Patents Assigned to Daikin Trade & Industry Co., Ltd.
  • Magnetic speaker
    Patent number: 4699242
    Abstract: A magnetic speaker equipped with a flat diaphragm comprising a straight-grain wood plate or a cross-grain wood plate, for instance, made of Sitka spruce having the specific gravity range from 0.25 to 0.8, presenting excellent acoustic properties, especially, suitable for low to medium frequency speakers. The flat diaphragm is treated to chemically modify hydroxyl groups contained in the wooden component. Modification may be by esterification, etherification, acetilation, formalinization, or the like to enhance acoustical characteristics.
    Type: Grant
    Filed: December 27, 1985
    Date of Patent: October 13, 1987
    Assignees: Daikin Trade & Industry Co., Ltd., Chubu Cone Co., Ltd.
    Inventor: Teruaki Ono