Patents by Inventor Akihiko Yoshida

Akihiko Yoshida 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: 20060229194
    Abstract: The present invention provides a polymer electrolyte fuel cell having an increased reaction area by forming a gas channel, a proton channel and an electron channel very close to each other inside a catalyst layer. This polymer electrolyte fuel cell includes a hydrogen ion conductive polymer electrolyte membrane; and a pair of electrodes having catalyst layers sandwiching the hydrogen ion conductive polymer electrolyte membrane between them and gas diffusion layers in contact with the catalyst layers, in which the catalyst layer of at least one of the electrodes comprises carbon particles supporting a noble metal catalyst, and the carbon particles include at least two kinds of carbon particles adsorbing a hydrogen ion conductive polymer electrolyte in mutually different dispersed states.
    Type: Application
    Filed: June 20, 2006
    Publication date: October 12, 2006
    Inventors: Makoto Uchida, Yasushi Sugawara, Eiichi Yasumoto, Akihiko Yoshida, Junji Morita, Masao Yamamoto, Shinya Kosako, Osamu Sakai, Yoshihiro Hori
  • Publication number: 20060221963
    Abstract: A master station surely and quickly transmits identical information to plural terminals while controlling consumption of a transmission capacity. First, the master station determines the number of times of multicast transmission from the master station to slave stations. The master station notifies the slave stations of the number of times of multicast transmission determined. Subsequently, the master station transmits information to the slave stations in multicast the determined number of times of multicast transmission. After receiving the information from the master station the number of times of multicast transmission notified, a slave station identifies lacking information in information to be received. The slave station transmits an identifier of the lacking information to the master station. The master station receives the identifier of the lacking information from the slave station and retransmits information corresponding to the identifier of the lacking information to the slave station in unicast.
    Type: Application
    Filed: February 14, 2006
    Publication date: October 5, 2006
    Inventors: Daigo Takayanagi, Shiro Mazawa, Yosuke Takahashi, Akihiko Yoshida
  • Patent number: 7097932
    Abstract: A polymer electrolyte fuel cell is provided comprising: a hydrogen ion conductive polymer electrolyte membrane; an anode and a cathode sandwiching the hydrogen ion conductive polymer electrolyte membrane; an anode side electroconductive separator having a gas channel for supplying a fuel gas to the anode; a cathode side electroconductive separator having a gas channel for supplying an oxidant gas to the cathode; characterized in that the anode and the cathode comprise a gas diffusion layer and a catalyst layer formed on the gas diffusion layer at the side in contact with the hydrogen ion conductive polymer electrolyte membrane, the catalyst layer has catalyst particles and a hydrogen ion conductive polymer electrolyte, and at least either of hydrogen ion conductivity and gas permeability of at least either of the anode and the cathode varies in a thickness direction of the anode or the cathode.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: August 29, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Osamu Sakai, Hisaaki Gyoten, Hiroki Kusakabe, Eiichi Yasumoto, Yasushi Sugawara, Teruhisa Kanbara, Akihiko Yoshida, Makoto Uchida, Junji Morita
  • Patent number: 7060384
    Abstract: A porous supporting carbon body of a gas diffusion layer is provided with a larger number of smaller pores at its catalyst layer side and a smaller number of larger pores at the other side, particularly with an appropriate distribution of finer mesh at its catalyst layer side and coarser mesh at the other side. As a result, a high performance polymer electrolyte fuel cell is obtained in which water generated at the catalyst layer is quickly sucked out to the gas diffusion layer, and is evaporated at the gas diffusion layer to be effectively exhausted to outside the fuel cell, so that excessive water can be prevented from retaining in the gas diffusion electrode, with the polymer electrolyte membrane being maintained at an appropriately wet condition.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: June 13, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akihiko Yoshida, Masao Yamamoto, Junji Niikura, Yasuo Takebe, Osamu Sakai, Makoto Uchida
  • Patent number: 6991870
    Abstract: It has been difficult to keep the voltage of a polymer electrolyte fuel cell stable for a long period of time because uniform water content control over the plane of the membrane-electrode assembly is impossible. A gas diffusion electrode is produced by forming a conductive polymer layer composed of conductive particles and a polymer material on a porous material composed of carbon fiber, and forming a catalyst layer composed of platinum-carried carbon particles on the plane of the conductive polymer layer. The conductive polymer layer is composed of conductive particles different in particle size, and the content of the conductive particles having the smaller particle size is decreased from one end towards the other end of the gas diffusion electrode.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: January 31, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Eiichi Yasumoto, Akihiko Yoshida, Makoto Uchida, Junji Morita, Yasushi Sugawara, Hisaaki Gyoten, Masao Yamamoto, Osamu Sakai, Junji Niikura
  • Publication number: 20050288025
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Application
    Filed: January 19, 2005
    Publication date: December 29, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20050227132
    Abstract: To provide a polymer electrolyte membrane having excellent size stability and excellent mechanical strength that can sufficiently prevent the size change due to the swelling condition, the displacement of the polymer electrolyte membrane and the formation of wrinkles during the production of the polymer electrolyte fuel cell, and can prevent damage during the production and operation of the polymer electrolyte fuel cell. In a composite electrolyte membrane including a porous reinforcement layer made of a resin and an electrolyte layer made of a polymer electrolyte and laminated at least one main surface of the reinforcement layer, the direction having a high tensile modulus of elasticity in the reinforcement layer is substantially corresponded with the direction having a high rate of size change in the electrolyte layer.
    Type: Application
    Filed: March 4, 2005
    Publication date: October 13, 2005
    Inventors: Yoshihiro Hori, Akihiko Yoshida, Mikiko Yoshimura, Makoto Uchida
  • Publication number: 20050214630
    Abstract: To provide a gas diffusion layer excellent in micro short-circuit resistance and anti-flooding characteristics by optimizing the surface shape of a gas diffusion layer. In a gas diffusion layer for a gas diffusion electrode including at least a catalyst layer containing an electrode catalyst and a gas diffusion layer having electron conductivity and gas diffusibility, a second surface of the gas diffusion layer, which is positioned opposite to a first surface thereof to be in contact with the catalyst layer, is made rougher than the first surface. The first surface has a maximum height Ry1 of 10 to 50 determined by JIS B 0601 surface roughness measurement method, and the second surface has a maximum height Ry2 of 100 to 500 determined by JIS B 0601 surface roughness measurement method.
    Type: Application
    Filed: February 23, 2005
    Publication date: September 29, 2005
    Inventors: Akihiko Yoshida, Masaki Yamauchi, Yoshihiro Hori, Makoto Uchida
  • Publication number: 20050214610
    Abstract: An object of the present invention is to provide a catalyst-coated membrane suitable for achieving a polymer electrolyte fuel cell that sufficiently prevents a decrease in the initial characteristics and also exhibits sufficient cell performance for a long period of time and has excellent durability. In at least the cathode catalyst layer, the ratio (WP/WCat-C) of the weight of the polymer electrolyte (WP) to the weight of the catalyst-carrying carbon (WCat-C) is decreased from an innermost layer positioned closest to the polymer electrolyte membrane toward an outermost layer positioned farthest from the polymer electrolyte membrane. The ratio (WP/WCat-C) in the innermost layer is 0.8 to 3.0, and the ratio (WP/WCat-C) in the outermost layer is 0.2 to 0.6.
    Type: Application
    Filed: January 26, 2005
    Publication date: September 29, 2005
    Inventors: Mikiko Yoshimura, Yoshihiro Hori, Yoichiro Tsuji, Akihiko Yoshida, Takeshi Yonamine, Makoto Uchida
  • Publication number: 20050214599
    Abstract: A polymer electrolyte fuel cell is provided comprising: a hydrogen ion conductive polymer electrolyte membrane; an anode and a cathode sandwiching the hydrogen ion conductive polymer electrolyte membrane; an anode side electroconductive separator having a gas channel for supplying a fuel gas to the anode; a cathode side electroconductive separator having a gas channel for supplying an oxidant gas to the cathode; characterized in that the anode and the cathode comprise a gas diffusion layer and a catalyst layer formed on the gas diffusion layer at the side in contact with the hydrogen ion conductive polymer electrolyte membrane, the catalyst layer has catalyst particles and a hydrogen ion conductive polymer electrolyte, and at least either of hydrogen ion conductivity and gas permeability of at least either of the anode and the cathode varies in a thickness direction of the anode or the cathode.
    Type: Application
    Filed: May 26, 2005
    Publication date: September 29, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Osamu Sakai, Hisaaki Gyoten, Hiroki Kusakabe, Eiichi Yasumoto, Yasushi Sugawara, Teruhisa Kanbara, Akihiko Yoshida, Makoto Uchida, Junji Morita
  • Publication number: 20050197246
    Abstract: The present invention provides a gas diffusion layer for a fuel cell which has proper rigidity, is easy to handle and contributes to the improvement of the productivity of fuel cells. A method for producing a gas diffusion layer for a fuel cell including a first step of: impregnating a conductive porous substrate made of a conductive carbon fiber cloth or conductive carbon fiber felt with a first dispersion containing a first fluorocarbon resin having thermoplasticity; and baking the first conductive porous substrate at a first baking temperature of not less than the melting point of the first fluorocarbon resin and less than the decomposition temperature of the first fluorocarbon resin to enhance the rigidity of the conductive porous substrate.
    Type: Application
    Filed: December 3, 2004
    Publication date: September 8, 2005
    Inventors: Akihiko Yoshida, Yoichiro Tsuji, Masaki Yamauchi, Yoshihiro Hori, Makoto Uchida, Hisaaki Gyoten, Teruhisa Kanbara
  • Publication number: 20050151732
    Abstract: Detailed model data having numerous polygons and rough model data having fewer polygons are prepared for one object. A rectangular parallelepiped including the entire object is defined as a bounding box. A virtual three-dimensional space is perspective-transformed to divide an image-drawing field, which is an image drawing range, into a far image-drawing field and a near image-drawing field according to a distance from a viewpoint of virtual camera. When at least a part of the bounding box is included in the far image-drawing field, polygons of rough model data included in the far image-drawing field are drawn in a frame buffer. When at least a part of the bounding box is included in the near image-drawing field, polygons of detailed model data included in the near image-drawing field are drawn in a frame buffer.
    Type: Application
    Filed: December 15, 2004
    Publication date: July 14, 2005
    Applicant: KABUSHIKI KAISHA SQUARE ENIX ( also trading as SQUARE ENIX CO., LTD.)
    Inventors: Akihiro Yamaguchi, Akihiko Yoshida
  • Publication number: 20050142430
    Abstract: By using a gas diffusion layer for a fuel cell comprising a fabric comprising a warp thread and a weft thread which are made of carbon fiber, wherein the distance X between adjacent intersections where the warp and weft threads cross each other and the thickness Y of the fabric satisfy the equation: 1.4?X/Y?3.5, the present invention reduces the surface asperities of the substrate and prevents a micro short-circuit resulting from the piercing of the polymer electrolyte membrane of the fuel cell by the carbon fibers of the fabric so as to improve the characteristics of the fuel cell.
    Type: Application
    Filed: March 25, 2003
    Publication date: June 30, 2005
    Inventors: Akihiko Yoshida, Yoshihiro Hori, Makoto Uchida, Eiichi Yasumoto, Yasuo Takebe, Osamu Sakai, Shinya Kosako, Takeshi Yonamine, Masaki Yamauchi, Yasushi Sugawara, Junji Morita
  • Publication number: 20050128996
    Abstract: In order to realize such communication control as to reliably reconstruct communication information transmitted from a plurality of ANs at a plurality of ATs even when a BCMCS flow is added or deleted, a radio communication system includes a transmitter for transmitting control information necessary for the ATs to receive the communication information from a radio communication system at intervals of a predetermined period, and a controller for controlling to transmit a plurality of pieces of communication information to the ATs at intervals of a constant cycle and in synchronism with a transmission period of the control information.
    Type: Application
    Filed: November 4, 2004
    Publication date: June 16, 2005
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Patent number: 6818339
    Abstract: The present specification discloses a polymer electrolyte fuel cell characterized in that each of the cathode and the anode comprises catalyst particles, a hydrogen ion-conductive polymer electrode, a conductive porous base material and a water repellent agent, and water repellency of at least one of the cathode and the anode varies in a direction of thickness or in a plane direction. As such, by varying the degree of the water repellency of the cathode and the anode on the basis of a position, an excellent polymer electrolyte fuel cell having a high discharge characteristic or more specifically a high current-voltage characteristic in a high current density range.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: November 16, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasushi Sugawara, Hisaaki Gyoten, Makoto Uchida, Eiichi Yasumoto, Teruhisa Kanbara, Junji Morita, Yoshihiro Hori, Akihiko Yoshida, Hidenobu Wakita, Hiroki Kusakabe, Masato Hosaka, Osamu Sakai
  • Publication number: 20040131920
    Abstract: A carbon fiber woven fabric for use as a gas diffusion layer base material in a polymer electrolyte fuel cell has a surface that is smoothed and further optimized to inhibit non-uniform infiltration of a coating for water-repellent-layer formation, to provide an electrolyte membrane-electrode assembly suitable for operation under a high humidification condition. The gas diffusion layer base material may be a carbon fiber woven fabric, wherein a ratio of the area of gap portions where neither warp thread nor weft thread exists: (10/W−Y)(10/Z−X) to the area of portions where warp thread is crossing weft thread: XY mm2 is in the range of about {fraction (1/1500)} to about ⅕, where the carbon fiber woven fabric has a warp density of Z threads/cm, a weft density of W threads/cm, a warp thickness of X mm and a weft thickness of Y mm.
