Patents by Inventor Akihiro Koyama

Akihiro Koyama 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: 9237994
    Abstract: A glass flake (10) having improved heat resistance and chemical resistance is formed from a glass base material satisfying, in mass %, 60?SiO2?75, 5<Al2O3?15, 3?CaO?20, 6?Na2O?20 and 9?(Li2O+Na2O+K2O)?13. When 9?(Li2O+Na2O+K2O)?13 is satisfied in mass %, the CaO content and the Na2O content are preferably set within the ranges of 5?CaO?20 and 6?Na2O?13, respectively. When 13?(Li2O+Na2O+K2O)?20 is satisfied in mass %, the CaO content and the Na2O content are preferably set within the ranges of 3?CaO?15 and 9?Na2O?20, respectively. The working temperature of the glass base material is preferably 1180° C.-1300° C. The temperature difference AT obtained by taking the devitrification temperature of the glass base material from the working temperature of the glass base material is preferably 0° C.-200° C. The glass transition temperature of the glass base material is preferably 550° C.-700° C. The acid resistance index ?W of the glass base material is preferably 0.05-1.5 mass %.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: January 19, 2016
    Assignee: NIPPON SHEET GLASS COMPANY, LIMITED
    Inventors: Kosuke Fujiwara, Akihiro Koyama
  • Publication number: 20160003889
    Abstract: The present invention provides a method for manufacturing silicon carbide semiconductor apparatus including a testing step of testing a PN diode for the presence or absence of stacking faults in a relatively short time and an energization test apparatus. The present invention sets the temperature of a bipolar semiconductor element at 150° C. or higher and 230° C. or lower, causes a forward current having a current density of 120 [A/cm2] or more and 400 [A/cm2] or less to continuously flow through the bipolar semiconductor element, calculates, in a case where a forward resistance of the bipolar semiconductor element through which the forward current flows reaches a saturation state, the degree of change in the forward resistance, and determines whether the calculated degree of change is smaller than a threshold value.
    Type: Application
    Filed: March 10, 2014
    Publication date: January 7, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shoyu WATANABE, Akihiro KOYAMA, Shigehisa YAMAMOTO, Yukiyasu NAKAO, Kazuya KONISHI
  • Patent number: 9212288
    Abstract: Disclosed is a glass flake (10) having improved heat resistance and improved chemical durability, which is composed of a glass base material satisfying, as expressed in mass %, 60?SiO2?70, 5?Al2O3?15, 1?MgO?10, 10?CaO?25 and 4<(Li2O+Na2O+K2O)<9. The temperature difference ?T obtained by taking the devitrification temperature of the glass base material from the working temperature thereof is preferably within the range of 0-200° C. The glass transition temperature of the glass base material is preferably within the range of 560-750° C. It is desirable that the value of ?W, which serves as an index for the acid resistance of the glass base material, is within the range of 0.05-1.2 mass %.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: December 15, 2015
    Assignee: NIPPON SHEET GLASS COMPANY, LIMITED
    Inventors: Kosuke Fujiwara, Akihiro Koyama
  • Publication number: 20150218040
    Abstract: A substrate for p-Si TFT flat panel displays made of a glass having a high low-temperature-viscosity characteristic temperature and manufactured while avoiding erosion/wear of a melting tank during melting through direct electrical heating. The glass substrate comprises 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-20 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-0.8 mass % of R2O, wherein R2O is total amount of Li2O, Na2O, and K2O, and 0-0.3 mass % of Sb2O3, and substantially does not comprise As2O3, wherein the mass ratio CaO/RO is equal to or greater than 0.65, the mass ratio (SiO2+Al2O3)/B2O3 is in a range of 7-30, and the mass ratio (SiO2+Al2O3)/RO is equal to or greater than 5. A related method involves melting glass raw materials blended to provide the glass composition; a forming step of forming the molten glass into a flat-plate glass; and an annealing step of annealing the flat-plate glass.
    Type: Application
    Filed: April 14, 2015
    Publication date: August 6, 2015
    Applicant: AVANSTRATE INC.
