Patents by Inventor Tomoo Sukagawa

Tomoo Sukagawa 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: 7336444
    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.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: February 26, 2008
    Assignee: Fujitsu Limited
    Inventors: Takuma Kido, Tomoo Sukagawa, Keiji Aruga
  • Publication number: 20060176617
    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.
    Type: Application
    Filed: May 26, 2005
    Publication date: August 10, 2006
    Applicant: FUJITSU LIMITED
    Inventors: Takuma Kido, Tomoo Sukagawa, Keiji Aruga
  • Patent number: 6738334
    Abstract: A miniaturized optical disc memory is receivable in a slot, of about 17 mm height, normally accommodating a floppy disc drive. A base includes a base plate with integral, peripheral sidewalls and an internal lateral partition wall which define a cartridge receiving slot on the upper surface of the base plate. First and second support plates extend from the partition wall to the rear peripheral sidewall of the base and define respective, first and second upper mounting surfaces and lower first and second cavities respectively receiving an ejection motor and a fixed optical system, individual optical components being mounted and aligned on integral, precision machined blocks in the second cavity for transmitting a laser beam and receiving a reflected beam along a central, longitudinal optical axis beneath the base plate.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: May 18, 2004
    Assignee: Fujitsu Limited
    Inventors: Hidenori Saitou, Toshitaka Iwamoto, Hirataka Ukai, Yasukiyo Kunimatsu, Shigeru Juman, Tomoo Sukagawa, Masateru Sasaki, Tatsutoshi Nagasaki, Masao Uchiyama
  • Patent number: 6690549
    Abstract: A magnetic disk unit has two actuators each rotating on a common rotary shaft. The two actuators are driven by a voice coil motor. The voice coil motor comprises: a magnetic circuit comprising a magnet provided for the two actuators on a common basis and two yokes, which are associated with the two actuators, respectively, said two yokes being disposed at both sides between which the magnet intervenes; and two coils provided for the two actuators, respectively.
    Type: Grant
    Filed: February 9, 2000
    Date of Patent: February 10, 2004
    Assignee: Fujitsu Limited
    Inventors: Koichi Aikawa, Tatsuro Sasamoto, Susumu Yoshida, Akihide Jinzenji, Tomoo Sukagawa, Keiji Aruga, Yoshiaki Koizumi, Yasuyoshi Asao
  • Patent number: 6411581
    Abstract: A miniaturized optical disc memory is receivable in a slot, of about 17 mm height, normally accommodating a floppy disc drive. A base includes a base plate with integral, peripheral sidewalls and an internal lateral partition wall which define a cartridge receiving slot on the upper surface of the base plate. First and second support plates extend from the partition wall to the rear peripheral sidewall of the base and define respective, first and second upper mounting surfaces and lower first and second cavities respectively receiving an ejection motor and a fixed optical system, individual optical components being mounted and aligned on integral, precision machined blocks in the second cavity for transmitting a laser beam and receiving a reflected beam along a central, longitudinal optical axis beneath the bass plate.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: June 25, 2002
    Assignee: Fujitsu Limited
    Inventors: Hidenori Saitou, Toshitaka Iwamoto, Hirataka Ukai, Yasukiyo Kunimatsu, Shigeru Juman, Tomoo Sukagawa, Masateru Sasaki, Tatsutoshi Nagasaki, Masao Uchiyama
  • Patent number: 6388972
    Abstract: A miniaturized optical disc memory is receivable in a slot, of about 17 mm height, normally accommodating a floppy disc drive. A base includes a base plate with integral, peripheral sidewalls and an internal lateral partition wall which define a cartridge receiving slot on the upper surface of the base plate. First and second support plates extend from the partition wall to the rear peripheral sidewall of the base and define respective, first and second upper mounting surfaces and lower first and second cavities respectively receiving an ejection motor and a fixed optical system, individual optical components being mounted and aligned on integral, precision machined blocks in the second cavity for transmitting a laser beam and receiving a reflected beam along a central, longitudinal optical axis beneath the base plate.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: May 14, 2002
