Patents by Inventor Mutsuro Ohta

Mutsuro Ohta has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7450347
    Abstract: A magnetic disk drive is to be provided wherein a ramp and a magnetic disk do not overlap each other and both rigidity and dynamic characteristics of a suspension are maintained. In one embodiment, a ramp and an actuator lying at a retractive position are spaced away from and do not overlap an outer peripheral end of a magnetic disk. A tab is formed centrally of a front end of a load beam and is bent in U shape. Flanges are formed along both longitudinal edges of the load beam. An aperture is formed in a front portion of the load beam. The aperture permits the tab to be machined in a desired shape. An aperture is formed behind the aperture. The apertures are not formed in an integrally contiguous manner but are separated from each other by a bridge portion.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: November 11, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kohichi Suzuki, Shingo Tsuda, Mutsuro Ohta, Hiroyasu Tsuchida, Akihiro Aoyagi
  • Publication number: 20070297093
    Abstract: Embodiments in accordance with the present invention reduce the height of a head gimbal assembly (HGA) while maintaining the rigidity of a load beam. According to one embodiment of the present invention, an HGA includes a slider, a flexure, and a load beam. The load beam includes a flange formed to protrude to the opposite side to a magnetic disk at the edge of the load beam extending in the length-wise direction. The load beam has a recessed portion opened to the side opposing the magnetic disk and having an opening area larger than the area of the back surface of the slider opposing the flexure. The slider is provided in the recessed portion so that the position of the surface of the load beam is between a virtual surface including the surface of the slider opposing the magnetic disk and a virtual surface including the slider back surface.
    Type: Application
    Filed: May 30, 2007
    Publication date: December 27, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takaaki Deguchi, Mutsuro Ohta, Shinichi Kimura, Hiroshi Matsuda
  • Publication number: 20070206330
    Abstract: Embodiments in accordance with the present invention provide achieve an increase of storage capacity and thinning down of a disk drive by reducing effects from an error in an assembly position of a ramp. A data storage device according to an embodiment of the present invention includes a head, a ramp, a load beam, and an actuator. The ramp includes a portion onto which the head is retracted from a surface of a medium. The load beam includes a head support portion that supports the head and a tab disposed more on the side of a leading end than the head support portion. The tab has a leading end that slides over, while being in contact with, a sliding surface of the ramp. The actuator includes the load beam and loads and unloads the head.
    Type: Application
    Filed: February 16, 2007
    Publication date: September 6, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takaaki Deguchi, Mutsuro Ohta, Hiroshi Matsuda, Katsuhiko Ohta, Shinichi Kimura
  • Publication number: 20070206331
    Abstract: Embodiments in accordance with the present invention relate to suppressing deterioration in rigidity and dynamic characteristics of a tab even when an initial point of contact between a tab and a ramp during unloading is set closer to the outer periphery of a disk. A data storage device in one embodiment of the present invention includes a head, a ramp for unloading the head, a load beam having a head support portion for supporting the head and a tab adapted to slide on a sliding surface of the ramp on a front end side with respect to the head support portion, and an actuator having the load beam and adapted to actuate the head for loading and unloading. During unloading, a portion of the tab offset from the center in the transverse direction of the tab first comes into contact with the sliding surface of the ramp. The load beam has a flange formed to be bent and continuously from the front end portion of the tab up to both ends of the head support portion.
