Patents by Inventor Naomichi Degawa

Naomichi Degawa 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: 11165128
    Abstract: A high-frequency device includes a magnetoresistance effect element which includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer positioned between the first and second ferromagnetic layers, a soft magnetic material body which covers at least a part of a periphery of the magnetoresistance effect element from outside in a plan view in a lamination direction of the magnetoresistance effect element, a non-magnetic material body which is positioned between the soft magnetic material body and the first ferromagnetic layer in the plan view in the lamination direction, and a high-frequency line which is connected to or spaced apart from the magnetoresistance effect element. The high-frequency line is configured to input or output a high-frequency current to or from the magnetoresistance effect element, or is configured to apply a high-frequency magnetic field caused by a high-frequency current flowing through the inside to the magnetoresistance effect element.
    Type: Grant
    Filed: July 16, 2020
    Date of Patent: November 2, 2021
    Assignee: TDK CORPORATION
    Inventors: Naomichi Degawa, Shinji Hara, Akimasa Kaizu
  • Publication number: 20210293909
    Abstract: A magnetoresistance effect device includes: at least one magnetoresistance effect element; at least one first signal line; and an output port, wherein the magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the first signal line is separated from the magnetoresistance effect element with an insulator interposed therebetween and a high frequency magnetic field caused by a first high frequency current flowing through the first signal line is applied to the first ferromagnetic layer, wherein a high frequency current flows through the magnetoresistance effect element, and wherein a signal including a DC signal component caused by an output of the magnetoresistance effect element is output from the output port.
    Type: Application
    Filed: March 17, 2021
    Publication date: September 23, 2021
    Applicant: TDK CORPORATION
    Inventors: Naomichi DEGAWA, Tetsuya SHIBATA
  • Patent number: 10885934
    Abstract: Provided is a magnetoresistance effect device comprising a magnetoresistance effect element including a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer, and a high-frequency signal line. The high-frequency signal line includes an overlapping part disposed at a position overlapping the magnetoresistance effect element and a non-overlapping part disposed at a position not overlapping the magnetoresistance effect element in a plan view from a stacking direction. At least a part of the non-overlapping part is disposed below the overlapping part in the stacking direction, assuming that the overlapping part is above the magnetoresistance effect element in the stacking direction.
    Type: Grant
    Filed: March 26, 2019
    Date of Patent: January 5, 2021
    Assignee: TDK CORPORATION
    Inventors: Naomichi Degawa, Tsuyoshi Suzuki
  • Patent number: 10756257
    Abstract: Provided is a magnetoresistance effect device comprising a magnetoresistance effect element including a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer and a high-frequency signal line. The high-frequency signal line includes an overlapping part disposed at a position overlapping the magnetoresistance effect element and a non-overlapping part disposed at a position not overlapping the magnetoresistance effect element in a plan view from a stacking direction. At least a part of the non-overlapping part is formed to be thicker than at least a part of the overlapping part. A distance in the stacking direction between a virtual plane including a surface on the side of the overlapping part of the first ferromagnetic layer and a center line in the high-frequency signal line in the stacking direction is shorter in at least a part of the overlapping part than in at least a part of the non-overlapping part.
    Type: Grant
    Filed: March 26, 2019
    Date of Patent: August 25, 2020
    Assignee: TDK CORPORATION
    Inventor: Naomichi Degawa
  • Patent number: 10680165
    Abstract: A magnetoresistance effect device includes: a magnetoresistance effect element formed by performing lamination such that a spacer layer is disposed between a first ferromagnetic layer and a second ferromagnetic layer; a high frequency signal line arranged on one side of the magnetoresistance effect element in a direction parallel to a lamination direction; and a magnetic member arranged at a position further away from the one side than the high frequency signal line when viewed from the magnetoresistance effect element, wherein the magnetic member has a concave portion which is recessed in a direction away from the high frequency signal line in a surface facing the high frequency signal line.
    Type: Grant
    Filed: December 3, 2018
    Date of Patent: June 9, 2020
    Assignee: TDK CORPORATION
    Inventor: Naomichi Degawa
  • Patent number: 10559412
    Abstract: At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.
