Patents by Inventor Keisuke Kojima

Keisuke Kojima 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: 6953729
    Abstract: In a heterojunction FET in which source and drain areas are formed by carrying out high temperature annealing process after carrying out ion implantation in areas to be formed into source and drain areas, conventionally, the N-type carrier supply layer and the N-type active layer are doped with Si. In place of doping with Si, doping with Se or Te is adopted. Thereby, in high temperature annealing process for activating the ion implanted areas, which serves as source and drain areas, unlike the Si donor, inactivation of donor due to reaction with F-atoms occurs scarcely with respect to the diffusion of F-atoms on the surface of the epitaxial substrate, which adhered during the process. Further, since the Se and Te are impurities from VI-family, when the Se or Te occupies any grid position of atoms from III-family or V-family, the Se or Te serves as the donor. Accordingly, a high performance heterojunction FET of little deterioration of the FET characteristics can be obtained.
    Type: Grant
    Filed: July 24, 2003
    Date of Patent: October 11, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akiyoshi Tamura, Keisuke Kojima, Yoshiaki Kato
  • Publication number: 20050199911
    Abstract: A heterojunction bipolar transistor comprises a collector layer, a base layer formed on the collector layer and an emitter layer formed on the base layer. The emitter layer includes a first semiconductor layer covering the entire top surface of the base layer and a second semiconductor layer formed on a predetermined part of the first semiconductor layer. An inactivated region is formed, by ion implantation, in a region of the collector layer located below the base layer except for a part thereof corresponding to the second semiconductor layer. The edge of the inactivated region is located away from the edge of the second semiconductor layer, and a region of the first semiconductor layer between the edge of the inactivated region and the edge of the second semiconductor layer is depleted.
    Type: Application
    Filed: February 23, 2005
    Publication date: September 15, 2005
    Inventors: Keisuke Kojima, Toshiharu Tanbo, Keiichi Murayama
  • Publication number: 20040258905
    Abstract: A laminate film includes a guard film layer (A), a clear coating layer (B), and a color coating layer (C). A color coating material, from which the color coating layer (C) is made, contains a shining material (C3) containing at least an aluminum flake. If necessary, the color coating layer further contains an orientation control material (C4).
    Type: Application
    Filed: March 29, 2004
    Publication date: December 23, 2004
    Inventors: Takakazu Hase, Masahiro Kitamura, Yoshihiko Saitou, Hitoshi Ohgane, Keisuke Kojima, Koichi Takahashi
  • Patent number: 6814376
    Abstract: A short pulse generation system and method of generating a short pulse signal are provided. The system includes a fiber chain having an input for receiving an optical signal having a plurality of optical pulses. The fiber chain is nonlinear with respect to the optical signal and includes a first normal fiber segment having a relatively small chromatic parameter, a first abnormal fiber segment having a relatively large chromatic parameter coupled to an output of the first normal fiber segment, and a second abnormal fiber segment having a relatively small chromatic parameter coupled to an out of the first abnormal fiber segment. The system includes a filter stage coupled to an output of the fiber chain and that has a transparent wavelength selected to regenerate the signal. A short pulse signal is produced when the optical signal is coupled to the input.
    Type: Grant
    Filed: August 8, 2002
    Date of Patent: November 9, 2004
    Assignee: Triquint Technology Holding Co.
    Inventors: Jianjun Yu, Keisuke Kojima
  • Publication number: 20040208555
    Abstract: Methods and apparatus for providing a time slot switch which performs switching in the optical domain without the need for O-E-O conversion is described. The time slot switching device of the present invention may be part of a large switching device capable of performing switching and other function on WDM, TDM and WDM signals which are time division multiplexed. An optical time slot switch implemented using a time slot demultiplexer, optical cross-connect, variable delay lines and time slot multiplexer are described. Frequency conversion may be performed on a per time slot basis in cases where time slot signals are switched between lines using different wavelengths. Wave division demultiplexers and multiplexers can be added to the basic time slot switch to provide support for WDM switching and switching of TDM signals which are transmitted using wave division multiplexing.
