Patents by Inventor Mikio Matsuzaki

Mikio Matsuzaki 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: 8724434
    Abstract: A magnetic recording system including follows: a recording head, a recording medium that includes a first recording medium layer, a second recording medium layer, and a substrate. The magnetic recording system includes an electric field applying device applying an electric field and a magnetic field applying device applying a magnetic field to the recording medium, a movement mechanism that moves them to an arbitrary position. The magnetic recording system has a function of controlling an applying direction of at least one of the electric field applying device and the magnetic field applying device, and the recording head is arranged at a position facing the recording medium.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: May 13, 2014
    Assignee: TDK Corporation
    Inventors: Mikio Matsuzaki, Koichi Shinohara, Tatsuo Shibata, Masashi Sahashi, Tomohiro Nozaki
  • Patent number: 8680855
    Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an S/N ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: March 25, 2014
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki, Tetsuya Roppongi, Noboru Yamanaka, Tsutomu Aoyama
  • Publication number: 20130279309
    Abstract: A magnetic recording system including follows: a recording head, a recording medium that includes a first recording medium layer, a second recording medium layer, and a substrate. The magnetic recording system includes an electric field applying device applying an electric field and a magnetic field applying device applying a magnetic field to the recording medium, a movement mechanism that moves them to an arbitrary position. The magnetic recording system has a function of controlling an applying direction of at least one of the electric field applying device and the magnetic field applying device, and the recording head is arranged at a position facing the recording medium.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 24, 2013
    Inventors: Mikio MATSUZAKI, Koichi Shinohara, Tatsuo Shibata, Masashi Sahashi, Tomohiro Nozaki
  • Patent number: 8358127
    Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.
    Type: Grant
    Filed: April 7, 2010
    Date of Patent: January 22, 2013
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki, Tetsuya Roppongi, Noboru Yamanaka, Tsutomu Aoyama
  • Patent number: 8094399
    Abstract: A magnetic recording apparatus includes a magnetic recording medium having a magnetic recording layer, a thin-film magnetic head with a microwave-band magnetic drive function, the head having a write field generation means that generates a write field to the magnetic recording medium in response to a write signal, and a microwave generator that is provided independent of the write field generation means and generates an alternating magnetic field in plane having a microwave-band frequency when microwave-excitation current is fed, an excitation current generation means that generates the microwave-excitation current by amplitude-modulating microwave carrier current with a modulating signal having a fixed period, and a write signal supply means that generates the write signal and applies it to the write field generation means of the thin-film magnetic head.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: January 10, 2012
    Assignee: TDK Corporation
    Inventors: Tetsuya Roppongi, Takuya Adachi, Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki
  • Publication number: 20110248710
    Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.
    Type: Application
    Filed: April 7, 2010
    Publication date: October 13, 2011
    Applicant: TDK CORPORATION
    Inventors: Isamu SATO, Hiroshi Ikeda, Mikio Matsuzaki, Tetsuya Roppongi, Noboru Yamanaka, Tsutomu Aoyama
  • Publication number: 20110222185
    Abstract: A magnetic recording apparatus includes a magnetic recording medium having a magnetic recording layer, a thin-film magnetic head with a microwave-band magnetic drive function, the head having a write field generation means that generates a write field to the magnetic recording medium in response to a write signal, and a microwave generator that is provided independent of the write field generation means and generates an alternating magnetic field in plane having a microwave-band frequency when microwave-excitation current is fed, an excitation current generation means that generates the microwave-excitation current by amplitude-modulating microwave carrier current with a modulating signal having a fixed period, and a write signal supply means that generates the write signal and applies it to the write field generation means of the thin-film magnetic head.
    Type: Application
    Filed: March 10, 2010
    Publication date: September 15, 2011
    Applicant: TDK Corporation
    Inventors: Tetsuya Roppongi, Takuya Adachi, Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki
  • Patent number: 7920357
    Abstract: Provided is a thin-film magnetic head capable of writing data with high accuracy on a magnetic recording medium having high coercive force without heating. The head comprises an electromagnetic coil element comprising: a main magnetic pole; an auxiliary magnetic pole; and a write coil formed so as to pass through at least between the main magnetic pole and the auxiliary magnetic pole, for generating the write magnetic field. In this head, a part of the write coil has a layered structure of: a resonance coil layer for generating a resonance magnetic field having ferromagnetic resonance frequency of a magnetic recording layer of a magnetic recording medium or having a frequency in the vicinity thereof; and a write coil layer. And further, the resonance coil layer and the write coil layer sandwich an insulating layer therebetween.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: April 5, 2011
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • Publication number: 20080151436
    Abstract: Provided is a thin-film magnetic head capable of writing data with high accuracy on a magnetic recording medium having high coercive force without heating. The head comprises an electromagnetic coil element comprising: a main magnetic pole; an auxiliary magnetic pole; and a write coil formed so as to pass through at least between the main magnetic pole and the auxiliary magnetic pole, for generating the write magnetic field. In this head, a part of the write coil has a layered structure of: a resonance coil layer for generating a resonance magnetic field having ferromagnetic resonance frequency of a magnetic recording layer of a magnetic recording medium or having a frequency in the vicinity thereof; and a write coil layer. And further, the resonance coil layer and the write coil layer sandwich an insulating layer therebetween.
