motor magnet. Consequently, there are no magnetic portions to interfere with the desired return path of the magnetic field. The actuator assembly includes a preloaded crash stop which provides an elastic as well as a dampening resistive force in stopping a positioner arm assembly upon a crash. Additionally, the crash stop is comprised substantially of non-magnetic material so as to avoid interfering with desired magnetic return paths required for the operation of the actuator. Furthermore, the crash stop comprises an integral magnetic latch which holds the positioner arm assembly in a fixed location when the disk drive is not operating.

Abstract: An information storage device for recording by means of a radiant energy beam such as a laser in which a disc-shaped base member, one or more regions of recording medium and one or more disc-shaped protective layers (or "windows") are arranged to form a layered structure or sandwich. The innermost portions of the protective layer(s) are fastened to the corresponding portions of the base member and an annular support ring radially spaced from the outermost edge of the base member is fastened to the outer edge of the protective layer(s). A circumferential gap is thereby provided between the annular support and base member to permit expansion and contraction of the base member.