Patents by Inventor Tetsuya Isshiki

Tetsuya Isshiki 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: 11135842
    Abstract: A piezoelectric element includes a first electrode disposed at a base body, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode. The piezoelectric layer includes a first piezoelectric layer containing a complex oxide having a perovskite structure that contains lead, zirconium, and titanium and a second piezoelectric layer containing a complex oxide having a perovskite structure that is denoted by formula (1) below. The first piezoelectric layer is disposed between the first electrode and the second piezoelectric layer and is preferentially oriented to (100) when the crystal structure of the first piezoelectric layer is assumed to be pseudo-cubic, xPb(Mg,Nb)O3-yPbZrO3-zPbTiO3??(1) where in formula (1), 0<x,y,z<1 and x+y+z=1.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: October 5, 2021
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Tetsuya Isshiki, Takayuki Yonemura
  • Patent number: 10916693
    Abstract: A piezoelectric element has a diaphragm, a first electrode on the diaphragm, a piezoelectric layer on the first electrode, and a second electrode on the piezoelectric layer. The piezoelectric layer is a stack of multiple piezoelectric films and is made of a perovskite composite oxide containing lead, zirconium, and titanium and represented by the general formula ABO3, with the molar ratio of the A-site to the B-site (A/B) in the perovskite composite oxide being 1.14 or more and 1.22 or less. In current-time curve measurement, the activation energy calculated from relaxation current using an Arrhenius plot is 0.6 [eV] or less. The relaxation current is the amount of current at the time at which a downward trend in current turns upward.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: February 9, 2021
    Inventors: Takayuki Yonemura, Chikara Kojima, Xiaoxing Wang, Tetsuya Isshiki, Yasuhiro Itayama
  • Publication number: 20200269579
    Abstract: A piezoelectric element includes a first electrode disposed at a base body, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode. The piezoelectric layer includes a first piezoelectric layer containing a complex oxide having a perovskite structure that contains lead, zirconium, and titanium and a second piezoelectric layer containing a complex oxide having a perovskite structure that is denoted by formula (1) below. The first piezoelectric layer is disposed between the first electrode and the second piezoelectric layer and is preferentially oriented to (100) when the crystal structure of the first piezoelectric layer is assumed to be pseudo-cubic, xPb(Mg,Nb)O3-yPbZrO3-zPbTiO3??(1) where in formula (1), 0<x,y,z<1 and x+y+z=1.
    Type: Application
    Filed: February 25, 2020
    Publication date: August 27, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tetsuya ISSHIKI, Takayuki YONEMURA
  • Patent number: 10756250
    Abstract: A piezoelectric element includes a first electrode; a second electrode; and a piezoelectric layer arranged between the first electrode and the second electrode, in which the piezoelectric layer is a thin film that includes a perovskite-type composite oxide which includes potassium, sodium, and niobium and which is preferentially oriented in the (100) plane, and a crystal structure of the perovskite-type composite oxide includes a basic lattice structure having an oxygen octahedron and a super lattice structure in which the oxygen octahedron is tilted.
    Type: Grant
    Filed: November 2, 2017
    Date of Patent: August 25, 2020
    Assignee: Seiko Epson Corporation
    Inventors: Tetsuya Isshiki, Koichi Morozumi
  • Patent number: 10427981
    Abstract: A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than the rhombohedral crystal in a single composition, has a Curie temperature Tc2<Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a crystal other than the rhombohedral crystal in a single composition similar to the second component, has a Curie temperature Tc3?Tc1, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the second component. When a molar ratio of the third component to the sum of the second component and the third component is ? and ?×Tc3+(1??)×Tc2 is Tc4, |Tc4?Tc2|?50° C.
    Type: Grant
    Filed: December 26, 2014
    Date of Patent: October 1, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Koji Sumi, Kazuya Kitada, Tomohiro Sakai, Yasuaki Hamada, Tetsuya Isshiki, Satoshi Kimura, Akio Ito, Tsuneo Handa
  • Patent number: 10386222
    Abstract: A liquid detecting apparatus includes an ultrasonic sensor that transmits and receives an ultrasonic wave, and includes a piezoelectric layer which is formed of a thin film and an ultrasonic element which is provided with a first electrode and a second electrode to interpose the piezoelectric layer between the first electrode and the second electrode, on a diaphragm which is disposed on a substrate having a cavity, and a flow path that forms the same liquid level as a liquid level of a liquid which is stored in a container, in which an acoustic matching layer and a detection surface of a surface of a lens, which are disposed on a side of the ultrasonic sensor that transmits and receives the ultrasonic wave, are disposed to be in contact with the liquid within the flow path.
    Type: Grant
    Filed: November 2, 2017
    Date of Patent: August 20, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Tetsuya Isshiki, Takayuki Yonemura
  • Patent number: 10297742
    Abstract: A piezoelectric element includes a first and a second electrode, a piezoelectric layer between the first electrode and the second electrode, and an orientation control layer between the first electrode and the piezoelectric layer. The orientation control layer contains perovskite complex oxide containing potassium, sodium, calcium, and niobium and preferentially oriented in the (100) plane.
