Patents by Inventor Mitsuru Kurashina

Mitsuru Kurashina 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).

  • Corrosion-resistant alumina member and arc tube for high-intensity discharge lamp
    Patent number: 6642656
    Abstract: An arc tube is formed by polycrystalline alumina so that an average crystal grain diameter of a surface is two to ten times as large as an average crystal grain diameter of an inside including a center line of a thickness and the average crystal grain diameter on the center portion of the thickness is 10 &mgr;m to 100 &mgr;m. As a result, in the arc tube, the total transmittance is 98%, and a linear ray transmittance is 5%.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: November 4, 2003
    Assignee: NGK Insulators, Ltd.
    Inventors: Mitsuru Kurashina, Michio Asai
  • Ceramic polycrystal and method of manufacturing the same
    Publication number: 20020155944
    Abstract: A ceramic polycrystal and a method of manufacturing such a ceramic polycrystal having thermal stability enough to be used in an arc tube are provided. The ceramic polycrystal has crystalline particles. Each of crystalline particles has a crystalline structure selected from triclinc, monoclinic, rhombi, tetragonal, trigonal, and hexagonal systems, with an average grain size being not less than 5 &mgr;m and a linear transmittance being not less than 8%.
    Type: Application
    Filed: March 15, 2002
    Publication date: October 24, 2002
    Applicant: NGK Insulators, Ltd.
    Inventors: Mitsuru Kurashina, Norikazu Niimi, Hirofumi Yamaguchi
  • Corrosion-resistant alumina member and arc tube for high-intensity discharge lamp
    Publication number: 20020017867
    Abstract: An arc tube is formed by polycrystalline alumina so that an average crystal grain diameter of a surface is two to ten times as large as an average crystal grain diameter of an inside including a center line of a thickness and the average crystal grain diameter on the center portion of the thickness is 10 &mgr;m to 100 &mgr;m. As a result, in the arc tube, the total transmittance is 98%, and a linear ray transmittance is 5%.
    Type: Application
    Filed: March 27, 2001
    Publication date: February 14, 2002
    Applicant: NGK Insulators, Ltd.
    Inventors: Mitsuru Kurashina, Michio Asai
  • Piezoelectric device
    Patent number: 5594292
    Abstract: A piezoelectric device includes a ceramic substrate having at least one cavity defined by a thin-walled region of the substrate. The thin-walled region has an outer surface provided with at least one piezoelectric transducer and also with a non-operative portion situated adjacent to the piezoelectric transducer such that each piezoelectric transducer surrounds the non-operative portion, or two piezoelectric transducers are arranged on both sides of the non-operative portion.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: January 14, 1997
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Koji Kimura, Mitsuru Kurashina