Patents by Inventor Masako Inagawa

Masako Inagawa 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: 6324049
    Abstract: An electric double layer capacitor is formed by stacking one or a plurality of basic cells each having a pair of polarized electrodes, collectors, and a gasket unit. The polarized electrodes oppose each other via a separator made from a porous material soaked in a water-based electrolytic solution such as sulfuric acid. The collectors contact surfaces of the polarized electrodes away from surfaces in contact with the separator. The gasket unit is so arranged as to surround peripheral end faces of the polarized electrodes with a predetermined spacing therebetween. In this electric double layer capacitor, a peripheral portion of the separator projecting from the polarized electrode end faces is surrounded by another material.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: November 27, 2001
    Assignee: NEC Corporation
    Inventors: Masako Inagawa, Keitaro Katsu, Yoshiki Inoue
  • Patent number: 6168882
    Abstract: A seawater electric power system has a solar cell or wind generator for generating electromotive force, a battery including a plurality of electric double layer capacitors each having seawater therein as an electrolytic solution for storing the electric energy, a voltage regulator, and a seawater replenishment section for replenishing seawater into the electric double layer capacitors. A long term operation can be obtained by the seawater electric power system substantially without regular maintenance.
    Type: Grant
    Filed: August 18, 1998
    Date of Patent: January 2, 2001
    Assignee: NEC Corporation
    Inventors: Yoshiki Inoue, Masako Inagawa
  • Patent number: 6097587
    Abstract: In order to combine improved self discharge characteristics and high reliability under high temperatures, an electric double layer capacitor includes a unit cell or a plurality of stacked unit cells in which each unit cell has a porous separator impregnated with an electrolyte solution, a pair of polarizing electrodes provided on both sides of the porous separator, collectors provided in contact with the external surfaces of the polarizing electrodes, and a gasket provided to seal the electrolyte solution contacting the polarizing electrodes and the porous separator. The porous separator includes two porous separator elements that each have different porosities and that are laminated together.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: August 1, 2000
    Assignee: NEC Corporation
    Inventors: Masako Inagawa, Yoshiki Inoue
  • Patent number: 6046903
    Abstract: The present invention provides an electric double layer capacitor including: a gasket; a pair of collectors tightly fitted with the gasket to form a tightly sealed internal space; and polarizable electrodes with an electrolyte solution being accommodated in the tightly sealed inner space, wherein the gasket has at least a separation wall which separates the internal space into at least two sub-spaces, so that each of the sub-spaces accommodates a pair of the polarizable electrodes and the electrolyte solution.
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: April 4, 2000
    Assignee: NEC Corporation
    Inventors: Masako Inagawa, Yoshiki Inoue
  • Patent number: 6021039
    Abstract: An electric double-layer capacitor is provided, which prevents the apparent capacitance decrease on operation or use at a large discharge current. This capacitor includes at least one basic cell and a pair of external terminals electrically connected to ends of the at least one basic cell, respectively. Each of the at least one basic cell has a tubular electrically-insulating gasket having a tubular inner space and opening ends, a pair of polarizable electrodes placed in the inner space of the gasket, a porous separator sandwiched between the pair of electrodes and placed in the inner space of the gasket, and a pair of collectors placed to close the opening ends of the gasket, respectively. An electrolyte solution is stored in the inner space of the gasket. The solution is absorbed to the pair of electrodes. Each of the pair of electrodes has an inner surface contacted with an opposing surface of the separator and an outer surface contacted with a corresponding one of the pair of collectors.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: February 1, 2000
    Assignee: NEC Corporation
    Inventor: Masako Inagawa
  • Patent number: 5959830
