Patents by Inventor Yoshiko Gokita

Yoshiko Gokita 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: 7309450
    Abstract: Provided is a piezoelectric ceramic with a wider operating temperature range capable of obtaining a larger amount of displacement and being easily sintered, as well as being superior in terms of ultra-low emission, environmental friendliness and ecology. A piezoelectric substrate 1 comprises a composition including a perovskite-type oxide (Na1?x?y?zKxLiyAgz)(Nb1?wTaw)O3 and a tungsten bronze-type oxide M(Nb1?vTav)2O6 (M is an element of Group 2 in the long form of the periodic table of the elements). The values of x, y and z are preferably within a range of 0.1?x?0.9, 0?y?0.2, and 0?z?0.05, respectively. The content of the tungsten bronze-type oxide is preferably 5.3 mol % or less. Thereby, a higher Curie temperature and a larger amount of displacement can be obtained, and sintering can be more easily carried out.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: December 18, 2007
    Assignee: TDK Corporation
    Inventors: Masaru Nanao, Yasuharu Miyauchi, Tamotsu Ishiyama, Masahito Furukawa, Shogo Murosawa, Yoshiko Gokita
  • Publication number: 20050006618
    Abstract: Provided is a piezoelectric ceramic with a wider operating temperature range capable of obtaining a larger amount of displacement and being easily sintered, as well as being superior in terms of ultra-low emission, environmental friendliness and ecology. A piezoelectric substrate 1 comprises a composition including a perovskite-type oxide (Na1-x-y-zKxLiyAgz)(Nb1-wTaw)O3 and a tungsten bronze-type oxide M(Nb1-vTav)2O6 (M is an element of Group 2 in the long form of the periodic table of the elements). The values of x, y and z are preferably within a range of 0.1?x?0.9, 0?y?0.2, and 0?z?0.05, respectively. The content of the tungsten bronze-type oxide is preferably 5.3 mol % or less. Thereby, a higher Curie temperature and a larger amount of displacement can be obtained, and sintering can be more easily carried out.
    Type: Application
    Filed: June 14, 2002
    Publication date: January 13, 2005
    Inventors: Masaru Nanao, Yasuharu Miyauchi, Tamotsu Ishiyama, Masahito Furukawa, Shogo Murosawa, Yoshiko Gokita
  • Patent number: 6793843
    Abstract: Provided is a piezoelectric ceramic capable of improving its piezoelectric properties. The piezoelectric ceramic comprises a rhombohedral perovskite structure compound such as (Na0.5Bi0.5)TiO3, a tetragonal perovskite structure compound such as BaTiO3 and (K0.5Bi0.5)TiO3 and an orthorhombic perovskite structure compound such as NaNbO3, KNbO3 and CaTiO3, or the rhombohedral perovskite structure compound, the tetragonal perovskite structure compound and a cubic perovskite structure compound such as SrTiO3. Three kinds of perovskite structure compounds having different crystal structures are comprised, so that the piezoelectric properties can be improved. The three kinds of compounds may perfectly form a solid solution or not.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: September 21, 2004
    Assignee: TDK Corporation
    Inventors: Masahito Furukawa, Kenji Horino, Shogo Murosawa, Yoshiko Gokita
  • Publication number: 20030134738
    Abstract: Provided is a piezoelectric ceramic capable of improving its piezoelectric properties. The piezoelectric ceramic comprises a rhombohedral perovskite structure compound such as (Na0.5Bi0.5)TiO3, a tetragonal perovskite structure compound such as BaTiO3 and (K0.5Bi0.5)TiO3 and an orthorhombic perovskite structure compound such as NaNbO3, KNbO3 and CaTiO3, or the rhombohedral perovskite structure compound, the tetragonal perovskite structure compound and a cubic perovskite structure compound such as SrTiO3. Three kinds of perovskite structure compounds having different crystal structures are comprised, so that the piezoelectric properties can be improved. The three kinds of compounds may perfectly form a solid solution or not.
    Type: Application
    Filed: July 16, 2002
    Publication date: July 17, 2003
    Inventors: Masahito Furukawa, Kenji Horino, Shogo Murosawa, Yoshiko Gokita
  • Patent number: 6413443
    Abstract: The piezoelectric ceramic includes oxide represented by (Pb1−aAa)s[Zn1/3Nb2/3)w(Mn1/3B2/3)xTiyZrz]O3. A represents at least one element in the group comprising Ca, Sr and Ba. B represents at least one element in the group comprising Nb, Sb and Ta and a, s, w, x, y and z are within a range of 0≦a≦0.1, 0.9≦s<1.0, 0.2≦w/x≦3.0, 0.1≦y≦0.5 and 0.2≦z≦0.6, respectively and w+x+y+z=1. Therefore, the high mechanical strength can be attained easily and reasonably and also the excellent piezoelectric properties are attained without grinding calcined powder or a hot press.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: July 2, 2002
    Assignee: TDK Corporation
    Inventors: Masahito Furukawa, Junichi Yamazaki, Yoshiko Gokita
  • Patent number: 6207069
    Abstract: Manganese oxide and tantalum oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate. The composition is suitable for piezo-electric transformers since its mechanical quality factor (Qm) is improved without reducing its electromechanical coupling coefficient (k31), and good high-power properties and high mechanical strength are obtained. In another embodiment, manganese oxide and at least one of antimony oxide and niobium oxide are added to a piezoelectric ceramic composition based on lead zinc-niobate titanate zirconate.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: March 27, 2001
    Assignee: TDK Corporation
    Inventors: Masahito Furukawa, Kazutaka Suzuki, Yoshiko Gokita, Takumi Satou, Keisuke Itakura