Patents by Inventor Kenji Yamaga

Kenji Yamaga 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: 20060078706
    Abstract: An inexpensive optical recording medium is provided that can ensure recording and reproduction of data even in case of using blue or blue-violet laser light as irradiation light and can be stored for a long time. The optical recording medium includes a recording layer. The recording layer includes a recording portion and a covering portion covering at least one side of the recording portion in a thickness direction of the recording portion. The recording portion and the covering portion are substantially formed from a plurality of types of common constituent elements. Composition ratios of the constituent elements are different between the recording portion and the covering portion.
    Type: Application
    Filed: September 23, 2005
    Publication date: April 13, 2006
    Applicant: TDK Corporation
    Inventors: Daisuke Yoshitoku, Koji Mishima, Kenji Yamaga
  • Publication number: 20060075419
    Abstract: An information recording medium includes a recording layer sandwiched between a pair of resin layers and has a track pitch in a range of 0.1 ?m to 0.5 ?m, inclusive. The recording layer has a higher refractive index than the pair of resin layers, is composed of a single layer of recording material of a same type, and is formed so that both surfaces thereof directly contact the pair of resin layers. At least one resin layer out of the pair of resin layers is formed with a refractive index in a range of 1.2 to 1.5, inclusive.
    Type: Application
    Filed: October 6, 2004
    Publication date: April 6, 2006
    Applicant: TDK Corporation
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Publication number: 20060072431
    Abstract: An intermediate for an optical recording medium, according to the present invention, is an intermediate produced beforehand for manufacturing an optical recording medium that has a central mounting hole formed in a central portion thereof and one or more kinds of functional layers formed on a surface thereof, for enabling at least one of information recording and information reproduction. The intermediate has a provisional central hole, which is smaller in diameter than the central mounting hole, formed in a central portion thereof. This makes it possible to drop resin in the vicinity of the center of the intermediate without using a disk-shaped member, in performing spin coating on the intermediate, whereby it is possible to make the layer of applied resin substantially uniform in thickness.
    Type: Application
    Filed: July 2, 2003
    Publication date: April 6, 2006
    Inventors: Junichi Ide, Mamoru Usami, Tomoki Ushida, Kenji Yamaga, Atsushi Koyama
  • Patent number: 7022743
    Abstract: The object of this invention is to provide a solid polymer electrolyte which is excellent in durability and of low cost, and membranes, solutions for electrode catalyst coating, membrane/electrode assemblies and fuel cells which use the electrolyte. According to this invention, there can be provided a fuel cell which comprises an electrode assembly having an electrode catalyst membrane formed therein, said catalyst membrane comprising a polymer electrolyte membrane held between an anode on one side of the principal plane of the electrolyte membrane and a cathode on the other side of the principal lane thereof, current collecting plates provided each independently in close contact, to the anode side and the cathode side of the electrode assembly, and electroconductive separators having gas supply passages to the anode and to the cathode provided on the outside surfaces of the current collecting plates.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: April 4, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Morishima, Tomoichi Kamo, Toshiyuki Kobayashi, Kenji Yamaga, Tohru Koyama
  • Patent number: 7018697
    Abstract: An optical recording medium including a substrate and a light transmitting layer provided on the substrate so as to have a smaller thickness than that of the substrate, which is hardly warped and excellent in electrical characteristics and productivity, is provided. An optical recording medium includes: a substrate; and a light transmitting layer having a smaller thickness than that of the substrate. In this medium, a material of the substrate is an olefin maleimide copolymer.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: March 28, 2006
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Komaki, Kenji Yamaga, Takashi Yamada
  • Patent number: 6989212
    Abstract: The object of this invention is to provide a solid polymer electrolyte which is excellent in durability and of low cost, and membranes, solutions for electrode catalyst coating, membrane/electrode assemblies and fuel cells which use the electrolyte. According to this invention, there can be provided a fuel cell which comprises an electrode assembly having an electrode catalyst membrane formed therein, said catalyst membrane comprising a polymer electrolyte membrane held between an anode on one side of the principal plane of the electrolyte membrane and a cathode on the other side of the principal lane thereof, current collecting plates provided each independently in close contact, to the anode side and the cathode side of the electrode assembly, and electroconductive separators having gas supply passages to the anode and to the cathode provided on the outside surfaces of the current collecting plates.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: January 24, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Morishima, Tomoichi Kamo, Toshiyuki Kobayashi, Kenji Yamaga, Tohru Koyama
  • Publication number: 20050277013
    Abstract: The present invention provides a fuel cell employing a metal separator in which low gas pressure loss, high hydrogen utilization factor operation and long term power generation are possible.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 15, 2005
    Inventors: Kenji Yamaga, Hiroshi Yamauchi, Kou Takahashi
  • Publication number: 20050271923
    Abstract: The object of this invention is to provide a solid polymer electrolyte which is excellent in durability and of low cost, and membranes, solutions for electrode catalyst coating, membrane/electrode assemblies and fuel cells which use the electrolyte. According to this invention, there can be provided a fuel cell which comprises an electrode assembly having an electrode catalyst membrane formed therein, said catalyst membrane comprising a polymer electrolyte membrane held between an anode on one side of the principal plane of the electrolyte membrane and a cathode on the other side of the principal lane thereof, current collecting plates provided each independently in close contact, to the anode side and the cathode side of the electrode assembly, and electroconductive separators having gas supply passages to the anode and to the cathode provided on the outside surfaces of the current collecting plates.