    Type: Application
    Filed: June 3, 2002
    Publication date: October 21, 2004
    Inventors: Stanley Pau, Jianjun Yu, Keisuke Kojima, Naresh Chand
  • Publication number: 20040202873
    Abstract: A nonstaining coating composition which comprises as essential components (A) a specific aliphatic sulfonic acid compound or amine salt thereof, (B) a compound having per molecule at least one functional group selected among carboxly, a carboxly anhydride group, and a carboxly group blocked with an alkyl vinyl ether, (C) a specific organosilicate and/or a condensate thereof, and (D) a resin having epoxy groups and/or alkoxysilyl groups in the molecule; and a method of finish coating. They give a cured coating film which has nonstaining properties based on a high degree of hydrophilicity from immediately after the formation thereof and has satisfactory long-term weatherability, water resistance, and chemical resistance. The film can impart an excellent finish appearance to the article.
    Type: Application
    Filed: February 24, 2004
    Publication date: October 14, 2004
    Applicants: BASF NOF Coatings Co., Ltd., HONDA GIKEN KOGYO KABUSHIKI KAISHA
    Inventors: Kishio Shibato, Yoshinori Nakane, Shinichi Ikehara, Keisuke Kojima
  • Patent number: 6797391
    Abstract: A nonstaining coating composition which comprises as essential components (A) a specific aliphatic sulfonic acid compound or amine salt thereof, (B) a compound having per molecule at least one functional group selected among carboxly, a carboxly anhydride group, and a carboxyl group blocked with an alkyl vinyl ether, (C) a specific organosilicate and/or a condensate thereof, and (D) a resin having epoxy groups and/or alkoxysilyl groups in the molecule; and a method of finish coating. They give a cured coating film which has nonstaining properties based on a high degree of hydrophilicity from immediately after the formation thereof and has satisfactory long-term weatherability, water resistance, and chemical resistance.
    Type: Grant
    Filed: April 23, 2002
    Date of Patent: September 28, 2004
    Assignees: BASF NOF Coatings Co., Ltd., Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Kishio Shibato, Yoshinori Nakane, Shinichi Ikehara, Keisuke Kojima
  • Publication number: 20040138368
    Abstract: A paint substitute film 1 is provided which has an excellent property that permits universal application to a variety of components, for example to a complexly shaped component, without decreasing marketability of the component due to undesirable change in color. The paint substitute film 1 includes a color coat 3 which contains metallic pigments 5 and orientation inhibitors 6 for inhibiting orientation of the metallic pigments 5. When the paint substitute film 1 is bonded onto an exterior component of an automobile or the like, the paint substitute film 1 is drawn, but the orientation inhibitors 6 each serve as an obstacle to prevent the metallic pigments 5 from being uniformly oriented toward a direction parallel to the drawing direction. Accordingly, even after the paint substitute film 1 is drawn, rays of light incident on the film 1 diffuses upon reflection off the metallic pigments 5, and thus unfavorable alteration of color in the film 1 can be prevented.
    Type: Application
    Filed: December 15, 2003
    Publication date: July 15, 2004
    Applicant: Honda Motor Co., Ltd.
    Inventors: Hitoshi Ohgane, Keisuke Kojima
  • Publication number: 20040131864
    Abstract: A paint substitute film product 1 for surfacing an object S includes a decorative coat including a light-curable resinous layer, and a protective film provided over a surface of the light-curable resinous layer of the decorative coat. An adhesion strength AS1 between a surface of the object and the decorative coat, an adhesion strength AS2 between the protective film and the decorative coat, and a tensile strength TS of the decorative coat are configured to exhibit the equation: AS1>AS2>TS. The paint substitute film product 1 can deliver increased economy in surfacing the object, and the step of forming the object to be surfaced and the step of applying the paint substitute film can be provided independently.
    Type: Application
    Filed: December 22, 2003
    Publication date: July 8, 2004
    Applicant: HONDA MOTOR CO., LTD.
    Inventors: Hitoshi Ohgane, Akihiro Shibuya, Keisuke Kojima, Noriyuki Yamanaka
  • Publication number: 20040079965
    Abstract: In a heterojunction FET in which source and drain areas are formed by carrying out high temperature annealing process after carrying out ion implantation in areas to be formed into source and drain areas, conventionally, the N-type carrier supply layer and the N-type active layer are doped with Si. In place of doping with Si, doping with Se or Te is adopted. Thereby, in high temperature annealing process for activating the ion implanted areas, which serves as source and drain areas, unlike the Si donor, inactivation of donor due to reaction with F-atoms occurs scarcely with respect to the diffusion of F-atoms on the surface of the epitaxial substrate, which adhered during the process. Further, since the Se and Te are impurities from VI-family, when the Se or Te occupies any grid position of atoms from III-family or V-family, the Se or Te serves as the donor. Accordingly, a high performance heterojunction FET of little deterioration of the FET characteristics can be obtained.
