Patents by Inventor Akio Kawana

Akio Kawana 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).

  • Single mode optical fibers
    Patent number: 4525027
    Abstract: In a single mode optical fiber comprising a core made of glass and a cladding surrounding the core and made of glass, when a difference .DELTA. between refractive indices n.sub.1 and n.sub.2 of the core and cladding is expressed by (n.sub.1 -n.sub.2)/(n.sub.1).times.100%, the refractive indices n.sub.1 and n.sub.2 are determined to satisfy a relation 1.0<.DELTA.<3.6 and a diameter of the core is determined according to this value of .DELTA..
    Type: Grant
    Filed: September 5, 1984
    Date of Patent: June 25, 1985
    Assignee: Nippon Telegraph & Telephone Public Corp.
    Inventors: Katsunari Okamoto, Takao Edahiro, Akio Kawana, Tetsuo Miya
  • Single mode optical fibers
    Patent number: 4372647
    Abstract: In a single mode optical fiber of the type comprising a core, a cladding surrounding the core and an intermediate layer, the refractive indices n1, n2 and n3 respectively of the core, the cladding and the intermediate layer are selected such that the following relations are satisfied0.5<.DELTA.1<1.5-0.3>.DELTA.2>-1.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: February 8, 1983
    Assignee: Nippon Telegraph & Telephone Public Corporation
    Inventors: Katsunari Okamoto, Takao Edahiro, Akio Kawana, Tetsuo Miya