Patents by Inventor Hisashi Takano

Hisashi Takano 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: 6710973
    Abstract: A magnetic head for perpendicular recording without writing from the lateral sides of a main pole and without erasing data on adjacent tracks. A magnetic disk storage apparatus using the magnetic head. The lateral side of the main pole of a magnetic head for perpendicular recording may have an inverted tapered shape obtained by forming a groove as a track portion to an inorganic insulating layer and then forming a magnetic layer and then flattening the upper surface. A leading edge, a trailing edge, or both lateral edges of the magnetic head may be tapered. The taper may be either smooth and linear or curved in profile.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: March 23, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Tomohiro Okada, Yoshiaki Kawato, Yasutaka Nishida, Yasuo Wakaki, Masafumi Mochizuki, Hisashi Takano
  • Patent number: 6687099
    Abstract: The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: February 3, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Ryoichi Nakatani, Masahiro Kitada, Naoki Koyama, Isamu Yuito, Hisashi Takano, Eijin Moriwaki, Mikio Suzuki, Masaaki Futamoto, Fumio Kugiya, Yoshibumi Matsuda, Kazuo Shiiki, Yoshinori Miyamura, Kyo Akagi, Takeshi Nakao, Hirotsugu Fukuoka, Takayuki Munemoto, Tokuho Takagaki, Toshio Kobayashi, Hideo Tanabe, Noboru Shimizu
  • Patent number: 6665141
    Abstract: In a composite magnetic head comprising a magnetoresistive read head including a magnetic thin film having a magnetoresistive effect and soft magnetic members interposing the soft magnetic film between them through a non-magnetic insulation layer, an induction type write head including poles formed in a moving direction of a medium and a conductor crossing the poles, and disposed in the proximity of the magnetoresistive head, and a substrate supporting these heads, the present invention discloses a composite magnetic head characterized in that part of a floating surface inclusive of the magnetic head constituent members has recesses and the read/write operations to and from the medium are effected by the portion interposed by these recesses.
    Type: Grant
    Filed: January 13, 2003
    Date of Patent: December 16, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Takano, Naoki Koyama, Hideo Tanabe, Eijin Moriwaki, Isamu Yuito, Kazuo Shiiki, Tsuyoshi Ohnishi, Tohru Ishitani, Toshio Kobayashi, Hideo Todokoro, Chiaki Ishikawa
  • Patent number: 6661606
    Abstract: A magnetic disk apparatus includes a magnetic disk for recording information and a magnetic head which has a reproducing head and a recording head. The reproducing head comprising a lower shield film, a magnetoresistive film, a pair of electrodes and an upper shield, and the recording head comprising an upper magnetic core, a lower magnetic core, and a coil disposed between said upper magnetic core and said lower magnetic core. The upper magnetic core and the lower magnetic core include an electroplated thin film with an average crystal grain size smaller than 500 Å, and the electroplated thin film is made of Ni—Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.
    Type: Grant
    Filed: December 2, 2002
    Date of Patent: December 9, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Sano, Yoshiaki Kita, Shun-ichi Narumi, Takashi Kawabe, Moriaki Fuyama, Hisashi Takano, Hisano Yamamoto, Kenzo Masuda
  • Patent number: 6661613
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: December 9, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Patent number: 6657813
    Abstract: To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW)/2(BS2×(Tm+TWW)) is satisfied.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: December 2, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yasutaka Nishida, Hisashi Takano, Masafumi Mochizuki
  • Patent number: 6657804
    Abstract: A magnetic recording disk drive can prevent the deterioration of the head off-track characteristics and the reduction of the drive performance even when an erase band asymmetry resulting from a skew angle exists. A write inhibit slice value for an inner peripheral side offset is made smaller than a write inhibit slice value for an outer peripheral side offset at a position where an erase band on the inner peripheral side is greater than an erase band on the outer peripheral side, so that the adjacent track on the outer peripheral side cannot easily erase a data track. On the contrary, the inner periphery and the outer periphery are paraphrased at a position where the erase band on the outer peripheral side is greater than the erase band on the inner peripheral side.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: December 2, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Futoshi Tomiyama, Takehiko Hamaguchi, Toru Matsushita, Hideki Zaitsu, Reijiro Tsuchiya, Hisashi Takano
  • Patent number: 6657805
    Abstract: When the amount of position error PE of a magnetic head meets the condition of Ewf>PE>=Eww for two threshold values Ewf and Eww meeting Ewf>Eww, the track is registered in the track information table as a track requiring rewrite and the tracks on both sides neighboring to the track are temporarily write-inhibited. The data of the track is rewritten on another track later so as to maintain the data. By doing this, the offtrack of the recording track can be made smaller without sacrifice of the access speed and the occurrence probability of write fault can be reduced. Furthermore, the reliability of a magnetic disk apparatus can be improved.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: December 2, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yasutaka Nishida, Takehiko Hamaguchi, Hisashi Takano, Hiroshi Ide, Hideki Sawaguchi, Futoshi Tomiyama
  • Publication number: 20030189774
    Abstract: For the purpose of letting through a magnetic flux which reverses the magnetization of the magnetic layer of the magnetic disk, a write element requires a predetermined sectional area. However, if a cross section of a magnetic pole is structured as the one having a large aspect ratio, the pole becomes less capable of letting the magnetic flux through effectively. This phenomenon brings about a lower limit on the track width of the magnetic poles and the track density cannot be raised. In the present invention, by making the width of the write element larger than the track pitch and securing a write magnetic field strong enough to reverse the magnetization of the magnetic layer, and further by writing while shifting a write head comprising the write element, a magnetic disk drive, of which the track width is narrower than the write element width, and the storage capacity is large, is realized.
