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: 20050167869
    Abstract: An optical information medium includes a disk-shaped substrate (100) having a center hole (101), an annular information recording area thereon, and an annular resin-based light-transmitting layer (102) thereon by which recording/reading laser beam is transmitted to the information recording area. The light-transmitting layer (102) terminates at a radially inner periphery which forms an annular raised rim (6). The rim is effective for protecting the light-transmitting layer from damages and dust adhesion, and when a plurality of such media are stacked, preventing the media from intimate contact.
    Type: Application
    Filed: March 29, 2005
    Publication date: August 4, 2005
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Komaki, Kenji Yamaga, Hideki Hirata
  • Publication number: 20050164040
    Abstract: An optical recording medium comprising: a substrate 11; and a recording layer 12, formed on substrate 11; and characterized in that recording layer 12 contains palladium oxide as the main component and contains oxygen at an amount of 19 atom % to 61 atom %.
    Type: Application
    Filed: December 16, 2004
    Publication date: July 28, 2005
    Applicant: TDK CORPORATION
    Inventors: Daisuke Yoshitoku, Koji Mishima, Kenji Yamaga, Hitoshi Arai
  • Publication number: 20050118530
    Abstract: An optical recording medium includes a substrate, a light transmission layer and a recording layer formed between the substrate and the light transmission layer, the recording layer containing at least one simple substance of a metal element M selected from a group consisting of Zn and La and an element X selected from a group consisting of S and O which can combine with the metal element M to form a compound of the element X with the metal element M and the optical recording medium being constituted so that upon being irradiated with a laser beam for recording data, a crystal of the compound of the element X with the metal element M is formed and grows to form a crystal region thereof. According to the thus constituted optical recording medium, a reproduced signal having a good C/N ratio can be obtained when data recorded in the recording layer are reproduced.
    Type: Application
    Filed: September 30, 2004
    Publication date: June 2, 2005
    Applicant: TDK Corporation
    Inventors: Koji Mishima, Kenji Yamaga, Hiroyasu Inoue, Hironori Kakiuchi, Daisuke Yoshitoku, Hitoshi Arai
  • Patent number: 6898796
    Abstract: An optical information medium includes a disk-shaped substrate (100) having a center hole (101), an annular information recording area thereon, and an annular resin-based light-transmitting layer (102) thereon by which recording/reading laser beam is transmitted to the information recording area. The light-transmitting layer (102) terminates at a radially inner periphery which forms an annular raised rim (6). The rim is effective for protecting the light-transmitting layer from damages and dust adhesion, and when a plurality of such media are stacked, preventing the media from intimate contact.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: May 24, 2005
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Komaki, Kenji Yamaga, Hideki Hirata
  • Publication number: 20050106444
    Abstract: It is an object of the present invention to reduce contact resistance of a fuel cell cooling section of stamped metal and thereby to improve output capacity of the fuel cell. The present invention provides a fuel cell having a stack structure of several unit cells, each containing electrolyte membrane electrodes, gas diffusion layer provided on each side of the electrode and metallic separator having corrugated passages and coming into contact with each gas diffusion layer, and a separator for cooling provided in the stack structure, wherein the separator for cooling is provided with an elastic and/or compressive and electroconductive intermediate sheet held between the passage planes, and a gasket in the portion other than the passage plane.
    Type: Application
    Filed: February 26, 2004
    Publication date: May 19, 2005
    Inventors: Hiroshi Yamauchi, Kenji Yamaga, Ko Takahashi
  • Patent number: 6893764
    Abstract: An object of the present invention is to provide a highly durable solid polymer electrolyte that has a deterioration resistance equal to or higher than that of the fluorine-containing solid polymer electrolytes or a deterioration resistance sufficient for practical purposes, and can be produced at a low cost. According to the present invention, there is provided a solid polymer electrolyte comprising a polyether ether sulfone that is used as a electrolyte and has sulfoalkyl groups bonded to its aromatic rings and represented by the general formula —(CH2)n—SO3H.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: May 17, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Tohru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Publication number: 20050095771
    Abstract: An optical recording medium and a method for manufacturing the same, which offer to an information layer formed on a spacer layer the same electric characteristics such as a jitter and a noise as those of an information layer formed on a substrate, are provided. A convexo-concave pattern is transferred to a face of a spacer layer, which is opposite to the side of a substrate, so that a radial width of a convex portion is limited to be 53% or larger and 72% or smaller with respect to a radial pitch of concavity and convexity. A second information layer (information layer on the spacer layer) is formed in accordance with the convexo-concave pattern.
