Patents by Inventor Nobuaki Ban

Nobuaki Ban 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).

  • Loudspeaker device
    Patent number: 4139075
    Abstract: A loudspeaker device comprises a bass reflexing duct formed on an enclosure on which the loudspeaker unit is provided, a passive radiator provided on the enclosure; an acoustic impedance body provided between at least one of the duct and passive radiator and the loudspeaker unit, so that the resonance frequencies of the duct and the passive radiator are different from each other thereby to markedly improve the low acoustic compass characteristic thereof.
    Type: Grant
    Filed: August 25, 1977
    Date of Patent: February 13, 1979
    Assignee: Sansui Electric Co., Ltd.
    Inventors: Fumio Kobayashi, Nobuaki Ban