Patents by Inventor Tohru Kikkawa

Tohru Kikkawa 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: 6069965
    Abstract: The loudspeaker includes: a frame; a magnetic circuit portion; a diaphragm transmitting air vibration; a cylindrical voice coil bobbin connected to the diaphragm; a voice coil fixed to an outer peripheral portion of the voice coil bobbin; and a damper holding the voice coil in such a manner that the voice coil is capable of vibrating in a magnetic gap formed between an annular top plate and a center pole included in the magnetic circuit portion. The damper includes a flat portion which has a hole for passing the voice coil bobbin therethrough at its center, and a plurality of roll structures connected to a periphery of the flat portion and having a cross-section including a bent periphery. Each of the plurality of roll structures is fixed to the frame, and the hole of the flat portion is fixed to an outer peripheral surface of the voice coil bobbin.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: May 30, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroyuki Takewa, Kazue Satoh, Mikio Iwasa, Tohru Kikkawa