    Abstract: A stack type electric double layer capacitor includes a plurality of unit cells, each with a pair of polarizing electrodes facing each other across a porous separator, a pair of current collecting members, and a gasket surrounding the electrodes and current collecting members. The gasket has a heat radiation notch in the direction parallel to or perpendicular to the stacking direction. This prevents heat from accumulating in the capacitor at the time of rapid charge and discharge, and thereby enhances the reliability of the capacitor.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: September 28, 1999
    Assignee: NEC Corporation
    Inventors: Masako Inagawa, Munekazu Aoki, Keitaro Katsu
  • Patent number: 5786981
    Abstract: A basic cell for an electric double layer capacitor has a pair of polarizing electrodes each including a plurality of chip electrodes arranged in matrix or honeycomb pattern. The plurality of chip electrodes are electrically connected by direct contact between each adjacent two chip electrodes for increasing the capacitance and decreasing the internal resistance. Excellent charging or discharging characteristic can be obtained even if the sheet collectors for providing charging or discharging current for the chip electrodes have different specific resistivities along the surface of the sheet collectors. The chip electrodes may be of a truncated pyramid shape for improving resistance against distorting or bending stress applied to the basic cell.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: July 28, 1998
    Assignee: NEC Corporation
    Inventors: Munekazu Aoki, Masako Inagawa, Keitaro Katsu
  • Patent number: 5781403
    Abstract: An electric double layer capacitor including a pair of activated charcoal electrodes facing each other with the intermediary of a porous separator, and current collecting members each being positioned on a surface of the respective electrode opposite to a surface contacting the separator is disclosed. Hydrophobic powdery activated charcoal is provided around the electrodes for adsorbing gases. With this arrangement, it is possible to prevent pressure inside the capacitor from being elevated by gases produced in the capacitor, thereby enhancing the reliability of the capacitor.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: July 14, 1998
    Assignee: NEC Corporation
    Inventors: Munekazu Aoki, Masako Inagawa, Keitaro Katsu
  • Patent number: 5568679
    Abstract: After forming a cavity in a laminated body of a plurality of piezoelectric ceramic films and internal electrodes, an insulator is formed on the end faces of the internal electrodes exposed on the wall surface of the cavity by electrophoretic process. According to this method, an insulator can be formed more inexpensively, in larger quantity, and with higher reliability than by the conventional method using a low pressure CVD method.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: October 29, 1996
    Assignee: NEC Corporation
    Inventors: Kazumasa Ohya, Masako Inagawa, Masahiro Miyauchi
  • Patent number: 5475278
    Abstract: A piezoelectric actuator is driven by continuously applying a pulse voltage or an AC voltage to a piezoelectric element, so as to cause the piezoelectric element to generate heat because of a dielectric loss of the piezoelectric element itself. If the temperature of the piezoelectric element reaches a temperature not less than 15.degree. C., moisture contained in atmosphere is effectively prevented from entering into a resin casing of the piezoelectric actuator enclosing therein the piezoelectric element. Otherwise, moisture condensation or sweating would occur on a surface of the piezoelectric element. Therefore, even if the piezoelectric actuator is used in atmosphere of high humidity, a discharge breakdown will not occur, and reliability is remarkably increased.
    Type: Grant
    Filed: March 30, 1994
    Date of Patent: December 12, 1995
    Assignee: NEC Corporation
    Inventors: Masako Inagawa, Sadayuki Takahashi, Koichi Morimoto, Satoru Tagami
  • Patent number: 5455477
    Abstract: A strain generating element for generating a strain in accordance with an externally provided driver voltage, a diaphragm secured to one end surface of the strain generating element and having a projecting portion, a case for encasing the strain generating element therein, a first coupler attached to the case, and a second coupler attached to the other end. A first coupler of a first piezoelectric actuator is connectable to a second coupler of a second piezoelectric actuator so that an elongation of the first actuator is transferred to the second actuator through a projecting portion of the first actuator to thereby add the elongation of the first actuator to an elongation of the second actuator in a uniform direction of elongation.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: October 3, 1995
    Assignee: NEC Corporation
    Inventors: Mitsunori Sano, Masako Inagawa