    Type: Application
    Filed: February 16, 2007
    Publication date: September 6, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takaaki Deguchi, Mutsuro Ohta, Shingo Tsuda, Taichi Nakamura
  • Patent number: 7203034
    Abstract: A mechanism is provided for restraining and releasing an actuator suspension assembly in a magnetic disk device which is in a retracted position. In a magnetic disk device, according to one embodiment, a magnetic disk 4a is formed of an electrically conductive material and there is disposed a latch member 50 which holds an eddy-current magnet at one end thereof and is provided with a latching portion at an opposite end thereof. An actuator suspension assembly 8 lies in a retracted position and is restrained at a frame engaging portion 23 thereof by means of the latch member. The eddy current magnet is disposed in such a manner that a magnetic pole thereof is opposed to a surface of the magnetic disk at a position close to the disk surface. When the magnetic disk is rotated, an eddy-current is generated and a force is exerted on the eddy-current magnet, so that the latch member turns and releases the actuator suspension assembly.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: April 10, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Mutsuro Ohta, Takeshi Chawanya, Satoshi Hayakawa
  • Publication number: 20070076323
    Abstract: Embodiments of the invention reduce the height of a ramp to provide a thin data storage device that is capable of inhibiting the deterioration of the dynamic characteristics at the time of loading/unloading. In one embodiment, a data storage device includes a head that accesses a recording region of a recording disk; a ramp that is positioned circumferentially apart from an outermost end of the recording disk to unload the head from a surface of the recording disk; and an actuator that includes a load beam for supporting the head and moves the head. The load beam includes a tab that is extended from a leading end section of the load beam, beyond the head support section of the load beam, and toward the recording disk, and slides over a ramp surface.
    Type: Application
    Filed: September 15, 2006
    Publication date: April 5, 2007
    Applicant: Hitachi Global Storage Technologies Netherland B.V.
    Inventors: Takaaki Deguchi, Mutsuro Ohta, Hiroshi Matsuda
  • Patent number: 7030527
    Abstract: Embodiments of the present invention effectively control, by a simple structure, floating of a rotor of a fluid dynamic bearing motor mounted in a hard disk drive. In one embodiment, a base is formed of a magnetic material. The attractive force caused by the magnetic force acts between a bottom of the base and a magnet unit that is constituted of a rotor magnet and a back yoke. This makes it possible to attract a rotor to the base against the buoyant force produced by a thrust bearing, and thereby to effectively control the rotation of the rotor. On the bottom of the base, at a position facing the magnet unit, a convex part protruding from the inner surface of the base is formed in a ring-shape. Adjusting the height, or the width, of the convex part makes it possible to control the magnetic back pressure applied to the rotor.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: April 18, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shingo Tsuda, Mutsuro Ohta, Hiroki Kitahori, Kazutaka Okasaka
  • Publication number: 20050264941
    Abstract: Embodiments of the invention permit a magnet-based actuator lock mechanism to operate smoothly in a magnetic disk drive that uses a base made of a magnetic material. In one embodiment, the base to be used is made of a magnetic material. The actuator lock mechanism includes a rotatable arm that retains a magnet. A magnetic attraction force, which is oriented toward the base as indicated by an arrow, is generated in the magnet. The base is provided with a cut to reduce the attraction force. The cut is covered with a sealing material to maintain internal airtightness. The actuator lock mechanism may be, for instance, an eddy-current latch, inertia latch, or magnetic latch.
    Type: Application
    Filed: May 31, 2005
    Publication date: December 1, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shingo Tsuda, Mutsuro Ohta, Kazutaka Okasaka
  • Publication number: 20050265113
    Abstract: Embodiments of the present invention provide a data storage device and a magnetic disk drive capable of maintaining the inside of a base in a hermetically sealed condition. In one embodiment, a data storage device includes a recording disk, a base having a through hole, a top cover having a tapping hole aligned with the through hole and a depressed portion with the tapping hole formed in a bottom thereof, and a screw inserted through the through hole into threaded engagement with the tapping hole and having a head which comes into close contact with an outer surface of the base. The top cover is fitted inside the base in a state in which the depressed portion is positioned on the base side, and the bottom of the depressed portion comes into close contact with the base in the threadedly engaged state of the screw and in an area which surrounds the through hole.