    Type: Application
    Filed: July 8, 2005
    Publication date: December 8, 2005
    Applicant: Hitachi, Ltd.
    Inventors: Makoto Morishima, Tomoichi Kamo, Toshiyuki Kobayashi, Kenji Yamaga, Tohru Koyama
  • Publication number: 20050271922
    Abstract: A solid polymer electrolyte is made up of a polymer compound having a hydrocarbon aromatic group in the backbone thereof and including a side chain expressed by FORMULA 1: CH2nSO3H??FORMULA 1 wherein ā€œnā€ is 1, 2, 3, 4, 5, or 6. The solid polymer electrolyte may be incorporated into a membrane and may be used in a solution for covering an electrode catalyst.
    Type: Application
    Filed: July 8, 2005
    Publication date: December 8, 2005
    Inventors: Toru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Publication number: 20050271853
    Abstract: An optical recording medium includes a support substrate 11, and a light transmission layer 12 that is disposed so as to come in contact with the support substrate 11. At least one of a refractive index of the support substrate 11 and a refractive index of the light transmission layer 12, and an extinction coefficient of the support substrate 11 and an extinction coefficient of the light transmission layer 12 is different. As such, according to the invention, a reflective layer is not formed between the support substrate 11 and the light transmission layer 12, such that the support substrate 11 and the light transmission layer 12 directly come in contact with each other. Accordingly, since at least one of the refractive index and the extinction coefficient is different, reflection occurs at the interface between the support substrate 11 and the light transmission layer 12.
    Type: Application
    Filed: June 1, 2005
    Publication date: December 8, 2005
    Applicant: TDK Corporation
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Publication number: 20050270961
    Abstract: An optical recording medium according to the present invention includes a support substrate and a light transmission layer formed on one side of the support substrate and constituted so that data are recorded therein or reproduced therefrom by projecting a laser beam having a wavelength of 380 nm to 450 nm thereonto, wherein the light transmission layer is formed so as to have a thickness of 5 ?m to 60 ?m.
    Type: Application
    Filed: June 4, 2004
    Publication date: December 8, 2005
    Applicant: TDK Corporation
    Inventors: Kentaro Iida, Kenji Yamaga, Mamoru Usami
  • Publication number: 20050270963
    Abstract: An optical recording medium according to the invention has a disc body 11 in which a label side 11b can be viewed from a light incident side 11a, a printing layer 12 that is provided on the label side 11b of the disc body 11, and an ink receiving layer that is provided on the printing layer 12. Accordingly, the printed content of the printing layer 12 can be viewed from the light incident side 11a and a user can print a desired design on the ink receiving layer 13. Therefore, the design flexibility can be enhanced and a possibility of erroneous handling of the optical recording medium by the user can be drastically reduced. In addition, the optical recording medium by manufacturer or brand can be visually discriminated.
    Type: Application
    Filed: June 6, 2005
    Publication date: December 8, 2005
    Applicant: TDK Corporation
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga, Junichi Satou
  • Publication number: 20050255367
    Abstract: A fuel cell includes multiple generating units layered in multiple, each unit including an electrolyte membrane electrode assembly, gas diffusion layers placed to sandwich the assembly, and a pair of separator units placed outside the gas diffusion layers, wherein a flow channel space is formed between the separator units and the gas diffusion layers, each of the separator units has a separator substrate with multiple gas flow channel grooves, and a pair of frames placed on both surfaces of the substrate, and the cross-sectional area of the flow channel in a direction orthogonal to the direction of the flow channel grooves is different in an upstream portion and a downstream portion. The present invention also discloses a fuel cell separator unit kit and a fuel cell generating unit kit.
