Patents by Inventor Koji Tojo

Koji Tojo 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: 20190011720
    Abstract: An optical coupling module reduces a number of optical elements, and includes a collimate lens 2a that collimates a light from the first semiconductor laser 1a and then outputs the first collimate light, a collimate lens 2b that collimates a light from the semiconductor laser 1b in a location at which an emission plane is approximately orthogonal to an emission plane of the semiconductor laser 1a and outputs the second collimate light. The collimate lens 2c collimates light from semiconductor laser 1c in-place in the location at which the emission plane faces the emission plane of the semiconductor laser 1b and outputs a third collimate light. A prism mirror 3 has a rectangular prism with a first reflection plane that reflects the second collimate light to a parallel direction to the first collimate light and a second reflection plane orthogonal to the first reflection plane and reflects the third collimate light to the parallel direction to the first collimate light.
    Type: Application
    Filed: June 27, 2018
    Publication date: January 10, 2019
    Applicant: SHIMADZU CORPORATION
    Inventors: Naoya Ishigaki, Koji Tojo
  • Patent number: 10153607
    Abstract: A passive Q-switch laser has an excitation source 1 for outputting excitation light; a laser medium 3 between a pair of reflective mirrors 5a, 5b that constitute part of an optical resonator, the laser medium emitting laser light upon being excited by the excitation light from the excitation source: a saturable absorber 4 disposed between the pair of reflective mirrors, the saturable absorber being configured such that the transmittance thereof increases as the laser light beam the laser medium is absorbed, a matrix table 22 in which the excitation-source output and the optimal value of the pulse width are stored in association with the repetition frequency; and a control unit 21 for referring to the matrix table, reading out the excitation-source output and the optimal value of the pulse width that correspond to an inputted repetition frequency, and controlling the excitation source such that the read-out excitation-source output and optimal value of the pulse width are attained.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: December 11, 2018
    Assignee: SHIMADZU CORPORATION
    Inventors: Rakesh Bhandari, Koji Tojo, Naoya Ishigaki, Shingo Uno
  • Patent number: 10139702
    Abstract: A wavelength conversion device having an excitation source 1, a laser medium 3 between an input mirror 5a and an output mirror 5b, consisting of an optic resonator. A laser beam is excited by the excitation light from the excitation source; a saturable absorber 4 is between the input mirror and the output mirror and increases a transmittance along with an absorption of the laser beam from the laser medium. A wavelength conversion element converts a fundamental wave of the laser light from the output mirror to a higher harmonic. A control element generates a phase-matched signal to adjust the phase-matching between the fundamental wave and the higher harmonic based on the output from the wavelength conversion element and the laser output setting value, and controls the laser output by outputting the phase-matched signal to the wavelength conversion element.
    Type: Grant
    Filed: October 6, 2015
    Date of Patent: November 27, 2018
    Assignee: SHIMADZU CORPORATION
    Inventors: Rakesh Bhandari, Koji Tojo, Naoya Ishigaki, Shingo Uno
  • Patent number: 10137526
    Abstract: A laser machining device machines a machining target subject by irradiating the converged laser beam output from each laser diode of a plurality of laser diodes connected in series to each other. A machining laser beam output-power driving circuit Q1 outputs a machining laser beam by driving the plurality of laser diodes 11a-11 d, 13. A guide light output-power driving circuit Q2 outputs a guide light by driving a partial laser diode 13 of the plurality of laser diodes. A selection means SW1, SW2 selects the guide light output-power driving circuit on determining the position and selects the machining laser output-power driving circuit on a laser machining. A setup value comparison circuit 16 controls the electric current flowing through the part of laser diodes to be below the electric current setup value to output the guide light having electric current not higher than the predetermined value.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: November 27, 2018
    Assignee: SHIMADZU CORPORATION
    Inventors: Junki Sakamoto, Ichiro Fukushi, Aklyuki Kadoya, Kazuma Watanabe, Jiro Saikawa, Naoya Ishigaki, Shingo Uno, Tomoyuki Hiroki, Koji Tojo
  • Publication number: 20180275487
    Abstract: A wavelength conversion device having an excitation source 1, a laser medium 3 between an input mirror 5a and an output mirror 5b, consisting of an optic resonator. A laser beam is excited by the excitation light from the excitation source; a saturable absorber 4 is between the input mirror and the output mirror and increases a transmittance along with an absorption of the laser beam from the laser medium. A wavelength conversion element converts a fundamental wave of the laser light from the output mirror to a higher harmonic. A control element generates a phase-matched signal to adjust the phase-matching between the fundamental wave and the higher harmonic based on the output from the wavelength conversion element and the laser output setting value, and controls the laser output by outputting the phase-matched signal to the wavelength conversion element.