    Type: Application
    Filed: May 25, 2005
    Publication date: December 1, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kanako Abe, Takaaki Deguchi, Akira Morita, Mutsuro Ohta
  • Publication number: 20050219757
    Abstract: A magnetic disk drive is to be provided wherein a ramp and a magnetic disk do not overlap each other and both rigidity and dynamic characteristics of a suspension are maintained. In one embodiment, a ramp and an actuator lying at a retractive position are spaced away from and do not overlap an outer peripheral end of a magnetic disk. A tab is formed centrally of a front end of a load beam and is bent in U shape. Flanges are formed along both longitudinal edges of the load beam. An aperture is formed in a front portion of the load beam. The aperture permits the tab to be machined in a desired shape. An aperture is formed behind the aperture. The aperture is used to clamp a head in a wire bonding step for the head. The apertures and are not formed in an integrally contiguous manner but are separated from each other by a bridge portion.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 6, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kohichi Suzuki, Shingo Tsuda, Mutsuro Ohta, Hiroyasu Tsuchida, Akihiko Aoyagi
  • Patent number: 6952323
    Abstract: A disk drive unit has a spindle motor for rotating a disk, a magnetic head for processing data, a actuator for seeking the magnetic head with respect to the disk, a voice coil motor for moving the actuator, and a base with an opening and a top cover that seals the opening. A damper is disposed between the voice coil motor and the top cover. The voice coil motor comprises first and second yokes, which are placed opposite each other at a predetermined gap, and a permanent magnet disposed between the first and second yokes. The first and second yokes respectively have an inner perimeter edge facing the pivot axis, an outer perimeter edge facing the base, and a pair of side perimeter edges combining the outer and inner perimeter edges. The damper includes first dampers with a predetermined width along the pair of side perimeter edges.
    Type: Grant
    Filed: November 5, 2002
    Date of Patent: October 4, 2005
    Assignee: International Business Machines Corporation
    Inventors: Yoshihiro Hirasaka, Mutsuro Ohta, Takaaki Deguchi
  • Publication number: 20050180045
    Abstract: Embodiments of the invention provide a rotating disk storage device which has a simple mounting structure facilitating mounting thereof to a host system and is reduced in noise. In one embodiment, the rotating disk storage device includes a magnetic disk, a voice coil motor for driving a head suspension assembly having a head for reading data from the magnetic disk, a base for rotatably supporting the magnetic disk and housing the head suspension assembly and the voice coil motor, a frame having fixing areas at which the base is fixed, the fixing areas being joined to the base via an adhesive double coated tape.
    Type: Application
    Filed: January 31, 2005
    Publication date: August 18, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Shingo Tsuda, Mutsuro Ohta, Akira Morita
  • Publication number: 20050140220
    Abstract: Embodiments of the present invention effectively control, by a simple structure, floating of a rotor of a fluid dynamic bearing motor mounted in a hard disk drive. In one embodiment, a base is formed of a magnetic material. The attractive force caused by the magnetic force acts between a bottom of the base and a magnet unit that is constituted of a rotor magnet and a back yoke. This makes it possible to attract a rotor to the base against the buoyant force produced by a thrust bearing, and thereby to effectively control the rotation of the rotor. On the bottom of the base, at a position facing the magnet unit, a convex part protruding from the inner surface of the base is formed in a ring-shape. Adjusting the height, or the width, of the convex part makes it possible to control the magnetic back pressure applied to the rotor.
    Type: Application
    Filed: November 19, 2004
    Publication date: June 30, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands, B. V.
    Inventors: Shingo Tsuda, Mutsuro Ohta, Hiroki Kitahori, Kazutaka Okasaka
  • Publication number: 20050117258
    Abstract: A mechanism is provided for restraining and releasing an actuator suspension assembly in a magnetic disk device which is in a retracted position. In a magnetic disk device, according to one embodiment, a magnetic disk 4a is formed of an electrically conductive material and there is disposed a latch member 50 which holds an eddy-current magnet at one end thereof and is provided with a latching portion at an opposite end thereof. An actuator suspension assembly 8 lies in a retracted position and is restrained at a frame engaging portion 23 thereof by means of the latch member. The eddy current magnet is disposed in such a manner that a magnetic pole thereof is opposed to a surface of the magnetic disk at a position close to the disk surface. When the magnetic disk is rotated, an eddy-current is generated and a force is exerted on the eddy-current magnet, so that the latch member turns and releases the actuator suspension assembly.