    Assignee: Fujitsu Limited
    Inventors: Hidenori Saitou, Toshitaka Iwamoto, Hirataka Ukai, Yasukiyo Kunimatsu, Shigeru Juman, Tomoo Sukagawa, Masateru Sasaki, Tatsutoshi Nagasaki, Masao Uchiyama
  • Patent number: 6008965
    Abstract: A disk drive includes a casing for enclosing at least a disk and a head. Rectification walls are disposed at corners of the casing. The walls serve to rectify an air stream generated by rotation of the disk at the periphery of the rotating disk. A bypass is defined between the side wall of the casing and at least one rectification wall. A filter is disposed in the bypass for catching dust in the air stream. A parameter d/L, where d is the width of an entrance of the bypass and L is the length of the comer along the periphery of the disk, is determined so that vibration of the rotating disk is equal to or less than an admissible value estimated from a tracking error margin. The tracking error margin is estimated from a track pitch on the disk. Reliable positioning of the head with respect to the disk can be achieved with the present invention.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: December 28, 1999
    Assignee: Fujitsu Limited
    Inventors: Mitsuhiro Izumi, Tomoo Sukagawa, Takeshi Ohyama, Keiji Aruga, Kazuhiro Suzuki
  • Patent number: 5986362
    Abstract: A magnetic circuit for a voice coil motor of flat-coil type used with a magnetic device is disclosed. The magnetic circuit is intended to flatten the torque constant curve for swinging the rotor of the voice coil motor while at the same time preventing the torque constant from decreasing. For this purpose, the magnetic circuit comprises an upper yoke and a lower yoke opposed to a flat coil arranged on the rotor, a pair of side yokes for coupling the upper and lower yokes to each other at the ends thereof, and a magnet arranged on the lower yoke. The magnet is shaped arcuate so that the width in the neighborhood of each end thereof in the direction of motion of the flat coil is larger than a standard width and smaller than the standard width in the portions of the magnet between each end and the central portion thereof.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: November 16, 1999
    Assignee: Fujitsu Limited
    Inventors: Tomoo Sukagawa, Keiji Aruga
  • Patent number: 5886851
    Abstract: A disk drive includes a disk drive housing and a frame that supports the disk drive housing, wherein a thermally conductive elastic member is interposed between the disk drive housing and the frame for conducting heat in the disk drive housing to the frame and for isolating vibration.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: March 23, 1999
    Assignee: Fujitsu Limited
    Inventors: Osamu Yamazaki, Yoshiaki Nagasawa, Katsuaki Ishida, Tomoo Sukagawa
  • Patent number: 5859746
    Abstract: A magnetic disk drive having one or more magnetic disks, one or more read/write heads each recording or reproducing information for a corresponding one of the magnetic disks, a servo head reading control information from a predetermined one of the magnetic disks, and an actuator supporting the one or more read/write heads and the servo head includes first leads extending from the one or more read/write heads along one side of the actuator, and second leads extending from the servo head along the other side of the actuator so that the second leads can be distanced in space from the first leads.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: January 12, 1999
    Assignee: Fujitsu Limited
    Inventors: Katsuaki Ishida, Mitsuhisa Sekino, Yoshiaki Nagasawa, Tomoo Sukagawa, Masaharu Sugimoto, Tsuyoshi Furukawa, Masaki Jinbo, Tsuneyori Ino, Hisashi Kaneko, Shinichi Fukuzawa
  • Patent number: 5764435
    Abstract: A breather filter unit for a magnetic disk drive including a base and a cover fixed to the base, the cover having a vent. The breather filter unit includes a casing fixed to an inner surface of the cover, the casing having a vent inlet communicating with the vent of the cover and a vent outlet communicating with an inside of the magnetic disk drive, and a first filter contained in the casing at a position adjacent to the vent inlet, the first filter being formed from a plurality of fibers extending in a direction substantially parallel to that of an air flow from the vent inlet to the vent outlet. The breather filter unit further includes a second filter bonded to the casing so as to cover the vent outlet, and an activated carbon layer contained in the casing at a position between the first filter and the second filter.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: June 9, 1998
