Patents by Inventor Kenji Inage

Kenji Inage 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).

  • Publication number: 20230087727
    Abstract: A magnetic sensor includes a plurality of resistor sections each including a plurality of MR elements, and a plurality of protruding surfaces each structured to cause the plurality of MR elements to detect a specific component of a target magnetic field. The plurality of MR elements are disposed dividedly in first to fourth areas corresponding respectively to the plurality of resistor sections. The plurality of protruding surfaces include a structural body extending across at least two of the first to fourth areas.
    Type: Application
    Filed: September 21, 2022
    Publication date: March 23, 2023
    Applicant: TDK CORPORATION
    Inventors: Takehiro ISODA, Norikazu OTA, Daichi TAKANO, Kenji INAGE
  • Publication number: 20230092845
    Abstract: A magnetic sensor includes an insulating layer including a flat portion and a protruding portion, a first MR element, and a second MR element. The protruding portion includes a first inclined surface and a second inclined surface. The first MR element is disposed on the first inclined surface. The second MR element is disposed on the second inclined surface. The protruding portion extends in a first direction parallel to a top surface of a substrate, and includes a plurality of recess portions each recessed in a direction parallel to the top surface of the substrate at an end of the protruding portion in the first direction.
    Type: Application
    Filed: September 15, 2022
    Publication date: March 23, 2023
    Applicant: TDK CORPORATION
    Inventors: Hiromichi UMEHARA, Keisuke TAKASUGI, Takehiro ISODA, Kenji INAGE
  • Patent number: 7916434
    Abstract: A TMR effect element with sufficiently reduced element resistance and restricted popping noise is provided, which comprises a tunnel barrier layer formed primarily of a metal oxide including many electric charge sites. The electric charge sites density n and the mobility ? of electrons trapped due to the electric charge sites satisfy a relationship expressed by: 0<(ns1?1?ns2?1)?1·(?0??)·(n?)?1<0.2, where ns1 and ns2 are densities of tunnel electrons when an element resistance is a minimum and maximum respectively during reading signals and ?0 is the mobility of electrons when not trapped.
    Type: Grant
    Filed: March 24, 2006
    Date of Patent: March 29, 2011
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Tetsuya Kuwashima, Hiroshi Kiyono, Katsumichi Tagami, Kazumasa Fukuda, Masahide Kohno
  • Patent number: 7417442
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Grant
    Filed: May 17, 2005
    Date of Patent: August 26, 2008
    Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Nozomu Hachisuka, Kenji Inage, Norio Takahashi, Tatsushi Shimizu, Pak Kin Wong
  • Patent number: 7372282
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: May 13, 2008
    Assignee: TDK Corporation
    Inventors: Nozomu Hachisuka, Hiroshi Kiyono, Takeo Kagami, Kenji Inage, Norio Takahashi
  • Patent number: 7333303
    Abstract: Provided is a magnetoresistive device capable of stably maintaining sufficient output characteristics even under a higher temperature environment while responding to a demand for a higher recording density. The magnetoresistive device comprises an MR film including a fixing layer made of IrMn, an outer pinned layer of which the magnetization direction is fixed in a +Y direction by the fixing layer, and an inner pinned layer of which the magnetization direction is fixed in a ?Y direction by the fixing layer, a pair of conductive lead layers and a constant current circuit which flows a sense current in a +X direction so as to generate a current magnetic field toward a ?Y direction in the inner pinned layer, and in the magnetoresistive device, a conditional expression (1) is satisfied.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: February 19, 2008
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Kenji Inage
  • Patent number: 7283328
    Abstract: A thin-film magnetic head includes at least one inductive write head element and at least one read magnetic head element, capable of controlling a spacing between a magnetic recording medium and the at least one magnetic read head element by heating. A gain SG (nm/° C.) of the spacing is greater than a spacing gain threshold SGTHLD (nm/° C.) defined by the following expression: SGLIMT=A*dPTP+B A=1.4642E?02*exp(?6.6769E?05*LRDMF) B=4.9602E?01*exp(?2.0423E?03*LRDMF) where dPTP represents an amount of change in protrusion (nm) of a top end of the at least one inductive write head element and/or the at least one read magnetic head element by heating, and LRDMF represents a line recording density (kFCI) at a frequency half of the maximum recording frequency.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: October 16, 2007
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Kenji Inage, Taro Oike
  • Patent number: 7236392
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: June 26, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Patent number: 7227772
    Abstract: Testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: June 5, 2007
    Assignee: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Publication number: 20060221511
    Abstract: A TMR effect element with sufficiently reduced element resistance and restricted popping noise is provided, which comprises a tunnel barrier layer formed primarily of a metal oxide including many electric charge sites. The electric charge sites density n and the mobility ? of electrons trapped due to the electric charge sites satisfy a relationship expressed by: 0<(ns1?1?ns2?1)?1·(?0??)·(n?)?1<0.2, where ns1 and ns2 are densities of tunnel electrons when an element resistance is a minimum and maximum respectively during reading signals and ?0 is the mobility of electrons when not trapped.
