Patents by Inventor Yasushi Ikuta

Yasushi Ikuta 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: 4842359
    Abstract: An optical star coupler having a biconically tapered optical star coupler suspensively inserted in a protection tube and the method for manufacturing the same are disclosed, and the manufacturing method is that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protection tube are sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, naturally in the case of an optical star coupler using multi-mode optical fiber, particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing cost.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: June 27, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Katsuyuki Imoto, Minoru Maeda, Masayoshi Kameyama, Yasushi Ikuta, Hiroshi Araki, Shigeru Oho
  • Patent number: 4726643
    Abstract: An optical star coupler having a biconically tapered optical star coupler inserted and suspended in a protection tube and the method for manufacturing the same are disclosed. The manufacturing method provides that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby forming a twisting, fusing and pulling portion. Both ends of the protection tube are then sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, in the case of an optical star coupler using multi-mode optical fibers, and particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing costs.
    Type: Grant
    Filed: September 5, 1985
    Date of Patent: February 23, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Katsuyuki Imoto, Minoru Maeda, Masayoshi Kameyama, Yasushi Ikuta, Hiroshi Araki, Shigeru Oho