Patents by Inventor Toshihiko Shimizu

Toshihiko Shimizu 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: 8064171
    Abstract: Embodiments of the present invention help to reduce out-of-plane excitation force exerted on a coil in a voice coil motor of a magnetic disk drive, so that vibration of a magnetic head is suppressed. According to one embodiment, a voice coil motor has a flat magnet that faces a coil, and generates a magnetic field, and yokes that apply the magnetic field generated by the magnet to the coil. The magnet is provided with a magnetic flux guiding section, absorbing leakage flux from the magnet, on a most distal end of the magnet as viewed from a pivot axis. A most distal part of the coil as viewed from the pivot axis, may be situated in an outer side with respect to the most distal end of the magnet, and the magnetic flux guiding section is provided between the most distal end of the magnet and the most distal part of the coil.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: November 22, 2011
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Toshihiko Shimizu, Keiko Watanabe, Shigeo Nakamura, Noritaka Otake
  • Publication number: 20110210649
    Abstract: The crystal resonator for surface mounting includes: a single-layer base substrate, including a pair of crystal holding terminals on a major face; a crystal piece, including an excitation electrode on two major faces, and electrically and mechanically connected to the crystal holding terminals; and a concave metal cover, including an opening end face bonded to an outer peripheral surface of the base substrate through curing of a liquid resin. The end face electrode is electrically connected through an electrically conducting path of the outer peripheral surface extended from the crystal holding terminals, and the crystal resonator for surface mounting is disposed as a structure that includes an end face region of two positions at least being opposite to the electrically conducting path in the opening end face of the metal cover spaced from a front end of a protruding portion through the protruding portion disposed on the opening end face.
    Type: Application
    Filed: February 18, 2011
    Publication date: September 1, 2011
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventor: TOSHIHIKO SHIMIZU
  • Publication number: 20110199158
    Abstract: Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.
    Type: Application
    Filed: April 25, 2011
    Publication date: August 18, 2011
    Inventors: Toshihiko Shimizu, Yoshikuni Matsunaga, Yuri Kusakari
  • Publication number: 20110141614
    Abstract: A magnetic head drive device including a suspension for supporting a magnetic head, and a main actuator that produces rotary movement of the magnetic head by applying current to a coil. The main actuator includes end arms each comprising a single micro-actuator, and an intermediate arm comprising two micro-actuators. The micro-actuators of the end arms are driven in the same direction, and the micro-actuators of the intermediate arm are driven in the opposite direction to the drive direction of the micro-actuators of said the arms.
    Type: Application
    Filed: December 8, 2010
    Publication date: June 16, 2011
    Inventors: Kenji Suzuki, Shinsuke Nakagawa, Toshihiko Shimizu, Eiji Soga, Takaaki Deguchi, Mutsuro Ohta
  • Patent number: 7952434
    Abstract: Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.
    Type: Grant
    Filed: April 30, 2009
    Date of Patent: May 31, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Toshihiko Shimizu, Yoshikuni Matsunaga, Yuri Kusakari
  • Patent number: 7864637
    Abstract: An object of the invention is to provide a disc autochanger without any disc reversing mechanism by using on A-side recording and reproducing apparatus and a B-side recording and reproducing apparatus while using a sheet-like optical disc in which both surfaces can be recorded and reproduced. The disc autochanger is constituted by a cartridge storing a plurality of sheet-like optical discs in which both surfaces are recorded and reproduced in a state of putting in a tray, the A-side recording and reproducing apparatus in which a moving table of an A-side recording and reproducing portion is arranged in an upper side of a tray take-out mechanism and a moving table of a cap is provided in a lower side thereof, and the B-side recording and reproducing apparatus in which a moving table of a B-side recording and reproducing portion is arranged in a lower side of the tray take-out mechanism and a moving table of a cap is provided in an upper side thereof.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: January 4, 2011
    Assignee: Hitachi-LG Data Storage, Inc.
    Inventors: Takashi Yoshida, Toshihiko Shimizu, Yukinobu Abe, Hiroyuki Awano, Yutaka Watanabe
  • Publication number: 20100301947
    Abstract: The RF power amplifier includes first and second amplifiers Q1 and Q2 as final-stage amplification power devices connected in parallel between an input terminal RF_In and an output terminal RF_Out. The amplifiers Q1 and Q2 are formed on one semiconductor chip. The first bias voltage Vg1 of the amplifier Q1 is set to be higher than the second bias voltage Vg2 of the amplifier Q2 so that the amplifier Q1 is operational between Class B and AB, and Q2 is operational in Class C. The first effective device size Wgq1 of the amplifier Q1 is intentionally set to be smaller than the second effective device size Wgq2 of the amplifier Q2 beyond a range of a manufacturing error of the semiconductor chip. An RF power amplifier that exhibits a high power-added efficiency characteristic regardless of whether the output power is High or Low can be materialized.