    Type: Application
    Filed: November 1, 2004
    Publication date: May 5, 2005
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Komaki, Kenji Yamaga
  • Publication number: 20050089747
    Abstract: It is an object of the present invention to simultaneously satisfy reduced separator thickness and pressure drop for power generation by a fuel cell. The present invention provides a fuel cell having two or more stacked units each containing a first separator in which a manifold and fuel gas passage section are formed, first seal sheet which seals the first separator periphery, membrane electrode assembly, second seal sheet which seals a second separator periphery and second separator in which a manifold and oxidizing gas passage section are formed, in this order, wherein each of the fuel gas passage section and oxidizing gas passage section is in communication with the corresponding manifold. Comb teeth structure having comb teeth are provided between the fuel gas passage section and manifold and between the oxidizing gas passage section and manifold in a diffusion layer on the membrane electrode assembly, wherein slits spaces formed between the comb teeth are in communication with the diffusion layer.
    Type: Application
    Filed: February 26, 2004
    Publication date: April 28, 2005
    Inventors: Kenji Yamaga, Hiroshi Yamauchi, Ko Takahashi
  • Publication number: 20050084731
    Abstract: The fuel cell assembly disclosed includes at least one unit fuel cell comprising a separator having flow channels for oxidizing gas, a cathode to which the oxidizing gas is fed, a membrane electrolyte of proton conductivity, an anode to which fuel gas is fed, and a separator having flow channels for the fuel gas, the above members being arranged in order. The fuel cell assembly further comprises a humidifier having a porous member to humidify at least the oxidizing gas to be fed to the anode. The porous member of the humidifier is so disposed as to face at least the flow channels for the oxidizing gas so that water is supplied to the flow channels from part of the surface of the porous member opposite to the water supplying face and/or from the outer periphery of the porous member.
    Type: Application
    Filed: October 16, 2003
    Publication date: April 21, 2005
    Inventors: Katsunori Nishimura, Jinichi Imahashi, Kenji Yamaga, Masahiro Komachiya, Makoto Morishima
  • Patent number: 6869713
    Abstract: To provide a compact power source best suited for portable use, which uses no separator and has no auxiliary equipment such as a fluid supply mechanism, and portable electronic equipment using the power source. A fuel cell, a fuel cell generator, and electric equipment using these have a construction such that the fuel cell, having an anode for oxidizing liquid fuel, a cathode for reducing oxygen, and an electrolyte membrane for insulating the anode from the cathode, has a construction of a hollow support, the anode, electrolyte membrane, and cathode are disposed on the outer peripheral surface of the hollow support to form a generator section, and the fuel is brought into contact with the inside of the hollow support and gas containing the oxygen is brought into contact with the outside of the generator section.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: March 22, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Tomoichi Kamo, Syuichi Oohara, Kenji Yamaga, Jinichi Imahashi, Masanori Yoshikawa, Norio Yamada
  • Publication number: 20050048250
    Abstract: A molding mold assembly is provided, for molding a mold substrate for an optical disc, to reduce an occurrence of burrs, etc. adversely affecting the optical disc and to improve accuracy of thickness of the optical disc made by the mold substrate. A substrate for an optical disc is provided that is capable of improving the accuracy of the thickness, as well as an optical disc with the improved accuracy of the thickness. The molding mold assembly is constructed such that a cavity for molding the mold substrate for the optical disc is configured, a stamper for transferring a hyperfine pattern onto the mold substrate is attached to the mold assembly so that a vicinal part of an innermost periphery portion of the stamper protrudes towards the cavity, and a face formed by a mold member configuring an inner peripheral portion of the mold substrate is substantially flush with an information area face on which the hyperfine pattern has been transferred.
    Type: Application
    Filed: August 25, 2004
    Publication date: March 3, 2005
    Applicant: TDK Corporation
    Inventors: Kenji Yamaga, Tsuyoshi Komaki
  • Publication number: 20050042371
    Abstract: A method for manufacturing an optical disc by forming at least one recording layer on a substrate with a temporary center hole and then forming a light transmitting layer on the recording layer includes a step of covering the lower end of the temporary center hole, a step of providing droplets containing a material for forming the light transmitting layer into the resulting temporary center hole, and a step of subjecting the material for forming the light transmitting layer to a spin coating process. In the method, the lower end of the temporary center hole is covered with a sealing member. An apparatus for manufacturing an optical disc by the method includes retaining sections for retaining the substrate, an affixing section for covering the lower end of the temporary center hole, and a spinner plate.
    Type: Application
    Filed: August 17, 2004
    Publication date: February 24, 2005
    Applicant: TDK Corporation
    Inventors: Tomoki Ushida, Kenji Yamaga
  • Publication number: 20050034617
    Abstract: A stamper for forming a data recording region on a recording medium substrate by means of a transfer surface thereof. The transfer surface transfers a predetermined set of data to the recording medium substrate. The stamper is fitted on at least one of metal molds that are arranged opposite one another for forming the recording medium substrate. The stamper includes a stepped portion formed as bends in the material of the stamper. The stepped portion is configured to project from the transfer surface toward the recording medium substrate.
