Abstract: In a spindle motor, a core with a specified thickness is formed by laminating thinnest possible magnetic steel sheets to allow consumed current to be reduced. For example, by providing a structure of a core of a spindle motor with seven 0.2 mm thick steel sheets being laminated, it becomes possible to make consumed current smaller than that for a core laminated with four 0.35 mm thick steel sheets. Thus, a spindle motor is provided as being suited for downsizing an HDD and possible to reduce consumed power.

Abstract: In a thin dynamic pressure hydraulic bearing motor used for a compact HDD device which motor is provided with a thin hydraulic dynamic pressure bearing comprising a flanged rotary shaft comprising a shaft and a flange, a sleeve into which the flanged rotary shaft is rotatably inserted, a ring-like lid 35, and lubricating oil filling minute clearances formed by those bearing components, the thrust clearance c is determined as being equal to or less than a value for which a product md of the maximum vertical shift m at a rim of a magnetic disk and a diameter d of the flange of the flanged rotary shaft is divided by 4r, four times a radius r of the magnetic disk. Thus, even when no bearing stiffness is provided for the hydraulic dynamic pressure bearing motor at rest, the magnetic disk is made so as not to contact with a head supporting system such as a head loading arm.

Abstract: In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.

Abstract: A vibration actuator includes an electromechanical transducer having a magnetic circuit (1-4) and a driving coil (5), a support frame (9), and a damper (270) elastically supporting the magnetic circuit onto the support frame to flexibly damp the vibration of the magnetic circuit when a driving AC current is supplied to the coil (5). The damper (270) comprises inner and outer ring portions (271, 272) and a plurality of spiral spring portions (273) determined by a plurality of spiral slits (274, 275) formed in the damper. In order to reduce the spiral spring portion determined by the adjacent two spiral slits in its compliance, each of the spiral spring portions has an effective spring length determined by an effective angle (&thgr;) which is determined as an angle (by angular degree) from an inner end of the inner spiral slit to an outer end of the outer spiral slit defining each respective spiral spring portion around a center of the damper. The effective angle is 55 angular degree or more.

Abstract: A magnetic field source movable type phantom head has a vessel filled with physiologic saline. The vessel preferably has an inner contour corresponding to an outer contour of a cerebrum of a patient to be tested. An electrode support tube has electrodes at one end. The electrodes are arranged within the vessel and movable at least in a vertical direction toward a center of the vessel as guided by a guiding and fixing device which guides the electrode support tube in a liquid tight fashion and fixes at a predetermined position. A position of the electrode support tube is measured to determine a position of the magnetic field source in the vessel.

Abstract: An apparatus includes the position determining members for determining the relative position between the reference frame and the head utilizing at least the teeth or external acoustic meatuses and the nose of the head, and the placement members for placing the magnetic field generating elements for MEG and the markers for MRI measurement at the predetermined reference positions on the head by operating the positioning mechanism movably provided on the reference frame. Thus, the reference points for MRI measurement and MEG can be precisely set at the same position with relatively simple operation.

Abstract: A magnetic disc drive device includes a labyrinth structure proximate to the ball bearings to effectively prevent scattering of particles. The labyrinth structures are formed by various arrangements where complicated passages are defined by elements arranged proximate to the inner ring and the outer ring of a ball bearing. One of the elements forming the passages being either the hub or the frame of the magnetic disc drive device.

Abstract: A magnetic disk drive device has a hub for driving a magnetic disk when the magnetic disk is placed on the hub. A drive magnet is fastened to the inner surface of the hub. A stator core, with a coil wound thereabout, is located in opposition to the drive magnet. A frame is provided for fixedly supporting the stator core. A cutout portion is formed in the bottom of the frame, and a flexible printed circuit is disposed within the cutout portion. The coil terminal wires of the stator core and flexible lead wires are connected to the flexible printed circuit. A plural number of protrusions integral with the frame are disposed within the cutout portion. An arc-shaped lead wire holder, which is arc-shaped along the circumference of the frame, is fitted to the plural number of protrusions.

Abstract: A motor, such as a spindle motor, and a method for making such motor, wherein the motor has a stationary part, a rotary part mounted on the stationary part rotatably with respect thereto by a bearing and a magnetic fluid seal mechanism interposed in a radial gap between the stationary part and the rotary part is disclosed. The magnetic fluid seal; mechanism comprises a magnetic ring mounted on the stationary part, a ringlike magnet unit mounted on the rotary part and a magnetic fluid held in a gap between the ringlike magnet unit and the magnetic ring. The magnetic ring is made of a sintered metal made by baking a magnetic metal powder. At last the outer peripheral surface of the magnetic ring is preferably treated with a water-repelling treatment which includes impregnation with resin. All of the surfaces of the magnetic ring are non-cut surfaces.

Abstract: A television monitor control apparatus has a signal processor supplied with a standard television signal, a color cathode ray tube supplied with a processed color signal obtained from the signal processor, a reference signal memory for storing at least a set of reference signals and a signal control circuit connected to the signal processor and the reference signal memory for adjusting the operation of the signal processor on the basis of the standard television signal and a reference signal from the memory.