Patents by Inventor Takahiro Hirai

Takahiro Hirai 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: 6468440
    Abstract: Magnet powder has a composition expressed by (R1XR2YBZT100−X−Y−Z)100−QNQ (in formula, R1 is at least one kind of element selected from rare earth elements, R2 is at least one kind of element selected from Zr, Hf and Sc, T is at least one kind of element selected from Fe and Co, and X, Y, Z and Q are numbers satisfying 2 atomic %≦X, 0.01 atomic %≦Y, 4≦X+Y≧20 atomic %, 0≦Z≦10 atomic %, and 0.1≦Q≦20 atomic %, respectively), and TbCu7 crystal phase as a principal phase. In such magnet powder, a ratio of fine particles of which maximum diameter is 22 &mgr;m or less is 20% by weight or less. Alternatively, surface roughness of particles constituting the magnet powder is 5 &mgr;m or less in terms of maximum height Ry provided in JIS B 0601-1994. Accordingly, to such a magnet powder, excellent magnetic properties can be obtained with reproducibility.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: October 22, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
  • Patent number: 6416593
    Abstract: A magnetic material has a composition expressed by the following general formula, general formula: {(R1XR21-X)YBZT1-Y-Z}1-QNQ (where, R1 is at least one kind of element selected from rare earth elements, R2 is at least one kind of element selected from Zr, Hf, Ti and Sc, T is at least one kind of element selected from Fe and Co, and X, Y, Z and Q designate numerical values satisfying 0.5≦X<1, 0.05≦Y≦0.2, 0≦Z≦0.1 and 0.1≦Q≦0.2), and includes 5 volume % or more of a Th2Ni17 crystal phase. The magnetic material has a recrystallization texture of which average grain diameter is in the range of from 0.02 to 50 &mgr;m, and is excellent in magnetic property. Such a magnetic material is obtained by giving a HDDR treatment to a mother alloy of which principal phase is a Th2Ni17 crystal phase.
    Type: Grant
    Filed: August 16, 2001
    Date of Patent: July 9, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
  • Patent number: 6406559
    Abstract: A magnetic material essentially consists of a composition represented by general formula: R1XR2YBZNUHVM100-X-Y-Z-C-V (in the formula, R1 denotes at least one kind element selected from rare earth elements, R2 denotes at least one kind element selected from Zr, Hf and Sc, M denotes at least one kind element selected from Fe and Co, X, Y, Z, U and V are numbers satisfying 2 at. %≦X, 0.01 at. %≦Y, 4≦X+Y≦20 at. %, 0≦Z≦10 at. %, 0.1≦U≦18 at. %, 0.01≦V≦10 at. %, respectively), and comprises a TbCu7 type crystal phase as a principal phase. A nitriding treatment to a mother alloy is carried out in a mixed gas of ammonia gas and hydrogen gas of which partial pressure ratio is set in the range of 3<Py/Px when partial pressure of ammonia gas is PX, that of the hydrogen gas is Py.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: June 18, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Takahiro Hirai, Keisuke Hashimoto, Tomohisa Arai
  • Publication number: 20020011279
    Abstract: A magnetic material has a composition expressed by the following general formula,
    Type: Application
    Filed: August 16, 2001
    Publication date: January 31, 2002
    Inventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
  • Publication number: 20010054453
    Abstract: A magnetic material essentially consists of a composition represented by general formula: R1XR2YBZNUHVM100-X-Y-Z-C-V (in the formula, R1 denotes at least one kind element selected from rare earth elements, R2 denotes at least one kind element selected from Zr, Hf and Sc, M denotes at least one kind element selected from Fe and Co, X, Y, Z, U and V are numbers satisfying 2 at. %≦X, 0.01 at. %≦Y, 4≦X+Y≦20 at. %, 0≦Z≦10 at. %, 0.1≦U≦18 at. %, 0.01≦V≦10 at. %, respectively), and comprises a TbCu7 type crystal phase as a principal phase. A nitriding treatment to a mother alloy is carried out in a mixed gas of ammonia gas and hydrogen gas of which partial pressure ratio is set in the range of 3<Py/Px when partial pressure of ammonia gas is PX, that of the hydrogen gas is Py.