    Type: Application
    Filed: September 30, 2004
    Publication date: February 17, 2005
    Applicant: TDK Corporation
    Inventors: Yuuichi Kawaguchi, Kenji Yamaga, Hiroaki Takahata, Hisaji Oyake, Yoshimi Sakai
  • Publication number: 20050031930
    Abstract: An object of the present invention is to provide a highly durable solid polymer electrolyte that has a deterioration resistance equal to or higher than that of the fluorine-containing solid polymer electrolytes or a deterioration resistance sufficient for practical purposes, and can be produced at a low cost. According to the present invention, there is provided a solid polymer electrolyte comprising a polyether ether sulfone that is used as an electrolyte and has sulfoalkyl groups bonded to its aromatic rings and represented by the general formula —(CH2)n—SO3H.
    Type: Application
    Filed: August 19, 2004
    Publication date: February 10, 2005
    Inventors: Tohru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Publication number: 20050022224
    Abstract: A surface treatment of a light transmissive layer by spin coating is carried out in a simple way at low cost. When a light transmissive layer is to be formed by spin coating, the transfer of an information recording layer is carried out using a resin stamper having a convex portion in an outer peripheral portion. At the same time, an inclined plane (concave portion) is formed on the side of a substrate (member on which transfer is performed). As a result, coating is achieved in such a manner that a raise in the outer peripheral portion is prevented from being noticeable.
    Type: Application
    Filed: August 21, 2002
    Publication date: January 27, 2005
    Inventors: Kenji Yamaga, Tsuyoshi Komaki, Kazuki Suzawa
  • Publication number: 20050007945
    Abstract: A disc-shaped optical recording medium formed by carrying out a film formation process on a disc-shaped substrate material and completed by forming a center hole at the last step is manufactured in a manner such that no eccentricity will occur when the recording medium is loaded onto a drive. At the last step of an optical disc manufacturing process, i.e., at the time of opening a hole in the center part 26 of the disc-shaped substrate material 12 formed with at least a resin layer on one side thereof, the center part 26 is removed in a manner such that the diameter of the chucking center hole 28 is larger on the disc-shaped substrate material 12 side than on the light transmitting resin layer 22 side of the disc-shaped optical recording medium 30, thereby manufacturing the disc-shaped optical recording medium 30.
    Type: Application
    Filed: January 17, 2003
    Publication date: January 13, 2005
    Inventors: Mamoru Usami, Tomoki Ushida, Kenji Yamaga, Yoshimi Sakai
  • Patent number: 6835435
    Abstract: A stamper for forming a data recording region on a recording medium substrate by means of a transfer surface thereof. The transfer surface transfers a predetermined set of data to the recording medium substrate. The stamper is fitted on at least one of metal molds that are arranged opposite one another for forming the recording medium substrate. The stamper includes a stepped portion formed as bends in the material of the stamper. The stepped portion is configured to project from the transfer surface toward the recording medium substrate.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: December 28, 2004
    Assignee: TDK Corporation
    Inventors: Yuuichi Kawaguchi, Kenji Yamaga, Hiroaki Takahata, Hisaji Oyake, Yoshimi Sakai
  • Publication number: 20040257970
    Abstract: A conventional mechanical precision measuring device is used effectively in the measurement of the eccentricity of a high density optical disc. A DVR optical disc 2 comprises a pattern 4 of fine depressions and protrusions conformed to the intended format of the disc (a first depressions and protrusions: pits and/or grooves) formed within an information recording area 6 of the disc, as well as a pattern 8 of fine depressions and protrusions for measuring the eccentricity (a second depressions and protrusions), which is formed in an area other than the information recording area 6, and is formed in accordance with a CD format having lower recording density than that of the format defined for the DVR optical disc 2. By using this pattern 8 of fine depressions and protrusions for mechanical detection, conventional mechanical precision measuring devices designed for the CD family can be used as it is, for measuring the eccentricity (mechanical precision) of the DVR optical disc 2.
    Type: Application
    Filed: April 22, 2004
    Publication date: December 23, 2004
    Inventors: Kenji Yamaga, Hideki Hirata
  • Publication number: 20040241377
    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 a polyether imide resin.
    Type: Application
    Filed: May 27, 2004
    Publication date: December 2, 2004
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Komaki, Kenji Yamaga, Takashi Yamada
  • Publication number: 20040241378
    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: Application
    Filed: May 27, 2004
    Publication date: December 2, 2004
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Komaki, Kenji Yamaga, Takashi Yamada