    Inventors: Akihiro KOYAMA, Satoshi AMI, Manabu ICHIKAWA
  • Patent number: 9096459
    Abstract: A flat panel display glass substrate includes a glass comprising, in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, and 3-25% RO (the total amount of MgO, CaO, SrO, and BaO). The contents in mol % of SiO2, Al2O3, and B2O3 satisfy a relationship (SiO2+Al2O3)/(B2O3)=7.5-17. The strain point of the glass is 665° C. or more. The devitrification temperature of the glass is 1250° C. or less. The substrate has a heat shrinkage rate of 75 ppm or less. The rate of heat shrinkage is calculated from the amount of shrinkage of the substrate measured after a heat treatment which is performed at a rising and falling temperature rate of 10° C./min and at 550° C. for 2 hours by the rate of heat shrinkage (ppm)={the amount of shrinkage of the substrate after the heat treatment/the length of the substrate before the heat treatment}×106.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: August 4, 2015
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Satoshi Ami, Manabu Ichikawa
  • Publication number: 20150191394
    Abstract: The disclosed cover glass is produced by etching a glass substrate that has been formed by a down-drawing process, and chemically strengthening the glass substrate to provide the glass substrate with a compressive-stress layer on the principal surfaces thereof. The glass substrate contains, as components thereof, 50% to 70% by mass of SiO2, 5% to 20% by mass of Al2O3, 6% to 30% by mass of Na2O, and 0% to less than 8% by mass of Li2O. The glass substrate may also contain 0% to 2.6% by mass of CaO, if necessary. The glass substrate has an etching characteristic in which the etching rate is at least 3.7 ?m/minute in an etching environment having a temperature of 22° C. and containing hydrogen fluoride with a concentration of 10% by mass.
    Type: Application
    Filed: March 18, 2015
    Publication date: July 9, 2015
    Inventors: Akihiro KOYAMA, Mikiko MORISHITA, Satoshi AMI, Kazuaki HASHIMOTO, Tetsuo TAKANO
  • Patent number: 9029280
    Abstract: A substrate for p-Si TFT flat panel displays made of a glass having a high low-temperature-viscosity characteristic temperature and manufactured while avoiding erosion/wear of a melting tank during melting through direct electrical heating. The glass substrate comprises 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-20 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-0.8 mass % of R2O, wherein R2O is total amount of Li2O, Na2O, and K2O, and 0-0.3 mass % of Sb2O3, and substantially does not comprise As2O3, wherein the mass ratio CaO/RO is equal to or greater than 0.65, the mass ratio (SiO2+Al2O3)/B2O3 is in a range of 7-30, and the mass ratio (SiO2+Al2O3)/RO is equal to or greater than 5. A related method involves melting glass raw materials blended to provide the glass composition; a forming step of forming the molten glass into a flat-plate glass; and an annealing step of annealing the flat-plate glass.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: May 12, 2015
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Satoshi Ami, Manabu Ichikawa
  • Patent number: 8932969
    Abstract: Provided are: a glass substrate for p-Si TFT flat panel displays that is composed of a glass having high characteristic temperatures in the low-temperature viscosity range, typified by the strain point and glass transition point, having a small heat shrinkage rate, and being capable of avoiding the occurrence of the problem regarding the erosion/wear of a melting tank at the time of melting through direct electrical heating; and a method for manufacturing same. The present glass substrate is composed of a glass comprising 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of Fe2O3, and 0-0.3 mass % of Sb2O3, and substantially not comprising As2O3, the glass having a mass ratio (SiO2+Al2O3)/B2O3 in a range of 7-30 and a mass ratio (SiO2+Al2O3)/RO equal to or greater than 6.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: January 13, 2015
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Satoshi Ami, Manabu Ichikawa
  • Patent number: 8895461
    Abstract: Provided are: a glass substrate for p-Si TFT flat panel displays that is composed of a glass having high characteristic temperatures in the low-temperature viscosity range, typified by the strain point and glass transition point, having a small heat shrinkage rate, and being capable of avoiding the occurrence of the problem regarding the erosion/wear of a melting tank at the time of melting through direct electrical heating; and a method for manufacturing same. The present glass substrate is composed of a glass comprising 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of Fe2O3, and 0-0.3 mass % of Sb2O3, and substantially not comprising As2O3, the glass having a mass ratio (SiO2+Al2O3)/B2O3 in a range of 7-30 and a mass ratio (SiO2+Al2O3)/RO equal to or greater than 6.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: November 25, 2014
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Satoshi Ami, Manabu Ichikawa
  • Publication number: 20140325837
    Abstract: A ground connection structure is a structure for collectively connecting, to a body of a vehicle, a plurality of grounding wires which are connected to respective electrical components installed in the vehicle. The ground connection structure includes: a connection box to which the plurality of grounding wires are connected; a grounding terminal part connected to the vehicle in an electrically conducting state; and an electrically conducting connection part having one end connected to the connection box and the other end connected to the grounding terminal part, the electrically conducting connection part connecting the connection box and the grounding terminal part in an electrically conducting manner. The electrically conducting connection part is made of a low-inductance material having low inductance.