    Type: Application
    Filed: July 13, 2001
    Publication date: December 27, 2001
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shinya Sakurada, Takahiro Hirai, Keisuke Hashimoto, Tomohisa Arai
  • Patent number: 6313812
    Abstract: When input equipment is instructed by a remote control unit on the basis of a display of a monitor, a data signal is transmitted from a microcomputer of an AV amplifier to a microcomputer of a CD changer. When the signal is received by a microcomputer of the CD changer, display data is formed in the microcomputer of the CD changer on the basis of data in a memory and is outputted. In the AV amplifier, a switch is switched to the CD changer side. A cursor is formed by the microcomputer of the AV amplifer, the cursor and display data from the CD changer are synthesized by an image synthesizing circuit and displayed on the monitor. When an instruction is generated by the remote control unit on the basis of the display on the monitor, position coordinates of the cursor on the picture plane are generated from the microcomputer of the A/V amplifier to the microcomputer of the CD changer. On the basis of the display data and the position coordinates, the CD changer is controlled by its microcomputer.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: November 6, 2001
    Assignee: Sony Corporation
    Inventors: Shuichi Nagano, Akira Katsuyama, Hiroshi Koyama, Takashi Ishizuka, Keiichi Asakura, Takahiro Hirai, Masami Ishikawa, Hiroshi Masuda, Takashi Koya
  • Patent number: 6290782
    Abstract: A magnetic material has a composition expressed by the following general formula, general formula: {(R1XR21−X)YBZT1−Y−Z}1−QNQ (where, R1 is at least one kind of element selected from rare earth elements, R2 is at least one kind of element selected from Zr, Hf, Ti and Sc, T is at least one kind of element selected from Fe and Co, and X, Y, Z and Q designate numerical values satisfying 0.5≦X<1, 0.05≦Y≦0.2, 0≦Z≦0.1 and 0.1≦Q≦0.2), and includes 5 volume % or more of a Th2Ni17 crystal phase. The magnetic material has a recrystallization texture of which average grain diameter is in the range of from 0.02 to 50 &mgr;m, and is excellent in magnetic property. Such a magnetic material is obtained by giving a HDDR treatment to a mother alloy of which principal phase is a Th2Ni17 crystal phase.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: September 18, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Tomohisa Arai, Masami Okamura, Keisuke Hashimoto, Takahiro Hirai
  • Patent number: 5968289
    Abstract: A permanent magnetic material of the present invention has a TbCu.sub.7 phase as the principal phase and high magnetic characteristics with an extremely small variation among the values. This permanent magnetic material is expressed in a general formula:R1.sub.X R2.sub.y A.sub.z O.sub.u B.sub.v M.sub.100-x-y-z-u-vwherein R1 is at least one element selected from the rare earth elements including Y, R2 is at least one element selected from Zr, Hf and Sc, A is at least one element selected from hydrogen, nitrogen, carbon and phosphorus, M is at least one element selected from Fe and Co, x, y, z, u and v are atomic percent individually defined as 2.ltoreq.x, 0.01.ltoreq.y, 4.ltoreq.x+y.ltoreq.20, 0.001.ltoreq.z.ltoreq.10, 0.01.ltoreq.u.ltoreq.2, 0<v.ltoreq.10, and a principal phase has a TbCu.sub.7 crystal structure.