    Type: Application
    Filed: October 9, 2007
    Publication date: June 26, 2008
    Applicant: TDK CORPORATION
    Inventors: Isamu Sato, Tetsuya Roppongi, Yuichi Watabe, Norikazu Ota, Hiroshi Ikeda, Mikio Matsuzaki
  • Patent number: 7123451
    Abstract: The thin-film magnetic head of the present invention is provided with an antiferromagnetic layer, a pinned layer whose direction of magnetization is fixed by exchange-coupling with the antiferromagnetic layer, a free layer whose direction of magnetization varies according to external magnetic field, an intermediate layer disposed between the pinned layer and free layer, and a pair of electrode layers for supplying a sense current in a layer thickness direction of the free layer. One electrode layer is connected to the pinned layer. Due to this configuration, a sense current flows through the free layer, the intermediate layer, and the pinned layer, but basically does not flow through the antiferromagnetic layer. As a consequence, the antiferromagnetic layer does not contribute to total resistance of the magnetoresistance element, allowing a high magnetoresistance ratio to be obtained.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: October 17, 2006
    Assignee: TDK Corporation
    Inventors: Rachid Sbiaa, Mikio Matsuzaki, Haruyuki Morita
  • Publication number: 20040114284
    Abstract: The thin-film magnetic head of the present invention is provided with an antiferromagnetic layer, a pinned layer whose direction of magnetization is fixed by exchange-coupling with the antiferromagnetic layer, a free layer whose direction of magnetization varies according to external magnetic field, an intermediate layer disposed between the pinned layer and free layer, and a pair of electrode layers for supplying a sense current in a layer thickness direction of the free layer. One electrode layer is connected to the pinned layer. Due to this configuration, a sense current flows through the free layer, the intermediate layer, and the pinned layer, but basically does not flow through the antiferromagnetic layer. As a consequence, the antiferromagnetic layer does not contribute to total resistance of the magnetoresistance element, allowing a high magnetoresistance ratio to be obtained.
    Type: Application
    Filed: September 24, 2003
    Publication date: June 17, 2004
    Applicant: TDK CORPORATION
    Inventors: Sbiaa Rachid, Mikio Matsuzaki, Haruyuki Morita
  • Patent number: 6707643
    Abstract: A perpendicular magnetic recording apparatus includes a perpendicular double-layer film medium including a stack of a soft magnetic backing layer and a perpendicular magnetic recording layer in which recording is performed under a condition that a recording track pitch as a total of a recording track width and a guard-band width between recording tracks is set to be 1 &mgr;m or less, and a perpendicular magnetic recording head including a recording main pole, an auxiliary pole disposed at a gap having a length of five or less times the guard-band width with respect to the recording main pole, and an exciting coil.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: March 16, 2004
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Akihiko Takeo, Tetsuya Roppongi, Shinichi Horinouchi, Haruyuki Morita, Mikio Matsuzaki
  • Patent number: 6680820
    Abstract: A method of maintaining a constant flying height of a magnetic head: adapted to maintain a flying height of a magnetic head on a magnetic disk substantially constant irrespective of a change of a skew angle, utilizing a device comprising a magnetic disk, a positioning device, a head supporting device and a magnetic head; said positioning device supporting one end of said head supporting device and rotating the head supporting device on a first plane placed on a second plane of said magnetic disk within a predetermined skew angle range; the head supporting device supporting said magnetic head at the other end thereof; the magnetic head being attached with reading/writing elements at an air discharge end of a slider having flying planes on a side of a third plane thereof opposing the magnetic disk; a thickness of said slider from each of the flying planes to an opposite surface on the reverse side thereof being 0.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: January 20, 2004
    Assignee: TDK Corporation
    Inventors: Mikio Matsuzaki, Kazumasa Fukuda, Takamitsu Tsuna
  • Patent number: 6639754
    Abstract: A perpendicular magnetic recording apparatus includes a magnetic disk having a perpendicular double-layer film and a perpendicular magnetic recording head having a leading pole positioned forward along the head traveling direction, a trailing pole positioned backward along the head traveling direction at a gap length from the leading pole and having, in an air-bearing surface, a forward pole and a rearward pole of which saturation magnetic flux density is higher than that of the forward pole, and an exciting coil. A length p of the trailing pole along the head traveling direction is longer than a length T of the trailing pole in a track width direction, the length p is longer than the gap length g1, and a length p1 of the rearward pole is shorter than a length p2 of the forward pole along the head traveling direction.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: October 28, 2003
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Tomoko Taguchi, Tetsuya Roppongi, Shinichi Horinouchi, Haruyuki Morita, Mikio Matsuzaki
  • Publication number: 20020191343
    Abstract: A method of maintaining a constant flying height of a magnetic head: adapted to maintain a flying height of a magnetic head on a magnetic disk substantially constant irrespective of a change of a skew angle, utilizing a device comprising a magnetic disk, a positioning device, a head supporting device and a magnetic head; said positioning device supporting one end of said head supporting device and rotating the head supporting device on a first plane placed on a second plane of said magnetic disk within a predetermined skew angle range; the head supporting device supporting said magnetic head at the other end thereof; the magnetic head being attached with reading/writing elements at an air discharge end of a slider having flying planes on a side of a third plane thereof opposing the magnetic disk; a thickness of said slider from each of the flying planes to an opposite surface on the reverse side thereof being 0.