    Type: Application
    Filed: April 7, 2003
    Publication date: October 9, 2003
    Inventors: Takehiko Hamaguchi, Atsushi Nakamura, Yasutaka Nishida, Hisashi Takano, Yohji Maruyama, Hiroshi Ide, Hideki Sawaguchi, Futoshi Tomiyama
  • Publication number: 20030123186
    Abstract: A slider having a thin film magnetic head. The thin film magnetic head has an upper magnetic core, a lower magnetic core and a coil disposed between the upper magnetic core and the lower magnetic core. The upper magnetic core and the lower magnetic core is an electroplated thin film with an average crystal grain size smaller than 500A.
    Type: Application
    Filed: December 2, 2002
    Publication date: July 3, 2003
    Inventors: Masaaki Sano, Yoshiaki Kita, Shun-ichi Narumi, Takashi Kawabe, Moriaki Fuyama, Hisashi Takano, Hisano Yamamoto, Kenzo Masuda
  • Publication number: 20030117750
    Abstract: The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer comprised of an insulating material, a semicondcutor or an antiferromagnetic material against said magnetic layers, and the magnetoresistance effect element has terminals formed with at least on the opposite magnetic layers, respectively, so that a current is sure to be flowed in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.
    Type: Application
    Filed: October 15, 2002
    Publication date: June 26, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Ryoichi Nakatani, Masahiro Kitada, Naoki Koyama, Isamu Yuito, Hisashi Takano, Eijin Moriwaki, Mikio Suzuki, Masaaki Futamoto, Fumio Kugiya, Yoshibumi Matsuda, Kazuo Shiiki, Yoshinori Miyamura, Kyo Akagi, Takeshi Nakao, Hirotsugu Fukuoka, Takayuki Munemoto, Tokuho Takagaki, Toshio Kobayashi, Hideo Tanabe, Noboru Shimizu
  • Publication number: 20030103294
    Abstract: Magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz, a magnetic head having at least a recording device to a magnetic recording medium, and also the electric wiring corresponding to a recording current supplying device to this magnetic head are formed on a suspension member for mechanically suspending the magnetic head, the recording current being supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Application
    Filed: December 13, 2002
    Publication date: June 5, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Publication number: 20030099063
    Abstract: In a composite magnetic head comprising a magnetoresistive read head including a magnetic thin film having a magnetoresistive effect and soft magnetic members interposing the soft magnetic film between them through a non-magnetic insulation layer, an induction type write head including poles formed in a moving direction of a medium and a conductor crossing the poles, and disposed in the proximity of the magnetoresistive head, and a substrate supporting these heads, the present invention discloses a composite magnetic head characterized in that part of a floating surface inclusive of the magnetic head constituent members has recesses and the read/write operations to and from the medium are effected by the portion interposed by these recesses.
