Patents by Inventor Koji Sumi

Koji Sumi 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: 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: 10355196
    Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer formed of a first piezoelectric film which is formed on the first electrode and which includes potassium, sodium, and niobium and a plurality of second piezoelectric films which are formed on the first piezoelectric film and which include potassium, sodium, and niobium, and a second electrode formed on the piezoelectric layer, in which the piezoelectric layer is a stack of a plurality of piezoelectric films, the first piezoelectric film has a thickness of 30 nm to 70 nm, a concentration of sodium in each of the piezoelectric films is along a gradient in the film thickness direction with the first electrode side being high and the second electrode side being low.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: July 16, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Sakai, Kazuya Kitada, Koji Sumi
  • Publication number: 20190198750
    Abstract: Provided is a piezoelectric element including a first electrode provided above a substrate, a piezoelectric layer provided above the first electrode, containing potassium, sodium, and niobium, and having a perovskite structure, and a second electrode provided above the piezoelectric layer. In a case where the piezoelectric layer is divided into two portions at a center thereof in a thickness direction, the piezoelectric layer includes a first portion on the first electrode side and a second portion on the second electrode side. The piezoelectric layer includes line defects. A density of the line defects in the second portion is higher than a density of the line defects in the first portion.
    Type: Application
    Filed: December 18, 2018
    Publication date: June 27, 2019
    Inventors: Tomohiro SAKAI, Koichi MOROZUMI, Kazuya KITADA, Harunobu KOIKE, Koji SUMI
  • Publication number: 20190181328
    Abstract: A piezoelectric element includes: a first electrode containing crystal grains; a piezoelectric layer which contains potassium, sodium, and niobium and which is provided above the first electrode; and a second electrode provided above the piezoelectric layer, and the average grain diameter of the crystal grains is less than 550 nm.
    Type: Application
    Filed: December 12, 2018
    Publication date: June 13, 2019
    Inventors: Koji SUMI, Harunobu KOIKE, Toshiaki TAKAHASHI, Koichi MOROZUMI
  • 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: 20190019941
    Abstract: A piezoelectric element includes a first electrode; a piezoelectric layer, placed on or above the first electrode, containing potassium, sodium, niobium, titanium, and oxygen; and a second electrode placed on or above the piezoelectric layer.
    Type: Application
    Filed: July 10, 2018
    Publication date: January 17, 2019
    Inventors: Koji SUMI, Tomokazu KOBAYASHI, Tomohiro SAKAI, Kazuya KITADA, Koichi MOROZUMI, Tsutomu ASAKAWA
  • Patent number: 10181555
    Abstract: A piezoelectric element includes a first electrode, a second electrode, and a thin piezoelectric layer. The thin piezoelectric layer is provided between the first electrode and the first electrode, and is formed of a perovskite type compound oxide which contains potassium, sodium, and niobium. In the piezoelectric layer, in an X-ray diffraction pattern obtained by ??2? measurement, peaks derived from a (002) plane and a (200) plane are provided in a range in which 2? is from 45° to 47°, a peak position of the peak on a high angle side among the peaks satisfies 46.0°?2??46.5°, and a difference of 2? between the peak on the high angle side and the peak on a low angle side is greater than 0.60°.
    Type: Grant
    Filed: February 14, 2018
    Date of Patent: January 15, 2019
    Assignee: Seiko Epson Corporation
    Inventors: Kazuya Kitada, Koji Sumi, Tomohiro Sakai, Toshiaki Takahashi
  • Publication number: 20180287048
    Abstract: A piezoelectric element includes a substrate, a first electrode formed on the substrate, a piezoelectric layer, which is a layered structure of a plurality of piezoelectric films each containing potassium, sodium, and niobium, formed on the first electrode, and a second electrode formed on the piezoelectric layer. A sodium concentration in the piezoelectric layer has a Na local maximum value, which is a local maximum value of the sodium concentration, in a first piezoelectric film, which is among the plurality of piezoelectric films, in the vicinity of the first electrode, a sodium concentration gradient decreasing from the Na local maximum value toward the second electrode, and a Na local minimum value, which is a local minimum value of the sodium concentration, near a boundary between the first piezoelectric film and a second piezoelectric film formed immediately above the first piezoelectric film.
