Patents Assigned to Nippan Kenkyujo Co., Ltd.
  • Speaker voice coil bobbin and method of manufacturing same
    Patent number: 6909788
    Abstract: A voice coil bobbin 1 is formed from a material combining a fiber-type material and a ceramic-type-coating agent including metal alkoxide, metal hydroxide, and a colloidal or fine-particulate inorganic substance. The combining process for the ceramic-type-coating agent is performed before or after the fiber-type material is formed into a shape of the voice coil bobbin 1.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: June 21, 2005
    Assignees: Pioneer Corporation, Tohoku Pioneer Corporation, Nippan Kenkyujo Co., Ltd.
    Inventors: Toshihiro Ishigaki, Tomoyuki Shimada
  • Speaker diaphragm and method of manufacturing same
    Patent number: 6740202
    Abstract: A speaker diaphragm is formed from a material combining a fiber-type material and a ceramic-type-coating agent including metal alkoxide, metal hydroxide, and a colloidal or fine-particulate inorganic substance. The combining process for the ceramic-type-coating agent is performed before or after the fiber-type material is formed into a shape of the diaphragm.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: May 25, 2004
    Assignees: Pioneer Corporation, Tohoku Pioneer Corporation, Nippan Kenkyujo Co., Ltd.
    Inventors: Toshihiro Ishigaki, Hideo Sekikawa, Koji Maekawa, Tomoyuki Shimada