Patents by Inventor Shigetaka Kaga

Shigetaka Kaga 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: 10873315
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate and excitation electrodes. The excitation electrode includes a main thickness portion and an inclined portion, the main thickness portion has a constant thickness, the inclined portion is formed on a peripheral area of the main thickness portion, the inclined portion gradually decrease in thickness from a part contacting the main thickness portion toward an outermost periphery of the excitation electrode. The inclined portion has a width as an inclination width in a length of 0.84 times or more and 1.37 times or less of a first flexural wavelength and 2.29 times or more and 3.71 times or less of a second flexural wavelength, the first flexural wavelength is a wavelength of a flexure vibration at a fundamental wave of the thickness-shear vibration, the second flexural wavelength is a wavelength of a flexure vibration at a third harmonic of the thickness-shear vibration.
    Type: Grant
    Filed: January 11, 2018
    Date of Patent: December 22, 2020
    Assignee: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka Kaga, Kazuhiro Hirota
  • Patent number: 10804876
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate, a first excitation electrode, and a second excitation electrode. The piezoelectric substrate is formed into a flat plate shape and vibrates in a thickness-shear vibration mode. The first excitation electrode is formed on one principal surface of the piezoelectric substrate. The second excitation electrode is formed on another principal surface of the piezoelectric substrate. The first excitation electrode is formed to entirely have an identical thickness. The second excitation electrode has a main thickness portion and an inclined portion. The main thickness portion has a constant thickness. The inclined portion is formed in a peripheral area of the main thickness portion and gradually decreases in thickness from a portion in contact with the main thickness portion to an outermost periphery of the second excitation electrode. The main thickness portion has a thickness larger than the thickness of the first excitation electrode.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: October 13, 2020
    Assignee: NIHON DEMPA KOGYO CO., LTD.
    Inventor: Shigetaka Kaga
  • Patent number: 10763821
    Abstract: A crystal resonator vibrates in a thickness-shear mode. The crystal resonator includes excitation electrodes being disposed on a front surface and a back surface of a crystal element. The excitation electrodes are disposed on the crystal element to have a positional relationship, where a displacement distribution at an edge of the excitation electrode on the front surface is identical to a displacement distribution at an edge of the excitation electrode on the back surface.
    Type: Grant
    Filed: August 21, 2017
    Date of Patent: September 1, 2020
    Assignee: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka Kaga, Yoshiro Teshima, Kazuhiro Hirota
  • Publication number: 20190149124
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate and excitation electrodes. The piezoelectric substrate is formed in a flat plate shape and vibrates in a thickness-shear vibration mode. The excitation electrodes are formed on respective both principal surfaces of the piezoelectric substrate and each include a main thickness portion and a flat portion. The main thickness portion has a first thickness. The flat portion is formed in a peripheral area of the main thickness portion and has a second thickness that is thinner than the first thickness between from a portion contacting the main thickness portion to an outermost periphery of the excitation electrode, extends from the portion contacting the main thickness portion to the outermost periphery of the excitation electrode, and has a width formed to have a length of 0.63 times or more and 1.88 times or less of a flexural wavelength of an unnecessary vibration.
    Type: Application
    Filed: November 13, 2018
    Publication date: May 16, 2019
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka KAGA, Masaaki NAKAHARA
  • Patent number: 10277197
    Abstract: A piezoelectric vibrating piece includes a vibrating piece body including a vibrator and at least one pair of excitation electrodes formed on a front surface and a back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece. The pair of excitation electrodes are arranged in a Z??-axis direction determined by an X??-axis and obliquely disposed with respect to the Y?-axis direction. The X??-axis is rotated by 260° to 300° counterclockwise about a Y?-axis using a +X?-axis direction as a reference. The pair of excitation electrodes are formed to have respective semicircle shapes including straight line portions extending in the X??-axis direction and to be disposed in a state where the straight line portions overlapping with one another. The straight line portion of the excitation electrode includes an inclined portion that gradually decreases in thickness toward an end portion of the excitation electrode.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: April 30, 2019
    Assignee: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka Kaga, Kazuhiro Hirota, Yoshiro Teshima, Masaaki Nakahara
  • Patent number: 10250224
    Abstract: A piezoelectric vibrating piece includes a vibrating piece body and at least a pair of excitation electrodes. The vibrating piece body includes a vibrator. The pair of excitation electrodes are formed on respective front surface and back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece cut out parallel to an X?-Z? surface. The X?-Z? surface is rotated around a Z-axis of a crystallographic axis of a crystal and further rotated around an X?-axis. The pair of excitation electrodes are collocated in a Z??-axis direction determined by an X??-axis. The X??-axis is defined by counterclockwise rotation from a +X?-axis direction around a Y?-axis by 260° to 300°. The pair of excitation electrodes are disposed inclined with respect to the Y?-axis direction.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: April 2, 2019
    Assignee: NIHON DEMPA KOGYO CO., LTD.