    Assignee: Fujitsu Limited
    Inventors: Masaharu Sugimoto, Yoshiaki Nagasawa, Katsuaki Ishida, Osamu Yamazaki, Yukihiro Komura, Tomoo Sukagawa
  • Patent number: 5602701
    Abstract: A head actuator for a magnetic disk drive unit which eliminates the possibility of track slip due to a mechanical external force and allows high-speed access. The head actuator includes a carriage having a body provided rotatably to a shaft fixed to a housing and an arm fixed to the body so as to extend substantially perpendicularly to the shaft, a supporting member mounted on the body on its side opposite to the arm with respect to the shaft, and a coil fixed to the supporting member and receiving a driving force from a static magnetic field. The supporting member is formed of a material having a specific gravity larger than that of a material forming the body of the carriage.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: February 11, 1997
    Assignee: Fujitsu Limited
    Inventors: Yukihiro Komura, Yoshiaki Nagasawa, Katsuaki Ishida, Osamu Yamazaki, Tomoo Sukagawa
  • Patent number: 5590001
    Abstract: A breather filter unit for a magnetic disk drive including a base and a cover fixed to the base, the cover having a vent. The breather filter unit includes a casing fixed to an inner surface of the cover, the casing having a vent inlet communicating with the vent of the cover and a vent outlet communicating with an inside of the magnetic disk drive, and a first filter contained in the casing at a position adjacent to the vent inlet, the first filter being formed from a plurality of fibers extending in a direction substantially parallel to that of an air flow from the vent inlet to the vent outlet. The breather filter unit further includes a second filter bonded to the casing so as to cover the vent outlet, and an activated carbon layer contained in the casing at a position between the first filter and the second filter.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: December 31, 1996
    Assignee: Fujitsu Limited
    Inventors: Tsuneyori Ino, Tsuyoshi Furukawa, Masaki Jinbo, Hisashi Kaneko, Shinichi Fukuzawa, Masaharu Sugimoto, Yoshiaki Nagasawa, Katsuaki Ishida, Osamu Yamazaki, Yukihiro Komura, Tomoo Sukagawa
  • Patent number: 5583720
    Abstract: A magnetic disk drive having one or more magnetic disks, one or more read/write heads each recording or reproducing information for a corresponding one of the magnetic disks, a servo head reading control information from a predetermined one of the magnetic disks, and an actuator supporting the one or more read/write heads and the servo head includes first leads extending from the one or more read/write heads along one side of the actuator, and second leads extending from the servo head along the other side of the actuator so that the second leads can be distanced in space from the first leads.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: December 10, 1996
    Assignee: Fujitsu Limited
    Inventors: Katsuaki Ishida, Mitsuhisa Sekino, Yoshiaki Nagasawa, Tomoo Sukagawa, Masaharu Sugimoto, Tsuyoshi Furukawa, Masaki Jinbo, Tsuneyori Ino, Hisashi Kaneko, Shinichi Fukuzawa
  • Patent number: 5541788
    Abstract: A magnetic disk device includes a flexible printed circuit board having a first portion provided with read/write ICs for read/write heads and first printed patterns connected to the read/write ICs and a second portion positioned within the first portion, an end of the second portion being connected to the first portion so as to be bendably projected from the first portion, the second portion being provided with a servo IC for the servo head and second printed patterns connected to the servo IC, the flexible printed circuit board being mounted on an actuator body such that one end of the first portion lies outside the actuator and the second portion lies on the actuator body. The magnetic disk device also includes first lead wires of the read/write heads extending to the flexible printed circuit board and being connected to the first patterns, and second lead wires of the servo head extending to the flexible printed circuit board and being connected to the second printed patterns.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: July 30, 1996
    Assignee: Fujitsu Limited
    Inventors: Katsuaki Ishida, Yoshiaki Nagasawa, Masaharu Sugimoto, Tomoo Sukagawa