Patents by Inventor Akihiro Takami

Akihiro Takami 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: 5547907
    Abstract: The present invention relates to a zinc oxide varistor as a characteristic element of an arrestor for protecting a transmission and distribution line and peripheral devices thereof from surge voltage created by lightning, and more particularly a highly reliable zinc oxide varistor excellent in the non-linearity with respect to voltage, the discharge withstand current rating properties, and the life characteristics under voltage, a method of preparing the same, and PbO type crystallized glass for coating oxide ceramics employed for a zinc oxide varistor, etc. A zinc oxide varistor of the present invention comprises a sintered body (1) and a high resistive side layer (3) consisting of crystallized glass with high crystallinity containing the prescribed amount of SiO.sub.2, MoO.sub.3, WO.sub.3, TiO.sub.2, NiO, etc.
    Type: Grant
    Filed: February 14, 1995
    Date of Patent: August 20, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaaki Katsumata, Osamu Kanaya, Nobuharu Katsuki, Akihiro Takami
  • Patent number: 5535699
    Abstract: A method for producing a photo-voltaic infrared detector including growing a crystalline CdHgTe layer on a CdTe substrate by liquid phase epitaxy using a growth melt including tellurium as a solvent to which indium is added as a dopant impurity in a concentration of from 0.01 to 0.1 ppm; annealing the CdHgTe layer to produce a p-type CdHgTe layer including indium as an n-type background dopant impurity; forming an n-type region of a desired depth as a light receiving region at the surface of the p-type CdHgTe layer by implanting a dopant impurity producing n-type conductivity and annealing; and forming an n-side electrode on the n-type region and a p-side electrode a prescribed distance from the n-type region on the p-type CdHgTe layer.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: July 16, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Zempei Kawazu, Akihiro Takami
  • Patent number: 5447892
    Abstract: The present invention relates to a zinc oxide varistor as a characteristic element of an arrestor for protecting a transmission and distribution line and peripheral devices thereof from surge voltage created by lightning, and more particularly a highly reliable zinc oxide varistor excellent in the non-linearity with respect to voltage, the discharge withstand current rating properties, and the life characteristics under voltage, a method of preparing the same, and PbO type crystallized glass for coating oxide ceramics employed for a zinc oxide varistor, etc. A zinc oxide varistor of the present invention comprises a sintered body (1) and a high resistive side layer (3) consisting of crystallized glass with high crystallinity containing the prescribed amount of SiO.sub.2, MoO.sub.3, WO.sub.3, TiO.sub.2, NiO, etc.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: September 5, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaaki Katsumata, Osamu Kanaya, Nobuharu Katsuki, Akihiro Takami
  • Patent number: 5294908
    Abstract: The present invention relates to a zinc oxide varistor as a characteristic element of an arrestor for protecting a transmission and distribution line and peripheral devices thereof from surge voltage created by lightning, and more particularly a highly reliable zinc oxide varistor excellent in the non-linearity with respect to voltage, the discharge withstand current rating properties, and the life characteristics under voltage, a method of preparing the same, and PbO type crystallized glass for coating oxide ceramics employed for a zinc oxide varistor, etc. A zinc oxide varistor of the present invention includes a sintered body (1) and a high resistive side layer (3) consisting of crystallized glass with high crystallinity containing the prescribed amount of SiO.sub.2, MoO.sub.3, WO.sub.3, TiO.sub.2, NiO, etc.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: March 15, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaaki Katsumata, Osamu Kanaya, Nobuharu Katsuki, Akihiro Takami
  • Patent number: 5268006
    Abstract: A method for manufacturing semiconductor-type laminated ceramic capacitors with a grain boundary-insulated structure including the steps of calcinating starting material of mixed powder in air or in nitrogen atmosphere after grinding, mixing and drying the mixed powder; forming raw sheets; printing a pattern of inner electrode paste on the surface of the raw sheets; calcinating the laminated body in air; sintering the laminated raw sheets in reducing atmosphere or in nitrogen atmosphere after calcination; re-oxidizing in air after sintering; and covering the edges of sintered ceramic sheets with outer electrode paste and baking after re-oxidation, terminals of inner electrodes being exposed to the edges, wherein: the starting material of mixed powder comprises a material of the composition Sr.sub.(1-x) Ba.sub.x TiO.sub.3 containing excess Ti to make a final molecular ratio of Ti to Sr.sub.(1-x) Ba.sub.x in the range of 0.95.ltoreq. Sr.sub.(1-x)Ba.sub.x /Ti< 1.00 (where x is in the range of 0< x.ltoreq.
    Type: Grant
    Filed: July 28, 1992
    Date of Patent: December 7, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Iwao Ueno, Yasuo Wakahata, Kimio Kobayashi, Kaori Okamoto, Akihiro Takami
  • Patent number: 5229321
    Abstract: A method of diffusing mercury into a crystalline compound semiconductor film including mercury includes forming an amalgam on a region of the semiconductor film into which mercury is to be diffused, forminq a protective film on the amalgam, and annealing, whereby mercury from the amalgam diffuses into the semiconductor film and the protective film prevents the mercury from escaping. Therefore, a complicated temperature profile is not required and the mercury diffusion is carried out without sealing the semiconductor film in a quartz tube. As a result, the instruments and materials used in the diffusion process are easily handled and the diffusion of mercury into a large-sized semiconductor film is possible.
