Patents by Inventor Hidetsugu Kawabata

Hidetsugu Kawabata 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: 5565278
    Abstract: A magneto-optical recording medium includes a magneto-optical layer, a reflection layer and an inorganic dielectric layer interposed therebetween. The dielectric layer is extremely thin so that it will exhibit almost no optical effect, thereby allowing a high CN ratio to be obtained. Thermal conductivity of the dielectric layer is so low that the magneto-optical and reflection layers are thermally isolated from each other. That is, if refractive index of the dielectric layer is n, thickness of the dielectric layer is T (nm), and the thermal conductivity of the dielectric layer is C (J (m sec K).sup.-1), then the thickness T is set within a range that satisfies the following equation:5n-4.ltoreq.T.ltoreq.(12n-4)(C/2.1).sup.-0.4where C.ltoreq.4J (m sec K).sup.-1.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: October 15, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahiro Birukawa, Motoyoshi Murakami, Hidetsugu Kawabata
  • Patent number: 5518826
    Abstract: A magneto-optical recording medium operable with a low external magnetic field intensity during recording and erasing and attenuating a variation in the external magnetic field intensity comprises a magneto-optical recording layer and protective and reflective layer provided adjacent to the magneto-optical recording layers, each of which has a size of microstructures (which are associated with the non-uniformity in composition, density, crystallizability, and the like and visible under a transmission electron microscope) less than the width of a magnetic domain wall in the magneto-optical recording layer.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: May 21, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshihiko Kudoh, Motoyoshi Murakami, Hidetsugu Kawabata
  • Patent number: 5517472
    Abstract: A sliding part of a magnetic-field generator is configured to slide above and spaced from a surface of a loaded magneto-optical disk in a floating manner. A magnetic-field generating part, which provides a magnetic field to the magneto-optical disk, includes a magnetic pole disposed on a side of the sliding part such that the magnetic pole and the sliding part are positioned adjacent to each other in a radial direction of the surface of the loaded magneto-optical disk and such that the magnetic pole is located closer to a periphery of the magneto-optical disk than the sliding part. An entire flat end surface of the magnetic pole confronting the surface of the magneto-optical disk is generally parallel to and recedes from a slide surface of the sliding part such that the entire flat end surface is spaced further from the surface of the magneto-optical disk than the slide surface of the sliding part.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: May 14, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Norio Miyatake, Hidetsugu Kawabata, Kiyoshi Uchida, Yasumori Hino, Teruyuki Takizawa, Tohru Nakamura
  • Patent number: 5202863
    Abstract: A magneto-optical disk unit has a first magnetic-field generator for generating a magnetic field corresponding to a frequency in a recording signal frequency band and a second magnetic-field generator for generating DC magnetic fields of both north-seeking and south-seeking poles in a non-contact manner with a loaded magneto-optical disk. The first magnetic-field generator has a slider part for sliding over a loaded magneto-optical disk in a floating manner using an aerodynamic effect. The unit further has a transfer driver for moving the first and second magnetic-field generators in a direction parallel to the loaded magneto-optical disk and a rotary plate for vertically moving the first magnetic-field generator.
    Type: Grant
    Filed: September 10, 1991
    Date of Patent: April 13, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Norio Miyatake, Hidetsugu Kawabata, Kiyoshi Uchida, Yasumori Hino, Teruyuki Takizawa, Tohru Nakamura
  • Patent number: 4952295
    Abstract: In a method of producing a deposition film of a composite material, a plurality of sputtering targets each containing one of a plurality of different components are disposed separately in a vacuum chamber. A substrate is subjected to sputtering from the sputtering targets while being moved at an adequately high speed relative to a deposition rate from each sputtering target so that extremely thin layers of the respective components are sequentially stacked repeatedly a plurality of times to thereby form a deposition film of a composite material in which the plurality of different components are mixed uniformly.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: August 28, 1990
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hidetsugu Kawabata, Yoshihiko Kudoh, Motoyoshi Murakami, Norio Miyatake, Masakazu Yamamoto
  • Patent number: 4497870
    Abstract: A magneto-optical recording medium comprising a layer of amorphous rare-earth-transition-metal alloy having a uniaxial magnetic anisotropy, the alloy containing germanium as additive, and the recording medium having high crystallization temperature, enough stability and good reading S/N ratio.
    Type: Grant
    Filed: April 6, 1983
    Date of Patent: February 5, 1985
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshihiko Kudo, Hidetsugu Kawabata, Masahiro Birukawa, Noriaki Hara, Akira Muto
  • Patent number: 4470479
    Abstract: A speaker diaphragm of the present invention is prepared in a manner such that a boron layer is formed on one face of a dome-shaped metal foil by means of a physical vapor deposition method such as ion-plating, cathode sputtering, vacuum evaporation or the like, when necessary the metal foil is thinned by etching, and then, if necessary, another boron layer is formed on the other face of the metal foil. Alternatively, a metal layer is formed on the surface of the boron layer. The resultant speaker diaphragm is light in weight and high in modulus and also has appropriate internal mechanical resistance against vibration, thereby providing a speaker of high efficiency and satisfactory characteristics.
    Type: Grant
    Filed: December 28, 1979
    Date of Patent: September 11, 1984
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideaki Inoue, Hiroshi Takeuchi, Hidetsugu Kawabata, Keizo Ishiwatari
  • Patent number: 4251297
    Abstract: A magnetic head having a high wear resistance and high workability such as by grinding, and a method for manufacturing the same. According to this method, at least a portion of that surface of the core forming the magnetic head or shielding case, which is to be brought into contact with a magnetic recording medium, is subjected to a boronizing treatment to form a boronized layer.
    Type: Grant
    Filed: January 8, 1979
    Date of Patent: February 17, 1981
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hidetsugu Kawabata, Yuji Nagata, Keizo Ishiwatari, Toshio Shimizu
  • Patent number: 4216271
    Abstract: A composite diaphragm for a speaker comprises a boron layer formed on a metal foil such as titanium foil, in which a layer of a low melting point metal such as aluminum or magnesium is interposed between the metal foil and the boron layer to provide high rigidity, high elasticity and high bonding strength between the metal foil and the boron layer.
    Type: Grant
    Filed: November 3, 1977
    Date of Patent: August 5, 1980
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Takeuchi, Hideaki Inoue, Hidetsugu Kawabata, Keizo Ishiwatari