    Type: Application
    Filed: March 9, 2018
    Publication date: October 4, 2018
    Inventors: Kazuya KITADA, Koji SUMI, Tomohiro SAKAI, Toshiaki TAKAHASHI, Tsutomu ASAKAWA
  • Patent number: 10059101
    Abstract: A liquid ejection head includes a substrate in which a pressure generating chamber that communicates with a nozzle opening is formed; and a piezoelectric element having a piezoelectric layer, a first electrode that is formed on a surface of the piezoelectric layer on a side of the substrate so as to correspond to the pressure generating chamber, and a second electrode that is formed on a surface of the piezoelectric layer opposite to the side on which the first electrode is formed so as to extend over a plurality of the pressure generating chambers, wherein the second electrode is formed to extend to an outside of the pressure generating chamber in a longitudinal direction of the pressure generating chamber.
    Type: Grant
    Filed: October 18, 2016
    Date of Patent: August 28, 2018
    Assignee: Seiko Epson Corporation
    Inventors: Eiju Hirai, Shiro Yazaki, Koji Sumi, Motoki Takabe, Jiro Kato, Hiroshi Ito, Toshihiro Shimizu, Takahiro Kamijo, Tatsuro Torimoto, Chikara Kojima
  • Publication number: 20180233656
    Abstract: A piezoelectric element includes a first electrode, a second electrode, and a thin piezoelectric layer. The thin piezoelectric layer is provided between the first electrode and the first electrode, and is formed of a perovskite type compound oxide which contains potassium, sodium, and niobium. In the piezoelectric layer, in an X-ray diffraction pattern obtained by ??2? measurement, peaks derived from a (002) plane and a (200) plane are provided in a range in which 2? is from 45° to 47°, a peak position of the peak on a high angle side among the peaks satisfies 46.0°?2??46.5°, and a difference of 2? between the peak on the high angle side and the peak on a low angle side is greater than 0.60°.
    Type: Application
    Filed: February 14, 2018
    Publication date: August 16, 2018
    Inventors: Kazuya KITADA, Koji SUMI, Tomohiro SAKAI, Toshiaki TAKAHASHI
  • 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: 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: 20170229637
    Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer formed of a first piezoelectric film which is formed on the first electrode and which includes potassium, sodium, and niobium and a plurality of second piezoelectric films which are formed on the first piezoelectric film and which include potassium, sodium, and niobium, and a second electrode formed on the piezoelectric layer, in which the piezoelectric layer is a stack of a plurality of piezoelectric films, the first piezoelectric film has a thickness of 30 nm to 70 nm, a concentration of sodium in each of the piezoelectric films is along a gradient in the film thickness direction with the first electrode side being high and the second electrode side being low.
    Type: Application
    Filed: December 14, 2016
    Publication date: August 10, 2017
    Inventors: Tomohiro SAKAI, Kazuya KITADA, Koji SUMI
  • Publication number: 20170179368
    Abstract: A vibrating plate is provided between a substrate and a piezoelectric element formed of electrodes and a piezoelectric layer and includes a first layer which is formed of a silicon oxide and a second layer which is formed of a ceramic having a Young's modulus larger than that of the silicon oxide. Under the condition in which the following expression (1) has a constant value, where in the expression (1), Ev1, dv1, Ev2, and dv2 represent Young's modulus of the first layer, the thickness thereof, Young's modulus of the second layer, and the thickness thereof, Ev1×dv12+Ev2×dv22??(1) when the combination of dv1 and dv2 which sets the value of the following expression (2) in a range of from the minimum value to +2% thereof is represented by (Dv1, Dv2), Ev1×dv13+Ev2×dv23??(2) the thickness of the first layer and the thickness of the second layer are represented by Dv1 and Dv2.
    Type: Application
    Filed: November 22, 2016
    Publication date: June 22, 2017
    Inventors: Koji SUMI, Eiji OSAWA
  • 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