    Type: Grant
    Filed: December 3, 1997
    Date of Patent: October 19, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Tomohisa Arai, Keisuke Hashimoto, Takahiro Hirai
  • Patent number: 5968290
    Abstract: A permanent magnet material has a principal phase of TbCu7 type crystal structure and improved magnetic properties. This permanent magnet material is represented by the general formula: R1.sub.x R2.sub.y B.sub.z N.sub.u M.sub.100-x-y-z-u, wherein R1 is at least one rare earth element including Y, R2 is at least one element selected from the group consisting of Zr, Hf and Sc, M is at least one element selected from Fe and Co, x, y, z and u are atomic percents individually defined as x.gtoreq.2, y.gtoreq.0.01, 4.ltoreq.x+y.ltoreq.20, 0.ltoreq.z.ltoreq.10, and 0<u.ltoreq.20. The permanent magnet material has a principal phase of a TbCu.sub.7 type crystal structure. The permanent magnet material satisfies the relation of t.ltoreq.60 and .sigma./t.ltoreq.0.7, wherein t(nm) is an average crystal grain size of the principal phase and .sigma.(nm) is a standard deviation of the crystal grain size.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: October 19, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Tomohisa Arai, Keisuke Hashimoto, Takahiro Hirai
  • Patent number: 5892519
    Abstract: An information display device includes a display, a detector for detecting an environmental variation around a place at which the device is mounted, and a detector for detecting date and time information, in which an image to be displayed on the display is varied on the basis of the detected environment variation information and/or the date and time information.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: April 6, 1999
    Assignee: Sony Corporation
    Inventor: Takahiro Hirai
  • Patent number: 5716462
    Abstract: There is provided a magnetic material having a TbCu.sub.7 phase as a principal phase and excellent in residual magnetic flux density. This magnetic material is formed of a composition represented by a general formula:R1.sub.x R2.sub.y B.sub.z A.sub.u M.sub.100-x-y-z-uwherein R1 is at least one element selected from rare earth elements including Y; R2 is at least one element selected from Zr, Hf and Sc; A is at least one element selected from H, N, C and P; M is at least one element selected from Fe and Co; x, y, z and u represent are atomic percent individually defined as 2.ltoreq.x, 2.ltoreq.x+y.ltoreq.20, 0.001.ltoreq.z.ltoreq.10, 0.ltoreq.u.ltoreq.20; and a principal phase of the magnetic material having a TbCu.sub.7 type crystal structure.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: February 10, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Akihiko Tsutai, Takahiro Hirai, Yoshitaka Yanagita, Masashi Sahashi, Tomohisa Arai, Keisuke Hashimoto
  • Patent number: 5658396
    Abstract: Disclosed is a magnetic material which exhibits an improved saturation magnetic flux density and an improved magnetic anisotropy and, thus, is adapted for use as a raw material of a permanent magnet or a bond magnet of a high performance. The magnetic material is represented by a general formulaR.sub.x Co.sub.y Fe.sub.100-x-y (I)where R is at least one element selected from the rare earth elements, x and y are atomic percent individually defined as 4.ltoreq.x.ltoreq.20 and 0.01.ltoreq.y.ltoreq.70, and Co and Fe occupy 90 atomic percent or more in the principal phase of the compound.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: August 19, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Takahiro Hirai, Akihiko Tsutai
  • Patent number: 5601662
    Abstract: There is disclosed a method of introducing magnetic anisotropy into a magnetic material, in which a laser beam is selectively radiated on the surface of a magnetic material to locally heat it, thereby forming a pattern of boundary phases for magnetically dividing a main phase of the magnetic material into a plurality of regions, and magnetic domains of the divided main phase regions are controlled to induce magnetic anisotropy in the main phase regions.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: February 11, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahiro Hirai, Tadahiko Kobayashi, Masashi Sahashi
  • Patent number: 5549766
    Abstract: A permanent magnet is composed of a magnetic material which is represented by a general formula R1.sub.x R2.sub.y A.sub.z Co.sub.u Fe.sub.100-x-y-z-u (where R1 is at least one element selected from rare earth elements, R2 is at least one element selected from the group consisting of Sc, Zr and Hf, A is at least one element selected from the group of C, N and P, and x,y,z and u are atomic percent defined as 2.ltoreq.x, 4.ltoreq.x+y.ltoreq.20, 0.ltoreq.z.ltoreq.20, 0.ltoreq.u.ltoreq.70), wherein the material includes a principal phase of TbCu.sub.7 structure and .alpha.-Fe, a peak width at half height of the main peak of X-ray diffraction of the principal phase obtained by using Cu-K.alpha. X-rays with the resolution of 0.02.degree. or less is about 0.8.degree. or less, and a ratio of peak intensity between the principal phase and .alpha.-Fe satisfies a relation that the value of I.sub.Fe /(I.sub.p +I.sub.Fe) is about 0.4 or less where I.sub.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: August 27, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Tsutai, Takahiro Hirai, Shinya Sakurada
