Patents by Inventor Yuzo Hirayama

Yuzo Hirayama 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: 4974232
    Abstract: A semiconductor laser device comprises a substrate having an n-type buffer layer, a semiconductor laser element and auxiliary element, provided side by side on the buffer layer. The semiconductor laser element includes a mesa portion having a p-type low resistant semiconductor region provided above the buffer layer, an active region consisting of a semiconductor formed on the buffer layer and low resistant region, a pair of buried portions integrally formed with the low resistive region and formed on and contiguous to opposite sides of the active region in the width direction. A lateral hole is provided between the buffer layer and low resistive region on the side of buried portion. The auxiliary element includes a high resistive regions integrally formed with the low resistant region and positioned on the sides of low resistive region.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: November 27, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motoyasu Morinaga, Hideto Furuyama, Masaru Nakamura, Nobuo Suzuki, Yuzo Hirayama, Hajime Okuda
  • Patent number: 4958202
    Abstract: An active layer is formed on an n-type InP buffer layer of a substrate. A pair of strip-shaped grooves are formed into the active layer to divide it into a contract portion and side portions. A p-type InP cladding layer is deposited on the entire surface of the active layer and grooves. The cladding layer is selectively etched to form a mesa portion including the central active portion and expose the buffer layer. An insulating film is coated on the mesa portion and buffer layer, so that a semiconductor light-emitting device is manufactured.
    Type: Grant
    Filed: July 20, 1989
    Date of Patent: September 18, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Jun'ichi Kinoshita, Motoyasu Morinaga, Hideto Furuyama, Yuzo Hirayama
  • Patent number: 4870468
    Abstract: An active layer is formed on an n-type InP buffer layer of a substrate. A pair of strip-shaped grooves are formed into the active layer to divide it into a contract portion and side portions. A p-type Inp cladding layer is deposited on the entire surface of the active layer and grooves. The cladding layer is selectively etched to form a mesa portion including the central active portion and expose the buffer layer. An insulating film is coated on the mesa portion and buffer layer, so that a semiconductor light-emitting device is manufactured.
    Type: Grant
    Filed: September 11, 1987
    Date of Patent: September 26, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Jun'ichi Kinoshita, Motoyasu Morinaga, Hideto Furuyama, Yuzo Hirayama
  • Patent number: 4862474
    Abstract: A semiconductor laser device comprises a substrate having an n-type buffer layer, a semiconductor laser element and auxiliary element, provided side by side on the buffer layer. The semiconductor laser element includes a mesa portion having a p-type low resistant semiconductor region provided above the buffer layer, an active region consisting of a semiconductor formed on the buffer layer and low resistant region, a pair of buried portions integrally formed with the low resistive region and formed on and contiguous to opposite sides of the active region in the width direction. A lateral hole is provided between the buffer layer and low resistive region on the side of buried portion. The auxiliary element includes a high resistive regions integrally formed with the low resistant region and positioned on the sides of low resistive region.
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: August 29, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motoyasu Morinaga, Hideto Furuyama, Masaru Nakamura, Nobuo Suzuki, Yuzo Hirayama, Hajime Okuda
  • Patent number: 4858241
    Abstract: A semiconductor laser device comprises a semiconductor mesa portion formed above semiconductor substrate by a predetermined interval, an active region, formed between the mesa portion and semiconductor substrate and consisting of a semiconductor having a forbidden band width smaller than those of the mesa portion and semiconductor substrate, for contributing to light emission, a pair of buried portions formed at both sides in a widthwise direction of and in contact with the active region and consisting of a semiconductor having a forbidden band width larger than that of the active region, a total width of the buried portions and the active region being smaller than that of the mesa portion, thereby forming a gap at a side of each of the buried portions between the mesa portion and semiconductor substrate to electrically insulate the mesa portion and semiconductor substrate, and supporting portions formed integrally with the mesa portion so as to support the mesa portion with respect to the substrate in associ
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: August 15, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Nobuo Suzuki, Motoyasu Morinaga, Hideto Furuyama, Yuzo Hirayama, Hajime Okuda, Masaru Nakamura, Nawoto Motegi
  • Patent number: 4826898
    Abstract: A colored polypropylene resin comprising a polypropylene resin, a carbon black pigment and a copper phthalocyanine pigment, said colored polypropylene resin further comprising 0.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: May 2, 1989
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Takumi Hirosawa, Yuzo Hirayama, Keiki Sagara, Mituhiro Isomichi, Junichi Kumabe
  • Patent number: 4676863
    Abstract: A method of fabricating a semiconductor crystal mesa stripe whose waist section is narrower than the upper plane of said mesa stripe. The method comprises the steps of forming a first striped mask on the semiconductor crystal wafer in order to fabricate a prescribed mesa stripe, linearly arranging a plurality of second striped masks, narrower than said first striped mask by the prescribed waist width of the main mesa stripe, on the semiconductor wafer plane at prescribed intervals and in parallel with said first striped mask in order to fabricate monitor mesa stripes; and of subjecting said semiconductor wafer plane to mesa etching.
    Type: Grant
    Filed: December 9, 1985
    Date of Patent: June 30, 1987
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideto Furuyama, Yuzo Hirayama