    Type: Application
    Filed: October 6, 2015
    Publication date: September 27, 2018
    Applicant: SHIMADZU CORPORATION
    Inventors: RAKESH BHANDARI, Koji TOJO, Naoya ISHIGAKI, Shingo UNO
  • Publication number: 20180123310
    Abstract: A passive Q-switch laser has an excitation source 1 for outputting excitation light; a laser medium 3 between a pair of reflective mirrors 5a, 5b that constitute part of an optical resonator, the laser medium emitting laser light upon being excited by the excitation light from the excitation source: a saturable absorber 4 disposed between the pair of reflective mirrors, the saturable absorber being configured such that the transmittance thereof increases as the laser light beam the laser medium is absorbed, a matrix table 22 in which the excitation-source output and the optimal value of the pulse width are stored in association with the repetition frequency; and a control unit 21 for referring to the matrix table, reading out the excitation-source output and the optimal value of the pulse width that correspond to an inputted repetition frequency, and controlling the excitation source such that the read-out excitation-source output and optimal value of the pulse width are attained.
    Type: Application
    Filed: May 12, 2015
    Publication date: May 3, 2018
    Applicant: SHIMADZU CORPORATION
    Inventors: Rakesh BHANDARI, Koji TOJO, Naoya ISHIGAKI, Shingo UNO
  • Publication number: 20180013263
    Abstract: A laser device has a plurality of laser diodes; a plurality of optical elements installed corresponding to the plurality of the laser diodes; a plurality of units formed by fixing the laser diodes and the optical elements per each laser diode and installed corresponding to the plurality of the laser diodes; a converging element that converges laser beams emitted from the plurality of the laser diodes to a fiber; a housing element houses the plurality of the units and the converging element; and a thermal transfer plate performs heat dissipation of the plurality of the units. The heat resistance reducing element having a heat resistance value that is smaller than a predetermined value is installed between the thermal transfer plate and each unit or the processing for reducing the heat resistance is performed.
    Type: Application
    Filed: February 6, 2015
    Publication date: January 11, 2018
    Applicant: SHIMADZU CORPORATION
    Inventors: JUNKI SAKAMOTO, Ichiro FUKUSHI, Akiyuki KADOYA, Kazuma WATANABE, Naoya ISHIGAKI, Jiro SAIKAWA, Shingo UNO, Tomoyuki HIROKI, Koji TOJO
  • Patent number: 9746615
    Abstract: The light-synthesizing laser device includes a plurality of collimating lenses that are arranged in a one-to-one relationship with a plurality of laser light sources which exhibit anisotropy in a laser light emission angle, and that convert laser light beams emitted from the laser light sources into parallel light; a condensing lens that condenses the laser light that has been converted into parallel light by the plurality of collimating lenses; and an optical fiber (5) having a square waveguide core (SC) which has a square shape, the fiber receiving and synthesizing the laser light condensed by the condensing lens. A longitudinal axis of a condensed beam condensed by the condensing lens is aligned with a diagonal axis of the square waveguide core.
    Type: Grant
    Filed: June 17, 2014
    Date of Patent: August 29, 2017
    Assignee: SHIMADZU CORPORATION
    Inventors: Jiro Saikawa, Naoya Ishigaki, Shingo Uno, Tomoyuki Hiroki, Ichiro Fukushi, Akiyuki Kadoya, Junki Sakamoto, Koji Tojo, Kazuma Watanabe
  • Patent number: 9696501
    Abstract: A fiber coupling module comprises an optical fiber connector detachable from an optical fiber cable, wherein an end surface of the optical fiber cable is treated with an anti-reflection coat to set the reflectance lower than a predetermined value relative to the light of a first wavelength band and to set the reflectance higher than a predetermined value relative to the light of a second wavelength band excluding the first wavelength band, and the fiber coupling module connects to the optical fiber cable through said optical fiber connector. A main light source outputs the light of the first wavelength band to the optical fiber cable. An aiming light source outputs the light of the second wavelength band to the optical fiber cable. A detection element that detects the connection status of the optical fiber cable to the optical fiber connector based on the light of the second wavelength band reflected from the end surface of the optical fiber cable.
