Patents by Inventor Yoshihiko Mizushima

Yoshihiko Mizushima 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).

  • Publication number: 20050106744
    Abstract: This optical analysis method comprises a first step of making light having a known intensity I0 at a known wavelength incident on a medium; a second step of measuring an optical intensity upon reflection or optical intensity upon transmission emitted from the medium; a third step of executing the first and second steps at a plurality of wavelengths and recording the optical intensity as a measurement result; and a fourth step of calculating a target physical quantity by a predetermined arithmetic operation utilizing a known physical quantity stored in a database and the optical intensity.
    Type: Application
    Filed: December 26, 2002
    Publication date: May 19, 2005
    Inventors: Yoshihiko Mizushima, Kazuji Matsumoto
  • Patent number: 6643020
    Abstract: Light is made incident into an inhomogeneous medium, and transmitted light or reflected light is detected. The intensity of the detected light is represented by the linear sum of exponential functions of penetration depth using e as a base, or a function formed from the exponents and a function derived from the function. This function includes the physical quantity of the inhomogeneous medium as a coefficient. When light amount measurement data are acquired at a plurality of wavelengths or thicknesses, and the light intensity or other known information is substituted into the function and an expression derived from the function, the physical quantity of the inhomogeneous medium can be determined. Thus, an optical analysis method for an inhomogeneous medium, which is capable of accurate analysis, can be provided.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: November 4, 2003
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yoshihiko Mizushima, Kazuji Matsumoto
  • Publication number: 20020082504
    Abstract: Light is made incident into an inhomogeneous medium, and transmitted light or reflected light is detected. The intensity of the detected light is represented by the linear sum of exponential functions of penetration depth using e as a base, or a function formed from the exponents and a function derived from the function. This function includes the physical quantity of the inhomogeneous medium as a coefficient. When light amount measurement data are acquired at a plurality of wavelengths or thicknesses, and the light intensity or other known information is substituted into the function and an expression derived from the function, the physical quantity of the inhomogeneous medium can be determined. Thus, an optical analysis method for an inhomogeneous medium, which is capable of accurate analysis, can be provided.
    Type: Application
    Filed: October 19, 2001
    Publication date: June 27, 2002
    Inventors: Yoshihiko Mizushima, Kazuji Matsumoto
  • Patent number: 5717627
    Abstract: The optical memory device of the present invention comprises a photodetector device which generates a current when light is incident thereon and a light-emitting device which is connected to the photodetector device in series so as to emit light upon receiving a supply of current from the photodetector device and feed back thus emitted light toward the photodetector device.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: February 10, 1998
    Assignee: Hamamatsu Photonics K.K.
    Inventor: Yoshihiko Mizushima
  • Patent number: 5534992
    Abstract: Laser light from LD (laser diode) is guided through a fiber to be projected onto a reflector. A receiver detects a return beam of modulated light reflected by the object and outputs a signal reflecting a phase difference between the laser light and the modulation signal. The frequency of the modulation signal is changed based on the signal value so as to finally achieve phase lock. When the phase lock fixes the frequency of the modulation signal, the frequency always corresponds to a distance from LD to the reflector or a group index of a substance filling the optical path. Thus, the distance to the object or the group index of the substance filling the optical path at the time of phase lock can be determined in a simple manner and with a high accuracy, based on the output frequency at the time of phase lock.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: July 9, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Akira Takeshima, Musubu Koishi, Yoshihisa Warashina, Yoshihiko Mizushima
  • Patent number: 5336902
    Abstract: This invention relates to a semiconductor photo-electron-emitting device for emitting photoelectrons excited from the valence band to the conduction band by incident photons on a semiconductor layer. The device includes a Schottky electrode formed on the emitting surface on a surface of the semiconductor layer, and a conductor layer formed on a surface opposite to the emitting surface. A set bias voltage is applied between the Schottky electrode and the conductor layer to accelerate photoelectrons generated by the excitation of incident photons to the emitting surface and to transfer the accelerated photoelectrons from an energy band of a smaller effective mass to an energy band of a larger effective mass.
    Type: Grant
    Filed: October 5, 1992
    Date of Patent: August 9, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Minoru Nigaki, Tuneo Ihara, Toru Hirohata, Tomoko Suzuki, Kimitsugu Nakamura, Norio Asakura, Masami Yamada, Yasuharu Negi, Tomihiko Kuroyanagi, Yoshihiko Mizushima
  • Patent number: 5227638
    Abstract: Photoluminescence or electroluminescence from a material substrate is measured in a photon-counting range. Luminous efficiency of the substrate in its normal operation range is evaluated on the basis of the measured data. The luminescence is measured in an excitation range of the material including a transition excitation level corresponding to a transition luminous level from a low luminous range to a regular, intense luminous range. Two-dimensional distribution of the luminous efficiencies can be obtained by measuring the luminescence from small divided areas of the substrate.