    Type: Application
    Filed: June 14, 2010
    Publication date: December 2, 2010
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Toru Fujioka, Toshihiko Shimizu, Masami Ohnishi, Hidetoshi Matsumoto, Satoshi Tanaka
  • Patent number: 7756494
    Abstract: The RF power amplifier includes first and second amplifiers Q1 and Q2 as final-stage amplification power devices connected in parallel between an input terminal RF_In and an output terminal RF_Out. The amplifiers Q1 and Q2 are formed on one semiconductor chip. The first bias voltage Vg1 of the amplifier Q1 is set to be higher than the second bias voltage Vg2 of the amplifier Q2 so that the amplifier Q1 is operational between Class B and AB, and Q2 is operational in Class C. The first effective device size Wgq1 of the amplifier Q1 is intentionally set to be smaller than the second effective device size Wgq2 of the amplifier Q2 beyond a range of a manufacturing error of the semiconductor chip. An RF power amplifier that exhibits a high power-added efficiency characteristic regardless of whether the output power is High or Low can be materialized.
    Type: Grant
    Filed: June 18, 2007
    Date of Patent: July 13, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Toru Fujioka, Toshihiko Shimizu, Masami Ohnishi, Hidetoshi Matsumoto, Satoshi Tanaka
  • Patent number: 7652850
    Abstract: Embodiments of the invention decrease bending vibrations and torsional vibrations of a voice coil generated by off-plane vibrational forces on the voice coil to reduce noise and to enable a large capacity. In one embodiment, a rotating disk type storage unit comprises a rotating disk recording medium, a head that moves radially relative to the rotating disk recording medium to perform recording or reproduction, a turnable actuator having mounted on one side thereof the head, and a voice coil motor to drive the actuator. The voice coil motor comprises a voice coil mounted on the other side end of the actuator, and a magnet arranged in opposition to the voice coil. A magnet outer periphery of the magnet disposed distant from an actuator turning center is formed to be arcuately concave in shape, and the concave-shaped outer periphery intersects the voice coil.
    Type: Grant
    Filed: May 17, 2005
    Date of Patent: January 26, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenji Suzuki, Toshihiko Shimizu, Shingo Tsuda, Kouki Uefune
  • Publication number: 20090212873
    Abstract: Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.
    Type: Application
    Filed: April 30, 2009
    Publication date: August 27, 2009
    Inventors: Toshihiko Shimizu, Yoshikuni Matsunaga, Yuri Kusakari
  • Patent number: 7576944
    Abstract: Embodiments of the invention provide a magnetic disk device capable of improving the shielding function for the magnetic head yet maintaining a form factor. In one embodiment, a magnetic disk device comprises a magnetic disk; a magnetic head for recording/reproducing information; a magnetic disk drive mechanism for moving magnetic head in the radial direction of the magnetic disk; a housing including a base and a cover having a nonmagnetic material; and a magnetic shielding member having a magnetic material. The housing has a cut-away portion corresponding to a range in which the magnetic head moves, and the magnetic shielding member is formed in a U-shape including an upper wall portion, a side wall portion and a bottom wall portion. The magnetic shielding member covers the range in which the magnetic head moves, and is disposed in the cut-away portion so as to form substantially the same surface as the surfaces of the upper wall, side wall and bottom wall of the housing.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: August 18, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takehiko Eguchi, Toshihiko Shimizu, Mikio Tokuyama
  • Publication number: 20090147406
    Abstract: Embodiments of the present invention relate disk drives, and in particular to realizing a positioning accuracy equal to that of an actuator having the mountable maximum number of suspensions, in an actuator having the smaller number of suspensions than the mountable maximum number. An embodiment of a magnetic disk device includes an actuator having an arm to which a suspension for applying a predetermined load onto a slider with a magnetic head is attached, and an arm to which a plate is attached instead of having the suspension. The plate attached to the arm in place of the suspension has a partially small section with respect to a section perpendicular to an arm longitudinal direction (constricted part), and the constricted part is located between a plate leading end and an arm attachment part.