    Type: Application
    Filed: February 17, 2005
    Publication date: November 17, 2005
    Inventors: Ko Takahashi, Hiroshi Yamauchi, Kenji Yamaga
  • Patent number: 6964823
    Abstract: A solid polymer electrolyte is made up of a polymer compound having a hydrocarbon aromatic group in the backbone thereof and including a side chain expressed by FORMULA 1: wherein ā€œnā€ is 1, 2, 3, 4, 5, or 6. The solid polymer electrolyte may be incorporated into a membrane and may be used in a solution for covering an electrode catalyst.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: November 15, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Toru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Publication number: 20050244753
    Abstract: An optical recording medium is provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium includes a substrate, and a recording layer formed over the substrate and having its optical characteristic changed by irradiation of the laser light. The recording layer is substantially composed of Bi and O, and the ratio of the number of the O atoms in the recording layer is 62% or higher.
    Type: Application
    Filed: April 22, 2005
    Publication date: November 3, 2005
    Applicant: TDK CORPORATION
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Publication number: 20050237904
    Abstract: The invention relates to a light-receiving element for receiving a reflection of laser light irradiated to a rotating multi-layer recording medium having a plurality of information recording layers stacked one over another and for converting the light into an electrical signal, an optical head having the element for recording information in the multi-layer recording medium or reproducing information recorded therein, and an optical recording/reproducing apparatus and a method of optical recording and reproduction. The invention provides a light-receiving element, an optical head, an optical recording/reproducing apparatus, and a method of optical recording and reproduction which make it possible to eliminate a noise component superimposed on reflected light from a multi-layer recording medium to reproduce an RF signal of high quality.
    Type: Application
    Filed: April 4, 2005
    Publication date: October 27, 2005
    Applicant: TDK CORPORATION
    Inventors: Giichi Shibuya, Teiichiro Oka, Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Publication number: 20050237894
    Abstract: An optical recording medium and a method of recording and reproducing of the optical recording medium are provided, which are capable of recording and reproducing data with reliability even when blue or blue violet laser light is used as irradiation light. The optical recording medium has a recording layer in which a recording mark composed of a plurality of cavities is formed by irradiation of the laser light. The recording layer is configured so that, in a plan view taken in a direction of irradiation of the laser light, cavities lying in an area of the center and its vicinities of the recording mark, out of the plurality of cavities, include cavities greater than ones lying around the area.
    Type: Application
    Filed: April 22, 2005
    Publication date: October 27, 2005
    Applicant: TDK CORPORATION
    Inventors: Koji Mishima, Kenji Yamaga, Daisuke Yoshitoku
  • Publication number: 20050221158
    Abstract: A fuel cell is provided therein with a metal separator for aiming at preventing corrosion and at reducing a contact resistance. The separator is compose of conductive passage board formed therein with passages, and a metal planar panel, the passage boards and the metal planar panel being superposed with one another. The metal planar panel is formed therein with a plurality of manifolds for passing reactive gas or cooling medium through an adjacent cell while the passage boards are formed therein with a plurality of meandering through channels for distributing the reactive gas or the cooling medium from the manifolds. Further, a part of the meandering through channels is superposed with a part or all parts of the manifolds, and a covering layer for preventing the metal planar panel from being corroded, and for restraining a growth of a nonconductive film is formed over an entire part of the metal planar panel or over at least a part thereof which makes contact with the meandering through channels.
    Type: Application
    Filed: March 2, 2005
    Publication date: October 6, 2005
    Inventors: Hiroshi Yamauchi, Kenji Yamaga, Ko Takahashi
  • Publication number: 20050201264
    Abstract: An optical recording medium including a light transmitting layer having a uniform thickness formed on a substrate, in which a burr or stripping hardly occurs at the inner periphery of the light transmitting layer, and a manufacturing method and a manufacturing device of the optical recording medium are provided. An optical recording medium 10 is manufactured by a manufacturing method including: molding a disc-like shaped substrate 12 including an information recording face 12A on one side; forming a light transmitting layer 14 thinner than the substrate 12 on the information recording face 12A; forming a circular cut 16 in the light transmitting layer 14; and punching out an area inside the cut 16 by a punching tool 18 to form a center hole 14A in the light transmitting layer 14 and a center hole 20 in the substrate 12.
    Type: Application
    Filed: June 6, 2003
    Publication date: September 15, 2005
    Inventors: Tomoki Ushida, Mamoru Usami, Kenji Yamaga
  • Publication number: 20050174922
    Abstract: The invention relates to an optical head and an optical recording/reproducing apparatus for recording information in an optical recording medium or reproducing information recorded therein and a method of optical recording/reproduction utilizing the same. The invention provides an optical head and an optical recording/reproducing apparatus capable of reproducing an RF signal of high quality by eliminating a noise component superimposed on reflected light from a recording medium and a method of optical recording/reproduction utilizing the same. The optical head has an RF signal extraction circuit for extracting an RF signal including information recorded in a rotating recording medium.
    Type: Application
    Filed: February 2, 2005
    Publication date: August 11, 2005
    Applicant: TDK CORPORATION
    Inventors: Giichi Shibuya, Teiichiro Oka, Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga