Patents by Inventor Sadao Minakawa

Sadao Minakawa 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: 5276499
    Abstract: A spectrophotometer which takes out monochromatic lights from lights from light sources by using spectroscopes and transmits the monochromatic lights through a sample and detects the transmitted lights by sensors includes a plurality of dispersing elements in the spectroscope which bear the dispersion of different wavelength ranges or a plurality of sensors which bear the detection of different wavelength ranges in order to widen a measurement wavelength range; and means for correcting the difference between measured values obtained when the different dispersing elements were used or the difference between measured values obtained when the different sensors were used at one wavelength in overlap wavelength regions between different wavelength ranges so as to be set to zero.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: January 4, 1994
    Assignees: Hitachi, Ltd., Hitachi Instrument Engineering Co., Ltd.
    Inventors: Sadao Minakawa, Masaru Enomoto, Masaya Kojima
  • Patent number: 5041727
    Abstract: The invention relates to a spectrophotometer having a light source capable of alternatively producing near infrared radiation and another radiation other than the near infrared radiation, a dispersing section for dispersing radiation from the light source to provide substantially monochromatic radiation so that a sample is irradiated with the substantially monochromatic radiation to thereby provide sample radiation, and a sensing section for sensing the sample radiation. The sample radiation is subjected to energy absorption of a specific wavelength by the sample. The sensing section includes a first sensing unit having a near infrared radiation sensor, a second sensing unit having a visible/ultraviolet radiation sensor and a temperature control unit for holding the near infrared radiation sensor at a substantially constant temperature lower than the room temperature.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: August 20, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Masaya Kojima, Sadao Minakawa
  • Patent number: 4981357
    Abstract: A spectrophotometer having functions of both of a double-monochromator and a single-monochromator including a light source, a first spectroscope having a first slit through which light from the light source passes and a first dispersion element for dispersing the light from the first slit, a second spectroscope having a second slit for receiving light dispersed from the first dispersion element for dispersing the light from the second slit, and a third slit for receiving the light dispersed from the second dispersion element. A sample compartment is provided for transmitting the light from the first dispersion element or from the third slit directly to a detector or through a sample to the detector. An optical unit is provided for changing transmitting light paths between a first light path for transmitting the light from the first dispersion element to the sample compartment through a fourth slit and a second light path for transmitting the light from the third slit to the sample compartment.
    Type: Grant
    Filed: September 20, 1989
    Date of Patent: January 1, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Sadao Minakawa, Yoshisada Ebata
  • Patent number: 4810872
    Abstract: Light irradiated to a sample is detected by a detector in order to measure the optical properties of the sample. The image of a minute virtual light source for the light is focused in the neighborhood of the measuring face of the sample by a first optical system arranged between the light source and the sample. The light outgoing from the sample is incident to the detector by way of a second optical system arranged between the sample and the detector and having conjugate points in the neighborhood of the measuring face of the sample and of the light receiving point of the detector.
    Type: Grant
    Filed: July 22, 1987
    Date of Patent: March 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Takeo Murakoshi, Sadao Minakawa
  • Patent number: 4810089
    Abstract: A photoelastic effect measuring device comprising a single white light source, a prism dispersing light emitted by said white light source and a variable slit device, which selects an arbitrary spectrum of light thus dispersed is disclosed, in which for a photoelastic effect measurement using white light, the slit width is opened totally so that all the light spectrum pass therethrough so as to pass through a sample to be measured and for a photoelastic effect measurement using a specified monochromatic light beam, the slit width is controlled so as to have a predetermined opening so that only a specified light spectrum can pass therethrough so as to pass through a sample to be measured.
    Type: Grant
    Filed: August 11, 1987
    Date of Patent: March 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Takeo Murakoshi, Masaki Yoshii, Shigeo Tohyama, Sadao Minakawa, Aizo Kaneda
  • Patent number: D323437
    Type: Grant
    Filed: August 4, 1989
    Date of Patent: January 28, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Kazunori Hashimoto, Kazuki Torai, Sadao Minakawa, Hitoshi Komatsu
  • Patent number: D325176
    Type: Grant
    Filed: August 7, 1989
    Date of Patent: April 7, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Kazunori Hashimoto, Kazuki Torai, Sadao Minakawa, Hitoshi Komatsu