Abstract: According to one embodiment, a magnetic disc apparatus includes a magnetic head which reads information stored in a magnetic disc, an arm which supports the magnetic head, and a feedback controller which controls a coarse actuator to move the magnetic head above the magnetic disc by driving the arm, a fine actuator to hold a position of the magnetic head, and a feedback path which feeds back a displacement of the actuator to a target value of the coarse actuator. The feedback controller controls decoupling of a double actuator system which adds up the coarse actuator and the fine actuator.

Abstract: According to one embodiment, a magnetic disc apparatus includes a magnetic head which reads information stored in a magnetic disc, an arm which supports the magnetic head, and a feedback controller which controls a coarse actuator to move the magnetic head above the magnetic disc by driving the arm, a fine actuator to hold a position of the magnetic head, and a feedback path which feeds back a displacement of the actuator to a target value of the coarse actuator. The feedback controller controls decoupling of a double actuator system which adds up the coarse actuator and the fine actuator.

Abstract: An apparatus that corrects a weight imbalance around an axis of a spindle motor that rotates a disc in a disc drive includes an impact applicator that applies an impact to a housing that houses the spindle motor and the disc, a plate that supports the housing and impact applicator, a spring member that supports the plate, and enables the plate and the housing to vibrate together when the spindle motor rotates, and a detector that detects a vibration of the housing when the spindle motor rotates.

Abstract: The present invention relates to a magnetic head actuator and a magnetic disk device in which a magnetic head is moved to a predetermined position by actuating an arm on a revolving magnetic disk. A magnetic head actuator comprises an arm in which a suspension for supporting a magnetic head is provided, the arm being actuated to move the magnetic head. A damper material is provided on at least one side of the arm, the damper material comprising a restriction material and a viscoelastic material, the restriction material suppressing vibrations of the arm, and the viscoelastic material absorbing vibrations of the arm.

Abstract: According to one embodiment, in a controller of a servo system that performs positioning control of a head by feedback control includes a generating module and a notch filter. The generating module compares a target position and position information decoded from data read by the head from a recording medium to generate a position error signal. The notch filter performs notch filter processing to remove machine vibration of a head driving module on the position error signal. The transfer function H(s) of the notch filter is set to H(s)=[{s2+2k??s+?2}/{s2+2??s+?2}]·[(?1s+1)] where s is a Laplace operator, k is a constant, ?1 and ?2 are time constants, ? is a damping constant, and ? is a notch frequency.

Abstract: A carriage block body is coupled to a support shaft for relative rotation. A carriage arm extends from the carriage block body along an imaginary plane perpendicular to the longitudinal axis of the support shaft. A head suspension is attached to the tip end of the carriage arm. A wiring extends outside the contour of the head suspension along the side of the carriage arm. A projection protrudes from the side of the carriage arm. An adhesive is utilized to bond the wiring to the projection. Even though airflow generated along the surface of a rotating disk medium collides against the carriage arm, the wiring is reliably prevented from fluttering outside the contour of the head suspension. The vibration of the wiring is thus significantly suppressed. The carriage arm is prevented from vibrating.

Abstract: A first component defines a threaded bore. A second component is kept in contact with the first component. A clamping screw penetrates through the second component and is screwed in the threaded bore. A lubricating agent film is interposed between the threaded bore and the clamping screw. The lubricating agent film is made of a macromolecular compound having a polar end group. The lubricating agent film serves to reduce the friction between the threaded bore and the clamping screw. Generation of dust is prevented when the clamping screw is being screwed into the threaded bore. In addition, the clamping screw exhibits a larger axial force at a certain amount of a fastening torque as compared with a conventional clamping screw. A larger axial force can thus be applied to hold the second component onto the first component.

Abstract: A method for manufacturing a head stack assembly that includes a pair of suspensions each of which supports a head, an arm that drives the head, and a pair of base plates that attach the pair of suspensions to both sides of the arm that has a perforation hole, each of the pair of base plates having a boss with an opening includes the step of swaging the pair of base plates with the arm by passing, in one direction, a processing member larger than the opening through the perforation hole and the base plates while the pair of base plates are being inserted into the perforation hole at both sides of the perforation hole, wherein where a neutral plane is defined as a plane that halves a thickness of the arm and is perpendicular to a section that includes a center axis of the perforation hole, a first position is defined as a position that has a minimum internal diameter of the base plate, and a second position is defined as a position closest to the neutral plane among contact positions between the base plates an

Abstract: A magnetic disc apparatus has a ramp holding the magnetic head in a position apart from the magnetic disc and a filter case holding a filter in the state of being bent in such a manner that the filter surrounds the ramp together with the magnetic disc. The filter removes dust in airflow which flows in the magnetic disc apparatus accompanying the rotation of the magnetic disc.

Abstract: A plate member is made of a metal material lighter than stainless steel in a suspension for a head slider. This leads to a reduction in the weight of the suspension. The natural frequency of the suspension is thus raised. Moreover, the viscoelastic member is interposed between the front surface of the plate member and the back surface of the flexure. This structure allows either the plate member or the flexure to act as a base and the other to act as a constraining member. In other words, the plate member, the flexure and the viscoelastic member in combination act as a so-called vibration damper including constraining layers. The viscoelastic member serves to further suppress vibration of the plate member and the flexure.

