Patents by Inventor Tetsuro Sasaki

Tetsuro Sasaki 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: 8867168
    Abstract: A magnetic head includes a main pole, a write shield, and a return path section. The write shield includes first and second shield portions located on opposite sides of the main pole in the track width direction. The return path section includes first and second yoke portions located on opposite sides of the main pole in the track width direction. The first yoke portion is connected to the first shield portion. The second yoke portion is connected to the second shield portion. A coil surrounds at least part of the entire outer periphery of the main pole when viewed from a medium facing surface.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: October 21, 2014
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Masahiro Saito, Taro Oike, Takeo Kagami, Yosuke Antoku, Kenkichi Anagawa, Kenta Hara, Tetsuro Sasaki, Shingo Miyata, Katsuki Kurihara
  • Publication number: 20140160597
    Abstract: A magnetic head includes a main pole, a write shield, and a return path section. The write shield includes first and second shield portions located on opposite sides of the main pole in the track width direction. The return path section includes first and second yoke portions located on opposite sides of the main pole in the track width direction. The first yoke portion is connected to the first shield portion. The second yoke portion is connected to the second shield portion. A coil surrounds at least part of the entire outer periphery of the main pole when viewed from a medium facing surface.
    Type: Application
    Filed: December 7, 2012
    Publication date: June 12, 2014
    Applicant: TDK CORPORATION
    Inventors: Norikazu OTA, Masahiro SAITO, Taro OIKE, Takeo KAGAMI, Yosuke ANTOKU, Kenkichi ANAGAWA, Kenta HARA, Tetsuro SASAKI, Shingo MIYATA, Katsuki KURIHARA
  • Patent number: 8085038
    Abstract: A noise-testing method for a thin-film magnetic head with an MR read head element and a heating unit capable of applying a heat and a stress to the MR read head element, includes a step of applying alternately and discontinuously with each other an electrical power having a first level and an electrical power having a second level higher than the first level to the heating unit, and a step of evaluating the thin-film magnetic head by measuring a noise output or noise outputs obtained from the MR read head element when the electrical power or the electrical powers are applied to the heating unit.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: December 27, 2011
    Assignees: TDK Corporation, SAE Magnectics (H.K.) Ltd.
    Inventors: Takumi Uesugi, Takeo Kagami, Tetsuro Sasaki, Kei Hirata, Masaru Hirose, Chi Man Lee, Kwok Piu Tso
  • Patent number: 7876537
    Abstract: An MR element incorporates a layered structure. The layered structure includes: a spacer layer having a first surface and a second surface that face toward opposite directions; a free layer disposed adjacent to the first surface of the spacer layer and having a direction of magnetization that changes in response to a signal magnetic field; and a pinned layer disposed adjacent to the second surface of the spacer layer and having a fixed direction of magnetization. The spacer layer is a layer at least part of which is made of a material other than a conductor, and the spacer layer intercepts the passage of currents or limits the passage of currents as compared with a layer entirely made of a conductor. The MR element further incorporates a conductive film that is disposed on the peripheral surface of the layered structure and allows conduction between the free layer and the pinned layer.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: January 25, 2011
    Assignee: TDK Corporation
    Inventors: Takumi Uesugi, Tetsuro Sasaki, Takeo Kagami, Kei Hirata
  • Patent number: 7864489
    Abstract: Provided is a thin-film magnetic head in which a noise due to the voltage potential difference between the read head element and the protective coat surface is suppressed. The thin-film magnetic head comprises: a read head element, one end surface of the read head element reaching an head end surface on the ABS side; a protective coat formed on the head end surface in such a way to cover at least the one end surface of the read head element; and at least one antistatic means for preventing the protective coat from being electrostatically charged, formed on/above the element formation surface, one end surface of the at least one antistatic means reaching the head end surface, the protective coat covering a portion, not the whole, of the one end surface of the at least one antistatic means on the head end surface.