    Type: Grant
    Filed: November 29, 2018
    Date of Patent: February 11, 2020
    Assignee: TDK CORPORATION
    Inventors: Akimasa Kaizu, Naomichi Degawa, Tetsuya Roppongi
  • Patent number: 10439592
    Abstract: A magnetoresistance effect device includes a magnetoresistance effect element including a magnetization fixed layer, a magnetization free layer of which a direction of magnetization is changeable relative to a direction of magnetization of the fixed layer, and a spacer layer sandwiched between the fixed and free layers, a first signal line configured to generate a high frequency magnetic field when a high frequency current flows and apply the field to the magnetization free layer, and a DC application terminal configured to be capable of connecting a power supply for applying a DC current or voltage in a stacking direction of the element, and the element is disposed with respect to the terminal so the DC current flows from the fixed layer to the free layer in the element or so the DC voltage at which the magnetization fixed layer is higher in potential than the magnetization free layer is applied.
    Type: Grant
    Filed: July 27, 2018
    Date of Patent: October 8, 2019
    Assignee: TDK CORPORATION
    Inventors: Naomichi Degawa, Takekazu Yamane
  • Publication number: 20190305215
    Abstract: Provided is a magnetoresistance effect device comprising a magnetoresistance effect element including a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer and a high-frequency signal line. The high-frequency signal line includes an overlapping part disposed at a position overlapping the magnetoresistance effect element and a non-overlapping part disposed at a position not overlapping the magnetoresistance effect element in a plan view from a stacking direction. At least a part of the non-overlapping part is formed to be thicker than at least a part of the overlapping part. A distance in the stacking direction between a virtual plane including a surface on the side of the overlapping part of the first ferromagnetic layer and a center line in the high-frequency signal line in the stacking direction is shorter in at least a part of the overlapping part than in at least a part of the non-overlapping part.
    Type: Application
    Filed: March 26, 2019
    Publication date: October 3, 2019
    Applicant: TDK CORPORATION
    Inventor: Naomichi DEGAWA
  • Publication number: 20190304491
    Abstract: Provided is a magnetoresistance effect device comprising a magnetoresistance effect element including a first ferromagnetic layer, a second ferromagnetic layer and a spacer layer, and a high-frequency signal line. The high-frequency signal line includes an overlapping part disposed at a position overlapping the magnetoresistance effect element and a non-overlapping part disposed at a position not overlapping the magnetoresistance effect element in a plan view from a stacking direction. At least a part of the non-overlapping part is disposed below the overlapping part in the stacking direction, assuming that the overlapping part is above the magnetoresistance effect element in the stacking direction.
    Type: Application
    Filed: March 26, 2019
    Publication date: October 3, 2019
    Applicant: TDK CORPORATION
    Inventors: Naomichi DEGAWA, Tsuyoshi SUZUKI
  • Publication number: 20190180901
    Abstract: At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.
    Type: Application
    Filed: November 29, 2018
    Publication date: June 13, 2019
    Applicant: TDK CORPORATION
    Inventors: Akimasa KAIZU, Naomichi DEGAWA, Tetsuya ROPPONGI
  • Publication number: 20190181332
    Abstract: A magnetoresistance effect device includes: a magnetoresistance effect element formed by performing lamination such that a spacer layer is disposed between a first ferromagnetic layer and a second ferromagnetic layer; a high frequency signal line arranged on one side of the magnetoresistance effect element in a direction parallel to a lamination direction; and a magnetic member arranged at a position further away from the one side than the high frequency signal line when viewed from the magnetoresistance effect element, wherein the magnetic member has a concave portion which is recessed in a direction away from the high frequency signal line in a surface facing the high frequency signal line.
