Patents by Inventor Isuke Hirano

Isuke Hirano 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: 5703491
    Abstract: This invention has as its object to provide a voltage measurement apparatus which has a compact probe unit, and which can perform a measurement in a non-contact manner. The voltage measurement apparatus includes detection means for detecting an electric field generated in a space by a voltage applied to the surface of a device to be measured, light-emitting means for modulating output light by superposing a detected signal obtained from the detection means on a bias current which is supplied to inductively radiate the output light, a constant current source for supplying the bias current to the light-emitting means, extraction means for extracting a signal component of the output light from the light-emitting means, and light-transmission means for guiding the output light from the light-emitting means to the extraction means, and measures the applied voltage to the surface of the device to be measured by bringing the detection means close to the device to be measured in a non-contact manner.
    Type: Grant
    Filed: August 27, 1996
    Date of Patent: December 30, 1997
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Takuya Nakamura, Isuke Hirano, Shinichiro Aoshima, Hironori Takahashi, Tsuneyuki Urakami
  • Patent number: 5592101
    Abstract: An electric field measuring apparatus for causing an optical probe head having an electro-optic member with an electro-optic material to oppose a sample such as a semiconductor integrated circuit device and for optically measuring a voltage of an opposite portion of the sample. The electro-optic material consists of an LiTaO.sub.3 electro-optic crystal or the like, the polarization characteristics of which change depending on the electric-field strength of the sample. The electro-optic member is supported on a guide mechanism to be reciprocally movable within a predetermined stroke range in a direction of the sample. The guide mechanism is reciprocated in the direction of the sample to control the distance between the electro-optic material and the sample.
    Type: Grant
    Filed: July 22, 1993
    Date of Patent: January 7, 1997
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5583444
    Abstract: This invention has as its object to provide a voltage measurement apparatus which has a compact probe unit, and which can perform a measurement in a non-contact manner. The voltage measurement apparatus includes detection means for detecting an electric field generated in a space by a voltage applied to the surface of a device to be measured, light-emitting means for modulating output light by superposing a detected signal obtained from the detection means on a bias current which is supplied to inductively radiate the output light, a constant current source for supplying the bias current to the light-emitting means, extraction means for extracting a signal component of the output light from the light-emitting means, and light-transmission means for guiding the output light from the light-emitting means to the extraction means, and measures the applied voltage to the surface of the device to be measured by bringing the detection means close to the device to be measured in a non-contact manner.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: December 10, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Takuya Nakamura, Isuke Hirano, Shinichiro Aoshima, Hironori Takahashi, Tsuneyuki Urakami
  • Patent number: 5552716
    Abstract: An method of positioning an E-O probe applied to an apparatus for the measurement of voltage. In the first step, the relative position of the E-O probe against the magnifying optical system in the first condition of being focused the magnifying optical system on the base of the E-O probe, and the focal point difference between the focal plane of the magnifying optical system in the second condition that the E-O probe is substantially out of the optical path for observation of the surface of the device and the focal plane in the first condition are stored. The relative position and the focal point difference are fixed in the apparatus for the measurement of voltage regardless of the device to be measured.
    Type: Grant
    Filed: March 14, 1994
    Date of Patent: September 3, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Shinichiro Aoshima, Isuke Hirano, Yutaka Tsuchiya
  • Patent number: 5500587
    Abstract: An E-O probe with improved spatial resolution has a light transmissive base part, an electro-optic material which is fixed to the base part and has an index of refraction which varies in response to an electrical field from a measured object, and a mirror which is fixed to the electro-optic material and reflects an incident beam penetrating the base part and the electro-optic material. The mirror is formed to be smaller than the incident beam in diameter. The electro-optic material is formed very thin.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: March 19, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5499190
    Abstract: A system for measuring timing relationship between two signals for accurately measuring a timing relationship between signals includes an electro-optic measuring unit and a waveform storage and processing unit. The electro-optic measuring unit samples electrical signals from a device under measurement via a strobe light so as to measure the signal waveform. The electro-optic unit uses a laser diode as a light source. The waveform storage and processing unit stores the electrical signal waveforms measured by the electro-optic measuring unit in digital form. The waveform storage and processing unit also calculates a correlation between two stored electrical signal waveforms via a correlation calculation unit, and also detects a peak of the correlation to detect a timing relationship between the signals.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: March 12, 1996
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Tsuneyuki Urakami, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5444365
