Patents by Inventor Ritsu Tanaka

Ritsu Tanaka 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: 7482739
    Abstract: A dielectric device of higher performance is provided. An electron emitter, to which the dielectric device is applied is provided with: an emitter including a dielectric; and an upper electrode and a lower electrode to which drive voltage is applied in order to emit electrons. The emitter is formed by the aerosol deposition method or the sol impregnation method, and the surface roughness of the upper surface thereof is controlled in the range from 0.1 to 3 in Ra.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: January 27, 2009
    Assignee: NGK Insulators, Ltd.
    Inventors: Tsutomu Nanataki, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20080302996
    Abstract: A (Li, Na, K)(Nb, Ta)O3 based piezoelectric/electrostrictive porcelain composition obtained by adding a slight amount of a Mn compound to a perovskite type oxide containing Li, Na and K as A-site elements and contains at least Nb out of Nb and Ta as B-site elements, where a ratio of a total number of atoms of the A-site elements to a total number of atoms of the B-site elements is not smaller than 1. A composition of the perovskite type oxide as a principal component is represented by a general formula: {Liy(Na1-xKx)1-y}a(Nb1-zTaz)O3. The A/B ratio “a” preferably satisfies 1<a?1.05. The Mn compound as an accessory component is desirably added such that the added amount is not more than 3 parts by mol in terms of Mn atom with respect to 100 parts by mol of said perovskite type oxide.
    Type: Application
    Filed: February 25, 2008
    Publication date: December 11, 2008
    Applicant: NGK Insulators, Ltd.
    Inventors: Yukinobu Yura, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20080074007
    Abstract: A monomorph type piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive body, which is composed of a non-lead based piezoelectric/electrostrictive crystalline body containing at least Nb, Ta, and one or more types of alkali metal element, which has a cubic crystal structure at a temperature higher than the phase transition point and at least any one of tetragonal and orthorhombic crystal structures at a temperature lower than the phase transition point, and which is curved to a large extent by a polarization treatment to take on a curved shape at a temperature lower than the phase transition point without application of a voltage after the polarization treatment. In the polarization treatment, an electric field is increased at a speed of from 0.1 (kV/mm)/sec or more to 5 (kV/mm)/sec or less, with applying the maximum electric field of from 2 kV/mm or more to 1.0 kV/mm or less.
    Type: Application
    Filed: September 6, 2007
    Publication date: March 27, 2008
    Applicant: NGK Insulators, Ltd.
    Inventors: Ritsu Tanaka, Hirofumi Yamaguchi, Yukinobu Yura, Shuichi Ozawa
  • Publication number: 20070216260
    Abstract: There is disclosed a piezoelectric/electrostrictive device which exhibits an excellent piezoelectric characteristic and which has an only small dependence on a temperature so that the piezoelectric characteristic does not easily change with the temperature. A piezoelectric/electrostrictive device includes a piezoelectric/electrostrictive portion made of a piezoelectric ceramic, and electrodes electrically connected to the piezoelectric/electrostrictive portion. The piezoelectric ceramic can reversibly transit to a tetragonal phase and an orthorhombic phase at a phase transition point as a boundary, and the piezoelectric/electrostrictive portion is formed by a polarization treatment performed on conditions that a treatment temperature ranges from a temperature which exceeds the phase transition point of the piezoelectric ceramic to a temperature which is 50° C. higher than the temperature.
    Type: Application
    Filed: March 13, 2007
    Publication date: September 20, 2007
    Applicant: NGK Insulators, Ltd.
    Inventors: Yukinobu Yura, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20060202170
    Abstract: A piezoelectric/electrostrictive porcelain composition contains at least Nb, Ta, and one or more kinds of alkali metal elements, and a ratio (molar ratio) of Nb, Ta, and the alkali metal element is represented by a non-stoichiometric composition ratio. The piezoelectric/electrostrictive porcelain composition is capable of obtaining a piezoelectric/electrostrictive device which is dense and which is superior in crystallinity and which exhibits superior piezoelectric/electrostrictive characteristics even in a case where the composition is fired on lower-temperature conditions as compared with a conventional technology.
    Type: Application
    Filed: March 7, 2006
    Publication date: September 14, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Takaaki Koizumi, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20060012279
    Abstract: A dielectric device of higher performance is provided. An electron emitter, to which the dielectric device is applied is provided with: an emitter including a dielectric; and an upper electrode and a lower electrode to which drive voltage is applied in order to emit electrons. The emitter is formed by the aerosol deposition method or the sol impregnation method.
    Type: Application
    Filed: July 13, 2005
    Publication date: January 19, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Tsutomu Nanataki, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20060012278
    Abstract: A dielectric device of higher performance is provided. An electron emitter, to which the dielectric device is applied is provided with: an emitter including a dielectric; and an upper electrode and a lower electrode to which drive voltage is applied in order to emit electrons. The emitter is formed by the aerosol deposition method or the sol impregnation method, and the surface roughness of the upper surface thereof is controlled in the range from 0.1 to 3 in Ra.
    Type: Application
    Filed: July 13, 2005
    Publication date: January 19, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Tsutomu Nanataki, Hirofumi Yamaguchi, Ritsu Tanaka
  • Publication number: 20040037708
    Abstract: A working-fluid moving device is a laminate of ceramic sheets, which constitute a channel. One of the ceramic sheets is formed to serve as a diaphragm. A piezoelectric/electrostrictive film is formed on the diaphragm. The channel houses first and second working fluids. The first working fluid is inferior to the second working fluid in wettability to the inner wall surface of the channel. When voltage is applied to the piezoelectric/electrostrictive film, the diaphragm is deformed, and the cross-sectional area of the channel at the central portion is reduced. The first working fluid which is present in the form of a single fluid mass at the central portion of the channel receives a repulsive force from the wall surface of the channel due to inferior wettability. As a result, the first working fluid is split into two fluid masses, which then move in the channel.
    Type: Application
    Filed: July 25, 2003
    Publication date: February 26, 2004
    Applicant: NGK Insulators, Ltd.
    Inventors: Masahiro Murasato, Ritsu Tanaka, Yuki Bessho
  • Patent number: 6401333
    Abstract: A method and apparatus (10) are used for manufacturing a wire structure wherein a wire (13) is three-dimensionally aligned at prescribed pitches. The method comprises the steps of providing one or more frame bodies (12) which have a prescribed thickness, peripherally of a rotary shaft (11). By rotating rotary shaft (11) about a rotation axis thereof, wires (13) are wound, at prescribed pitches, around frame bodies (12). Another frame body (12) is stacked on at least one existing frame body and wire (13) is wound thereon at prescribed pitches. The above steps are repeated to yield a wire structure having a wire aligned three-dimensionally and accurately at prescribed pitches.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: June 11, 2002
    Assignee: NGK Insulators, Ltd.
    Inventors: Tomio Suzuki, Ritsu Tanaka
  • Patent number: 5306368
    Abstract: A process for forming a ceramic thin film on a surface of a ceramic body, including the steps of preparing an annular body from a ceramic green sheet, inserting the ceramic body into the annular body, and firing the thus assembled annular body and ceramic body, whereby the annular body is shrunk and joined to the ceramic body.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: April 26, 1994
    Assignee: NGK Insulators, Ltd.
    Inventors: Hirotake Yamada, Ritsu Tanaka