  • Patent number: 5482573
    Abstract: A magnetic material with an improved maximum energy product useful for high performance permanent magnet, bond magnet and other applications is disclosed. The magnetic material is expressed in a general formula R1.sub.x R2.sub.y M.sub.100-x-y where R1 is at least one element selected from the rare earth elements, R2 is at least one element selected from elements having an atomic radius in a range of 0.156 to 0.174 nm, M is at least one element selected from Fe and Co and x and y are atomic percent individually defined as x.gtoreq.2, y.gtoreq.0.01 and 4.ltoreq.x+y.ltoreq.20, and M occupying 90 atomic percent or more in the principal phase of the compound.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: January 9, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Takahiro Hirai, Akihiko Tsutai, Masashi Sahashi, Hideo Nagai, Tsutomu Yamashita
  • Patent number: 5480495
    Abstract: Disclosed is a magnetic material which suppresses formation of impurity phase of Fe, Co or Fe-Co alloy, possesses a stable ThMn.sub.12 crystal structure as the principal phase, and is excellent in magnetic properties and lower in cost. Such magnetic material is expressed in a general formula:R1.sub.x R2.sub.y Si.sub.z M.sub.u T.sub.vwhere R1is at least one element selected from Zr and Hf, R2is at least one element selected from rare earth element, M is at least one element selected from C, N and P, T is at least one element selected from Fe and Co, x+y+z+u+v=100, x, y, z, u, v are atomic percent individually defined as 0.1.ltoreq.x.ltoreq.20, 2.ltoreq.y.ltoreq.20, 0.5.ltoreq.z.ltoreq.20, 0.ltoreq.u.ltoreq.20, v.gtoreq.50, and of which principal phase possesses a ThMn.sub.12 crystal structure.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: January 2, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Takahiro Hirai, Akihiko Tsutai, Masashi Sahashi
  • Patent number: 5456769
    Abstract: Disclosed is a magnetic material which exhibits an improved saturation magnetic flux density and an improved magnetic anisotropy and, thus, is adapted for use as a raw material of a permanent magnet or a bond magnet of a high performance. The magnetic material is represented by a general formulaR.sub.X Co.sub.y Fe.sub.100-x-y (I)where R is at least one element selected from the rare earth elements, x and y are atomic percent individually defined as 4.ltoreq.x.ltoreq.20 and 0.01.ltoreq.y.ltoreq.70, and Co and Fe occupy 90 atomic percent or more in the principal phase of the compound, and the principal phase has a TbCu.sub.7 crystal structure.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: October 10, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Sakurada, Takahiro Hirai, Akihiko Tsutai
  • Patent number: 4891399
    Abstract: The thermoplastic polymeric molding composition of the invention has good moldability in shaping by injection molding, extrusion molding and compression molding and capable of giving shaped articles having good machinability in mechanical working such as cutting, grinding and latching. The composition is compounded from 2 to 70 parts by weight of a thermoplastic polymer such as a polyamide resin and from 98 to 30 parts by weight of a metallic filler such as zinc powder and zinc oxide powder having a surface coated with a water repellent agent such as silane coupling agents, titanate coupling agents and silicone fluids in a specified amount. A part of the above mentioned particulate filler may optionally be replaced with a fibrous filler such as glass fibers and carbon fibers so that the shaped articles of the molding composition may be imparted with increased impact strength.
    Type: Grant
    Filed: October 19, 1987
    Date of Patent: January 2, 1990
    Assignee: CALP Corporation
    Inventors: Hideo Ohkawa, Masakuni Chikushi, Hironori Nakamura, Shinji Funayama, Takashi Hashimoto, Takahiro Hirai
  • Patent number: 4234469
    Abstract: Flame retarded resin compositions are formed of specified quantities of polypropylene, polyethylene, inorganic filler and flame retarder such as an organic halide.
    Type: Grant
    Filed: January 22, 1979
    Date of Patent: November 18, 1980
    Assignee: Idemitsu Kosan Company Limited
    Inventors: Yuzo Ohta, Norio Sugi, Osamu Isogai, Takahiro Hirai, Hidehiko Kaji