    Type: Application
    Filed: June 3, 2002
    Publication date: December 19, 2002
    Applicant: TDK CORPORATION
    Inventors: Mikio Matsuzaki, Kazumasa Fukuda, Takamitsu Tsuna
  • Publication number: 20020039254
    Abstract: A perpendicular magnetic recording apparatus includes a magnetic disk having a perpendicular double-layer film and a perpendicular magnetic S recording head having a leading pole positioned forward along the head traveling direction, a trailing pole positioned backward along the head traveling direction at a gap length from the leading pole and having, in an air-bearing surface, a forward pole and a rearward pole of which saturation magnetic flux density is higher than that of the forward pole, and an exciting coil. A length p of the trailing pole along the head traveling direction is longer than a length T of the trailing pole in a track width direction, the length p is longer than the gap length g1, and a length p1 of the rearward pole is shorter than a length p2 of the forward pole along the head traveling direction.
    Type: Application
    Filed: September 14, 2001
    Publication date: April 4, 2002
    Inventors: Tomoko Taguchi, Tetsuya Roppongi, Shinichi Horinouchi, Haruyuki Morita, Mikio Matsuzaki
  • Publication number: 20020036863
    Abstract: A perpendicular magnetic recording apparatus includes a perpendicular double-layer film medium including a stack of a soft magnetic backing layer and a perpendicular magnetic recording layer in which recording is performed under a condition that a recording track pitch as a total of a recording track width and a guard-band width between recording tracks is set to be 1 &mgr;m or less, and a perpendicular magnetic recording head including a recording main pole, an auxiliary pole disposed at a gap having a length of five or less times the guard-band width with respect to the recording main pole, and an exciting coil.
    Type: Application
    Filed: September 14, 2001
    Publication date: March 28, 2002
    Inventors: Akihiko Takeo, Tetsuya Roppongi, Shinichi Horinouchi, Haruyuki Morita, Mikio Matsuzaki
  • Publication number: 20020008941
    Abstract: A method of maintaining a constant flying height of a magnetic head: adapted to maintain a flying height of a magnetic head on a magnetic disk substantially constant irrespective of a change of a skew angle, utilizing a device comprising a magnetic disk, a positioning device, a head supporting device and a magnetic head; said positioning device supporting one end of said head supporting device and rotating the head supporting device on a first plane placed on a second plane of said magnetic disk within a predetermined skew angle range; the head supporting device supporting said magnetic head at the other end thereof; the magnetic head being attached with reading/writing elements at an air discharge end of a slider having flying planes on a side of a third plane thereof opposing the magnetic disk; a thickness of said slider from each of the flying planes to an opposite surface on the reverse side thereof being 0.
    Type: Application
    Filed: May 21, 2001
    Publication date: January 24, 2002
    Applicant: TDK Corporation
    Inventors: Mikio Matsuzaki, Kazumasa Fukuda, Takamitsu Tsuna
  • Patent number: 6166880
    Abstract: A thin film magnetic head includes a slider and a thin film magnetic transducing element, wherein the slider is provided with an insulating film on a surface of an electric conductive substrate, the thickness of the insulating film being in a range of 0.5 .mu.m-3 .mu.m, and the thin film magnetic transducing element is formed on the insulating film and has a thin film magnetic circuit including a magnetic film and a coil film.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: December 26, 2000
    Assignee: TDK Corporation
    Inventors: Atsuo Kobayashi, Mikio Matsuzaki
  • Patent number: 5991110
    Abstract: In the thin film magnetic transducer element, the front end portions of the upper pole piece and the lower pole piece are partially removed in such a manner that they align non parallel to the gap film on the opposite sides of the gap film. The condition .DELTA.P1>.DELTA.P2 is satisfied when the difference between the maximum pole length P1max and the minimum pole length P1min of the lower pole piece is .DELTA.P1 and the difference between the maximum pole length P2max and the minimum pole length P2min of the upper pole piece is .DELTA.P2. The sub pulse is reduced and so the partial response method can be employed.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: November 23, 1999
    Assignee: TDK Corporation
    Inventors: Masanori Sakai, Makoto Yoshida, Kazumasa Fukuda, Mikio Matsuzaki