    Type: Application
    Filed: July 24, 2003
    Publication date: April 29, 2004
    Inventors: Akiyoshi Tamura, Keisuke Kojima, Yoshiaki Kato
  • Publication number: 20040028355
    Abstract: A short pulse generation system and method of generating a short pulse signal are provided. The system includes a fiber chain having an input for receiving an optical signal having a plurality of optical pulses. The fiber chain is nonlinear with respect to the optical signal and includes a first normal fiber segment having a relatively small chromatic parameter, a first abnormal fiber segment having a relatively large chromatic parameter coupled to an output of the first normal fiber segment, and a second abnormal fiber segment having a relatively small chromatic parameter coupled to an out of the first abnormal fiber segment. The system includes a filter stage coupled to an output of the fiber chain and that has a transparent wavelength selected to regenerate the signal. A short pulse signal is produced when the optical signal is coupled to the input.
    Type: Application
    Filed: August 8, 2002
    Publication date: February 12, 2004
    Inventors: Jianjun Yu, Keisuke Kojima
  • Publication number: 20030235227
    Abstract: A transmit optical subassembly (TOSA) includes a spot-size-converted (SSC) semiconductor laser coupled to an optical fiber without a lens or isolator. The spot-size-converted semiconductor laser includes an active region and an expander region that expands the spot size of the laser while maintaining efficient active laser performance. The SSC laser is coupled to a submount and passively aligned to an optical fiber positioned within a V-shaped groove formed within the submount. The SSC laser includes a narrow far field advantageous for providing a high coupling efficiency and high quality data transmission. The SSC laser is resistant to back reflection and produces a 1.3 or 1.55 micron optical wavelength and a data rate ranging from 1 to 10 Gbps. The TOSA provides high coupled power due to narrow far field, with potential extra reflection resistance due to absorption and mode transfer losses in coupling reflections through the expander back into the active region.
    Type: Application
    Filed: June 19, 2002
    Publication date: December 25, 2003
    Inventors: Naresh Chand, Julie Eng, Martin Christian Fischer, Philip Anthony Kiely, David J. Klotzkin, Keisuke Kojima, Genji Tohmon, Yan Xu
  • Publication number: 20030165285
    Abstract: Methods and apparatus for providing improving optical signal transmission results over standard mode fiber using a combination of negative chirp, low extinction ratio, and self-phase modulation transmission techniques in combination are described. The use of pre-transmission signal distortion in combinations with one or more of the other transmission techniques is also described. Pre-transmission signal distortion may be introduced by controlling a modulator with a large symmetric AC signal which causes the modulator to operation in a non-linear region or, alternatively, by using a relatively small non-symmetric AC signal to drive the modulator. Use of the small non-symmetric signal has the advantage of reduced power requirements. The pre-transmission distortion acts to counter some of the distortion introduced by the transmission of the signal over an optic fiber.
    Type: Application
    Filed: August 9, 2002
    Publication date: September 4, 2003
    Inventors: Jianjun Yu, Keisuke Kojima, Naresh Chand
  • Publication number: 20030043431
    Abstract: Simultaneous demultiplexing and clock recovery of high-speed (e.g., 80 Gbps or 160 Gbps) optical time division multiplexing (OTDM) signals is achieved using a tandem electro-absorption modulator (TEAM). The TEAM has a monolithically integrated SOA to compensate the insertion loss and two EAMs to reduce the switching window. The demultiplexing and clock recovery may be performed by a single TEAM, or by two or more TEAMs. A fiber Raman amplifier may be used to boost the intensity of the OTDM signals during transmission.
