Abstract: Embodiments of the present invention provide a magnetic disk device that can reduce an external force applied to the carriage. According to one embodiment, in a magnetic disk device, a bracket inserted between a carriage and a base is supported toward the base side by support portions owned by the bracket and by a band with a space provided between the bracket and the opposed side of the carriage (such as a top surface of the mounting stand). This configuration cannot apply an external force in the rotation direction to the carriage from the bracket even when the bracket is thermally expanded due to heat generated from a head amplifier or the like mounted on a flexible substrate.

Abstract: A magnetic disk apparatus capable of reducing deformation of a magnetic disk is disclosed. The magnetic disk apparatus comprises a magnetic disk on which data is recorded while the disk is driven, a hub around which the magnetic disk is supported from an under side of the magnetic disk, and a clamp in contact with the other side of the magnetic disk and fixing the magnetic disk. An O-ring is interposed between a flange formed at an outer circumference of the hub and the magnetic disk, and a spacer is interposed between the magnetic disk and the O-ring. Thus an upper surface of the hub is in contact with an under surface of the clamp and defines a vertical position of the magnetic disk.

Abstract: Embodiments of the present invention provide a magnetic disk device that can reduce an external force applied to the carriage. According to one embodiment, in a magnetic disk device, a bracket inserted between a carriage and a base is supported toward the base side by support portions owned by the bracket and by a band with a space provided between the bracket and the opposed side of the carriage (such as a top surface of the mounting stand). This configuration cannot apply an external force in the rotation direction to the carriage from the bracket even when the bracket is thermally expanded due to heat generated from a head amplifier or the like mounted on a flexible substrate.

Abstract: Embodiments of the invention provide a magnetic disk drive and magnetic disk drive control method for unloading a head safely with a simple configuration when a positioning control signal cannot be detected due, for instance, to a seek error. In one embodiment, when a head cannot detect servo information prerecorded on a disk, a positioning control section resets and starts a time counting section, and switches to an unloading control section for causing the unloading control section to output a position control signal to a VCM driver. The time counting section counts tacho-pulses generated by a motor driver, and outputs time information. The unloading control section receives the time information from the time counting section. In accordance with the received time information, the unloading control section computes the position control signal that the positioning control section outputs to the VCM driver.

Abstract: Embodiments of the invention provide a magnetic disk drive and magnetic disk drive control method for unloading a head safely with a simple configuration when a positioning control signal cannot be detected due, for instance, to a seek error. In one embodiment, when a head cannot detect servo information prerecorded on a disk, a positioning control section resets and starts a time counting section, and switches to an unloading control section for causing the unloading control section to output a position control signal to a VCM driver. The time counting section counts tacho-pulses generated by a motor driver, and outputs time information. The unloading control section receives the time information from the time counting section. In accordance with the received time information, the unloading control section computes the position control signal that the positioning control section outputs to the VCM driver.

Abstract: A control device for preventing abrasion inside bearings in an information recording and reproducing device mounted on an automobile and preventing degradation in rotational accuracy, the information recording and reproducing device including disk media holding information, heads for recording or reproducing information from the disk media, a carriage for turning to position the heads on surfaces of the disk, a bearing part permitting the carriage to turn, a spindle motor for rotatingly driving the disk media, and a bearing part of the spindle motor, the control device comprising a detecting unit for detecting a vehicle operating manner, which is carried out before vehicular vibrations are caused, and a control unit for starting rotation and/or starting swings the bearing part of the spindle motor and/or the bearing part of the carriage on the basis of a signal from the detecting unit.

Abstract: A magnetic disk apparatus capable of reducing deformation of a magnetic disk is disclosed. The magnetic disk apparatus comprises a magnetic disk on which data is recorded while the disk is driven, a hub around which the magnetic disk is supported from an under side of the magnetic disk, and a clamp in contact with the other side of the magnetic disk and fixing the magnetic disk. An O-ring is interposed between a flange formed at an outer circumference of the hub and the magnetic disk, and a spacer is interposed between the magnetic disk and the O-ring. Thus an upper surface of the hub is in contact with an under surface of the clamp and defines a vertical position of the magnetic disk.

Abstract: In a magnetic disc apparatus, it is hard to fix a pivot mechanism in a carriage, in view of a mounting space, and in the case that a casing is made of resin, it is hard to fix in accordance with a conventional screwing method in view of a rigidity and a strength. A pivot mechanism (107) is fixed to a base (100) by press fitting a plastically deformable pivot pin (108) of the pivot mechanism (107) to the base (100), passing the pivot pin (108) through a sleeve (107-a) of the pivot mechanism (107) and plastically deforming the pivot pin (108). In the case of dissembling, the pivot pin (108) is pushed out from the base (100) together with a carriage (104), and thereafter the pivot pin (108) is separated from the pivot mechanism (107). Only the pivot pin (108) is disposable.

Abstract: The motor drive method is for a magnetic disk drive apparatus having a magnetic disk as an information recording medium, a magnetic head for recording/reproducing information to/from the magnetic disk, and a motor for driving the magnetic disk, the motor having a connection point connecting middle points in a multi-phase Y-connection and capable of realizing a unipolar drive method for successively exciting phases and a bipolar drive method for simultaneously exciting two adjacent phases, wherein the unipolar drive method is selected when the temperature in the magnetic disk drive apparatus is lower than a predetermined temperature and the bipolar drive method is selected when the temperature exceeds the predetermined temperature. The motor stationary rotation is assured by selecting the unipolar drive method or the bipolar drive method.