Abstract: In a magnetic recording device, a semiconductor laser (LD) is disposed at a position with a predetermined distance from a swing arm having a slider. The laser beam output from the LD is irradiated, via a beam converter and a mirror, to a spherical aberration lens that generates spherical aberration. The laser beam transmitted through the spherical aberration lens is directed to a light incident opening of the slider at a constant angle (perpendicularly), and then to a position of a recording medium at which information is recorded, thereby performing thermal assist at the magnetic recording time.

Abstract: A magnetic head structure has a coil and a magnetic pole allowing a magnetic flux generated by the coil to be transmitted therethrough and forming a magnetic gap. An insulating layer surrounds the coil, and a protective layer covers the insulating layer and the magnetic pole. The insulating layer has a volume equal to or greater than a value which is determined with respect to a thickness of the protective layer. It is preferable to increase the volume of the insulating layer as the thickness of the protective layer is made greater. By increasing the volume of the insulating layer, the protrusion of a portion of a floating surface of the magnetic head slider near the magnetic pole, toward the disk, is reduced.

Abstract: Vibrations in a magnetic head assembly equipped with a magnetic head, caused by the effects of the flow of air arising from the high-speed rotation of a magnetic disk, can be suppressed by affixing a damping material to the magnetic head assembly. As a result, accurate positioning is possible with high reliability, the frequency of occurrence of errors during data recording and playback can be suppressed, high data transfer rates can be maintained, and high recording densities for a magnetic disk device can be realized.

Abstract: A clamp device that clamps a disc onto a spindle motor that rotates the disc includes a clamp ring stacked on the disc and clamps the disc onto the spindle motor, a screw that fixes the clamp ring onto the spindle motor, and an axial force adjuster that nonlinearly changes a relationship between a tightening force of the screw and an axial force actually applied to the disc, and includes an elastic part that has a spring constant smaller than that of the clamp ring.

Abstract: An apparatus that corrects a weight imbalance around an axis of a spindle motor that rotates a disc in a disc drive includes an impact applicator that applies an impact to a housing that houses the spindle motor and the disc, a plate that supports the housing and impact applicator, a spring member that supports the plate, and enables the plate and the housing to vibrate together when the spindle motor rotates, and a detector that detects a vibration of the housing when the spindle motor rotates.

Abstract: A first component defines a threaded bore. A second component is kept in contact with the first component. A clamping screw penetrates through the second component and is screwed in the threaded bore. A lubricating agent film is interposed between the threaded bore and the clamping screw. The lubricating agent film is made of a macromolecular compound having a polar end group. The lubricating agent film serves to reduce the friction between the threaded bore and the clamping screw. Generation of dust is prevented when the clamping screw is being screwed into the threaded bore. In addition, the clamping screw exhibits a larger axial force at a certain amount of a fastening torque as compared with a conventional clamping screw. A larger axial force can thus be applied to hold the second component onto the first component.

Abstract: A magnetic head structure has a coil and a magnetic pole allowing a magnetic flux generated by the coil to be transmitted therethrough and forming a magnetic gap. An insulating layer surrounds the coil, and a protective layer covers the insulating layer and the magnetic pole. The insulating layer has a volume equal to or greater than a value which is determined with respect to a thickness of the protective layer. It is preferable to increase the volume of the insulating layer as the thickness of the protective layer is made greater. By increasing the volume of the insulating layer, the protrusion of a portion of a floating surface of the magnetic head slider near the magnetic pole, toward the disk, is reduced.

Abstract: A magnetic head structure has a coil and a magnetic pole allowing a magnetic flux generated by the coil to be transmitted therethrough and forming a magnetic gap. An insulating layer surrounds the coil, and a protective layer covers the insulating layer and the magnetic pole. The insulating layer has a volume equal to or greater than a value which is determined with respect to a thickness of the protective layer. It is preferable to increase the volume of the insulating layer as the thickness of the protective layer is made greater. By increasing the volume of the insulating layer, the protrusion of a portion of a floating surface of the magnetic head slider near the magnetic pole, toward the disk, is reduced.

Abstract: A magnetic disc apparatus has a ramp holding the magnetic head in a position apart from the magnetic disc and a filter case holding a filter in the state of being bent in such a manner that the filter surrounds the ramp together with the magnetic disc. The filter removes dust in airflow which flows in the magnetic disc apparatus accompanying the rotation of the magnetic disc.

Abstract: A plate member is made of a metal material lighter than stainless steel in a suspension for a head slider. This leads to a reduction in the weight of the suspension. The natural frequency of the suspension is thus raised. Moreover, the viscoelastic member is interposed between the front surface of the plate member and the back surface of the flexure. This structure allows either the plate member or the flexure to act as a base and the other to act as a constraining member. In other words, the plate member, the flexure and the viscoelastic member in combination act as a so-called vibration damper including constraining layers. The viscoelastic member serves to further suppress vibration of the plate member and the flexure.