Patents by Inventor Masaharu Hirakawa

Masaharu Hirakawa 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: 20210104658
    Abstract: A multilayer piezoelectric device includes a laminated body and an external electrode. The laminated body includes a piezoelectric layer formed along a plane including a first axis and a second axis intersecting each other and an internal electrode layer laminated on the piezoelectric layer. The external electrode is electrically connected to the internal electrode layer. The internal electrode layer includes a first slit parallel to the first axis and a second slit parallel to the second axis.
    Type: Application
    Filed: October 7, 2020
    Publication date: April 8, 2021
    Applicant: TDK CORPORATION
    Inventors: Makoto ISHIZAKI, Masaharu HIRAKAWA
  • Publication number: 20200313069
    Abstract: A multilayer piezoelectric element includes a laminated body and a lateral electrode. The laminated body includes a piezoelectric layer and an internal electrode layer. The piezoelectric layer is formed along a plane including a first axis and a second axis perpendicular to each other. The internal electrode layer is laminated on the piezoelectric layer. The internal electrode layer has a leading portion exposed to the lateral surface of the laminated body and is electrically connected with the lateral electrode via the leading portion. Ro is higher than Rc in the the laminated body. Ro is an existence rate of outer circumferential pores existing in the piezoelectric layer located in an outer circumferential part of the internal electrode layer. Rc is an existence rate of central pores existing in a central part of the laminated body.
    Type: Application
    Filed: March 25, 2020
    Publication date: October 1, 2020
    Applicant: TDK CORPORATION
    Inventors: Makoto ISHIZAKI, Masaharu HIRAKAWA
  • Publication number: 20200313067
    Abstract: A multilayer piezoelectric element includes a laminated body and a lateral electrode. The laminated body includes a piezoelectric layer and an internal electrode layer. The piezoelectric layer is formed along a plane including a first axis and a second axis perpendicular to each other. The internal electrode layer is laminated on the piezoelectric layer. The internal electrode layer has a leading portion exposed to the lateral surface of the laminated body and is electrically connected with the lateral electrode via the leading portion. A dummy electrode layer is formed with a gap to surround the internal electrode layer excluding the leading portion on the plane of the piezoelectric layer. The dummy electrode layer is composed of a material whose thermal shrinkage start temperature is higher than that of a conductive metal constituting the internal electrode layer.
    Type: Application
    Filed: March 26, 2020
    Publication date: October 1, 2020
    Applicant: TDK CORPORATION
    Inventors: Makoto ISHIZAKI, Masaharu HIRAKAWA
  • Publication number: 20200243745
    Abstract: A multilayer piezoelectric element includes a laminated body and a lateral electrode. The laminated body includes a piezoelectric layer, an internal electrode layer, and a dummy electrode layer. The piezoelectric layer is formed along a plane including a first axis and a second axis perpendicular to each other. The internal electrode layer and the dummy electrode layer are laminated on the piezoelectric layer. The lateral electrode is formed on a lateral surface of the laminated body perpendicular to the first axis. The internal electrode layer has a leading portion exposed to the lateral surface of the laminated body and is electrically connected with the lateral electrode via the leading portion. The dummy electrode layer is formed on the plane to surround the internal electrode layer excluding the leading portion with a gap therebetween. A slit is formed at least at one or more positions of the dummy electrode layer.
    Type: Application
    Filed: January 30, 2020
    Publication date: July 30, 2020
    Applicant: TDK CORPORATION
    Inventors: Makoto ISHIZAKI, Masaharu HIRAKAWA
  • Patent number: 10271413
    Abstract: The present invention relates to an electrostatic discharge protection device containing a first insulating substrate and a second insulating substrate; a first opposing electrode and a second opposing electrode which two are disposed between the first insulating substrate and the second insulating substrate; external electrodes connected to the first opposing electrode and the second opposing electrode; and a discharge inducing section disposed apart from the front end of the first opposing electrode and the front end of the second opposing electrode.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: April 23, 2019
    Assignee: TDK CORPORATION
    Inventors: Shingo Suzuki, Takahiro Fujimori, Masaharu Hirakawa
  • Publication number: 20160105947
    Abstract: The present invention relates to an electrostatic discharge protection device containing a first insulating substrate and a second insulating substrate; a first opposing electrode and a second opposing electrode which two are disposed between the first insulating substrate and the second insulating substrate; external electrodes connected to the first opposing electrode and the second opposing electrode; and a discharge inducing section disposed apart from the front end of the first opposing electrode and the front end of the second opposing electrode.
    Type: Application
    Filed: September 30, 2015
    Publication date: April 14, 2016
    Inventors: Shingo SUZUKI, Takahiro FUJIMORI, Masaharu HIRAKAWA
  • Patent number: 7733663
    Abstract: A multilayer ceramic substrate includes a plurality of ceramic layers laminated each other. The plurality of ceramic layers form a bulge and a cavity having such a shape that an opening area of the cavity gradually becomes smaller toward a bottom of the cavity.