    Type: Application
    Filed: January 30, 2002
    Publication date: March 6, 2003
    Inventors: Naresh Chand, Keisuke Kojima, Thomas Gordon Beck Mason, Jianjun Yu, Rolando Espindola
  • Publication number: 20030040561
    Abstract: A nonstaining coating composition which comprises as essential components (A) a specific aliphatic sulfonic acid compound or amine salt thereof, (B) a compound having per molecule at least one functional group selected among carboxyl, a carboxylic anhydride group, and a carboxyl group blocked with an alkyl vinyl ether, (C) a specific organosilicate and/or a condensate thereof, and (D) a resin having epoxy groups and/or alkoxysilyl groups in the molecule; and a method or finish coating.
    Type: Application
    Filed: April 23, 2002
    Publication date: February 27, 2003
    Inventors: Kishio Shibato, Yoshinori Nakane, Shinichi Ikehara, Keisuke Kojima
  • Patent number: 5644681
    Abstract: A learning method for a neural network, in which at least a portion of the interconnection strength between neurons takes discrete values, includes the steps of updating an imaginary interconnection strength taking continuous values by using the quantity of update of the interconnection strength which has been calculated by using the discrete interconnection strength, and discretizing the imaginary interconnection strength so as to provide a novel interconnection strength.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: July 1, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masanobu Takahashi, Shuichi Tai, Keisuke Kojima, Toshio Shinnishi, Kazuo Kyuma
  • Patent number: 5539762
    Abstract: A novel InP-based semiconductor laser comprises an unpatterned active region that is essentially co-extensive with the substrate of the laser, an electron stopper layer, and a separate confinement heterostructure (SCH) layer that has a portion of thickness greater than the thickness of the remainder of the SCH layer. The difference in thickness serves to provide lateral guiding of the laser mode. A patterned current blocking layer is disposed on the SCH layer, with a window in the blocking layer defining the region of increased thickness of the SCH layer. The inventive laser is readily manufacturable and can have improved properties.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: July 23, 1996
    Assignee: AT&T Corp.
    Inventors: Gregory Belenky, Rudolf F. Kzarinov, Keisuke Kojima, Claude L. Reynolds, Jr.
  • Patent number: 4999688
    Abstract: An optical logic element includes an optical bistable npnp element for switching from a high resistance state to a low resistance state in response to electrical bias and incident light energy in which the switching time becomes shorter as the incident light energy becomes larger. The elements emit light in the low resistance on state. The optical logic element is designed for analog threshold processing of light energy. A plurality of optical bistable elements connected in parallel differentially threshold process incident light energy. An opto-electronic conversion apparatus includes linear arrays of light emitting elements, a two-dimensional array of optical memories, i.e., optical bistable elements, and linear light receiving element arrays arranged transverse to the light emitting element arrays, all integrated with each other. Corresponding light emitting elements, optical memories, and light receiving elements permit arbitrary transfers of signals.
    Type: Grant
    Filed: January 6, 1990
    Date of Patent: March 12, 1991
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kunihiko Hara, Keisuke Kojima, Kazuo Kyuma
  • Patent number: 4888783
    Abstract: In a light-responsive semiconductor device in which the laser oscillation state is controlled by incident light, a layer of material having a conductivity modulatable by light is integrated in a semiconductor laser structure and is responsive to the incident light for the control of the laser oscillation state of the device. In one embodiment constituting a light logic element, a plurality of semiconductor lasers are integrated on a substrate with each respective semiconductor laser having a grating along the entirety or a portion thereof and provided with a light waveguide connecting with a waveguide of an adjacent semiconductor laser. In a bistable semiconductor laser there are provided two different conductivity type light confinement layers, an active layer comprising a multiple quantum well structure which is between the two light confinement layers, a grating provided close to the quantum well active layer.
    Type: Grant
    Filed: March 17, 1988
    Date of Patent: December 19, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Keisuke Kojima, Kazuo Kyuma, Susumu Noda, Masaaki Kameya, Jun Ohta, Koichi Hammanaka
  • Patent number: 4847844
    Abstract: A surface-emitting semiconductor laser device comprises a first electrode, a first-conductivity-type clad layer provided on the first electrode, an active layer provided on the first-conductivity-type clad layer, a guide layer provided on the active layer and having an even-numbered-order diffraction grating opposite to the active layer, a second-conductivity-type clad layer provided on the guide layer, contact layers provided on portions of the second-conductivity-type clad layer, and second electrodes provided on the contact layers.
    Type: Grant
    Filed: January 26, 1988
    Date of Patent: July 11, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Susumu Noda, Keisuke Kojima, Kazuo Kyuma