    Type: Application
    Filed: December 9, 2003
    Publication date: July 8, 2004
    Inventors: Akihiko Yoshida, Yoshihiro Hori, Osamu Sakai, Makoto Uchida, Eiichi Yasumoto, Shinya Kosako
  • Publication number: 20040131919
    Abstract: In a polymer electrolyte fuel cell including a hydrogen ion conductive polymer electrolyte membrane; a pair of electrodes composed of catalyst layers sandwiching the hydrogen ion conductive polymer electrolyte membrane between them and gas diffusion layers in contact with the catalyst layers; a conductive separator plate having a gas flow channel for supplying a fuel gas to one of the electrodes; and a conductive separator plate having a gas flow channel for supplying an oxidant gas to the other electrode, in order to bring a hydrogen ion conductive polymer electrolyte and a catalyst metal of the catalyst layers containing the hydrogen ion conductive polymer electrolyte and conductive carbon particles carrying the catalyst metal sufficiently and uniformly into contact with each other, the polymer electrolyte is provided in pores of an agglomerate structure of the conductive carbon particles. Consequently, the reaction area inside the electrodes is increased, and higher performance is exhibited.
    Type: Application
    Filed: January 3, 2003
    Publication date: July 8, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Eiichi Yasumoto, Akihiko Yoshida, Makoto Uchida, Hisaaki Gyoten, Kazuhito Hatoh, Yasushi Sugawara, Junji Morita, Teruhisa Kanbara, Yasuo Takebe, Masato Hosaka, Junji Niikura
  • Publication number: 20040009389
    Abstract: An electrode material, particularly a gas diffusion layer, for a fuel cell is provided which prevents electrode exfoliation during the manufacturing process by optimizing a water repellent material incorporated in the gas diffusion layer. The resulting electrode made from the gas diffusion layer has a high discharge performance at a low cost. This gas diffusion layer contacts a catalyst layer to form an electrode of the fuel cell layer, and the catalyst layer in turn contacts a polymer electrolyte membrane of the fuel cell. The gas diffusion layer contains a fibrillatable, water repellent material, and is subjected to heat treatment below the melting point of the water repellent material to fibrillate the material.
    Type: Application
    Filed: April 30, 2003
    Publication date: January 15, 2004
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Osamu Sakai, Junji Niikura, Teruhisa Kanbara, Masao Yamamoto, Akihiko Yoshida, Makoto Uchida, Eiichi Yasumoto, Junji Morita, Yasushi Sugawara
  • Publication number: 20030198860
    Abstract: A polymer electrolyte fuel cell comprising: a hydrogen ion-conductive polymer electrolyte membrane; an anode and a cathode with the electrolyte membrane interposed therebetween; an anode-side conductive separator having a gas flow channel for supply of a fuel gas to the anode; and a cathode-side conductive separator having a gas flow channel for supply of an oxidant gas to the cathode, wherein each of the anode and the cathode comprises at least a catalyst layer in contact with the electrolyte membrane and a gas diffusion layer in contact with the catalyst layer and the separator, and at least one of the anode and the cathode contains a compound represented by the formula (I):
    Type: Application
    Filed: February 26, 2003
    Publication date: October 23, 2003
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Eiichi Yasumoto, Akihiko Yoshida, Makoto Uchida, Junji Morita, Yasushi Sugawara, Teruhisa Kanbara
  • Publication number: 20030175579
    Abstract: To improve the performance of a catalyst layer of a fuel cell electrode, the weight ratio of a hydrogen ion conductive polymer electrolyte and electroconductive carbon particles in the catalyst layer is controlled to satisfy the formula (1): Y=a·logX−b+c, where log represents natural logarithm, X represents the specific surface area of the electroconductive carbon particles (m2/g), Y=(the weight of the hydrogen ion conductive polymer electrolyte)/(the weight of the electroconductive carbon particles), a=0.216, c=±0.300, b=0.421 at an air electrode and b=0.221 at an fuel electrode.
    Type: Application
    Filed: February 14, 2003
    Publication date: September 18, 2003
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Makoto Uchida, Eiichi Yasumoto, Akihiko Yoshida, Yasushi Sugawara, Osamu Sakai, Kazuhito Hatoh, Junji Niikura, Masato Hosaka, Teruhisa Kanbara, Takeshi Yonamine, Yasuo Takebe, Yoshihiro Hori, Hisaaki Gyoten, Hiroki Kusakabe