    Type: Grant
    Filed: November 6, 2017
    Date of Patent: May 21, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Koji Sumi, Tomohiro Sakai, Tetsuya Isshiki, Toshiaki Takahashi, Kazuya Kitada
  • Patent number: 10243137
    Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from compound oxide which has a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. The piezoelectric layer has a peak derived from a (200) plane and a peak derived from a (002) plane in an X-ray diffraction pattern obtained by ?-2? measurement.
    Type: Grant
    Filed: August 26, 2016
    Date of Patent: March 26, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Sakai, Koji Sumi, Tetsuya Isshiki, Toshiaki Takahashi, Tomokazu Kobayashi, Kazuya Kitada
  • Patent number: 10186652
    Abstract: There is provided a piezoelectric element which includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from a compound oxide having a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. A cross-sectional SEM image of the piezoelectric layer is captured at a magnification of 100,000. When evaluation is performed under a condition in which a measured value in a transverse direction is set to 1,273 nm, two or more voids are included in the piezoelectric layer, a difference between the maximum value and the minimum value among diameters of the voids to be largest in a film thickness direction is equal to or smaller than 14 nm, and the maximum value is equal to or smaller than 24 nm.
    Type: Grant
    Filed: April 27, 2016
    Date of Patent: January 22, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Sakai, Koji Sumi, Tetsuya Isshiki, Toshiaki Takahashi, Tomokazu Kobayashi, Kazuya Kitada
  • Publication number: 20180277742
    Abstract: A piezoelectric element has a diaphragm, a first electrode on the diaphragm, a piezoelectric layer on the first electrode, and a second electrode on the piezoelectric layer. The piezoelectric layer is a stack of multiple piezoelectric films and is made of a perovskite composite oxide containing lead, zirconium, and titanium and represented by the general formula ABO3, with the molar ratio of the A-site to the B-site (A/B) in the perovskite composite oxide being 1.14 or more and 1.22 or less. In current-time curve measurement, the activation energy calculated from relaxation current using an Arrhenius plot is 0.6 [eV] or less. The relaxation current is the amount of current at the time at which a downward trend in current turns upward.
    Type: Application
    Filed: March 14, 2018
    Publication date: September 27, 2018
    Inventors: Takayuki YONEMURA, Chikara KOJIMA, Xiaoxing WANG, Tetsuya ISSHIKI, Yasuhiro ITAYAMA
  • Publication number: 20180217561
    Abstract: A solar cell device includes an information display, a protective substrate that protects an information display surface of the information display, and a photoelectric conversion element. The photoelectric conversion element is disposed on a surface of the protective substrate. The surface faces the information display surface of the information display. The photoelectric conversion element includes a first electrode including a transparent electrode material, a second electrode including a transparent electrode material, a photoelectric conversion layer disposed between the first electrode and the second electrode and including an organic-inorganic perovskite compound, an electron transport layer, disposed between the first electrode and the photoelectric conversion layer, and a hole transport layer, disposed between the photoelectric conversion layer and the second electrode.
    Type: Application
    Filed: January 17, 2018
    Publication date: August 2, 2018
    Inventors: Tetsuya Isshiki, Xiaoxing Wang
  • Publication number: 20180175277
    Abstract: A piezoelectric element includes a first electrode formed on a substrate, a piezoelectric layer formed on the first electrode and composed of a complex oxide having a perovskite structure containing potassium (K), sodium (Na), niobium (Nb), and manganese (Mn), and a second electrode formed on the piezoelectric layer. The manganese includes divalent manganese (Mn2+), trivalent manganese (Mn3+), and tetravalent manganese (Mn4+), a molar ratio of the divalent manganese to a sum of the trivalent manganese and the tetravalent manganese ((Mn2+/(Mn3++Mn4+)) is 1 or more and 10 or less, and a molar ratio of the potassium to the sodium (K/Na) is 1.1 or less.
    Type: Application
    Filed: December 7, 2017
    Publication date: June 21, 2018
    Inventors: Kazuya KITADA, Koji SUMI, Tetsuya ISSHIKI, Tomohiro SAKAI, Toshiaki TAKAHASHI
  • Publication number: 20180143063
    Abstract: A liquid detecting apparatus includes an ultrasonic sensor that transmits and receives an ultrasonic wave, and includes a piezoelectric layer which is formed of a thin film and an ultrasonic element which is provided with a first electrode and a second electrode to interpose the piezoelectric layer between the first electrode and the second electrode, on a diaphragm which is disposed on a substrate having a cavity, and a flow path that forms the same liquid level as a liquid level of a liquid which is stored in a container, in which an acoustic matching layer and a detection surface of a surface of a lens, which are disposed on a side of the ultrasonic sensor that transmits and receives the ultrasonic wave, are disposed to be in contact with the liquid within the flow path.