    Type: Application
    Filed: March 24, 2006
    Publication date: October 5, 2006
    Applicant: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Tetsuya Kuwashima, Hiroshi Kiyono, Katsumichi Tagami, Kazumasa Fukuda, Masahide Kohno
  • Publication number: 20060216837
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by applying a plurality of voltages with different voltage values each other to the TMR element, respectively, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Application
    Filed: March 13, 2006
    Publication date: September 28, 2006
    Applicant: TDK CORPORATION
    Inventors: Nozomu HACHISUKA, Hiroshi Kiyono, Takeo Kagami, Kenji Inage, Norio Takahashi
  • Patent number: 7102859
    Abstract: A thin-film magnetic head includes a TMR element and a resistor element connected in parallel with the TMR element. A resistance value RTMR of the TMR element itself is RTMR?240 ?, a product RA of the resistance value of the TMR element itself and a cross-sectional area of the TMR element is RA?3 ?·?m2, and a resistance value RPARA of the resistor element is RPARA?480?.
    Type: Grant
    Filed: January 28, 2004
    Date of Patent: September 5, 2006
    Assignee: TDK Corporation
    Inventors: Kenji Inage, Shunji Saruki, Nozomu Hachisuka
  • Patent number: 7027271
    Abstract: A magnetoresisive device comprises an MR element, bias field applying layers located adjacent to the side portions of the MR element, and two electrode layers that feed a sense current to the MR element. The electrode layers overlap one of the surfaces of the MR element. The total overlap amount of the two electrode layers is smaller than 0.3 ?m. The MR element is a spin-valve GMR element. The MR element incorporates a base layer, a free layer, a spacer layer, a pinned layer, an antiferromagnetic layer, and a cap layer that are stacked in this order. The pinned layer includes a nonmagnetic spacer layer, and two ferromagnetic layers that sandwich this spacer layer.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: April 11, 2006
    Assignee: TDK Corporation
    Inventors: Kenji Inage, Yoshihiro Kudo, Ken-ichi Takano, Koichi Terunuma, Yuzuru Iwai
  • Publication number: 20060028773
    Abstract: Provided is a magnetoresistive device capable of stably maintaining sufficient output characteristics even under a higher temperature environment while responding to a demand for a higher recording density. The magnetoresistive device comprises an MR film including a fixing layer made of IrMn, an outer pinned layer of which the magnetization direction is fixed in a +Y direction by the fixing layer, and an inner pinned layer of which the magnetization direction is fixed in a ?Y direction by the fixing layer, a pair of conductive lead layers and a constant current circuit which flows a sense current in a +X direction so as to generate a current magnetic field toward a ?Y direction in the inner pinned layer, and in the magnetoresistive device, a conditional expression (1) is satisfied.
