Patents by Inventor Hiroyasu Konaka

Hiroyasu Konaka 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: 6939822
    Abstract: A dielectric ceramic has a ceramic structure of crystal grains and grain boundaries between the crystal grains. The crystal grains are of a main component represented by the formula ABO3 and an additive containing a rare earth element wherein A is at least one of barium, calcium, and strontium, barium being an essential element, and B is at least one of titanium, zirconium, and hafnium, titanium being an essential element. The average rare earth element concentration in the interior of the crystal grains is about 50% or less the average rare earth element concentration at the grain boundaries. Furthermore, about 20% to 70% of the crystal grains have a rare earth element concentration in the center of the crystal grain of at least about 1/50 the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: September 6, 2005
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroyasu Konaka, Tomoyuki Nakamura, Toshihiro Okamatsu, Harunobu Sano
  • Patent number: 6853536
    Abstract: A dielectric ceramic includes, in composition, a perovskite-type compound having the general formula ABO3 containing Ba, Ca and Ti, and an additive component containing Si, R(La or the like), and M (Mn or the like), the additive component not being solid-dissolved and, moreover, the major component existing in at least 90% of the cross-section of each of the crystal grains of which the number is equal to at least 85% of that of all of the crystal grains contained in the dielectric ceramic, at least the Ba, the Ca, the Ti, the Si, the R, and the M being contained at at least 85% of the analytical points in the crystal grain boundaries of the dielectric ceramic.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: February 8, 2005
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tomoyuki Nakamura, Hiroyasu Konaka, Akira Kata, Kazuo Muto, Harunobu Sano
  • Patent number: 6829137
    Abstract: A dielectric ceramic includes a principal component which contains Ba, Ca and Ti and which has a perovskite structure represented by the general formula ABO3; additive components containing, for example, La and Mn; and a sintering aid, wherein crystal grains of the dielectric ceramic contain Ca, and the intergranular variation in the average Ca concentration within each grain is about 5% or more, in terms of CV value, or the ratio of the number of crystal grains in which the intragranular variation in the Ca concentration is about 5% or more, in terms of CV value, to the total number of crystal grains containing Ca is about 10% or more. A monolithic ceramic capacitor fabricated using the dielectric ceramic is also disclosed.
    Type: Grant
    Filed: December 17, 2003
    Date of Patent: December 7, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroyasu Konaka, Shozo Kobayashi, Harunobu Sano
  • Publication number: 20040169967
    Abstract: A dielectric ceramic includes a principal component which contains Ba, Ca and Ti and which has a perovskite structure represented by the general formula ABO3; additive components containing, for example, La and Mn; and a sintering aid, wherein crystal grains of the dielectric ceramic contain Ca, and the intergranular variation in the average Ca concentration within each grain is about 5% or more, in terms of CV value, or the ratio of the number of crystal grains in which the intragranular variation in the Ca concentration is about 5% or more, in terms of CV value, to the total number of crystal grains containing Ca is about 10% or more. A monolithic ceramic capacitor fabricated using the dielectric ceramic is also disclosed.
    Type: Application
    Filed: December 17, 2003
    Publication date: September 2, 2004
    Inventors: Hiroyasu Konaka, Shozo Kobayashi, Harunobu Sano
  • Publication number: 20040145856
    Abstract: A dielectric ceramic includes, in composition, a perovskite-type compound having the general formula ABO3 containing Ba, Ca and Ti, and an additive component containing Si, R(La or the like), and M (Mn or the like), the additive component not being solid-dissolved and, moreover, the major component existing in at least 90% of the cross-section of each of the crystal grains of which the number is equal to at least 85% of that of all of the crystal grains contained in the dielectric ceramic, at least the Ba, the Ca, the Ti, the Si, the R, and the M being contained at at least 85% of the analytical points in the crystal grain boundaries of the dielectric ceramic.
    Type: Application
    Filed: December 19, 2003
    Publication date: July 29, 2004
    Inventors: Tomoyuki Nakamura, Hiroyasu Konaka, Akira Kata, Kazuo Muto, Harunobu Sano
  • Publication number: 20030147198
    Abstract: A dielectric ceramic has a ceramic structure of crystal grains and grain boundaries between the crystal grains. The crystal grains are of a main component represented by the formula ABO3 and an additive containing a rare earth element wherein A is at least one of barium, calcium, and strontium, barium being an essential element, and B is at least one of titanium, zirconium, and hafnium, titanium being an essential element. The average rare earth element concentration in the interior of the crystal grains is about 50% or less the average rare earth element concentration at the grain boundaries. Furthermore, about 20% to 70% of the crystal grains have a rare earth element concentration in the center of the crystal grain of at least about {fraction (1/50)} the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain.
    Type: Application
    Filed: January 28, 2003
    Publication date: August 7, 2003
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Hiroyasu Konaka, Tomoyuki Nakamura, Toshihiro Okamatsu, Harunobu Sano
  • Patent number: 6556423
    Abstract: A dielectric ceramic has a ceramic structure of crystal grains and grain boundaries between the crystal grains. The crystal grains are of a main component represented by the formula ABO3 and an additive containing a rare earth element wherein A is at least one of barium, calcium, and strontium, barium being an essential element, and B is at least one of titanium, zirconium, and hafnium, titanium being an essential element. The average rare earth element concentration in the interior of the crystal grains is about 50% or less the average rare earth element concentration at the grain boundaries. Furthermore, about 20% to 70% of the crystal grains have a rare earth element concentration in the center of the crystal grain of at least about {fraction (1/50)} the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: April 29, 2003
    Assignee: Murata Manufacturing Co. Ltd.
    Inventors: Hiroyasu Konaka, Tomoyuki Nakamura, Toshihiro Okamatsu, Harunobu Sano
  • Publication number: 20030039090
    Abstract: A dielectric ceramic has a ceramic structure of crystal grains and grain boundaries between the crystal grains. The crystal grains are of a main component represented by the formula ABO3 and an additive containing a rare earth element wherein A is at least one of barium, calcium, and strontium, barium being an essential element, and B is at least one of titanium, zirconium, and hafnium, titanium being an essential element. The average rare earth element concentration in the interior of the crystal grains is about 50% or less the average rare earth element concentration at the grain boundaries. Furthermore, about 20% to 70% of the crystal grains have a rare earth element concentration in the center of the crystal grain of at least about {fraction (1/50)} the maximum rare earth element concentration in a region extending inward from the surface by a distance corresponding to about 5% of the diameter of the crystal grain.
    Type: Application
    Filed: March 7, 2002
    Publication date: February 27, 2003
    Inventors: Hiroyasu Konaka, Tomoyuki Nakamura, Toshihiro Okamatsu, Harunobu Sano