    Inventor: Shigetaka Kaga
  • Publication number: 20180205364
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate and excitation electrodes. The excitation electrode includes a main thickness portion and an inclined portion, the main thickness portion has a constant thickness, the inclined portion is formed on a peripheral area of the main thickness portion, the inclined portion gradually decrease in thickness from a part contacting the main thickness portion toward an outermost periphery of the excitation electrode. The inclined portion has a width as an inclination width in a length of 0.84 times or more and 1.37 times or less of a first flexural wavelength and 2.29 times or more and 3.71 times or less of a second flexural wavelength, the first flexural wavelength is a wavelength of a flexure vibration at a fundamental wave of the thickness-shear vibration, the second flexural wavelength is a wavelength of a flexure vibration at a third harmonic of the thickness-shear vibration.
    Type: Application
    Filed: January 11, 2018
    Publication date: July 19, 2018
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka KAGA, Kazuhiro HIROTA
  • Publication number: 20180167051
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate, a first excitation electrode, and a second excitation electrode. The piezoelectric substrate is formed into a flat plate shape and vibrates in a thickness-shear vibration mode. The first excitation electrode is formed on one principal surface of the piezoelectric substrate. The second excitation electrode is formed on another principal surface of the piezoelectric substrate. The first excitation electrode is formed to entirely have an identical thickness. The second excitation electrode has a main thickness portion and an inclined portion. The main thickness portion has a constant thickness. The inclined portion is formed in a peripheral area of the main thickness portion and gradually decreases in thickness from a portion in contact with the main thickness portion to an outermost periphery of the second excitation electrode. The main thickness portion has a thickness larger than the thickness of the first excitation electrode.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 14, 2018
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventor: Shigetaka KAGA
  • Publication number: 20180115301
    Abstract: A piezoelectric vibrating piece includes a piezoelectric substrate and excitation electrodes. The piezoelectric substrate is formed in a flat plate shape and vibrates in a thickness-shear vibration mode. The excitation electrodes are disposed on respective both principal surfaces of the piezoelectric substrate. The excitation electrode includes a main thickness portion and an inclined portion. The main thickness portion has a constant thickness. The inclined portion is formed in a peripheral area of the main thickness portion. The inclined portion has a thickness that gradually decreases from a portion contacting the main thickness portion to an outermost periphery of the excitation electrode. An inclination width as a width of the inclined portion has a length that is equal to or more than 0.5 times and equal to or less than three times of a flexural wavelength. The flexural wavelength is a wavelength of a flexure vibration as an unnecessary vibration.
    Type: Application
    Filed: October 16, 2017
    Publication date: April 26, 2018
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka KAGA, Yoshiro TESHIMA, Kazuhiro HIROTA
  • Publication number: 20180054181
    Abstract: A crystal resonator vibrates in a thickness-shear mode. The crystal resonator includes excitation electrodes being disposed on a front surface and a back surface of a crystal element. The excitation electrodes are disposed on the crystal element to have a positional relationship, where a displacement distribution at an edge of the excitation electrode on the front surface is identical to a displacement distribution at an edge of the excitation electrode on the back surface.
    Type: Application
    Filed: August 21, 2017
    Publication date: February 22, 2018
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka KAGA, Yoshiro TESHIMA, Kazuhiro HIROTA
  • Publication number: 20170187348
    Abstract: A piezoelectric vibrating piece includes a vibrating piece body including a vibrator and at least one pair of excitation electrodes formed on a front surface and a back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece. The pair of excitation electrodes are arranged in a Z??-axis direction determined by an X??-axis and obliquely disposed with respect to the Y?-axis direction. The X??-axis is rotated by 260° to 300° counterclockwise about a Y?-axis using a +X?-axis direction as a reference. The pair of excitation electrodes are formed to have respective semicircle shapes including straight line portions extending in the X??-axis direction and to be disposed in a state where the straight line portions overlapping with one another. The straight line portion of the excitation electrode includes an inclined portion that gradually decreases in thickness toward an end portion of the excitation electrode.
    Type: Application
    Filed: December 22, 2016
    Publication date: June 29, 2017
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Shigetaka KAGA, Kazuhiro HIROTA, Yoshiro TESHIMA, Masaaki NAKAHARA
  • Publication number: 20170126199
    Abstract: A piezoelectric vibrating piece includes a vibrating piece body and at least a pair of excitation electrodes. The vibrating piece body includes a vibrator. The pair of excitation electrodes are formed on respective front surface and back surface of the vibrator. The vibrating piece body is a twice rotated quartz-crystal vibrating piece cut out parallel to an X?-Z? surface. The X?-Z? surface is rotated around a Z-axis of a crystallographic axis of a crystal and further rotated around an X?-axis. The pair of excitation electrodes are collocated in a Z??-axis direction determined by an X??-axis. The X??-axis is defined by counterclockwise rotation from a +X?-axis direction around a Y?-axis by 260° to 300°. The pair of excitation electrodes are disposed inclined with respect to the Y?-axis direction.
