Patents by Inventor Junichiro Shimizu

Junichiro Shimizu 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: 7898759
    Abstract: A second waveguide is formed near a first waveguide for guiding light to the vicinity of a main pole of a thermally assisted magnetic recording head, and a portion of light propagated through the waveguide 1 is branched to the second waveguide. The light transmitting in the second waveguide is detected by a photodetector to detect an intensity of the light propagated through the first waveguide. In the magnetic recording apparatus, an intensity of a semiconductor laser is decreased when an amount of light incident to the photodetector is large and the intensity of the semiconductor laser is increased when the amount of light incident to the photodetector is small. By constituting a feedback loop as described above, the intensity of the light propagated through the first waveguide is kept constant.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: March 1, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Takuya Matsumoto, Junichiro Shimizu
  • Publication number: 20110038235
    Abstract: A thermally assisted magnetic recording head includes a flying slider, a magnetic field generation device mounted on the flying slider, a first waveguide disposed near the magnetic field generation device for guiding incident light from a top surface of the flying slider on a side of the flying slider toward an air bearing bottom surface of the flying slider, an optical near-field generator disposed at an emission end of the first waveguide, a second waveguide which is separate from the first waveguide and which is spaced from and coupled to the first waveguide at a distance of no greater than a light wavelength, and a first optical detector for detecting the intensity of light propagating in the second waveguide. The first waveguide and the second waveguide are disposed so as to extend in a direction substantially perpendicular to the air bearing bottom surface of the flying slider.
    Type: Application
    Filed: October 26, 2010
    Publication date: February 17, 2011
    Inventors: Takuya Matsumoto, Junichiro Shimizu
  • Patent number: 7864635
    Abstract: It is an objective that the optical loss and the number of optical components are reduced in an optical recording head using a near-field where a laser beam is guided from a light source to the tip of the head and a thermally assisted magnetic recording head. A structure where the traveling direction of emitted beam is rotated in the direction of the cavity of the laser diode element and a reflector for guiding the beam to the surface of the surface of the laser diode element is monolithically integrated in the laser diode element is mounted over the slider so that the direction of the cavity of the laser diode element is parallel to the surface of the recording medium, and the substrate side of the laser diode element is mounted to be in the direction opposite the face adjacent to the upper face of the slider.
    Type: Grant
    Filed: July 16, 2007
    Date of Patent: January 4, 2011
    Assignee: Hitachi, Ltd.
    Inventor: Junichiro Shimizu
  • Publication number: 20100111126
    Abstract: In a horizontal-cavity vertical-emitting semiconductor laser including an Al-containing semiconductor layer, deterioration of light output property due to oxidization of the Al-containing semiconductor layer is suppressed. A lower cladding layer, an active layer, and an upper cladding layer are stacked in this order from the lower layer on a main surface of a substrate made of GaAs. The upper cladding layer is made of AlGaAs or AlGaInP containing Al in high concentration. An emitting plane layer combining a function of preventing the oxidization of Al contained in the upper cladding layer is formed on an upper portion of the upper cladding layer, and an electric contact layer is formed on an upper portion of the emitting plane layer. The emitting plane layer is made of InGaP, and the electric contact layer is made of GaAs.
    Type: Application
    Filed: October 29, 2009
    Publication date: May 6, 2010
    Inventors: Junichiro Shimizu, Etsuko Nomoto, Shinichi Nakatsuka, Tsukuru Ohtoshi, Takafumi Taniguchi
  • Publication number: 20080316872
    Abstract: An optical device integrated head having high light utilizing efficiency by decreasing the propagation loss caused from an optical source to a recording medium, conducting by mounting according to compact active alignment method for efficiently guiding a light generated from a laser device to the top end of a head, in which a light source device mounted on a submount has a mirror portion having an inclinated surface to at least a portion of one edge thereof for reflecting an output light from the optical source device at the inclinated surface, a structural member including a lens structure for further allowing a light to pass through the submount, and an optical waveguide disposed passing through a slider for mounting the submount, and the optical source and the slider are positioned by using active alignment of light in a chip-on carrier structure having the optical source device mounted on the submount.
    Type: Application
    Filed: February 14, 2008
    Publication date: December 25, 2008
    Inventors: Junichiro SHIMIZU, Masato Shishikura
  • Publication number: 20080204916
    Abstract: A second waveguide is formed near a first waveguide for guiding light to the vicinity of a main pole of a thermally assisted magnetic recording head, and a portion of light propagated through the waveguide 1 is branched to the second waveguide. The light transmitting in the second waveguide is detected by a photodetector to detect an intensity of the light propagated through the first waveguide. In the magnetic recording apparatus, an intensity of a semiconductor laser is decreased when an amount of light incident to the photodetector is large and the intensity of the semiconductor laser is increased when the amount of light incident to the photodetector is small. By constituting a feedback loop as described above, the intensity of the light propagated through the first waveguide is kept constant.