    Type: Application
    Filed: July 18, 2014
    Publication date: November 6, 2014
    Applicant: YAZAKI CORPORATION
    Inventors: Yukinari NAGANISHI, Akira BABA, Takashi ODAJIMA, Hirohito HABARA, Hideaki SAITOH, Takao OTA, Akihiro KOYAMA, Atsushi NAKATA
  • Publication number: 20140327303
    Abstract: A ground connection structure is a structure for collectively connecting, to a body of a vehicle, a plurality of grounding wires which are connected to respective electrical components installed in the vehicle. The ground connection structure includes: a connection box to which the plurality of grounding wires are connected; a grounding terminal part connected to the vehicle in an electrically conducting state; and an electrically conducting connection part having one end connected to the connection box and the other end connected to the grounding terminal part, the electrically conducting connection part connecting the connection box and the grounding terminal part in an electrically conducting manner. The electrically conducting connection part is made of a low-inductance material having low inductance.
    Type: Application
    Filed: July 18, 2014
    Publication date: November 6, 2014
    Applicant: YAZAKI CORPORATION
    Inventors: Yukinari NAGANISHI, Akira BABA, Takashi ODAJIMA, Hirohito HABARA, Hideaki SAITOH, Takao OTA, Akihiro KOYAMA, Atsushi NAKATA
  • Publication number: 20140309098
    Abstract: A flat panel display glass substrate includes a glass comprising, in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, and 3-25% RO (the total amount of MgO, CaO, SrO, and BaO). The contents in mol % of SiO2, Al2O3, and B2O3 satisfy a relationship (SiO2+Al2O3)/(B2O3)=7.5-17. The strain point of the glass is 665° C. or more. The devitrification temperature of the glass is 1250° C. or less. The substrate has a heat shrinkage rate of 75 ppm or less. The rate of heat shrinkage is calculated from the amount of shrinkage of the substrate measured after a heat treatment which is performed at a rising and falling temperature rate of 10° C./min and at 550° C. for 2 hours by the rate of heat shrinkage (ppm)={the amount of shrinkage of the substrate after the heat treatment/the length of the substrate before the heat treatment}×106.
    Type: Application
    Filed: June 25, 2014
    Publication date: October 16, 2014
    Applicant: AvanStrate Inc.
    Inventors: Akihiro KOYAMA, Satoshi AMI, Manabu ICHIKAWA
  • Patent number: 8853113
    Abstract: A flat panel display glass substrate according to the present invention includes a glass comprising, as expressed in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, 3-25% RO (the total amount of MgO, CaO, SrO, and BaO), and substantially no As2O3 and Sb2O3. The devitrification temperature of the glass is 1250° C. or less. The glass substrate has a heat shrinkage rate of 75 ppm or less. The heat shrinkage rate is calculated from the amount of shrinkage of the glass substrate measured after a heat treatment which is performed at a temperature rising and falling rate of 10° C./min and at 550° C. for 2 hours by the heat shrinkage rate (ppm)={the amount of shrinkage of the glass substrate after the heat treatment/the length of the glass substrate before the heat treatment}×106.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: October 7, 2014
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Satoshi Ami, Manabu Ichikawa
  • Patent number: 8840997
    Abstract: A cover glass having a compressive-stress layer on the principal surfaces thereof, and having a glass composition containing 50% to 70% by mole of SiO2, 3% to 20% by mole of Al2O3, 5% to 25% by mole of Na2O, more than 0% by mole and less than or equal to 2.5% by mole of Li2O, 0% to 5.5% by mole of K2O, and 0% to less than 3% by mole of B2O3. Also disclosed is a method for producing a cover glass which includes: (i) preparing molten glass by melting a glass raw material; (ii) forming the prepared molten glass into a plate-like shape by a down-draw process and thereby obtaining a glass substrate; and (iii) forming a compressive-stress layer on the surface of the glass substrate.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: September 23, 2014
    Assignees: AvanStrate Inc., Hoya Corporation
    Inventors: Akihiro Koyama, Satoshi Ami, Kazuaki Hashimoto, Tetsuo Takano
  • Publication number: 20140249018
    Abstract: A flat panel display glass substrate according to the present invention includes a glass comprising, as expressed in mol %, 55-80% SiO2, 3-20% Al2O3, 3-15% B2O3, 3-25% RO (the total amount of MgO, CaO, SrO, and BaO), and substantially no As2O3, and Sb2O3. The devitrification temperature of the glass is 1250° C. or less. The glass substrate has a heat shrinkage rate of 75 ppm or less. The heat shrinkage rate is calculated from the amount of shrinkage of the glass substrate measured after a heat treatment which is performed at a temperature rising and falling rate of 10° C./min and at 550° C. for 2 hours by the heat shrinkage rate (ppm)={the amount of shrinkage of the glass substrate after the heat treatment/the length of the glass substrate before the heat treatment}×106.
    Type: Application
    Filed: May 13, 2014
    Publication date: September 4, 2014
    Applicant: AVANSTRATE INC.