    Type: Grant
    Filed: June 12, 2014
    Date of Patent: July 4, 2017
    Assignee: SHIMADZU CORPORATION
    Inventors: Akiyuki Kadoya, Koji Tojo
  • Patent number: 9647422
    Abstract: A laser device has a plurality of semiconductor lasers, a driving device that supplies a driving electric current to the semiconductor laser, a trigger generation circuit that sends a trigger signal to the driving device in order to output the driving electric current, and a wave-combining device that wave-combines laser light emitted from the semiconductor lasers at the combined-wave end, and at least any one of a signal transmitting time, an electric current transmitting time and a light transmitting time is adjusted so as to be the time set respectively for transmitting paths; wherein the signal transmitting time in which the trigger signal transmits over the signal path, the electric current transmitting time in which the laser light transmits over the electric current path, a light transmitting time in which the laser light transmits over the optical path.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: May 9, 2017
    Assignee: SHIMADZU CORPORATION
    Inventors: Tomoyuki Hiroki, Koji Tojo, Kazuma Watanabe, Ichiro Fukushi, Akiyuki Kadoya, Junki Sakamoto, Jiro Saikawa, Naoya Ishigaki, Shingo Uno
  • Publication number: 20170110849
    Abstract: A laser device has a plurality of semiconductor lasers, a driving device that supplies a driving electric current to the semiconductor laser, a trigger generation circuit that sends a trigger signal to the driving device in order to output the driving electric current, and a wave-combining device that wave-combines laser light emitted from the semiconductor lasers at the combined-wave end, and at least any one of a signal transmitting time, an electric current transmitting time and a light transmitting time is adjusted so as to be the time set respectively for transmitting paths; wherein the signal transmitting time in which the trigger signal transmits over the signal path, the electric current transmitting time in which the laser light transmits over the electric current path, a light transmitting time in which the laser light transmits over the optical path.
    Type: Application
    Filed: March 26, 2014
    Publication date: April 20, 2017
    Applicant: SHIMADZU CORPORATION
    Inventors: Tomoyuki HIROKI, Koji TOJO, Kazuma WATANABE, Ichiro FUKUSHI, Akiyuki KADOYA, Junki SAKAMOTO, Jiro SAIKAWA, Naoya ISHIGAKI, Shingo UNO
  • Publication number: 20170082805
    Abstract: The light-synthesizing laser device includes a plurality of collimating lenses that are arranged in a one-to-one relationship with a plurality of laser light sources which exhibit anisotropy in a laser light emission angle, and that convert laser light beams emitted from the laser light sources into parallel light; a condensing lens that condenses the laser light that has been converted into parallel light by the plurality of collimating lenses; and an optical fiber (5) having a square waveguide core (SC) which has a square shape, the fiber receiving and synthesizing the laser light condensed by the condensing lens. A longitudinal axis of a condensed beam condensed by the condensing lens is aligned with a diagonal axis of the square waveguide core.
    Type: Application
    Filed: June 17, 2014
    Publication date: March 23, 2017
    Applicant: SHIMADZU CORPORATION
    Inventors: JIRO SAIKAWA, Naoya ISHIGAKI, Shingo UNO, Tomoyuki HIROKI, Ichiro FUKUSHI, Akiyuki KADOYA, Junki SAKAMOTO, Koji TOJO, Kazuma WATANABE
  • Publication number: 20170082811
    Abstract: A fiber coupling module comprises an optical fiber connector detachable from an optical fiber cable, wherein an end surface of the optical fiber cable is treated with an anti-reflection coat to set the reflectance lower than a predetermined value relative to the light of a first wavelength band and to set the reflectance higher than a predetermined value relative to the light of a second wavelength band excluding the first wavelength band, and the fiber coupling module connects to the optical fiber cable through said optical fiber connector. A main light source 2 outputs the light of the first wavelength band to the optical fiber cable. An aiming light source outputs the light of the second wavelength band to the optical fiber cable.
    Type: Application
    Filed: June 12, 2014
    Publication date: March 23, 2017
    Applicant: SHIMADZU CORPORATION
    Inventors: Akiyuki KADOYA, Koji TOJO
  • Publication number: 20170021449
    Abstract: A laser machining device machines a machining target subject by irradiating the converged laser beam output from each laser diode of a plurality of laser diodes connected in series to each other. A machining laser beam output-power driving circuit Q1 outputs a machining laser beam by driving the plurality of laser diodes 11a-11 d, 13. A guide light output-power driving circuit Q2 outputs a guide light by driving a partial laser diode 13 of the plurality of laser diodes. A selection means SW1, SW2 selects the guide light output-power driving circuit on determining the position and selects the machining laser output-power driving circuit on a laser machining. A setup value comparison circuit 16 controls the electric current flowing through the part of laser diodes to be below the electric current setup value to output the guide light having electric current not higher than the predetermined value.