    Type: Application
    Filed: January 13, 2003
    Publication date: May 29, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Hisashi Takano, Naoki Koyama, Hideo Tanabe, Eijin Moriwaki, Isamu Yuito, Kazuo Shiiki, Tsuyoshi Ohnishi, Tohru Ishitani, Toshio Kobayashi, Hideo Todokoro, Chiaki Ishikawa
  • Patent number: 6538844
    Abstract: In a composite magnetic head comprising a magnetoresistive read head including a magnetic thin film having a magnetoresistive effect and soft magnetic members interposing the soft magnetic film between them through a non-magnetic insulation layer, an induction type write head-including poles formed in a moving direction of a medium and a conductor crossing the poles, and disposed in the proximity of the magnetoresistive head, and a substrate supporting these heads, the present invention discloses a composite magnetic head characterized in that part of a floating surface inclusive of the magnetic head constituent members has recesses and the read/write operations to and from the medium are effected by the portion interposed by these recesses.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: March 25, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Takano, Naoki Koyama, Hideo Tanabe, Eijin Moriwaki, Isamu Yuito, Kazuo Shiiki, Tsuyoshi Ohnishi, Tohru Ishitani, Toshio Kobayashi, Hideo Todokoro, Chiaki Ishikawa
  • Patent number: 6530141
    Abstract: A method of forming a thin film magnetic head, including forming a first magnetic layer, forming a second magnetic layer as a magnetic flux passage in combination with the first magnetic layer, and forming a laminate structure body between the first magnetic layer and the second magnetic layer. The forming of the laminate structure body includes forming a third magnetic layer, a fourth magnetic layer and a non-magnetic conductive layer between the third magnetic layer and the fourth magnetic layer, projecting the laminate structure body more toward an air bearing surface than a projection of the first magnetic layer and the second magnetic layer toward the air bearing surface, and providing the laminate structure body with a width which is smaller than a width of the first magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: June 14, 2001
    Date of Patent: March 11, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Tomohiro Okada, Moriaki Fuyama, Tetsuo Ito, Hiroshi Fukui, Yohji Maruyama, Miki Hara, Hisashi Takano
  • Patent number: 6529348
    Abstract: The magnetic disk apparatus includes an electric wiring capable of satisfying an electric condition under which high frequency recording higher than or equal to 200 MHz can be accomplished. A magnetic head having at least a recording device for recording to a magnetic recording medium is provided as well as an electric wiring corresponding to a recording current supplying device for this magnetic head are formed on a suspension member for mechanically suspending the magnetic head. The recording current is supplied to a magnetic head recording device by employing such electric wiring, the characteristic impedance of which is higher than a maximum impedance of the magnetic head recording device.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: March 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yohji Maruyama, Hiroshi Ikekame, Hisashi Takano
  • Patent number: 6515817
    Abstract: A magnetic disk drive has a low power consumption state in which the spindle motor is stopped for reducing the average power consumption when no read or write commands have been received. When a read or write command is received, the spindle motor is started. The time it takes to complete a read command is shorter than that for a write command as measured from the receipt of the read command or write command with the spindle motor stopped in the low power consumption state.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: February 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Hamaguchi, Hisashi Takano, Futoshi Tomiyama, Toru Matsushita
  • Publication number: 20020191328
    Abstract: A magnetic disk drive has a low power consumption state in which the spindle motor is stopped for reducing the average power consumption when no read or write commands have been received. When a read or write command is received, the spindle motor is started. The time it takes to complete a read command is shorter than that for a write command as measured from the receipt of the read command or write command with the spindle motor stopped in the low power consumption state.
    Type: Application
    Filed: August 14, 2002
    Publication date: December 19, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Takehiko Hamaguchi, Hisashi Takano, Futoshi Tomiyama, Toru Matsushita
  • Patent number: 6490131
    Abstract: A slider having a thin film magnetic head. The thin film magnetic head has an upper magnetic core, a lower magnetic core and a coil disposed between the upper magnetic core and the lower magnetic core. The upper magnetic core and the lower magnetic core is an electroplated thin film with an average crystal grain size smaller than 500 Å, and the electroplated thin film is made of Ni—Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: December 3, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Sano, Yoshiaki Kita, Shun-ichi Narumi, Takashi Kawabe, Moriaki Fuyama, Hisashi Takano, Hisano Yamamoto, Kenzo Masuda
  • Patent number: 6483677
    Abstract: The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Ryoichi Nakatani, Masahiro Kitada, Naoki Koyama, Isamu Yuito, Hisashi Takano, Eijin Moriwaki, Mikio Suzuki, Masaaki Futamoto, Fumio Kugiya, Yoshibumi Matsuda, Kazuo Shiiki, Yoshinori Miyamura, Kyo Akagi, Takeshi Nakao, Hirotsugu Fukuoka, Takayuki Munemoto, Tokuho Takagaki, Toshio Kobayashi, Hideo Tanabe, Noboru Shimizu