    Type: Application
    Filed: June 12, 2015
    Publication date: May 4, 2017
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventor: Shigetaka KAGA
  • Patent number: 8508102
    Abstract: A piezoelectric plate in the piezoelectric sensor is obtained from a rotated Y-plate where a rotation angle around the X-axis is set according to a type of the piezoelectric crystalline material, a detection region is located on a surface parallel to an X-Z plane, and a transmitting and a receiving parts are opposite to each other at positions sandwiching the detection region along an X-axis direction of the piezoelectric plate. When a guided wave excited by applying a frequency signal from the transmitting part satisfies ?h=m?/(2?) (2h: thickness of the piezoelectric plate, ?: wave number in the X-axis, ?: wave number in thickness direction normalized by ?, m: positive even number), the rotation angle satisfies the displacement of a P wave component of the guided wave becomes the maximum, or the displacement of the SH wave component of the guided wave becomes the maximum.
    Type: Grant
    Filed: May 28, 2012
    Date of Patent: August 13, 2013
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventors: Shigetaka Kaga, Morio Onoe
  • Publication number: 20120306315
    Abstract: A piezoelectric plate in the piezoelectric sensor is obtained from a rotated Y-plate where a rotation angle around the X-axis is set according to a type of the piezoelectric crystalline material, a detection region is located on a surface parallel to an X-Z plane, and a transmitting and a receiving parts are opposite to each other at positions sandwiching the detection region along an X-axis direction of the piezoelectric plate. When a guided wave excited by applying a frequency signal from the transmitting part satisfies ?h=m?/(2?) (2h: thickness of the piezoelectric plate, ?: wave number in the X-axis, ?: wave number in thickness direction normalized by ?, m: positive even number), the rotation angle satisfies the displacement of a P wave component of the guided wave becomes the maximum, or the displacement of the SH wave component of the guided wave becomes the maximum.
    Type: Application
    Filed: May 28, 2012
    Publication date: December 6, 2012
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: SHIGETAKA KAGA, MORIO ONOE
  • Patent number: 8242856
    Abstract: There is provided a temperature compensated piezoelectric oscillator which excels in frequency stability and has a good electronic noise characteristic, and with which a circuit can be structured simply. An auxiliary oscillator unit 21 sharing a crystal substrate 2 with a main oscillator unit 11 outputting a set frequency f0 to an outside is used as a temperature detecting unit 32 detecting a temperature T for obtaining a compensation voltage ?V in a temperature compensated piezoelectric oscillator (TCXO), and electrodes 13, 23 of the main oscillator unit 11 and the auxiliary oscillator unit 21 are provided separately on the crystal substrate 2. For example, a fundamental wave and an overtone are used or a thickness shear vibration and a contour shear vibration are used in the main oscillator unit 11 and the auxiliary oscillator unit 21, respectively.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: August 14, 2012
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventors: Mitsuaki Koyama, Shigetaka Kaga, Kazuo Akaike, Shigenori Watanabe
  • Publication number: 20110221538
    Abstract: To provide a technique capable of suppressing electric energy by a fundamental wave vibration and reducing phase noise in a piezoelectric oscillator using an overtone of a thickness shear vibration in a piezoelectric piece. An excitation electrode portion in an electrode 2 on one surface side of an AT cut crystal piece 1 is separated from each other in a direction perpendicular to a thickness shear vibration direction (in a Z?-axis direction) and separated portions are formed in parallel in a strip shape as divided electrodes 21, 22. The divided electrodes 21, 22 have end portions thereof connected to each other to be formed in an angular C-shape as a whole. An electrode 3 on the other surface side has strip-shaped excitation electrode portions 31, 32 formed at positions facing the first divided electrode 21 and the second divided electrode 22 on the one surface side respectively to be formed in an angular C-shaped electrode in the opposite direction.
    Type: Application
    Filed: February 10, 2011
    Publication date: September 15, 2011
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Mitsuaki Koyama, Shigetaka Kaga, Shigenori Watanabe
  • Publication number: 20110156823
    Abstract: There is provided a temperature compensated piezoelectric oscillator which excels in frequency stability and has a good electronic noise characteristic, and with which a circuit can be structured simply. An auxiliary oscillator unit 21 sharing a crystal substrate 2 with a main oscillator unit 11 outputting a set frequency f0 to an outside is used as a temperature detecting unit 32 detecting a temperature T for obtaining a compensation voltage ?V in a temperature compensated piezoelectric oscillator (TCXO), and electrodes 13, 23 of the main oscillator unit 11 and the auxiliary oscillator unit 21 are provided separately on the crystal substrate 2. For example, a fundamental wave and an overtone are used or a thickness shear vibration and a contour shear vibration are used in the main oscillator unit 11 and the auxiliary oscillator unit 21, respectively.
    Type: Application
    Filed: November 29, 2010
    Publication date: June 30, 2011
    Applicant: NIHON DEMPA KOGYO CO., LTD.
    Inventors: Mitsuaki Koyama, Shigetaka Kaga, Kazuo Akaike, Shigenori Watanabe