    Type: Application
    Filed: March 11, 2014
    Publication date: January 26, 2017
    Applicant: SHIMADZU CORPORATION
    Inventors: JUNKI SAKAMOTO, Ichiro FUKUSHI, Aklyuki KADOYA, Kazuma WATANABE, Jiro SAIKAWA, Naoya ISHIGAKI, Shingo UNO, Tomoyuki HIROKI, Koji TOJO
  • Patent number: 9083146
    Abstract: During temperature tuning, first, the temperature of a third harmonic generating element is swept to determine the optimal temperature Ttp of the third harmonic generating element in a state where the temperature of a second harmonic generating element has been set to a temperature shifted away from the vicinity of the optimal temperature. Next, the temperature of second harmonic generating element is swept to determine the optimal temperature Tsp of the second harmonic generating element in a state where the temperature of the third harmonic generating element has been set to a temperature shifted away from the vicinity of the optimal temperature.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: July 14, 2015
    Assignee: SHIMADZU CORPORATION
    Inventors: Naoya Ishigaki, Koji Tojo, Shingo Uno, Jiro Saikawa
  • Patent number: 8369366
    Abstract: To make it possible to use a type I nonlinear optical crystal or a quasi phase matching element as a third harmonic generation crystal there is provided a semiconductor laser, a solid state laser medium that outputs a fundamental wave, a second harmonic generation crystal that outputs a second harmonic wave from the fundamental wave, and a third harmonic generation crystal that outputs a third harmonic wave from the fundamental wave and the second harmonic wave. A quasi phase matching elements is utilized as the second harmonic generation crystal. It is possible to use a type I nonlinear optical crystal or a quasi phase matching element as the third harmonic generation crystal.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: February 5, 2013
    Assignee: Shimadzu Corporation
    Inventors: Koji Tojo, Naoya Ishigaki
  • Publication number: 20120218763
    Abstract: A device is provided with a semiconductor gain medium (1) having an inclined or curved stripe structure, a Volume Bragg Grating element (3) constituting a resonator with the semiconductor gain medium (1), and a wavelength conversion element (5) which outputs a harmonic wave (H) of a fundamental wave (A) from the resonator. Preferably, the semiconductor gain medium (1) is a frequency incoherent and broadband semiconductor gain medium, the wavelength conversion element (5) is a periodic polarization type nonlinear wavelength conversion element, and the Volume Bragg Grating element (3) and the periodic polarization type nonlinear wavelength conversion element (5) have a grating period having a chirped structure.
    Type: Application
    Filed: November 11, 2009
    Publication date: August 30, 2012
    Applicant: SHIMADZU CORPORATION
    Inventors: Jiro Saikawa, Koji Tojo, Yutaka Ido
  • Publication number: 20100254413
    Abstract: To make it possible to use a type I nonlinear optical crystal or a quasi phase matching element as a third harmonic generation crystal there is provided a semiconductor laser, a solid state laser medium that outputs a fundamental wave, a second harmonic generation crystal that outputs a second harmonic wave from the fundamental wave, and a third harmonic generation crystal that outputs a third harmonic wave from the fundamental wave and the second harmonic wave. A quasi phase matching elements is utilized as the second harmonic generation crystal. It is possible to use a type I nonlinear optical crystal or a quasi phase matching element as the third harmonic generation crystal.
    Type: Application
    Filed: March 28, 2008
    Publication date: October 7, 2010
    Applicant: SHIMADZU CORPORATION
    Inventors: Koji Tojo, Noaya Ishigaki
  • Patent number: 7620079
    Abstract: A compact apparatus is provided for stably converting a wavelength of a laser diode with the use of an optical fiber and a wavelength selective device. Employing a bulk type element as a wavelength selective device makes the action of controlling the temperature of the device easy, and can stabilize the wavelength emitted from the laser diode. The optical fiber (2) is placed between the output side of a laser diode (1) and a wavelength selective device (5) of bulk type. While the optical fiber (2) is arranged compact in the form of a coil, the length of an extra-cavity defined by the wavelength selective device (5) is sufficiently longer than the coherence length. Accordingly, the action of stably converting the wavelength can be carried out by the compact apparatus.
    Type: Grant
    Filed: April 30, 2008
    Date of Patent: November 17, 2009
    Assignee: Shimadzu Corporation
    Inventors: Ichiro Fukushi, Koji Tojo, Kazuma Watanabe
  • Patent number: 7599410
    Abstract: A solid state laser medium is composed of Nd:YAG, the wavelength of a second harmonic wave is 557 to 559 nm and a free spectral range of a solid etalon falls in any of the values of a range A of 1.04 to 1.07 nm, a range B of 1.42 to 1.61 nm, a range C of 2.07 to 2.14 nm and a range D of 2.37 to 3.21 nm.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: October 6, 2009
    Assignee: Shimadzu Corporation
    Inventor: Koji Tojo