    Type: Grant
    Filed: February 26, 2007
    Date of Patent: January 4, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Takeo Kagami, Takumi Uesugi, Tetsuro Sasaki
  • Patent number: 7843667
    Abstract: Provided is a thin film magnetic head capable of suppressing an occurrence of a track erase, decreasing an influence on a magnetoresistive element caused by a magnetic flux generated from a thin film coil, and further decreasing the parasitic capacity. The thin film magnetic head has, in order in a stacked direction, a first magnetic shield layer, a magnetoresistive element, a second magnetic shield layer, a third magnetic shield layer, a main magnetic pole layer and a return yoke layer. A width in a track width direction of at least one of the first and the second magnetic shield layers is smaller than widths in a track width direction of the third magnetic shield layer and the return yoke layer.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: November 30, 2010
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Norikazu Ota, Yuichi Watabe, Tetsuro Sasaki, Takeo Kagami, Tetsuya Roppongi, Kazuki Sato, Yuji Otsubo, Sohei Horiuchi, Yoshiaki Tanaka, Kenji Yokoyama, Noriaki Kasahara
  • Patent number: 7832085
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: November 16, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Patent number: 7542236
    Abstract: A magnetic head part is constituted by a reproducing head part having a GMR device and a recording head part acting as an inductive electromagnetic transducer which are laminated on a support. The magnetic head part further comprises a heater. One of poles of the heater is electrically connected to a heater electrode pad disposed on a first surface of a head slider. The other pole is electrically connected to a substrate constituting the support, and is energized by way of a second surface of the head slider.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: June 2, 2009
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Tetsuro Sasaki, Nobuya Oyama, Soji Koide
  • Publication number: 20080291582
    Abstract: Provided is a thin film magnetic head capable of suppressing an occurrence of a track erase, decreasing an influence on a magnetoresistive element caused by a magnetic flux generated from a thin film coil, and further decreasing the parasitic capacity. The thin film magnetic head has, in order in a stacked direction, a first magnetic shield layer, a magnetoresistive element, a second magnetic shield layer, a third magnetic shield layer, a main magnetic pole layer and a return yoke layer. A width in a track width direction of at least one of the first and the second magnetic shield layers is smaller than widths in a track width direction of the third magnetic shield layer and the return yoke layer.
    Type: Application
    Filed: May 21, 2007
    Publication date: November 27, 2008
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Norikazu Ota, Yuichi Watabe, Tetsuro Sasaki, Takeo Kagami, Tetsuya Roppongi, Kazuki Sato, Yuji Otsubo, Sohei Horiuchi, Yoshiaki Tanaka, Kenji Yokoyama, Noriaki Kasahara
  • Publication number: 20080291579
    Abstract: A noise-testing method for a thin-film magnetic head with an MR read head element and a heating unit capable of applying a heat and a stress to the MR read head element, includes a step of applying alternately and discontinuously with each other an electrical power having a first level and an electrical power having a second level higher than the first level to the heating unit, and a step of evaluating the thin-film magnetic head by measuring a noise output or noise outputs obtained from the MR read head element when the electrical power or the electrical powers are applied to the heating unit.
    Type: Application
    Filed: May 25, 2007
    Publication date: November 27, 2008
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Takumi Uesugi, Takeo Kagami, Tetsuro Sasaki, Kei Hirata, Masaru Hirose, Chi Man Lee, Kwok Piu Tso
  • Publication number: 20080222878
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance thus obtained, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 18, 2008
    Applicant: TDK CORPORATION
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Publication number: 20080222879
    Abstract: A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.
    Type: Application
    Filed: December 27, 2007
    Publication date: September 18, 2008
    Applicant: TDK CORPORATION
    Inventors: Takeo Kagami, Tetsuro Sasaki, Yuichi Watabe, Takamitsu Sakamoto
  • Publication number: 20080218915
    Abstract: Provided is a TMR effect element having no special structures needing much man-hour cost for the formation, in which the high temperature noise and the low temperature noise are suppressed and a sufficiently high resistance-change ratio is provided. The TMR effect element comprises: a tunnel barrier layer formed by oxidizing a base film; and two ferromagnetic layers stacked so as to sandwich the tunnel barrier layer, the base film having a film thickness larger than a film thickness at which a resistance-change ratio of the TMR effect element indicates a maximum value. Here, in the case that the base film is an aluminum film, the film thickness of the aluminum film is preferably in the range of 0.50 nm to 1.5 nm.
