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: 20090291348
    Abstract: The present invention provides an electrolyte membrane with high proton conductivity and low methanol permeability, a high output MEA and DMFC. The electrolyte membrane is characterized by comprising a metal oxide hydrate having proton conductivity and an organic polymer having proton conductivity. A preferable metal oxide hydrate is zirconium oxide hydrate or tungsten oxide hydrate. The composite electrolyte membrane has an ion exchange capacity of 0.75 to 1.67 meq/g as a preferable range. The composite electrolyte membrane constituted by the metal oxide hydrate and the organic polymer is provided with high proton conductivity and low methanol permeability so that MEA for DMFC with high output is provided.
    Type: Application
    Filed: December 14, 2004
    Publication date: November 26, 2009
    Inventors: Takayuki Hirashige, Tomoichi Kamo, Kenji Yamaga
  • Patent number: 7560185
    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 “n” 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: July 8, 2005
    Date of Patent: July 14, 2009
    Assignee: Hitachi, Ltd
    Inventors: Toru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Patent number: 7553574
    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 “n” 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: July 8, 2005
    Date of Patent: June 30, 2009
    Assignee: Hitachi, Ltd
    Inventors: Toru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Patent number: 7541107
    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: Grant
    Filed: August 19, 2004
    Date of Patent: June 2, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Tohru Koyama, Toshiyuki Kobayashi, Kenji Yamaga, Tomoichi Kamo, Kazutoshi Higashiyama
  • Patent number: 7524548
    Abstract: The optical recording medium is an optical recording medium having at least one information layer including a recording film, characterized in that the recording film is formed by a phase change material including at least Sb, Ge and Mg as main components.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: April 28, 2009
    Assignee: TDK Corporation
    Inventors: Hiroshi Shingai, Hironori Kakiuchi, Hideaki Miura, Kenji Yamaga
  • Patent number: 7517574
    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: Grant
    Filed: September 23, 2005
    Date of Patent: April 14, 2009
    Assignee: TDK Corporation
    Inventors: Daisuke Yoshitoku, Koji Mishima, Kenji Yamaga
  • Publication number: 20090081524
    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: November 24, 2008
    Publication date: March 26, 2009
    Inventors: Hiroshi Yamauchi, Kenji Yamaga, Ko Takahashi
  • Patent number: 7507457
    Abstract: An optical recording medium includes a support substrate, and a light transmission layer 12 that is disposed so as to come in contact with the support substrate. At least one of a refractive index of the support substrate and a refractive index of the light transmission layer, and an extinction coefficient of the support substrate and an extinction coefficient of the light transmission layer is different. As such, according to the invention, a reflective layer is not formed between the support substrate and the light transmission layer, such that the support substrate and the light transmission layer 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 and the light transmission layer. Therefore, data held by a plurality of pits, that are arranged on the support substrate in a spiral shape or a concentric shape, can be correctly read out.
    Type: Grant
    Filed: June 1, 2005
    Date of Patent: March 24, 2009
    Assignee: TDK Corporation
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Patent number: 7502309
    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: Grant
    Filed: November 1, 2004
    Date of Patent: March 10, 2009
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Komaki, Kenji Yamaga
  • Patent number: 7458088
    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: Grant
    Filed: July 2, 2003
    Date of Patent: November 25, 2008
    Assignee: TDK Corporation
    Inventors: Junichi Ide, Mamoru Usami, Tomoki Ushida, Kenji Yamaga, Atsushi Koyama
  • Patent number: 7447139
    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: Grant
    Filed: April 4, 2005
    Date of Patent: November 4, 2008
    Assignee: TDK Corporation
    Inventors: Giichi Shibuya, Teiichiro Oka, Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Patent number: 7399511
    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 to the total number of Bi and O atoms in the recording layer is 63-73%.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: July 15, 2008
    Assignee: TDK Corporation
    Inventors: Koji Mishima, Daisuke Yoshitoku, Kenji Yamaga
  • Publication number: 20080166610
    Abstract: An object of the present invention is to provide a polymer electrolyte fuel cell capable of producing a high output without causing a drop or instability of the cell voltage of the fuel cell and a generating system having the polymer electrolyte fuel cell mounted thereon.
    Type: Application
    Filed: October 25, 2007
    Publication date: July 10, 2008
    Inventors: Katsunori Nishimura, Hironori Sasaki, Kenji Yamaga
  • Patent number: 7385911
    Abstract: In an information recording medium according to the present invention, a recording layer, a first layer, and a second layer are formed so that a thermal conductivity of the first layer that contacts one surface of the recording layer and a thermal conductivity of the second layer that contacts another surface of the recording layer are both lower than a thermal conductivity of the recording layer and a track pitch is in a range of 0.1 ?m to 0.5 ?m, inclusive.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: June 10, 2008
    Assignee: TDK Corporation
    Inventors: Daisuke Yoshitoku, Koji Mishima, Kenji Yamaga, Tsuyoshi Komaki, Shigeru Yamatsu
  • Patent number: 7368156
    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: Grant
    Filed: January 17, 2003
    Date of Patent: May 6, 2008
    Assignee: TDK Corporation
    Inventors: Mamoru Usami, Tomoki Ushida, Kenji Yamaga, Yoshimi Sakai
  • Patent number: 7357970
    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: Grant
    Filed: December 16, 2004
    Date of Patent: April 15, 2008
    Assignee: TDK Corporation
    Inventors: Daisuke Yoshitoku, Koji Mishima, Kenji Yamaga, Hitoshi Arai
  • Publication number: 20080081235
    Abstract: A fuel cell system having a fuel cell 1, a load 8 connected to the output line of the fuel cell 1 and a control apparatus 20 for controlling an amount of current flowing to the load 8, wherein a stopping state for stopping the fuel cell system includes a first stage stopping state for stopping while remaining hydrogen in the hydrogen line and a second stage stopping state for stopping substituting the hydrogen line with air, and transfers to the second stage stopping state by way of the first stage stopping state.
    Type: Application
    Filed: January 26, 2007
    Publication date: April 3, 2008
    Inventors: Kenji Yamaga, Hironori Sasaki, Katsunori Nishimura
  • Publication number: 20080081242
    Abstract: A separator for fuel cell comprising an electrolyte with ionic conductivity, a pair of electrodes with the electrolyte sandwiched therebetween, and a separator 10 for individually supplying a fuel gas and an oxidizing agent gas to the pair of the electrodes, respectively, wherein the separator 10 is provided with a multilayered metal sheet with at least the outermost layer thereof, and a corrosion-resistant film covering the whole surface of the metal sheet in order to form a metal separator, and the metal separator is further provided with a reacting gas sealing unit 21, a reacting gas manifold junction unit 22, and a reacting gas rectification unit 23, formed of an elastic body.
    Type: Application
    Filed: January 25, 2007
    Publication date: April 3, 2008
    Inventors: Hironori Sasaki, Kenji Yamaga, Katsunori Nishimura
  • Patent number: 7320841
    Abstract: Disclosed is 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: Grant
    Filed: February 26, 2004
    Date of Patent: January 22, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Yamaga, Hiroshi Yamauchi, Ko Takahashi
  • Patent number: 7283457
    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: Grant
    Filed: October 21, 2002
    Date of Patent: October 16, 2007
    Assignee: TDK Corporation
    Inventors: Kenji Yamaga, Hideki Hirata