Patents by Inventor Takao Maeda

Takao Maeda 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: 5386193
    Abstract: A partial discharge detecting device for a resin-molded transformer having no-load switching tap terminals on a high voltage winding thereof. An amplifier amplifies the output detection signal of a partial discharge detecting sensor connected between the tap terminals, and an electro-optic converter converts the output signal of the amplifier into an optical signal. The optical signal is applied through an optical fiber to an opto-electric converter where it is converted into an electrical signal. The electrical signal is applied to an indicator. The partial discharge detecting sensor, the amplifier circuit, and the electro-optic converter are held at a potential corresponding to a potential of the tap terminals.
    Type: Grant
    Filed: May 19, 1993
    Date of Patent: January 31, 1995
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Takao Maeda, Tatsuo Nishizawa, Kenji Watanabe
  • Patent number: 5369220
    Abstract: A wiring board has a wiring circuit which is reliable and which can be easily miniaturized, and used for the production of a highly integrated, lighter, thinner, shorter, smaller and low-cost semiconductor device. This wiring board can be sealed in a plastic package. The wiring board has a metal plate and a thin-film dielectric layer formed on the surface of the metal plate. A semiconductor device is mounted on the surface of the dielectric layer or the exposed surface of the metal plate. Film wirings are formed on the dielectric layer. Each film wiring is in the form of a laminate formed by laminating, by vapor phase deposition or by plating, a an aluminum conductive layer, an adhesive layer of chromium, titanium or a laminate thereof, a diffusion barrier layer of nickel, copper or a laminate thereof, and a corrosion-preventive and wire bonding layer of gold.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: November 29, 1994
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Keizo Harada, Takatoshi Takikawa, Takao Maeda, Shunsuke Ban, Shosaku Yamanaka
  • Patent number: 5306679
    Abstract: A heat conductive aluminum nitride sintered body contains 100 parts by weight of aluminum nitride, at least 0.005 parts by weight and not more than 0.5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of at least one element selected from a group of compounds containing elements belonging to the groups IVB, VB and VIB of the periodic table in terms of the simple substance of the element. Such a sintered body has a heat conductivity of at least 100 W/m.multidot.K. and not more than 270 W/m.multidot.K. at room temperature.
    Type: Grant
    Filed: March 1, 1993
    Date of Patent: April 26, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kouhei Shimoda, Takao Maeda, Kouichi Sogabe, Masaya Miyake
  • Patent number: 5294388
    Abstract: A heat conductive aluminum nitride sintered body contains 100 parts by weight of aluminum nitride, at least 0.005 parts by weight and not more than 0.5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of at least one element selected from a group of compounds containing elements belonging to the groups IVB, VB and VIB of the periodic table in terms of the simple substance of the element. Heat conductivity of the aluminum nitride sintered body is at least 100 W/m.multidot.K and not more than 270 W/m.multidot.K at the ordinary temperature. According to a method of preparing such an aluminum nitride sintered body, at least 0.01 parts by weight and not more than 5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of an oxide of a rare earth element, and at least 0.
    Type: Grant
    Filed: July 29, 1992
    Date of Patent: March 15, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kouhei Shimoda, Takao Maeda, Kouichi Sogahe, Masaya Miyake
  • Patent number: 5233305
    Abstract: Typically, in a partial discharge detecting device for a resin-molded transformer with tap terminals of a no-load switching type on the high voltage winding, the output signal of a partial discharge detecting sensor connected between the tap terminals is applied through an amplifier circuit to an indicator. The sensor is arranged on the high potential side whose potential corresponds to the potential to ground of the tap terminals. This construction contributes to detection of void coronas formed in the transformer with high accuracy.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: August 3, 1993
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Tatsuo Nishizawa, Takao Maeda, Hiroshi Moriya
  • Patent number: 5147832
    Abstract: An AlN sintered body which has a color within the range of gray to black and a thermal conductivity within the range of 100 to 270 W/m.multidot.K at room temperature. Such a body is useful as an electronic material and a method of preparing the same. The AlN sintered body contains 100 parts by weight of AlN, 0.005 to 0.5 parts by weight of carbon, not more than 1 part by weight of a boron compound in terms of the simple substance of boron, 0.01 to 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of the rare earth element, and 0.01 to 15 parts by weight of a compound containing an element belonging to the group IVB of the periodic table in terms of the simple substance of the element. This AlN sintered body is obtained by shaping a mixture of the above components into a prescribed configuration and thereafter firing the as-formed compact in a non-oxidizing atmosphere containing at least 10 percent by volume of nitrogen, at a temperature of 1500.degree. to 2100.degree. C.
    Type: Grant
    Filed: July 31, 1991
    Date of Patent: September 15, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kouhei Shimoda, Takao Maeda, Kouichi Sogabe, Masaya Miyake
  • Patent number: 5134459
    Abstract: A lead frame for a high-density, sealed type of semiconductor device having many input/output pins and capable of high-speed operation is made of a magnetic material with a covering layer of a non-magnetic metal. The covering layer covers a top surface, a bottom surface, both side surfaces and an inner end face of a portion of the leads of the lead frame which is to be sealed in a semiconductor package. The covering layer has a thickness of 1 micron or more at both side surfaces of each lead. Therefore, the inductance at the leads can be reduced remarkably. Thus, the semiconductor can be operated at a high speed with improved reliability.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: July 28, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Maeda, Tomohiko Ihara, Masaharu Yasuhara, Shosaku Yamanaka
  • Patent number: 5038377
    Abstract: A voice synthesis system includes the use of a group of representative sound data for synthesizing voice data. A ROM circuit in the system includes a multilevel address system that stores starting addresses of the representative sound data. The memory capacity required for storing the representative voice data synthesized is reduced by accessing nondistinguishable data through a multilevel address system.
    Type: Grant
    Filed: November 22, 1989
    Date of Patent: August 6, 1991
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshiro Kihara, Sigeaki Masuzawa, Takao Maeda, Akitomo Kiriyama
  • Patent number: 4562104
    Abstract: A method of bonding a metallic object to another object includes scatter coating an aluminum containing metal on the surface of the metallic object, after cleaning the surface, and bonding the metallic object to the other object with an adhesive. Where both objects are metallic, the surfaces to be bonded are each scatter coated with aluminum. The scatter coating can be formed by friction coating aluminum containing metal onto each metal surface to be bonded.
    Type: Grant
    Filed: June 20, 1978
    Date of Patent: December 31, 1985
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Takao Maeda
  • Patent number: 4195607
    Abstract: A blow-by gas recirculating device includes an inlet pipe in communication with the intake passage for an automobile engine, and a heat-insulating member. Particularly, the inlet pipe communicates between a blow-by gas producing source and a heat-insulating member positioned between a carburetor and an intake manifold, all forming part of an intake system for the engine. The heat-insulating member has two intake through-holes which form part of the intake passage for the engine and an inlet-pipe-admitting hole which extends from the outer side-surface of the member to the peripheral surface of one of the intake through-holes. The inlet pipe, one end of which is disposed in the inlet-pipe-admitting hole, has an average coefficient of linear expansion of no less than 16.7.times.10.sup.-6 /deg. in a temperature range of -20.degree. to 200.degree. C., and a modulus of longitudinal elasticity of no more than 12980 kg/mm.sup.2.
    Type: Grant
    Filed: September 7, 1978
    Date of Patent: April 1, 1980
    Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha
    Inventors: Yasumasa Nagasaka, Haruki Furukawa, Takao Maeda, Masatsugu Tsukatani