    Type: Application
    Filed: November 2, 2017
    Publication date: May 24, 2018
    Inventors: Tetsuya ISSHIKI, Takayuki YONEMURA
  • Publication number: 20180138392
    Abstract: A piezoelectric element includes a first electrode; a second electrode; and a piezoelectric layer arranged between the first electrode and the second electrode, in which the piezoelectric layer is a thin film that includes a perovskite-type composite oxide which includes potassium, sodium, and niobium and which is preferentially oriented in the (100) plane, and a crystal structure of the perovskite-type composite oxide includes a basic lattice structure having an oxygen octahedron and a super lattice structure in which the oxygen octahedron is tilted.
    Type: Application
    Filed: November 2, 2017
    Publication date: May 17, 2018
    Inventors: Tetsuya ISSHIKI, Koichi MOROZUMI
  • Publication number: 20180138393
    Abstract: A piezoelectric element includes a first and a second electrode, a piezoelectric layer between the first electrode and the second electrode, and an orientation control layer between the first electrode and the piezoelectric layer. The orientation control layer contains perovskite complex oxide containing potassium, sodium, calcium, and niobium and preferentially oriented in the (100) plane.
    Type: Application
    Filed: November 6, 2017
    Publication date: May 17, 2018
    Inventors: Koji SUMI, Tomohiro SAKAI, Tetsuya ISSHIKI, Toshiaki TAKAHASHI, Kazuya KITADA
  • Publication number: 20170313625
    Abstract: A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than the rhombohedral crystal in a single composition, has a Curie temperature Tc2<Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a crystal other than the rhombohedral crystal in a single composition similar to the second component, has a Curie temperature Tc3?Tc1, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the second component. When a molar ratio of the third component to the sum of the second component and the third component is ? and ?×Tc3+(1??)×Tc2 is Tc4, |Tc4?Tc2|?50° C.
    Type: Application
    Filed: December 26, 2014
    Publication date: November 2, 2017
    Inventors: Koji SUMI, Kazuya KITADA, Tomohiro SAKAI, Yasuaki HAMADA, Tetsuya ISSHIKI, Satoshi KIMURA, Akio ITO, Tsuneo HANDA
  • Publication number: 20170309810
    Abstract: A piezoelectric material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than a rhombohedral crystal in a single composition, has a Curie temperature Tc2 higher than Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc3 equal to or higher than Tc2, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the first component. When a molar ratio of the third component to the sum of the first component and the third component is ? and ?×Tc3+(1??)×Tc1 is Tc4, |Tc4?Tc2| is 50° C. or lower.
    Type: Application
    Filed: December 26, 2014
    Publication date: October 26, 2017
    Inventors: Koji SUMI, Kazuya KITADA, Tomohiro SAKAI, Yasuaki HAMADA, Tetsuya ISSHIKI, Satoshi KIMURA, Akio ITO, Tsuneo HANDA
  • Publication number: 20170062697
    Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from compound oxide which has a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. The piezoelectric layer has a peak derived from a (200) plane and a peak derived from a (002) plane in an X-ray diffraction pattern obtained by ??2? measurement.
    Type: Application
    Filed: August 26, 2016
    Publication date: March 2, 2017
    Inventors: Tomohiro SAKAI, Koji SUMI, Tetsuya ISSHIKI, Toshiaki TAKAHASHI, Tomokazu KOBAYASHI, Kazuya KITADA
  • Publication number: 20170062693
    Abstract: There is provided a piezoelectric element which includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from a compound oxide having a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. A cross-sectional SEM image of the piezoelectric layer is captured at a magnification of 100,000. When evaluation is performed under a condition in which a measured value in a transverse direction is set to 1,273 nm, two or more voids are included in the piezoelectric layer, a difference between the maximum value and the minimum value among diameters of the voids to be largest in a film thickness direction is equal to or smaller than 14 nm, and the maximum value is equal to or smaller than 24 nm.
    Type: Application
    Filed: April 27, 2016
    Publication date: March 2, 2017
    Inventors: Tomohiro SAKAI, Koji SUMI, Tetsuya ISSHIKI, Toshiaki TAKAHASHI, Tomokazu KOBAYASHI, Kazuya KITADA
  • Publication number: 20160346808
    Abstract: A piezoelectric device includes: an elastic layer that forms an insulating surface region at least partially and has an amorphous structure or random orientation at least in the surface region; a piezoelectric body that is provided on the elastic layer, has a first surface in contact with the elastic layer and a second surface on an opposite side to the first surface, and is preferentially oriented in an orientation region corresponding to the surface region in a plan view; a first electrode provided on the second surface of the piezoelectric body; and a second electrode that is provided on the second surface of the piezoelectric body. A gap is formed between the first and second electrodes corresponding to the orientation region in the plan view.
    Type: Application
    Filed: May 27, 2016
    Publication date: December 1, 2016
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hiromu MIYAZAWA, Tetsuya ISSHIKI, Hiroshi ITO, Masayoshi YAMADA, Jiro TSURUNO, Tomoaki NAKAMURA