    Type: Application
    Filed: December 3, 2018
    Publication date: June 13, 2019
    Applicant: TDK CORPORATION
    Inventor: Naomichi DEGAWA
  • Publication number: 20190044500
    Abstract: A magnetoresistance effect device includes a magnetoresistance effect element including a magnetization fixed layer, a magnetization free layer of which a direction of magnetization is changeable relative to a direction of magnetization of the fixed layer, and a spacer layer sandwiched between the fixed and free layers, a first signal line configured to generate a high frequency magnetic field when a high frequency current flows and apply the field to the magnetization free layer, and a DC application terminal configured to be capable of connecting a power supply for applying a DC current or voltage in a stacking direction of the element, and the element is disposed with respect to the terminal so the DC current flows from the fixed layer to the free layer in the element or so the DC voltage at which the magnetization fixed layer is higher in potential than the magnetization free layer is applied.
    Type: Application
    Filed: July 27, 2018
    Publication date: February 7, 2019
    Applicant: TDK CORPORATION
    Inventors: Naomichi DEGAWA, Takekazu YAMANE
  • Patent number: 10109302
    Abstract: A magnetic recording head is provided with a main magnetic pole that generates a recording magnetic field to be applied to a magnetic recording medium from an end surface which makes a portion of an air bearing surface, a trailing shield that is placed by interposing a write gap at a trailing side of the main magnetic pole, a spin torque oscillator that is placed within the write gap to be between the main magnetic pole and the trailing shield, and two side shields that are placed at both sides of the main magnetic pole in the cross track direction, and when viewed from the air bearing surface side, at least a portion of the trailing-side end surfaces of the side shields are offset toward a leading-side of the main magnetic pole from the leading-side end surface of the spin torque oscillator.
    Type: Grant
    Filed: July 18, 2017
    Date of Patent: October 23, 2018
    Assignee: TDK Corporation
    Inventors: Tetsuhito Shinohara, Tetsuya Roppongi, Naomichi Degawa
  • Patent number: 10032470
    Abstract: A magnetic recording head comprises: a main magnetic pole for generating a recording magnetic field applied to a magnetic recording medium from an end surface that is one part of an air bearing surface facing the magnetic recording medium; a trailing shield that is placed by interposing a write gap at a trailing side of the main magnetic pole; and a spin torque oscillator provided in the write gap; wherein, when viewed from the air bearing surface side, the length in the down-track direction between the trailing shield and the cross-track direction end portion of a first end face positioned at the main magnetic pole side of the spin torque oscillator is longer than the length in the down-track direction between the trailing shield and the main magnetic pole at a center position in the cross-track direction of the spin torque oscillator.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: July 24, 2018
    Assignee: TDK Corporation
    Inventors: Naomichi Degawa, Tetsuhito Shinohara, Shinji Hara, Tetsuya Roppongi
  • Patent number: 9747933
    Abstract: A magneto-resistive effect element (MR element) has an upper shield that is magnetized in a cross track direction, a lower shield that is positioned at an interval relative to the upper shield in a down track direction, and a multilayer film that is positioned between the upper shield and the lower shield and that faces an air bearing surface (ABS). The multilayer film has a free layer where its magnetization direction fluctuates relative to an external magnetic field, a pinned layer where its magnetization direction is pinned against the external magnetic field, a nonmagnetic spacer layer that is positioned between the free layer and the pinned layer, and an insulating layer that is positioned at a back side of the free layer viewed from the ABS. The MR element further has a pair of side shields that are positioned at both sides of the free layer and the insulating layer in a cross track direction.
    Type: Grant
    Filed: February 16, 2016
    Date of Patent: August 29, 2017
    Assignee: TDK Corporation
    Inventors: Hisayoshi Watanabe, Naomichi Degawa, Satoshi Miura, Masachika Hashino, Tetsuya Hiraki, Hidekazu Kojima
  • Publication number: 20170236538
    Abstract: A magneto-resistive effect element (MR element) has an upper shield that is magnetized in a cross track direction, a lower shield that is positioned at an interval relative to the upper shield in a down track direction, and a multilayer film that is positioned between the upper shield and the lower shield and that faces an air bearing surface (ABS). The multilayer film has a free layer where its magnetization direction fluctuates relative to an external magnetic field, a pinned layer where its magnetization direction is pinned against the external magnetic field, a nonmagnetic spacer layer that is positioned between the free layer and the pinned layer, and an insulating layer that is positioned at a back side of the free layer viewed from the ABS. The MR element further has a pair of side shields that are positioned at both sides of the free layer and the insulating layer in a cross track direction.