    Type: Grant
    Filed: June 9, 1992
    Date of Patent: July 20, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Akihiro Takami
  • Patent number: 5166759
    Abstract: The present invention provides a semiconductor-type laminated ceramic capacitor with a grain boundary-insulated structure made of Sr.sub.(1-x) Ba.sub.x TiO.sub.3 as a main component, comprising the functions of a conventional capacitor which absorbs low voltage noises and high frequency noises, and a varistor when high voltage noises and electrostatic charges invade, wherein simultaneous sintering of the materials of ceramic capacitor together with the materials of inner electrodes was made possible in the manufacturing process. Besides a material to be made semiconductive is added to the main component of Sr.sub.(1-x) Ba.sub.x TiO.sub.3 with excess Ti, the materials of Mn-Si, which are converted to MnO.sub.2 and SiO.sub.2 in the sintering process, are also added to the main component.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: November 24, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Iwao Ueno, Yasuo Wakahata, Kimio Kobayashi, Kaori Shiraishi, Akihiro Takami
  • Patent number: 5166859
    Abstract: A laminated semiconductor ceramic capacitor with a grain boundary-insulated structure comprises a semiconductor ceramic block with a grain boundary-insulated structure, a plurality of Ni inner electrodes and outer electrodes, wherein the Ni inner electrodes are obtained from a paste containing a powder prepared by solubilizing at least one compound containing an atom selected from the group consisting of Li, Na and K into Ni or an Ni containing compound; the Ni inner electrodes are placed in a substantially parallel manner within the ceramic block to reach to the corresponding opposite edges of the ceramic block alternatively one by one; and the outer electrodes are electrically connected to the corresponding edges of the inner electrodes, respectively.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: November 24, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Iwao Ueno, Yasuo Wakahata, Kimio Kobayashi, Kaori Shiraishi, Akihiro Takami, Youichi Ogoshi
  • Patent number: 5075818
    Abstract: A semiconductor-type laminated ceramic capacitor with a grain boundary-insulated structure made of SrTiO.sub.3 as the main component, comprising the functions of a conventional capacitor which absorbs low voltage noises and high frequency noises, and a varistor when high voltage noises and electrostatic charges invade, wherein simultaneous sintering of the materials of the ceramic capacitor together with the materials of inner electrodes has been made possible in the manufacturing process. A material to be made semiconducting is added to the main component of SrTiO.sub.3 with an excess in Ti, the materials of Mn--Si, which are converted to MnO.sub.2 and SiO.sub.2 in the sintering process are also added to the main component.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: December 24, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Iwao Ueno, Yasuo Wakahata, Kimio Kobayashi, Kaori Okamoto, Akihiro Takami
  • Patent number: 4897219
    Abstract: It is a voltage-dependent non-linear resistance ceramic composition comprising SrTiO.sub.3 as host material, Dy.sub.2 O.sub.3 or Dy.sub.2 O.sub.3 and Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.5 as accelerating agent for semiconductorization, thereby changing crystal to a low resistance, and changing crystal boundary to a high resistance.In case Dy.sub.2 O.sub.3 or Dy.sub.2 O.sub.3 and Nb.sub.2 O.sub.5 are used as the accelerating agent for semiconductorization, one kind or more selected from the group consisting of Na, K, Ca, Cd, In, Ba, Pb, Ag, Ce, La, Sc, Y, Cs, Au, Mg, Zr, Sn, Sb, W, Bi, Ni, Fe, Ga, Pt, Tl, Al, Si, Be, Li, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf and Ru. Alternatively, in case Ta.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 and Nb.sub.2 O.sub.
    Type: Grant
    Filed: November 7, 1988
    Date of Patent: January 30, 1990
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichi Noi, Akihiro Takami, Kazuhide Ebine, Kimiko Kumazawa
  • Patent number: 4839097
    Abstract: This is a voltage-dependent non-linear resistance ceramic composition wherein resistance of crystal is decreased by containing SrTiO.sub.3 as host material, and Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5 as semiconductorization accelerating agent, and further by adding as additive one kind or more oxide of element selected from the group consisting of MnO.sub.2, Ga, Pt, Tl, Si, Ti, Li, La, Cu, Y, Cs, Au, Mo, S, Be, Al, Na, K, Ca, Cd, In, Ba, Pb, Eu, Gd, Tb, Tm, Lu, Th, Ir, Os, Hf, Ru, Mg, Zr, Sn, Sb and W, these additive is segregated at crystal granule boundaries, thereby making the crystal granule boundaries to high resistance.Accordingly, by the high resistance layer at the crystal boundaries the varistor characteristic is obtainable, and a capacitance characteristic is obtainable between the crystal granule-crystal granule boundary-crystal granule.
    Type: Grant
    Filed: February 9, 1987
    Date of Patent: June 13, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichi Noi, Akihiro Takami, Kazuhide Ebine, Kimiko Kumazawa
  • Patent number: 4060661
    Abstract: There is provided a voltage-dependent resistor comprising a bulk consisting essentially of zinc oxide as the major part and as additives 0.01 to 10 mol % of Bi.sub.2 O.sub.3, CoO, MnO, TiO and NiO and electrodes on the bulk, said electrodes having been formed by baking a silver paste comprising silver powder and a glass frit on the bulk, said glass frit containing as its principal content 80 to 95% by weight of Bi.sub.2 O.sub.3 and correspondingly 20 to 5% by weight of SiO.sub.2, said glass frit also containing 1 to 5 parts by weight of B.sub.2 O.sub.3 for 100 parts of said principal content. The electrodes can also contain minor amounts of CoO, Sb.sub.2 O.sub.3, a mixture of Sb.sub.2 O.sub.3 with Ag.sub.2 O or MgO, or a mixture of CoO with MgO or Ag.sub.2 O.
    Type: Grant
    Filed: August 4, 1976
    Date of Patent: November 29, 1977
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiro Takami, Takayuki Kuroda, Katsuo Nagano, Michio Matsuoka