    Type: Grant
    Filed: July 24, 1991
    Date of Patent: July 13, 1993
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yoshihiko Mizushima, Takashi Iida, Eiji Inuzuka
  • Patent number: 5138191
    Abstract: A junction, such as a Schottky junction, is formed between a conductive electrode and a semiconductor. A bias voltage is applied between the conductive electrode and an outward-emission-side electrode formed on the semiconductor at the side opposite to the junction. Upon illumination, photoelectrons are internally emitted in the conductive electrode into the semiconductor, transported through the semiconductor, and emitted outward from the semiconductor surface, which has been so treated as to reduce the surface barrier height. The semiconductor is semi-insulating, or a p-n junction is formed therein.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: August 11, 1992
    Assignee: Hamamatsu Photonics K. K.
    Inventors: Yoshihiko Mizushima, Toru Hirohata, Tsuneo Ihara, Minoru Niigaki, Kenichi Sugimoto, Koichiro Oba, Toshihiro Suzuki, Tomoko Suzuki
  • Patent number: 5109358
    Abstract: An optical flip-flop circuit which includes an electrical power source for providing an electrical signal, a light-receiving element provided in series with the power source for switching the electrical signal in response to an optical signal, a light-emitting element for emitting the optical signal in response to the electric signal, an electrical signal path between the light-receiving element and the light-emitting element, whereby the electrical signal passes from the power source to the light-emitting element in response to the optical signal received by the light-receiving element, a light path for directing the optical signal from the light-emitting element to the light-receiving element, wherein the light path and the electrical signal path form a signal loop through which a signal circulates, said circulating signal comprising the electrical signal through the electrical signal path portion of the signal loop and the optical signal through the light path portion of the signal loop, and input/output m
    Type: Grant
    Filed: October 17, 1989
    Date of Patent: April 28, 1992
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Yoshihiko Mizushima, Kazutoshi Nakajima, Toru Hirohata, Takashi Iida, Yoshihisa Warashina, Kenichi Sugimoto, Hirofumi Kan
  • Patent number: 5068815
    Abstract: SUM and CARRY output signals of a first optical half adder are provided to one input terminal of a second optical half adder and an optical latch memory, respectively, and an output signal of the optical latch memory is provided to the other input terminal of the second optical half adder. Input and output of the two optical half adders and optical latch memory are performed through an optical signal. Each optical half adder includes two light-receiving elements each having a symmetrical electrode arrangement in which two Schottky junctions are connected to each other opposite in polarity, and peripheral elements of resistors, a capacitor and an amplifier.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: November 26, 1991
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Yoshihiko Mizushima, Kazutoshi Nakajima, Toru Hirohata, Takashi Iida, Yoshihisa Warashina, Kenichi Sugimoto, Tomoko Suzuki, Hirofumi Kan
  • Patent number: 5051573
    Abstract: A plurality of ultra-high speed light receiving elements are provided each of which has two rectifier junctions being connected to each other opposite in polarity and has a substantially symmetrical electrode arrangement. A bias voltage is applied to each of the light receiving elements from one or a plurality of power sources. Electrical signals produced by the light receiving elements in response to input optical pulse signals are superposed on one another to produce one or a plurality of output electrical signals representing a predetermined logic operation with respect to the input optical pulse signals. Depending on the arrangement of its elements, the optical logic operation system functions as an OR circuit, AND circuit, NOT circuit, EXCLUSIVE OR circuit, or half-adder circuit.
    Type: Grant
    Filed: November 14, 1989
    Date of Patent: September 24, 1991
    Assignee: Hamamatsu Photonics Kabushiki kaisha
    Inventors: Yoshihiko Mizushima, Kazutoshi Nakajima, Toru Hirohata, Takashi Iida, Yoshihisa Warashina, Kenichi Sugimoto, Hirofumi Kan
  • Patent number: 5044744
    Abstract: Times t.sub.1 and t.sub.2 required for two electromagnetic waves having different wavelengths to propagate from a reference point to a target point are measured. Necessary meteorological conditions along the path are also measured to determine refractivities N.sub.1 and N.sub.2 of the path for the two electromagnetic waves as:N.sub.1 =.alpha..sub.1 .multidot..rho..sub.s +.beta..sub.1 .multidot..rho..sub.wN.sub.2 =.alpha..sub.2 .multidot..rho..sub.s +.beta..sub.2 .multidot..rho..sub.wwhere .rho..sub.s and .rho..sub.w are densities of dry air and water vapor in the path, respectively. Length of the path D is calculated using the following formula:D=[t.sub.1 +{(.alpha..sub.1 +.beta..sub.1 .multidot..rho..sub.w /.rho..sub.s).multidot.(t.sub.2 -t.sub.1)}/{(.alpha..sub.1 +.beta..sub.1 .multidot..rho..sub.w /.rho..sub.s)-(.alpha..sub.2 +.beta..sub.2 .multidot..rho..sub.w /.rho..sub.s)}].multidot.C.where C is the speed of an electromagnetic wave in vacuum.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: September 3, 1991
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Ichizo Ogawa, Yoshihisa Warashina, Yoshihiko Mizushima, Koji Ichie, Morio Takeichi, Akira Takeshima
  • Patent number: 5034921
    Abstract: An optical memory circuit comprises two photodetectors, and an intermediate signal conductor for connecting the two photodetectors, wherein the two photodetectors and the signal conductor are connected in series in a closed circuit, wherein each of the photodetectors comprises two spaced Schottky electrodes symmetrically disposed on a semiconductor substrate and the signal conductor has a capacitance with a time constant of a potential of the signal conductor such that charges are stored in the signal conductor when an optical write signal is incident on one photodetector and stored charges are released from the signal conductor when an optical read signal is incident on the other photodetector.