    Type: Application
    Filed: November 18, 2008
    Publication date: June 11, 2009
    Inventors: Noritaka Otake, Keiko Watanabe, Toshihiko Shimizu, Kenji Tomida
  • Patent number: 7545607
    Abstract: A carriage includes a slider on which a magnetic head for reading/writing information from/to a disk is mounted, a suspension for carrying the slider and for applying a predetermined load to the slider, a carriage arm to which the suspension is attached, and a body section to which the carriage arm is connected. The carriage arm includes a suspension fixing portion, as arm arranged substantially in parallel with a disk surface, and a restricting member which is a thin-plate-like member having a surface which is opposite to the plane of arm which is parallel to the disk surface. The restricting member and the arm are coupled via a viscoelastic body.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: June 9, 2009
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Toshihiko Shimizu, Tetsuya Hamaguchi, Toshihiro Arisaka, Hiromitsu Masuda, Gentaro Nakamura, Takenori Atsumi
  • Patent number: 7525759
    Abstract: Embodiments of the invention provide a magnetic disk device which improves the shielding function for the magnetic heads while maintaining a form factor having an inexpensive constitution. In one embodiment, a magnetic disk device comprises a rotary disk-type magnetic disk; a magnetic head for recording or reproducing information; a magnetic head support mechanism for supporting the magnetic head; a shroud having an opening in which the magnetic head support mechanism is inserted, and surrounding the outer circumference of the magnetic disk; and a housing. The housing includes a base and a cover, and accommodates the magnetic disk, the magnetic head, the magnetic head support mechanism and the shroud. The base is constituted by using a nonmagnetic material and the shroud is constituted by using a magnetic material.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: April 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takehiko Eguchi, Masayuki Kurita, Toshihiko Shimizu, Mikio Tokuyama
  • Publication number: 20090080117
    Abstract: A head support mechanism includes a head to read/write information, and an actuator for moving the head. Flanges are provided on opposite sides of a load beam of the head support mechanism, and at least one recessed portion is provided on the load beam. A thickness of the load beam at the at least one recessed portion is smaller than a thickness at other portions of the load beam at least one of oscillation damping material and an IC circuit is arranged in the at least one recessed portion.
    Type: Application
    Filed: November 19, 2008
    Publication date: March 26, 2009
    Inventors: Toshihiko Shimizu, Hiromitsu Masuda, Irizo Naniwa, Mikio Tokuyama, Shigeo Nakamura, Kousaku Wakatsuki, Haruhide Takahashi, Masaki Odai
  • Patent number: 7468861
    Abstract: In a magnetic disk apparatus, a function of shielding a magnetic head is improved while maintaining the form factor with an inexpensive structure. In one embodiment, a magnetic disk apparatus has a magnetic disk, a magnetic head that records or plays back information, a magnetic head support mechanism supporting the magnetic head, a positioning mechanism that moves the magnetic head in a radial direction of the magnetic disk to place the head in position, an enclosure made of a nonmagnetic material, and a shield member made of a magnetic material. The magnetic disk, magnetic head, magnetic head support mechanism, positioning mechanism, and shield member are housed in the enclosure.
    Type: Grant
    Filed: September 9, 2005
    Date of Patent: December 23, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Takehiko Eguchi, Toshihiko Shimizu, Toshiya Shiramatsu, Mikio Tokuyama
  • Patent number: 7460341
    Abstract: Embodiments of the invention suppress head jump at the time of application of an impact to provide for an excellent impact resistance performance in a magnetic disk device. In one embodiment, an actuator of a magnetic disk device comprises a suspension mounting the slider on a tip end side thereof to give a predetermined load to the slider, and an arm that holds the suspension, the arm being supported to be able to turn. The arm comprises two arm portions juxtaposed in a direction perpendicular to a surface of the disk, and a spacing between the two arm portions on a side of supported portions thereof in the direction perpendicular to the surface of the disk is larger than that on a side of the slider in the direction perpendicular to the surface of the disk.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: December 2, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Toshihiko Shimizu, Haruhide Takahashi, Kousaku Wakatsuki, Keiko Watanabe
  • Patent number: 7408738
    Abstract: Embodiments of the invention efficiently improve the stray field robustness without changing the size or weight of the drive on a large scale. Because a stray field concentrates on a magnetic field element, a symptom in which already recorded data is erased is prevented. According to one embodiment, in a magnetic recording system that uses a perpendicular recording medium having a soft magnetic under layer, a soft magnetic shield is provided on an upper part and a side of a slider on which a magnetic head is mounted, and a distance C between the shield and the medium is made smaller than a distance A or B between the shield and the slider.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: August 5, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yasutaka Nishida, Ikuya Tagawa, Toshihiko Shimizu
  • Publication number: 20080164947
    Abstract: Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.
    Type: Application
    Filed: February 12, 2008
    Publication date: July 10, 2008
    Inventors: Toshihiko Shimizu, Yoshikuni Matsunaga, Yuri Kusakari
  • Patent number: D584192
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: January 6, 2009
    Assignee: Honda Motor Co., Ltd.
    Inventors: Masaru Hasegawa, Toshihiko Shimizu, Atsushi Murakawa