    Type: Application
    Filed: March 5, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Takumi Uesugi, Satoshi Miura, Tetsuro Sasaki, Takeo Kagami, Kei Hirata
  • Publication number: 20080218912
    Abstract: An MR element includes: a free layer whose direction of magnetization changes in response to a signal magnetic field; a pinned layer whose direction of magnetization is fixed; and a spacer layer disposed between these layers. The spacer layer includes: a semiconductor layer made of an n-type semiconductor; and a Schottky barrier forming layer made of a metal material having a work function higher than that of the n-type semiconductor that the semiconductor layer is made of, the Schottky barrier forming layer being disposed in at least one of a position between the semiconductor layer and the free layer and a position between the semiconductor layer and the pinned layer, touching the semiconductor layer and forming a Schottky barrier at an interface between the semiconductor layer and itself The semiconductor layer is 1.1 to 1.7 nm in thickness, and the Schottky barrier forming layer is 0.1 to 0.3 nm in thickness.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Satoshi Miura, Takeo Kagami, Tetsuro Sasaki
  • Patent number: 7418777
    Abstract: A method of manufacturing a spin valve film, produces a large read out signal. After a completion of a film making process for forming a previous film of two films to be formed successively, but before an initiation of a film making process for forming a succeeding film of the two films, a step of decreasing an anisotropic magnetic field of the spin valve film is introduced by interrupting a film making process. This step may be performed by keeping a substrate within a sputtering vacuum chamber. The interruption can be shortened by exposing the substrate to a plasma, transferring the substrate in a separate vacuum chamber is lower or whose H2O or O2 concentration is higher than that in the sputtering vacuum chamber, conducting a surface treatment with a gas containing H2O or O2, or flowing a process gas.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: September 2, 2008
    Assignee: TDK Corporation
    Inventors: Hajime Amano, Hiroaki Takezutsumi, Tetsuro Sasaki, Jun-ichi Sato
  • Publication number: 20080204938
    Abstract: Provided is a thin-film magnetic head in which a noise due to the voltage potential difference between the read head element and the protective coat surface is suppressed. The thin-film magnetic head comprises: a read head element, one end surface of the read head element reaching an head end surface on the ABS side; a protective coat formed on the head end surface in such a way to cover at least the one end surface of the read head element; and at least one antistatic means for preventing the protective coat from being electrostatically charged, formed on/above the element formation surface, one end surface of the at least one antistatic means reaching the head end surface, the protective coat covering a portion, not the whole, of the one end surface of the at least one antistatic means on the head end surface.
    Type: Application
    Filed: February 26, 2007
    Publication date: August 28, 2008
    Applicant: TDK Corporation
    Inventors: Kei Hirata, Takeo Kagami, Takumi Uesugi, Tetsuro Sasaki
  • Publication number: 20080121513
    Abstract: A processing condition obtaining method obtains a processing condition that makes it possible to form an extremely thin film of a desired thickness.
    Type: Application
    Filed: March 1, 2007
    Publication date: May 29, 2008
    Applicant: TDK CORPORATION
    Inventors: Takumi UESUGI, Tetsuro SASAKI, Satoshi MIURA
  • Publication number: 20080024934
    Abstract: An MR element incorporates a layered structure. The layered structure includes: a spacer layer having a first surface and a second surface that face toward opposite directions; a free layer disposed adjacent to the first surface of the spacer layer and having a direction of magnetization that changes in response to a signal magnetic field; and a pinned layer disposed adjacent to the second surface of the spacer layer and having a fixed direction of magnetization. The spacer layer is a layer at least part of which is made of a material other than a conductor, and the spacer layer intercepts the passage of currents or limits the passage of currents as compared with a layer entirely made of a conductor. The MR element further incorporates a conductive film that is disposed on the peripheral surface of the layered structure and allows conduction between the free layer and the pinned layer.
    Type: Application
    Filed: April 25, 2007
    Publication date: January 31, 2008
    Applicant: TDK CORPORATION
    Inventors: Takumi Uesugi, Tetsuro Sasaki, Takeo Kagami, Kei Hirata
  • Publication number: 20070218500
    Abstract: A method and apparatus for detection whereby live bacteria among microbes as an antigen can be detected rapidly in a short period of time through specifically labeling of live bacteria within a test subject antigen and whereby testing assurance can be ensured. The method and apparatus are characterized in that labeled antigen (14) is formed by action, on a test subject antigen such as Escherichia coli, of labeled substance (13) zymolyzable by live bacteria (target bacteria (12)) within the test subject antigen, and the resultant labeled antigen (14) is trapped on an immobilization phase having, immobilized thereon, a specific binding antibody capable of specifically binding to the test subject antigen.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 20, 2007
    Inventors: Tohru Mikoshiba, Tetsuro Sasaki, Takaharu Enjoji
  • Patent number: 7224553
    Abstract: A thin-film magnetic head comprises at least one of an electromagnetic transducer and a magnetoresistive device, and a heater member adapted to generate heat upon energization. The heater member contains NiCu or NiCr.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: May 29, 2007
    Assignee: TDK Corporation
    Inventors: Tetsuro Sasaki, Nubuya Oyama, Eiichi Omata, Masashi Sano, Soji Koide