    Type: Application
    Filed: March 26, 2004
    Publication date: June 2, 2005
    Applicant: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Mutsuro Ohta, Takeshi Chawanya, Satoshi Hayakawa
  • Patent number: 6900956
    Abstract: A magnetic circuit is provided in an enclosure that can efficiently generate magnetic flux from the enclosure, configuring a magnetic disk, to a magnetic disk. Thus, by providing such a magnetic circuit, a magnetic field different from that in other enclosure parts, that is, a local magnetic field, is generated from the magnetic circuit in case the disk device is set in an external magnetic field. Hence, this local magnetic field can effectively erase data in the magnetic disk. In particular, since the local magnetic field is generated even if the external magnetic field is weak, it is possible to not only suppress the demagnetization of permanent magnets used in the spindle motor at minimum, but also effectively erase data in the magnetic disk.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: May 31, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroki Kitahori, Kenji Kuroki, Hiroshi Matsuda, Satoshi Noguchi, Mutsuro Ohta, Keishi Takahashi, Hitoshi Tamura
  • Publication number: 20030218819
    Abstract: A disk drive (HDD) subject to linear and rotational vibration, includes an independent sensing unit for sensing a rotational velocity component of the HDD rotational vibration in a predetermined frequency range.
    Type: Application
    Filed: May 24, 2002
    Publication date: November 27, 2003
    Applicant: International Business Machines Corporation
    Inventors: Sri M. Sri-Jayantha, Hien Dang, Vijayeshwar Das Khanna, Gerard McVicker, Mutsuro Ohta
  • Patent number: 6639758
    Abstract: The present invention provides a depopulation version hard disk drive apparatus that has a reduced number of magnetic heads and suspension arms from a standard hard disk drive apparatus, wherein the magnetic head can still be properly controlled during a loading state. The hard disk drive apparatus includes a ramp which interfaces with the suspension arm when loading and unloading the arm. An angle of a second slope surface 61c of the ramp in the depopulation version hard disk drive is set larger than that of the corresponding slope surface of the ramp 6 the a standard version hard disk drive.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: October 28, 2003
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mutsuro Ohta, Hiroshi Matsuda, Takahide Nakamura, Keishi Takahashi
  • Patent number: 6636380
    Abstract: A hard disk drive includes a spindle, a motor and multiple disks. The motor is attached to the spindle for rotatably turning the spindle along an axis of the spindle. The disks are disposed coaxially along the axis of the spindle. The distance between a first disk and a second disk is greater than the distance between the second disk and a third disk. The distance between the second disk and the third disk is greater than the distance between the third disk and a fourth disk. The first, second, third and fourth disks are located adjacent to each other consecutively.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: October 21, 2003
    Assignee: International Business Machines Corporation
    Inventors: Dale C. Goeke, Mutsuro Ohta, Koichi Takeuchi, Shingo Tsuda
  • Patent number: 6633452
    Abstract: A hard disk drive apparatus is capable of reducing a noise effectively during operation and capable of enhancing the reliability of the drive. The hard disk drive has first and second ribs that are formed near a pivot for an actuator so that a tilt of the pivot is prevented when the actuator is operated. Also, vibration absorbing members are interposed between the first and second ribs on the side of a base and a cover so that the vibration absorbing members are brought into contact with the cover. These vibration absorbing members are located in an intermediate portion between fixing places for fixing the cover to the base and a fixing place for fixing the cover to the pivot.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: October 14, 2003
    Assignee: International Business Machines Corporation
    Inventors: Yoshihiro Hirasaka, Keishi Takahasi, Kohji Serizawa, Mutsuro Ohta
  • Publication number: 20030128461
    Abstract: A disk drive unit has a spindle motor for rotating a disk, a magnetic head for processing data, a actuator for seeking the magnetic head with respect to the disk, a voice coil motor for moving the actuator, and a base with an opening and a top cover that seals the opening. A damper is disposed between the voice coil motor and the top cover. The voice coil motor comprises first and second yokes, which are placed opposite each other at a predetermined gap, and a permanent magnet disposed between the first and second yokes. The first and second yokes respectively have an inner perimeter edge facing the pivot axis, an outer perimeter edge facing the base, and a pair of side perimeter edges combining the outer and inner perimeter edges. The damper includes first dampers with a predetermined width along the pair of side perimeter edges.
    Type: Application
    Filed: November 5, 2002
    Publication date: July 10, 2003
    Applicant: International Business Machines Corporation
    Inventors: Yoshihiro Hirasaka, Mutsuro Ohta, Takaaki Deguchi