    Abstract: A change in voltage can be sensitively detected at a local part of a measured object. A set of laser medium and E-O probe are disposed between a pair of mirrors, a first one and a second one, forming a laser resonator. A linearly polarized light is emitted from the laser medium. The polarized light enters the E-O probe, and returns after being reflected by the second mirror. When a voltage is given to the E-O probe from the measured object, depending on the voltage, a refractive index of the E-O probe is changed, the light emitted from the E-O probe is ovally polarized, and a resonance status of the laser resonator then varies. Therefore, the light intensity emitted through the partially penetrating first mirror to the outside of the laser resonator corresponds to the voltage at the measured object in the proximity of the E-O probe. Consequently, a voltage distribution on the measured object such as IC with fine structures can be two-dimensionally detected.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: August 22, 1995
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Hironori Takahashi, Tsuneyuki Urakami, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5350913
    Abstract: Input light incident into fiber end is separated by a light separator. Light traveling straight through the light separator is guided through an optical fiber to a light amplifying and deflecting section, where only components with deflection angle in a predetermined range are amplified and deflected then to be extracted. The extracted components are output as output light through an optical fiber. The other part of light separated by the light separator is received by a photo detector. The light received by the photo detector is converted into an electric signal, and the electric signal is then input into the light amplifying and deflecting section. Using the electric signal generated from the photo detector, desired wave shaping may be effected by adjusting a light amplification factor of the light amplifying and deflecting section, a change speed of deflection angle, and/or a range of deflection angle selected.
    Type: Grant
    Filed: April 23, 1993
    Date of Patent: September 27, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5319654
    Abstract: An object of this invention is to provide a pulsed laser beam source device which is easy to handle and is operative stably. Pumping light is irradiated to a laser medium from a light source for optical pumping. The stimulated laser medium pumps radiation of a set wavelength. This radiation is stimulated to be amplified while reciprocating between resonator mirrors. A multi layer film is inserted in an optical path of the radiation. Feeble light of the radiation from the laser medium is absorbed by the multi-layer to be weaker, and that part of the radiation having intensities above a set intensity is compressed in terms of time to be emitted outside. The emitted radiation has a very short pulse duration.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: June 7, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Tsuneyuki Urakami, Shinichiro Aoshima, Isuke Hirano
  • Patent number: 5311350
    Abstract: The present invention provides an optical device according to this invention comprising a light transmitting optical member of a high molecular material containing mobile ions, and a pair of electrodes formed on surfaces of the optical member, a required potential difference being provided between the electrodes so as to cause ion conduction in the optical member and to reversibly vary a refractive index of the optical member. According to this invention, a refractive index is reversibly varied due to ion conduction, whereby the modulation of a transmitted beam or a reflected beam by the optical device can be reversibly controlled.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: May 10, 1994
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Mitsuo Hiramatsu, Isuke Hirano, Tatsuo Fujinami
  • Patent number: 5237388
    Abstract: Young's interferometer consisting of a single slit and a double slit member, and an analyzer are arranged along the axis of light to be measured. Parallel slits of the double slit member are provided with respective polarizers whose paralyzing directions are at .+-.45.degree. to the longitudinal direction of the parallel slits. The polarizing direction of the analyzer is set in parallel with the parallel slits. The incident light passes through Young's interferometer and the analyzer to form an interference fringe, which is detected by an image detector unit. An image analyzer unit produces an intensity profile of the interference fringe and determines the polarization state of the incident light, for instance, by comparing the produced intensity profile with conceivable profiles stored in advance.
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: August 17, 1993
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Isuke Hirano, Hironori Takahashi, Tsuneyuki Urakami, Tamiki Takemori, Yutaka Tsuchiya, Shinichiro Aoshima
  • Patent number: 4762418
    Abstract: An angle-of-optical-rotation variation measuring apparatus for measuring the highly speedy time-variation of an angle of optical rotation of an optical active substance. The angle-of-optical-rotation variation measuring apparatus comprises an exciting pulse generating source for producing and providing an exciting pulse to a specimen, a light source for providing a monochromatic linearly polarized light beam with the specimen, continuous analysis means for optically rotating the light beam passed through the specimen at successively different angles in the direction of a reference line predetermined to the apparatus and transmitting as an output light beam a part of the light beam which is optically rotated at a predetermined angle, and a streak tube for receiving the output light beam from the analysis means in a direction perpendicular to a time axis of the streak tube.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: August 9, 1988
    Assignee: Hamamatsu Photonics Kabushiki Kaisha
    Inventors: Toshiaki Ito, Mitsuo Hiramatsu, Isuke Hirano