Abstract: The motor drive method is for a magnetic disk drive apparatus having a magnetic disk as an information recording medium, a magnetic head for recording/reproducing information to/from the magnetic disk, and a motor for driving the magnetic disk, the motor having a connection point connecting middle points in a multi-phase Y-connection and capable of realizing a unipolar drive method for successively exciting phases and a bipolar drive method for simultaneously exciting two adjacent phases, wherein the unipolar drive method is selected when the temperature in the magnetic disk drive apparatus is lower than a predetermined temperature and the bipolar drive method is selected when the temperature exceeds the predetermined temperature. The motor stationary rotation is assured by selecting the unipolar drive method or the bipolar drive method.

Abstract: A control device for preventing abrasion inside bearings in an information recording and reproducing device mounted on an automobile and preventing degradation in rotational accuracy, the information recording and reproducing device including disk media holding information, heads for recording or reproducing information from the disk media, a carriage for turning to position the heads on surfaces of the disk, a bearing part permitting the carriage to turn, a spindle motor for rotatingly driving the disk media, and a bearing part of the spindle motor, the control device comprising a detecting unit for detecting a vehicle operating manner, which is carried out before vehicular vibrations are caused, and a control unit for starting rotation and/or starting swings the bearing part of the spindle motor and/or the bearing part of the carriage on the basis of a signal from the detecting unit.

Abstract: A rotor magnet is attached to the inner peripheral portion of a hub to attach a magnetic disk or the like and a stator is provided in the outer peripheral portion of a bearing housing so as to face the rotor magnet, thereby forming a rotating mechanism. A magnetic pre-load mechanism is provided and a spindle is pressed to one side of a radial bearing, thereby stabilizing the rotation.

Abstract: A motor for a disc drive unit is spatially separated from an enclosure housing the magnetic disks and read-write heads. The disks are mounted on a hub that is fixed to a shaft extending through the hub, having bearings at either end of the shaft. One end of the shaft extends outside of the enclosure, the rotor of the motor is fixed to this end of the shaft and is concentric therewith. The rotor has a rotor housing that is cup-shaped, with an opening facing away from the interior of the enclosure. Inwardly of the rotor housing is a stator mounted on a supporting member. The supporting member is detachably mounted to the enclosure for easy access to the stator. Further, a circuit board having control elements for the motor, including a Hall element mounted thereon, is provided on the supporting member for easy access to the circuit board.

Abstract: A disk drive housing structure has a rotating disk for recording information and a transducer adapted to write and read information on and from the disk. The structure further includes a positioning system having at least an arm to which the transducer is fixed and which is adapted to selectively position the transducer along the radial direction of the disk transducer by turning the arm. The structure also includes a member on which the disk, transducer and positioning system are mounted, wherein the mounting member includes a first housing which supports thereon both ends of a rotary shaft of the recording medium and both ends of a rotary shaft of the positioning system, and which has a first aperture part. The first housing further includes a second aperture part through which the disk and the rotary shaft supporting the disk are inserted and to which a supporting member for the rotary shaft of the recording medium is fixed.

Abstract: A method of adjusting the position of a magnetic head in a magnetic head positioning mechanism positions the magnetic head at a target track on a magnetic disk. Since a floppy disk system is so designed as to make a floppy disk replaceable, it is necessary to adjust accurately the position of the magnetic head from the position of a spindle. According to the present invention, the position of the magnetic head is adjusted by the method wherein the displacement of an amount of deviation from a prescribed track in the magnetic head positioning mechanism is calculated beforehand, the amount of deviation is sampled subsequently by moving the magnetic head, this sampled amount of deviation is compared with the aforesaid calculated displacement to know the maximum and minimum values of the amounts of deviation on the track of movement of the magnetic head, and the adjustment is implemented on the basis of these values.

Abstract: A method and apparatus for moving a moving member of a positioning mechanism to a target position by means of a stepper motor as a driver. The method and apparatus alleviate the positioning error attributable to the hysteresis of the stepper motor, which is inherent in stepper motor drive systems, by controlling the oscillation damping condition when the stepper motor has entered a damped oscillation phase in the vicinity to the target positon. The damping condition is controlled by varying the solid friction factor of the mechanism or the drawback torque constant of the stepper motor.

Abstract: A device for preventing abnormal flow of gas fuel from a gas fuel injector of a diesel engine. The device has a pipe for supplying a pressurized gas fuel, a fuel injector including a passage connected to the pipe and leading to fuel injection nozzle ports, and a fuel cut-off valve means adapted to close the gas fuel passage upon detection of a reduction of the fuel pressure in the fuel passage. Any abnormal supply of fuel due to stick of the fuel injector is prevented so as to avoid any risk of explosion which otherwise may be caused by the abnormal supply of the gas fuel.

Abstract: A magnetic disc head positioning system using a stepper motor eliminates positioning errors due to different approach directions and distances to a target track position through a drive control of temporarily stopping the head at a position immediately preceding or following the target track depending on the approach direction and, thereafter, moving the head from this position to the target track with a constant transient response. The head is brought to the temporary stop position by utilizing the overshooting response of the stepper motor so as to minimize the positioning time.