Patents by Inventor Shuhei Ohta

Shuhei Ohta 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).

  • Loudspeaker structure
    Patent number: 5668886
    Abstract: A high performance loudspeaker structure is provided which is of reduced thickness yet resistible to large vibration amplitudes. A repulsion magnetic circuit is formed by two magnets with the same poles being faced each other and a center plate interposed between the two magnets. The repulsion magnetic circuit is held in position by two frames. A diaphragm is mounted at the level flush with the center of the winding width of a voice coil. The outer periphery of an edge (suspension) bonded to the outer circumference of the diaphragm is held by flanges of the frames.
    Type: Grant
    Filed: June 13, 1996
    Date of Patent: September 16, 1997
    Assignee: Kabushiki Kaisha Kenwood
    Inventors: Yoshio Sakamoto, Shuhei Ohta
  • Speaker diaphragm
    Patent number: 5031720
    Abstract: A speaker diaphragm is formed by heat-pressurized molding a composite structure of fabric cloth and resin sank into the fabric cloth. The fabric cloth is woven from high strength and high elasticity polyethylene fiber which has at least tensile modulus of 4,500 kg/mm.sup.2 (500 g/d).
    Type: Grant
    Filed: November 28, 1988
    Date of Patent: July 16, 1991
    Assignees: Kabushiki Kaisha Kenwood, Toyo Boseki Kabushiki Kaisha
    Inventors: Shuhei Ohta, Masakatu Sakamoto, Shiro Iwakura, Yoshikazu Shirasaki, Ichiro Yoshida
  • Method for forming a hard carbon thin film on article and applications thereof
    Patent number: 4772513
    Abstract: A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atomosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.
    Type: Grant
    Filed: November 4, 1987
    Date of Patent: September 20, 1988
    Assignees: Trio Kabushiki Kaisha, Namiki Precision Jewel Co., Ltd.
    Inventors: Masakatsu Sakamoto, Shuhei Ohta, Shiro Iwakura, Kaoru Yamazaki, Yoichi Yaguchi, Hiroaki Toshima, Tsugio Sato
  • Method for forming a hard carbon thin film on article and applications thereof
    Patent number: 4725345
    Abstract: A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atmosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: February 16, 1988
    Assignee: Kabushiki Kaisha Kenwood
    Inventors: Masakatsu Sakamoto, Shuhei Ohta, Shiro Iwakura, Kaoru Yamazaki, Yoichi Yaguchi, Hiroaki Toshima, Tsugio Sato