Patents Assigned to Sumitono Electric Inds., Ltd.
  • Process for producing optical fiber preform
    Patent number: 4414008
    Abstract: A process for producing a porous optical fiber preform by hydrolyzing a gaseous glass forming material with a flame from an oxyhydrogen burner and depositing the resulting soot in a rod form in a muffle furnace is described, wherein the muffle furnace is supplied with a gas other than that from the oxyhydrogen burner, and said gas is maintained at a constant temperature.
    Type: Grant
    Filed: December 11, 1981
    Date of Patent: November 8, 1983
    Assignees: Nippon Telegraph & Telephone Public Corporation, Sumitono Electric Inds., Ltd.
    Inventors: Takao Edahiro, Tetsuo Miyajiri, Hiroshi Yokota, Toru Kuwahara