    Type: Application
    Filed: December 29, 2004
    Publication date: February 9, 2006
    Applicant: TDK CORPORATION
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Kenji Inage
  • Publication number: 20060023333
    Abstract: A method for testing a TMR element includes a step of measuring a plurality of resistances of the TMR element by feeding a plurality of sense currents with different current values each other through the TMR element, a step of calculating a ratio of change in resistance from the measured plurality of resistances of the TMR element, and a step of evaluating the TMR element using the calculated ratio of change in resistance.
    Type: Application
    Filed: May 17, 2005
    Publication date: February 2, 2006
    Applicants: TDK Corporation, SAE Magnetics (H.K.) Ltd.
    Inventors: Nozomu Hachisuka, Kenji Inage, Norio Takahashi, Tatsushi Shimizu, Pak Wong
  • Patent number: 6972933
    Abstract: A head suspension assembly includes a magnetic head slider with at least one thin-film magnetic head element, a support member for supporting the magnetic head slider at a top end portion thereof, a drive circuit electrically connected to the at least one thin-film magnetic head element, and at least two diode elements connected toward one direction in parallel with terminals which are connected across the at least one thin-film magnetic head element. Each of the diode elements has a turn-on voltage higher than the maximum output voltage of the at least one thin-film magnetic head element.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: December 6, 2005
    Assignee: TDK Corporation
    Inventors: Takeshi Wada, Kenji Inage, Masashi Shiraishi, Haruyuki Morita
  • Publication number: 20050254171
    Abstract: A thin-film magnetic head includes at least one inductive write head element and at least one read magnetic head element, capable of controlling a spacing between a magnetic recording medium and the at least one magnetic read head element by heating. A gain SG (nm/° C.) of the spacing is greater than a spacing gain threshold SGTHLD (nm/° C.) defined by the following expression: SGLIMT=A*dPTP+B A=1.4642E?02*exp(?6.6769E?05*LRDMF) B=4.9602E?01*exp(?2.0423E?03*LRDMF) where dPTP represents an amount of change in protrusion (nm) of a top end of the at least one inductive write head element and/or the at least one read magnetic head element by heating, and LRDMF represents a line recording density (kFCI) at a frequency half of the maximum recording frequency.
    Type: Application
    Filed: April 26, 2005
    Publication date: November 17, 2005
    Applicant: TDK Corporation
    Inventors: Norikazu Ota, Kenji Inage, Taro Oike
  • Publication number: 20050237789
    Abstract: A method for testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element from a anti-substrate side to a substrate side for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element by comparing the first resistance value and the second resistance value with each other.
    Type: Application
    Filed: April 8, 2005
    Publication date: October 27, 2005
    Applicant: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Publication number: 20050195648
    Abstract: A method for testing a TMR element includes a step of measuring initially a resistance value of the TMR element to provide the measured resistance value as a first resistance value, a step of measuring a resistance value of the TMR element after continuously feeding a current through the TMR element for a predetermined period of time, to provide the measured resistance value as a second resistance value, and a step of evaluating the TMR element depending upon a degree of change in resistance of the TMR element. The degree of change in resistance is determined based upon the first resistance value and the second resistance value.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 8, 2005
    Applicant: TDK Corporation
    Inventors: Shunji Saruki, Kenji Inage, Nozomu Hachisuka, Hiroshi Kiyono
  • Publication number: 20040185304
    Abstract: A thin-film magnetic head includes a TMR element and a resistor element connected in parallel with the TMR element. A resistance value RTMR of the TMR element itself is RTMR≧240 &OHgr;, a product RA of the resistance value of the TMR element itself and a cross-sectional area of the TMR element is RA≧3 &OHgr;·&mgr;m2, and a resistance value RPARA of the resistor element is RPARA≦480 &OHgr;.
    Type: Application
    Filed: January 28, 2004
    Publication date: September 23, 2004
    Applicant: TDK CORPORATION
    Inventors: Kenji Inage, Shunji Saruki, Nozomu Hachisuka