Abstract: The invention provides an optical disc apparatus having a dynamic damper mechanism which does not use any part for exclusive use for absorbing a shock of an optical pickup. The optical disc apparatus is provided with a chassis attached to a base chassis via a first elastic body, shafts provided on the chassis, an optical pickup moving on the shaft, and a weight attached to the chassis via a second elastic body, the weight is provided with stoppers on a moving path of the optical pickup.

Abstract: In the case when a disk is transported into or out of an apparatus, local contact noise is generated in a drive transmission gear and a clutch portion of a disk loading mechanism. Also, this phenomenon gives rise to problems relating to damage of parts, life of a loading motor and the like. Thus, a disk loading mechanism is provided to perform two operations of driving a disk tray in a disk transportation direction by means of a loading motor provided with a worm gear, via a first wheel gear and a second wheel gear, and also vertically raising and lowering a unit mechanism via a slide plate. In addition, a unit for controlling whirling of the above worm gear is provided to reduce contact noise of the gear and clutch portion and improve the reliability of a disk drive apparatus.

Abstract: Disk storage devices have exhibited an increase in rotational vibrations which attend high speed rotation due to weight unbalance of a disk. Accordingly, an unbalance correcting mechanism, provided with correcting balls to correct the aforesaid unbalance, meets a problem that the correcting balls are made unstable at the time of low speed rotation to generate vibrations and noises. A disk drive device is provided with an unbalance correcting mechanism comprising an annular-shaped groove provided in a turntable on a spindle motor and a plurality of correcting balls received in the groove, and in which a sliding resistance member is provided on a bottom surface of the annular-shaped groove to suppress a sliding resistance of the correcting balls on the sliding resistance member, and a correcting ball motion auxiliary member is provided on an inner peripheral side wall of the groove (toward an axis of rotation).

Abstract: A disk drive apparatus is provided in which there is a disk tray having a disk-receiving face shaped in the form of a circular groove for mounting a recording disk thereon. The disk tray has a plurality of disk holding parts for holding a recording disk onto the disk-receiving face. A disk loading mechanism provides for loading/unloading the disk tray in/out of the apparatus, and a disk position regulator is placed near the disk tray to position the disk when the disk tray is loaded/unloaded. The regulator has a contact surface contacting a part of the rim of a recording disk protruding out of the sides the disk tray.

Abstract: A disk drive is realized, which omits running-in for stabilizing a change in a correcting function produced by sliding between balls and a rolling groove in an unbalance correcting mechanism, and prevents immobility and straying of balls, and which comprises a unit mechanism assembled by using 12 balls subjected to surface treatment with heptadecafluorodecyltrimethoxysilane and a turntable plated with a chemical nickel plating containing phosphorus and boron to have a thickness of 5 &mgr;m and by injecting 1 microliter of ester oil into the rolling groove, and further comprises a recess formed in a sidewall of the rolling groove of the unbalance correcting mechanism to prolong the service life of the correcting function.

Abstract: The number of revolutions of a disk is once increased to a higher level than a resonance frequency of a rotation support system at the startup of rotation of the disk, and subsequently servo control for a pickup actuator is made to work to read information from the disk. It is possible to increase reproducibility of the disk unbalance correction and improve the apparatus in reliability without generation of vibrations and noises, and to spin the disk at high speed.

Abstract: A disc device which includes a rotary drive mechanism for rotating a replaceable recording medium. An unbalance correcting mechanism adapted to correct unbalance is incorporated in a rotary body rotating unit in the rotary drive mechanism, and includes a holding system having a holding member for holding the rotary drive mechanism and a head having at least a reproducing function. Further included is a support member composed of resilient members, for supporting a casing and a unit holder to each other. The holding system has a natural frequency higher than 30 Hz but lower than 70 Hz, and exhibits a transmission characteristic having a lift-up degree of higher than 8 dB at a resonant point.

Abstract: A brushless motor includes a minimum number of parts and is assembled easily. A molded, substantially annular plastic permanent magnet on a rotor is magnetized in axially opposite directions alternatively such that a plurality of pairs of S and N poles are formed alternatively. The substantially annular permanent magnet includes an annular portion associated with air-core coils provided on a stator for generating a driving torque for the rotor and associated with a frequency signal generating circuit pattern provided on the stator for generating an electric signal indicative of a rotor speed and a protruded portion protruding from an outer peripheral side surface of the annular portion and associated with a rotor position detecting means provided on the stator for generating an electric signal indicative of a rotor position. A boundary line between an S and N pole of one of the plural pole pairs passes through the protruded portion.