Patents by Inventor Shinichi Nakatsuka

Shinichi Nakatsuka 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: 11923325
    Abstract: A memory chip unit includes a pad electrode including first and second portions, and a memory cell array. A prober includes a probe card and a movement mechanism. The probe card includes a probe electrode to be in contact with the pad electrode, and a memory controller electrically coupled to the probe electrode and executes reading and writing on the memory cell array. The movement mechanism executes a first operation that brings the probe electrode into contact with the first portion and does not bring the probe electrode into contact with the second portion, and a second operation that does not bring the probe electrode into contact with the first portion and brings the probe electrode into contact with the second portion.
    Type: Grant
    Filed: March 15, 2022
    Date of Patent: March 5, 2024
    Assignee: Kioxia Corporation
    Inventors: Yasuhito Yoshimizu, Takashi Fukushima, Tatsuro Hitomi, Arata Inoue, Masayuki Miura, Shinichi Kanno, Toshio Fujisawa, Keisuke Nakatsuka, Tomoya Sanuki
  • Patent number: 7888146
    Abstract: According to an aspect of the present invention, there is provided a method for assembling a semiconductor laser device, including: preparing a laser chip including: a substrate; stripe waveguides that are formed on the substrate and that each includes a gain producing area and a window area; electrodes formed on the stripe waveguides; an insulating layer formed on the electrodes; a metal layer formed on the insulating layer; projections arranged at an interval in the window areas; and joining structures connected to the electrodes and formed in the window areas; preparing a submount including: a first solder; second solders arranged at the interval; and submount electrodes connected to the second solders; contacting the laser chip to the submount by fitting the projections with respect to the second solders; and heating the submount and the laser chip.
    Type: Grant
    Filed: July 16, 2008
    Date of Patent: February 15, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Shinichi Nakatsuka
  • Publication number: 20100158067
    Abstract: An optical module comprising a laser device adapted to emit a laser beam from a convex surface and including a horizontal resonator surface-emitting structure provided with a first lens through which an optical axis of the laser beam passes, and a second lens through which the laser beam having passed through the first lens passes, a surface opposed to the second lens-provided surface and the surface provided with the first lens being bonded together through a first adhesive transparent to the laser beam.
    Type: Application
    Filed: December 8, 2009
    Publication date: June 24, 2010
    Applicant: HITACHI, LTD.
    Inventors: Shinichi NAKATSUKA, Yasunobu MATSUOKA
  • 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
  • Patent number: 7653110
    Abstract: According to an aspect of the present invention, there is provided a semiconductor laser apparatus including: a laser device including: a semiconductor substrate, first and second resonators formed on the semiconductor substrate, and first and second electrodes that are respectively connected with the first and the second resonators and extend away from each other; and a submount including: third and fourth electrodes respectively adhered with the first and the second electrodes; wherein each of the first and the second electrodes includes: an energizing portion covering the corresponding resonator, an adhering portion being disposed separately from the energizing portion and having a height larger than that of the energizing portion, and a stress-absorbing portion formed in the adhering portion.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: January 26, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Nakatsuka, Tsukuru Ootoshi
  • Patent number: 7564886
    Abstract: In a semiconductor laser diode array, first electrodes of a laser chip are coated with an insulating substance, and contact holes are formed in the insulating substance. The laser chip is assembled by being secured on a submount while facing downward, wherein electrodes and a solder pattern are provided in the submount in a direction crossing resonators.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: July 21, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Shinichi Nakatsuka
  • Patent number: 7542396
    Abstract: To achieve stable, high capacity, high speed recording. Of two light beams emitted from a light irradiation means, one or two beams are made pass through an optical path changeable member whereof at least one of the thickness and refractive index changes continuously or in two or more steps immediately after emission from the light irradiation means, so that a difference is introduced into the optical path length of the two beams, and the focusing point of one beam is made to vary to coincide with a position in the recording layer used for playback or recording. Another light beam is used for servo. Converging of light during recording or read of a multilayer recording medium is performed with higher precision than in the prior art, so higher density, higher capacity recording/playback can be performed.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: June 2, 2009
    Assignees: Hitachi, Ltd., Hitachi Computer Peripherals Co., Ltd
    Inventors: Motoyasu Terao, Toshimasa Kamisada, Shinichi Nakatsuka, Takeshi Shimano, Hitoshi Ishii, Kazuhiro Soga, Yoshiaki Ogino
  • Publication number: 20090042327
    Abstract: According to an aspect of the present invention, there is provided a method for assembling a semiconductor laser device, including: preparing a laser chip including: a substrate; stripe waveguides that are formed on the substrate and that each includes a gain producing area and a window area; electrodes formed on the stripe waveguides; an insulating layer formed on the electrodes; a metal layer formed on the insulating layer; projections arranged at an interval in the window areas; and joining structures connected to the electrodes and formed in the window areas; preparing a submount including: a first solder; second solders arranged at the interval; and submount electrodes connected to the second solders; contacting the laser chip to the submount by fitting the projections with respect to the second solders; and heating the submount and the laser chip.