    Type: Grant
    Filed: July 6, 1989
    Date of Patent: July 23, 1991
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Kazutoshi Nakajima, Hirofumi Kan, Kenichi Sugimoto, Yoshihiko Mizushima, Toru Hirohata, Takashi Iida, Yoshihisa Warashina, Toru Hirohata, Takashi Iida
  • Patent number: 5020064
    Abstract: An electromagnetic wave device having an amplification function comprises a medium containing free carriers, means for applying a magnetic field to the medium, means for applying an input electromagnetic wave to the medium in a direction perpendicular to the magnetic field, and means for generating an electric field to accelerating the carriers in the direction of the input electromagnetic wave. A frequency of the input electromagnetic wave is within the range of the plasma frequency plus or minus the cyclotron frequency, and a polarization direction of the input electromagnetic wave is perpendicular both to the magnetic field and its own traveling direction. Furthermore, the device has such functions as oscillation, modulation, frequency conversion, etc. depending on the type of added units.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: May 28, 1991
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Yoshihiko Mizushima, Takashi Iida, Toru Hirohata, Kenichi Sugimoto, Yoshihisa Warashina, Kazutoshi Nakajima
  • Patent number: 4875093
    Abstract: An apparatus continous imaging apparatus comprising a camera portion and an image receiving portion, Specifically, the image pickup portion comprises an image pickup tube that deflects and scans electron beams and allows electron signals correponding to one pixel or a one-dimensional array of pixels to be converted successively and continuously to time-series light signals. The image receiving portion comprises means that converts to electron beams the time-series light signals transmitted from the pickup tube through at least one optical fiber and which reproduces an image by deflecting the electron beams in synchronism with the camera portion.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: October 17, 1989
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Musubu Koishi, Yoshihiko Mizushima, Hirofumi Kan
  • Patent number: 4827317
    Abstract: In a device for measuring the time interval between first and second optical pulses, the time interval between the first optical pulse and a first one of the train of reference optical clock pulses which is closest to the first optical pulse, and the time interval between the second optical pulse and a second one of the train of reference optical clock pulses which is closest to the second optical pulse are measured, and the time interval between the first and second optical pulses is calculated according to the time intervals thus measured and the time interval between the first and second reference optical clock pulses.
    Type: Grant
    Filed: June 26, 1987
    Date of Patent: May 2, 1989
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Yoshihiko Mizushima, Yutaka Tsuchiya, Musubu Koishi, Akira Takeshima
  • Patent number: 4720734
    Abstract: A diode having a Schottky barrier which permits bidirectional passage of minority carriers as well as majority carriers through the provision of a bidirectional conducting Schottky electrode that substitutes for the conventional Schottky electrode used in Schottky diodes or for the low-high electrode in Pn junction diodes.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: January 19, 1988
    Assignee: Nippon Telegraph and Telephone Public Corporation
    Inventors: Yoshihito Amemiya, Yoshihiko Mizushima
  • Patent number: 4629486
    Abstract: Disclosed are the processes of how to fabricate the microchannel plate for use in electron image intensifying by using a number of glass pipes, each consisting of glass material containing oxides of alkaline earth metals, i.e., magnesium oxide (MgO) or a mixture of magnesium oxide (MgO) and calcium oxide (CaO).
    Type: Grant
    Filed: November 18, 1985
    Date of Patent: December 16, 1986
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Toshiyuki Uchiyama, Takeo Sugawara, Chiyoshi Okuyama, Yoshihiko Mizushima
  • Patent number: 4587547
    Abstract: An electrode structure for use in semiconductor devices comprising: a semiconductive layer; a conductive layer disposed on one surface of the semiconductive layer; first regions which intervene between the layers and serve as passages for transmitting minority carriers from the semiconductive layer to said conductive layer; and second regions which intervene between said layers and serve as passages for conveying majority carriers between the semiconductive layer and conductive layer, the first and second regions being selectively formed on the semiconductive layer so as to be adjacent to one another.
    Type: Grant
    Filed: July 12, 1983
    Date of Patent: May 6, 1986
    Assignee: Nippon Telegraph & Telephone Public Corp.
    Inventors: Yoshihito Amemiya, Takayuki Sugeta, Yoshihiko Mizushima
  • Patent number: 4521794
    Abstract: A semiconductor layer is formed on at least one portion of a silicon substrate. The layer is made of poly-crystalline or amorphous multicomponent containing silicon, at least one element of Group IV having an atomic radius larger than that of silicon, such as germanium or tin, and donor impurity or acceptor impurity.
    Type: Grant
    Filed: July 3, 1984
    Date of Patent: June 4, 1985
    Assignee: Nippon Telegraph & Telephone Public Corporation
    Inventors: Katsumi Murase, Yoshihiko Mizushima