    Type: Application
    Filed: January 17, 2008
    Publication date: August 28, 2008
    Inventors: Takuya MATSUMOTO, Junichiro Shimizu
  • Publication number: 20080056073
    Abstract: It is an objective that the optical loss and the number of optical components are reduced in an optical recording head using a near-field where a laser beam is guided from a light source to the tip of the head and a thermally assisted magnetic recording head. A structure where the traveling direction of emitted beam is rotated in the direction of the cavity of the laser diode element and a reflector for guiding the beam to the surface of the surface of the laser diode element is monolithically integrated in the laser diode element is mounted over the slider so that the direction of the cavity of the laser diode element is parallel to the surface of the recording medium, and the substrate side of the laser diode element is mounted to be in the direction opposite the face adjacent to the upper face of the slider.
    Type: Application
    Filed: July 16, 2007
    Publication date: March 6, 2008
    Inventor: Junichiro Shimizu
  • Patent number: 7199441
    Abstract: An optical integrated circuit having optical devices is fabricated. These optical devices must be biased in the mutually opposite directions. If such an optical integrated circuit is fabricated using a conductive semiconductor substrate as conventionally, it is not possible to drive the devices by a single power supply since the substrate side is shared as a common polarity by the devices. The present invention realizes a structure where both anode and cathode of each device can be isolated electrically by conventional process technology and provides an optical integrated circuit which can be driven by a single power supply. An optical integrated circuit is formed on a semi-insulative or insulative substrate. A high resistivity region which extends at least from the active layer to the substrate and includes part of an optical waveguide between the devices is formed so as to electrically isolate the anode and cathode of each integrated device from the other device.
    Type: Grant
    Filed: August 11, 2004
    Date of Patent: April 3, 2007
    Assignees: Hitachi, Ltd., Opnext Japan, Inc.
    Inventors: Junichiro Shimizu, Shigeki Makino, Masahiro Aoki
  • Publication number: 20050275053
    Abstract: An optical integrated circuit having optical devices is fabricated. These optical devices must be biased in the mutually opposite directions. If such an optical integrated circuit is fabricated using a conductive semiconductor substrate as conventionally, it is not possible to drive the devices by a single power supply since the substrate side is shared as a common polarity by the devices. The present invention realizes a structure where both anode and cathode of each device can be isolated electrically by conventional process technology and provides an optical integrated circuit which can be driven by a single power supply. An optical integrated circuit is formed on a semi-insulative or insulative substrate. A high resistivity region which extends at least from the active layer to the substrate and includes part of an optical waveguide between the devices is formed so as to electrically isolate the anode and cathode of each integrated device from the other device.
    Type: Application
    Filed: August 11, 2004
    Publication date: December 15, 2005
    Inventors: Junichiro Shimizu, Shigeki Makino, Masahiro Aoki
  • Patent number: 6826212
    Abstract: A module for optical communication intended for decreasing the consumption power of a modulator integrated laser, in which a, multiple-quantum well constituting a laser active layer region comprises InGaAlAs/InGaNAs to keep the reliability and optical power level even when a chip is kept at a high temperature, and the difference of wavelength between the oscillation wavelength and the band gap wavelength of the modulator and the laser should be made greater in proportion with the elevation of the chip setting temperature for maintaining the transmission performance, by which the temperature difference between the module case temperature and the chip setting temperature is reduced to decrease the module consumption power.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: November 30, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Shirai, Junichiro Shimizu, Shinji Tsuji
  • Publication number: 20020118713
    Abstract: A module for optical communication intended for decreasing the consumption power of a modulator integrated laser, in which a, multiple-quantum well constituting a laser active layer region comprises InGaAlAs/InGaNAs to keep the reliability and optical power level even when a chip is kept at a high temperature, and the difference of wavelength between the oscillation wavelength and the band gap wavelength of the modulator and the laser should be made greater in proportion with the elevation of the chip setting temperature for maintaining the transmission performance, by which the temperature difference between the module case temperature and the chip setting temperature is reduced to decrease the module consumption power.
    Type: Application
    Filed: August 31, 2001
    Publication date: August 29, 2002
    Inventors: Masataka Shirai, Junichiro Shimizu, Shinji Tsuji
  • Patent number: 5433822
    Abstract: A semiconductor device has circuit patterns formed on upper and lower surfaces of a laminated board with both surfaces lined with copper and interconnected by through holes, an IC chip mounted on the upper pattern, and external connection terminals mounted on the lower pattern, the external connection terminals comprising copper core bumps. According to a method of manufacturing such a semiconductor device, the same etching process as pattern etching for forming the circuit pattern are effected in bump forming regions on the circuit pattern formed by the resist pattern.
    Type: Grant
    Filed: December 22, 1992
    Date of Patent: July 18, 1995
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Seiichi Mimura, Junichiro Shimizu, Takayuki Tajiri, Shingo Ichikawa, Hiroyuki Kaneko, Masayuki Ohi