    Type: Application
    Filed: July 16, 2008
    Publication date: February 12, 2009
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventor: Shinichi Nakatsuka
  • Publication number: 20080279246
    Abstract: According to an aspect of the present invention, there is provided a semiconductor laser apparatus including: a laser device including: a semiconductor substrate, first and second resonators formed on the semiconductor substrate, and first and second electrodes that are respectively connected with the first and the second resonators and extend away from each other; and a submount including: third and fourth electrodes respectively adhered with the first and the second electrodes; wherein each of the first and the second electrodes includes: an energizing portion covering the corresponding resonator, an adhering portion being disposed separately from the energizing portion and having a height larger than that of the energizing portion, and a stress-absorbing portion formed in the adhering portion.
    Type: Application
    Filed: April 25, 2008
    Publication date: November 13, 2008
    Applicant: RICOH PRINTING SYSTEMS, LTD.
    Inventors: Shinichi Nakatsuka, Tsukuru Ootoshi
  • Patent number: 7206329
    Abstract: When a semiconductor laser is energized, a virtual junction temperature rises to reduce a threshold current, which fluctuates a light output by the unit of a several microseconds, thereby causing printing irregularity. An object of the invention is to prevent the fluctuation in light output occurring due to the temperature change caused by the energization of the semiconductor laser with a simple circuit structure and under the driving condition of a small bias current. A constant voltage driving is performed with a circuit or device having negative resistance characteristics being arranged in series with the semiconductor laser. Thus, the reduction in light output of the semiconductor laser due to the temperature rise is compensated for by an increase in driving current thanks to a reduction in rising voltage of current/voltage characteristics.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: April 17, 2007
    Assignee: Ricoh Printing Systems Co., Ltd.
    Inventors: Shinichi Nakatsuka, Jyunshin Sakamoto, Hiroshi Inenaga, Susumu Saito
  • Publication number: 20060227670
    Abstract: To achieve stable, high capacity, high speed recording. Of two light beams emitted from a light irradiation means, one or two beams are made pass through an optical path changeable member whereof at least one of the thickness and refractive index changes continuously or in two or more steps immediately after emission from the light irradiation means, so that a difference is introduced into the optical path length of the two beams, and the focusing point of one beam is made to vary to coincide with a position in the recording layer used for playback or recording. Another light beam is used for servo. Converging of light during recording or read of a multilayer recording medium is performed with higher precision than in the prior art, so higher density, higher capacity recording/playback can be performed.
    Type: Application
    Filed: August 24, 2005
    Publication date: October 12, 2006
    Inventors: Motoyasu Terao, Toshimasa Kamisada, Shinichi Nakatsuka, Takeshi Shimano, Hitoshi Ishii, Kazuhiro Soga, Yoshiaki Ogino
  • Publication number: 20060007977
    Abstract: In a semiconductor laser diode array, first electrodes of a laser chip are coated with an insulating substance, and contact holes are formed in the insulating substance. The laser chip is assembled by being secured on a submount while facing downward, wherein electrodes and a solder pattern are provided in the submount in a direction crossing resonators.
    Type: Application
    Filed: July 6, 2005
    Publication date: January 12, 2006
    Applicant: Ricoh Printing Systems, Ltd.
    Inventor: Shinichi Nakatsuka
  • Publication number: 20050169329
    Abstract: When a semiconductor laser is energized, a virtual junction temperature rises to reduce a threshold current, which fluctuates a light output by the unit of a several microseconds, thereby causing printing irregularity. An object of the invention is to prevent the fluctuation in light output occurring due to the temperature change caused by the energization of the semiconductor laser with a simple circuit structure and under the driving condition of a small bias current. A constant voltage driving is performed with a circuit or device having negative resistance characteristics being arranged In series with the semiconductor laser. Thus, the reduction in light output of the semiconductor laser due to the temperature rise is compensated for by an increase in driving current thanks to a reduction in rising voltage of current/voltage characteristics.
    Type: Application
    Filed: June 21, 2004
    Publication date: August 4, 2005
    Inventors: Shinichi Nakatsuka, Jyunshin Sakamoto, Hiroshi Inenaga, Susumu Saito
  • Patent number: 6829265
    Abstract: The subject of the disclosed art is to prevent a short circuit between plural electrodes caused by soldering in the assembling process for a semiconductor laser element. The constitution for improving the subject is as follows. A semiconductor laser device comprises a semiconductor laser chip having a first electrode and a laser sustaining material, in which the laser sustaining material has electrodes and solder layers connected electrically therewith on the surface where the semiconductor laser chip is mounted, the first electrode of the semiconductor laser chip is connected with the solder layer of the laser sustaining material and at least the solder layer of the laser sustaining material extends from at least one end face in the longitudinal direction of an optical resonator of the semiconductor laser chip to the outside of the optical resonator.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: December 7, 2004
    Assignees: Hitachi, Ltd., Hitachi Printing Solutions Ltd.