    Inventors: Akihiro KOYAMA, Satoshi AMI, Manabu ICHIKAWA
  • Publication number: 20140249019
    Abstract: A glass substrate for p-Si TFT flat panel displays that is composed of a glass comprising 52-78 mass % of SiO2, 3-25 mass % of Al2O3, 3-15 mass % of B2O3, 3-25 mass % of RO, wherein RO is total amount of MgO, CaO, SrO, and BaO, 0.01-1 mass % of Fe2O3, and 0-0.3 mass % of Sb2O3, and substantially not comprising As2O3, the glass having a mass ratio (SiO2+Al2O3)/B2O3 in a range of 7-30 and a mass ratio (SiO2+Al2O3)/RO equal to or greater than 6. A method for manufacturing a glass substrate involves: a melting step of obtaining a molten glass by melting, by employing at least direct electrical heating, glass raw materials blended so as to provide the aforementioned glass composition; a forming step of forming the molten glass into a flat-plate glass; and an annealing step of annealing the flat-plate glass.
    Type: Application
    Filed: May 15, 2014
    Publication date: September 4, 2014
    Applicant: AvanStrate Inc.
    Inventors: Akihiro KOYAMA, Satoshi AMI, Manabu ICHIKAWA
  • Patent number: 8741794
    Abstract: A glass substrate for a display, which is formed of a glass having a light weight and having high refinability with decreasing environmental burdens, the glass comprising, by mass %, 50 to 70% of SiO2, 5 to 18% of B2O3, 10 to 25% of Al2O3, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 10% of BaO, 5 to 20% of RO (in which R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba), and over 0.20% but not more than 2.0% of R?2O (in which R? is at least one member selected from the group consisting of Li, Na and K), and containing, by mass %, 0.05 to 1.5% of oxide of metal that changes in valence number in a molten glass, and substantially containing none of As2O3, Sb2O3 and PbO.
    Type: Grant
    Filed: January 18, 2013
    Date of Patent: June 3, 2014
    Assignee: Avanstrate Inc.
    Inventors: Junji Kurachi, Akihiro Koyama, Yoichi Hachitani
  • Publication number: 20140031192
    Abstract: A glass substrate for a display, which is formed of a glass having a light weight and having high refinability with decreasing environmental burdens, the glass comprising, by mass %, 50 to 70% of SiO2, 5 to 18% of B2O3, 10 to 25% of Al2O3, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 10% of BaO, 5 to 20% of RO (in which R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba), and over 0.20% but not more than 2.0% of R?2O (in which R? is at least one member selected from the group consisting of Li, Na and K), and containing, by mass %, 0.05 to 1.5% of oxide of metal that changes in valence number in a molten glass, and substantially containing none of As2O3, Sb2O3 and PbO.
    Type: Application
    Filed: January 18, 2013
    Publication date: January 30, 2014
    Applicant: AVANSTRATE, INC.
    Inventors: Junji Kurachi, Akihiro Koyama, Yoichi Hachitani
  • Publication number: 20130345041
    Abstract: Provided is a glass composition suitable for a glass substrate for a flat panel display such as a liquid crystal display. This glass composition has high thermal stability, and is substantially free of BaO but has a low devitrification temperature. It is suitable for the production of a glass substrate by a downdraw process. This glass composition contains, in terms of mass %: 54 to 62% of SiO2; 4 to 11% of B2O3; 15 to 20% of Al2O3; 2 to 5% of MgO; 0 to 7% of CaO; 0 to 13.5% of SrO; 0 to 1% of K2O; 0 to 1% of SnO2; and 0 to 0.2% of Fe2O3, and is substantially free of BaO. In this glass composition, the total content of alkaline earth metal oxides (MgO+CaO+SrO) is 10 to 18.5 mass %. The devitrification temperature of the glass composition is 1200° C. or lower.
    Type: Application
    Filed: August 30, 2013
    Publication date: December 26, 2013
    Applicant: AvanStrate Inc.
    Inventors: Akihiro KOYAMA, Mikiko HASHIMOTO
  • Patent number: 8575050
    Abstract: Provided is a glass composition suitable for a glass substrate for a flat panel display such as a liquid crystal display. This glass composition has high thermal stability, and is substantially free of BaO but has a low devitrification temperature. It is suitable for the production of a glass substrate by a downdraw process. This glass composition contains, in terms of mass %; 54 to 62% of SiO2; 4 to 11% of B2O3; 15 to 20% of Al2O3; 2 to 5% of MgO; 0 to 7% of CaO; 0 to 13.5% of SrO; 0 to 1% of K2O; 0 to 1% of SnO2; and 0 to 0.2% of Fe2O3, and is substantially free of BaO. In this glass composition, the total content of alkaline earth metal oxides (MgO+CaO+SrO) is 10 to 18.5 mass %. The devitrification temperature of the glass composition is 1200° C. or lower.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: November 5, 2013
    Assignee: AvanStrate Inc.
    Inventors: Akihiro Koyama, Mikiko Hashimoto