    Type: Application
    Filed: February 16, 2016
    Publication date: August 17, 2017
    Inventors: Hisayoshi WATANABE, Naomichi DEGAWA, Satoshi MIURA, Masachika HASHINO, Tetsuya HIRAKI, Hidekazu KOJIMA
  • Patent number: 9478238
    Abstract: A magneto-resistive effect element (MR element) has a first shield layer; a second shield layer; an inner shield layer that is positioned between the first shield layer and the second shield layer, and that makes contact with the first shield layer and faces the air bearing surface (ABS); and a multilayer film that is positioned between the first shield layer and the second shield layer. The multilayer film has a free layer; a first pinned layer; a nonmagnetic spacer layer; a second pinned layer that fixes the magnetization direction of the first pinned layer; and an antiferromagnetic layer that is exchange-coupled with the second pinned layer. The antiferromagnetic layer faces the back surface of the inner shield layer viewed from the ABS. The MR element has an insulating layer positioned between the antiferromagnetic layer and the inner shield layer.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: October 25, 2016
    Assignee: TDK Corporation
    Inventors: Naomichi Degawa, Kenzo Makino, Satoshi Miura, Takayasu Kanaya
  • Publication number: 20160293188
    Abstract: A magneto-resistive effect element (MR element) has a first shield layer; a second shield layer; an inner shield layer that is positioned between the first shield layer and the second shield layer, and that makes contact with the first shield layer and faces the air bearing surface (ABS); and a multilayer film that is positioned between the first shield layer and the second shield layer. The multilayer film has a free layer; a first pinned layer; a nonmagnetic spacer layer; a second pinned layer that fixes the magnetization direction of the first pinned layer; and an antiferromagnetic layer that is exchange-coupled with the second pinned layer. The antiferromagnetic layer faces the back surface of the inner shield layer viewed from the ABS. The MR element has an insulating layer positioned between the antiferromagnetic layer and the inner shield layer.
    Type: Application
    Filed: June 29, 2015
    Publication date: October 6, 2016
    Inventors: Naomichi DEGAWA, Kenzo MAKINO, Satoshi MIURA, Takayasu KANAYA
  • Patent number: 9129622
    Abstract: A magnetoresistive effect element that prevents a recording medium from deteriorating by effectively inhibiting erroneous writing to a medium or the like includes a magnetoresistive effect part, and an upper shield layer and a lower shield layer that are laminated and formed in a manner sandwiching the magnetoresistive effect part from above and below, and is in a current perpendicular to plane (CPP) structure in which a sense current is applied in a lamination direction.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: September 8, 2015
    Assignee: TDK Corporation
    Inventors: Takahiko Machita, Naomichi Degawa, Takekazu Yamane, Takumi Yanagisawa, Satoshi Miura, Kenta Hamamoto, Minoru Ota, Kenzo Makino, Shohei Kawasaki
  • Patent number: 8913349
    Abstract: An MR element includes an MR part and upper and lower shield layers in a CPP structure. The MR element has side shield layers so as to interpose the MR part between the side shield layers in a track width direction. The MR part comprises a nonmagnetic intermediate layer and first and second ferromagnetic layers so as to interpose the nonmagnetic intermediate layer between the ferromagnetic layers. Each of the upper and lower shield layers has an inclined magnetization structure such that its magnetization is inclined relative to the track width direction. The side shield layers are magnetically coupled with the upper shield layer, respectively. The second ferromagnetic layer is indirectly magnetically coupled with the lower shield layer via an exchange-coupling functional gap layer. The side shield layer applies a bias magnetic field to the first ferromagnetic layer; and magnetizations of the first and second ferromagnetic layers are substantially orthogonal.
    Type: Grant
    Filed: March 29, 2013
    Date of Patent: December 16, 2014
    Assignee: TDK Corporation
    Inventors: Takekazu Yamane, Takahiko Machita, Naomichi Degawa, Minoru Ota, Kenta Hamamoto