    Inventors: Shinichi Nakatsuka, Susumu Saito, Junshin Sakamoto, Kazuo Sakaki, Masahide Tokuda
  • Patent number: 6657653
    Abstract: An electric photograph system for improving non-linearities of an exposing light intensity and an operating current at a low exposing level when performing analog printing operation. A range (saturable absorber) having a saturable absorbing characteristic is provided in a part of an optical path including a semiconductor laser as light source to improve the non-linearity of the operating current when the light intensity is weak. The saturable absorber may be made in the form of a non current injected area provided in a part of the semiconductor laser as the light source or a thin film layer provided partly in films coated on a facet of the semiconductor laser. Due to the provision of the saturable absorber, the light output power characteristic can exhibit its linearity in its low optical power range, the size of a printing dot can be arithmetically changed, and thus fine laser printing can be realized.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: December 2, 2003
    Assignees: Hitachi, Ltd., Hitachi Printing Solutions, Ltd.
    Inventors: Shinichi Nakatsuka, Junshin Sakamoto, Akira Arimoto
  • Publication number: 20030103516
    Abstract: In a surface-emitting laser comprising an active region for emitting light and upper and lower DBR's sandwiching this active region from below and above to form resonators, a plurality of selective oxidation layers having an aperture which is an unoxidized region are formed in the upper DBR, lower DBR or both of them and the aperture is made wider stepwise as it becomes farther from the active region, thereby greatly reducing the capacitance of the laser. A high-speed optical module comprising the above surface-emitting laser as a light source has high performance, long service life and is inexpensive.
    Type: Application
    Filed: July 3, 2002
    Publication date: June 5, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takeshi Kitatani, Masahiko Kondow, Makoto Kudo, Shinichi Nakatsuka, Masahiro Aoki
  • Publication number: 20020172245
    Abstract: The subject of the disclosed art is to prevent a short circuit between plural electrodes caused by soldering in the assembling process for a semiconductor laser element. The constitution for improving the subject is as follows. A semiconductor laser device comprises a semiconductor laser chip having a first electrode and a laser sustaining material, in which the laser sustaining material has electrodes and solder layers connected electrically therewith on the surface where the semiconductor laser chip is mounted, the first electrode of the semiconductor laser chip is connected with the solder layer of the laser sustaining material and at least the solder layer of the laser sustaining material extends from at least one end face in the longitudinal direction of an optical resonator of the semiconductor laser chip to the outside of the optical resonator.
    Type: Application
    Filed: May 15, 2002
    Publication date: November 21, 2002
    Inventors: Shinichi Nakatsuka, Susumu Saito, Junshin Sakamoto, Kazuo Sakaki, Masahide Tokuda
  • Publication number: 20020024586
    Abstract: An electric photograph system for improving non-linearities of an exposing light intensity and an operating current at a low exposing level when performing analog printing operation. A range (saturable absorber) having a saturable absorbing characteristic is provided in a part of an optical path including a semiconductor laser as light source to improve the non-linearity of the operating current when the light intensity is weak. The saturable absorber may be made in the form of a non current injected area provided in a part of the semiconductor laser as the light source or a thin film layer provided partly in films coated on a facet of the semiconductor laser. Due to the provision of the saturable absorber, the light output power characteristic can exhibit its linearity in its low optical power range, the size of a printing dot can be arithmetically changed, and thus fine laser printing can be realized.
    Type: Application
    Filed: June 19, 2001
    Publication date: February 28, 2002
    Inventors: Shinichi Nakatsuka, Junshin Sakamoto, Akira Arimoto
  • Patent number: 6091439
    Abstract: A laser printer is provided printing with a high precision simply and at a high speed, and the laser printer uses a semiconductor laser which can vary the diameter of the emitted light while the light density is held constant. In the laser printer, laser rays emitted from a semiconductor laser are irradiated onto a photoconductor to vary its surface potential to produce a charge pattern particles adhere, and printing is performed by transferring the changed particles to a printing object. The semiconductor laser has a plurality of waveguide type resonators, the emitted beams of the resonators having a spatial superposition, and light emission is possible so that the emitted beams of the resonators having a spatial superposition with respect to each other among the resonators of the semiconductor laser are not substantially superimposed in time.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: July 18, 2000
    Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.
    Inventors: Shinichi Nakatsuka, Susumu Saito, Akira Arimoto
  • Patent number: 5959655
    Abstract: A light beam scanning apparatus in which laser power and spot shape of an emitted laser beam are controlled, has a laser control signal generating part for changing a picture signal to a laser power control signal and a spot shape control signal, a laser power control current generating part which is driven by the laser power control signal, a spot shape control current generating part which is driven by the shape control signal, and a laser beam emission part for emitting a laser beam having a laser power and a spot shape which are controlled by the control signals via a commonly used light wave guiding part, wherein the control signal generating part generates or corrects the control signals based on at least one of the difference between the laser power of a beam to be emitted and a detected laser power, the difference between the spot shape of a beam to be emitted and a detected laser power, a detected temperature at the laser beam emission part, and an effective light emission pixel number.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: September 28, 1999
    Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.
    Inventors: Seiji Maruo, Shinichi Nakatsuka, Akira Arimoto, Kunio Sato, Shinya Kobayashi, Susumu Saito