Patents by Inventor Tatsushi Nakamura

Tatsushi Nakamura 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: 5069132
    Abstract: A water-in-oil type emulsion explosive envelope comprises a water-in-oil type emulsion explosive and a paper wrapping the explosive. In this envelope, the paper is coated with a low-temperature melt resin and wrapped double so as to adhere joint faces to each other through heat.
    Type: Grant
    Filed: December 18, 1990
    Date of Patent: December 3, 1991
    Assignee: Nippon Oil and Fats Company, Limited
    Inventors: Shigeru Kakino, Tatsushi Nakamura, Toshinori Tamari, Masao Takahashi
  • Patent number: 4852076
    Abstract: An optical information recording and reproducing disc information has a substrate in the surface of which are formed signal recording grooves and cue signal recording pits. A light-absorbing thin film is formed on the surface of the substrate, the optical characteristics of the light-absorbing film being changeable thermally through irradiation by a light beam. The pitches of the grooves and pits, as well as the widths of the grooves and pits, are determined to meet specific conditions in relation to the diameter of the laser beam which is used for recording and reproduction of the signals. In addition, the depths of the grooves and pits are determined suitably in relation to the wavelength of the laser beam. With this arrangement, it is possible to attain a high quality of reproduction of information from the disc.
    Type: Grant
    Filed: June 16, 1987
    Date of Patent: July 25, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takeo Ohta, Tatsushi Nakamura, Shizuhiko Tanigawa
  • Patent number: 4547875
    Abstract: An optical disc for optical recording, retrieving and erasing of informations. The phase difference .psi. of reflected light produced by the tracking groove in the form of convexity or protrusion of concavity or groove and the change .DELTA..psi. in the phase difference caused by a recording in a recording film are selected in relation to each other to provide a stable detection signal for tracking, thereby to permit a highly accurate tracking on the optical disc carrying information at a high density.
    Type: Grant
    Filed: October 7, 1982
    Date of Patent: October 15, 1985
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takeo Ohta, Tatsushi Nakamura, Nobuo Akahira
  • Patent number: 4330883
    Abstract: A system and a method of recording information by changes of refractive index and light absorption coefficient on a thin film, and reproducing the recorded information byscanning a focussed monochromatic light along a track on a thin film of a selected thickness andletting a light component reflected at a light-incident surface of said thin film and the other light component reflected at an inside face of the opposite surface to said incident surface of the thin film interfere with each other thereby efficiently to vary intensity of reflection light.
    Type: Grant
    Filed: September 18, 1979
    Date of Patent: May 18, 1982
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takeo Ohta, Nobuo Akahira, Tatsushi Nakamura, Tadaoki Yamashita
  • Patent number: 4322839
    Abstract: The optical density and/or the reflectivity of a recording layer included in an optical disk is selectively changed to record information by irradiation with a semiconductor laser beam, while the recording layer may be covered with a suitable protective film. The thickness of the recording layer is so determined that it is able to record information by means of a continuous wave type semiconductor laser beam, while the optical absorption rate of the recording layer is adjusted by setting the percentages of particular additives. The recorded information may be reproduced by the application of a laser beam, the incident power of which is lower than that of the recording beam, to detect the reflected light.
    Type: Grant
    Filed: August 24, 1979
    Date of Patent: March 30, 1982
    Assignee: Matsushita Electric Industrial Company, Limited
    Inventors: Tadaoki Yamashita, Takeo Ohta, Nobuo Akahira, Tatsushi Nakamura, Mutsuo Takenaga
  • Patent number: 4278734
    Abstract: An optical information recording material comprising a thin film of a suboxide of a metal or semimetal of Group IIIB, IVB, VB or VIB, e.g. TeO.sub.x where x<2.0 or BiO.sub.x where x<1.5, added with up to 50 mole % of S and/or Se. When irradiated with light of relatively low energy density, the thin film exhibits such changes in optical density that information can be optically recorded on this material with high contrast ratio. Recorded information can be reproduced by either transmitted light or reflected light and, when desired, can be erased by light irradiation of adequate energy density.
    Type: Grant
    Filed: August 8, 1979
    Date of Patent: July 14, 1981
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takeo Ohta, Nobuo Akahira, Tatsushi Nakamura, Tadaoki Yamashita