    Type: Grant
    Filed: April 29, 2008
    Date of Patent: June 8, 2010
    Assignee: TDK Corporation
    Inventors: Kenji Endou, Kiyoshi Hatanaka, Masaharu Hirakawa, Haruo Nishino, Hideaki Fujioka
  • Patent number: 7662477
    Abstract: A highly reliable ceramics substrate which can sufficiently secure a bonding strength of a surface conductor in an initial state and after a lapse of time (e.g., after a PCT) is provided. The multilayer ceramics substrate has a surface conductor on at least one surface of a multilayer body constituted by a plurality of laminated ceramics substrate layers. A reaction phase formed by a reaction between a ceramics component in the ceramics substrate layers and a glass component in the surface conductor is deposited at an interface between the surface conductor and ceramics substrate layers. For example, an alumina filler in the ceramics substrate layers and Zn in the surface conductor react with each other, thereby forming ZnAl2O4 as the reaction phase.
    Type: Grant
    Filed: December 10, 2007
    Date of Patent: February 16, 2010
    Assignee: TDK Corporation
    Inventors: Yasuharu Miyauchi, Toshiyuki Suzuki, Masaharu Hirakawa, Tomoko Nakamura, Toshinobu Miyakoshi, Kiyoshi Hatanaka
  • Patent number: 7578058
    Abstract: A multilayer ceramic substrate having a cavity is formed by the steps of laminating a plurality of ceramic green sheets including ceramic green sheets having through holes corresponding to the cavity to form a multilayer body, pressing the multilayer body and firing the pressed body. At this time, a shrinkage suppression green sheet is laminated on the surface of the a ceramic green sheet constituting the outermost layer of the multilayer body, and a shrinkage suppression green sheet piece is disposed on the ceramic green sheet exposed to the bottom of the cavity in accordance with the shape of the cavity. A burnable sheet is further disposed on the shrinkage suppression green sheet piece. Before the pressing step, an embedded green sheet separate from the ceramic green sheets (portion separated by inserting a cut) is disposed on the shrinkage suppression green sheet piece or the burnable sheet so that it is filled in the cavity. After the firing step, the embedded green sheet fired is removed.
    Type: Grant
    Filed: April 18, 2006
    Date of Patent: August 25, 2009
    Assignee: TDK Corporation
    Inventors: Kenji Endou, Kiyoshi Hatanaka, Masaharu Hirakawa, Haruo Nishino, Hideaki Fujioka
  • Publication number: 20080283281
    Abstract: A multilayer ceramic substrate includes a plurality of ceramic layers laminated each other. The plurality of ceramic layers form a bulge and a cavity having such a shape that an opening area of the cavity gradually becomes smaller toward a bottom of the cavity.
    Type: Application
    Filed: April 29, 2008
    Publication date: November 20, 2008
    Applicant: TDK CORPORATION
    Inventors: Kenji Endou, Kiyoshi Hatanaka, Masaharu Hirakawa, Haruo Nishino, Hideaki Fujioka
  • Publication number: 20080152928
    Abstract: A highly reliable ceramics substrate which can sufficiently secure a bonding strength of a surface conductor in an initial state and after a lapse of time (e.g., after a PCT) is provided. The multilayer ceramics substrate has a surface conductor on at least one surface of a multilayer body constituted by a plurality of laminated ceramics substrate layers. A reaction phase formed by a reaction between a ceramics component in the ceramics substrate layers and a glass component in the surface conductor is deposited at an interface between the surface conductor and ceramics substrate layers. For example, an alumina filler in the ceramics substrate layers and Zn in the surface conductor react with each other, thereby forming ZnAl2O4 as the reaction phase.
    Type: Application
    Filed: December 10, 2007
    Publication date: June 26, 2008
    Applicant: TDK CORPORATION
    Inventors: Yasuharu Miyauchi, Toshiyuki Suzuki, Masaharu Hirakawa, Tomoko Nakamura, Toshinobu Miyakoshi, Kiyoshi Hatanaka
  • Publication number: 20060234023
    Abstract: A multilayer ceramic substrate having a cavity is formed by the steps of laminating a plurality of ceramic green sheets including ceramic green sheets having through holes corresponding to the cavity to form a multilayer body, pressing the multilayer body and firing the pressed body. At this time, a shrinkage suppression green sheet is laminated on the surface of the a ceramic green sheet constituting the outermost layer of the multilayer body, and a shrinkage suppression green sheet piece is disposed on the ceramic green sheet exposed to the bottom of the cavity in accordance with the shape of the cavity. A burnable sheet is further disposed on the shrinkage suppression green sheet piece. Before the pressing step, an embedded green sheet separate from the ceramic green sheets (portion separated by inserting a cut) is disposed on the shrinkage suppression green sheet piece or the burnable sheet so that it is filled in the cavity. After the firing step, the embedded green sheet fired is removed.
    Type: Application
    Filed: April 18, 2006
    Publication date: October 19, 2006
    Applicant: TDK CORPORATION
    Inventors: Kenji Endou, Kiyoshi Hatanaka, Masaharu Hirakawa, Haruo Nishino, Hideaki Fujioka
  • Patent number: 6515230
    Abstract: A case for a noise absorber including a first case member and a second case member. The first case member includes a first cable guide and a second cable guide at opposite sides and a first core housing provided therebetween. The second case member includes a third cable guide and a fourth cable guide at opposite sides and a second core housing provided therebetween. The first case member and the second case member are interlocked and a hinge arrangement movably connects one of the sides of the first case member with one of the sides of the second case member. A magnetic core having a cable through passage can be housed inside the case to provide a noise absorber.
    Type: Grant
    Filed: March 2, 2000
    Date of Patent: February 4, 2003
    Assignee: TDK Corporation
    Inventors: Masaharu Hirakawa, Yuetsu Watanabe