Patents by Inventor Munehisa Fujimaki

Munehisa Fujimaki 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).

  • Publication number: 20030148025
    Abstract: The present invention provides a manufacturing method of optical fiber that improves the adherence between a coating and a bare optical fiber composed of silica glass during the formation of the coating on the bare optical fiber in high-speed drawing of optical fiber. In this method, the temperature of the bare optical fiber prior to being introduced into a coating material in the coating apparatus is made to be between 60 and 110° C. The bare optical fiber is cooled by blowing cooling gas onto that prior to being introduced into the coating material in the coating apparatus. Furthermore, during cooling of bare optical fiber, at least two types of cooling gases having different coefficients of thermal conductivity are mixed and blown onto the bare optical fiber. In addition, the temperature of the bare optical fiber is made to be within a prescribed range by changing the mixing ratio of the cooling gas.
    Type: Application
    Filed: January 24, 2003
    Publication date: August 7, 2003
    Applicant: Fujikura Ltd.
    Inventors: Koji Azegami, Munehisa Fujimaki
  • Publication number: 20030136340
    Abstract: An optical fiber coating die is made such that an interfacial shear rate of the optical fiber to the resin coat is calculated in accordance with a pressure value of resin inside a coating cup, and the interfacial shear rate is in a range of −1.5×105 to 0 sec−1. Also, an optical fiber drawing die is made such that the interfacial shear rate of the optical fiber to the resin coat is calculated in accordance with a diameter of a coating resin, and the interfacial shear rate is in a range of range of −3×105 to 2×105 sec−1. By doing this, an optical fiber drawing die which can be used in an optical fiber drawing method so as to realize stable resin coating operation even in high-speed drawing operation and high productivity can be realized.
    Type: Application
    Filed: December 6, 2002
    Publication date: July 24, 2003
    Applicant: Fujikura Ltd.
    Inventors: Munehisa Fujimaki, Takahiro Hamada, Koichi Harada
  • Publication number: 20030138230
    Abstract: A manufacturing method and apparatus for manufacturing a coated optical fiber which has a superior surface smoothness of a resin coating and which can be coated with a colored ink with high coating performance. In the method including the steps of making a coated optical fiber by forming an outer coating layer around a bare optical fiber; and winding the coated optical fiber via pulleys by a take-up, the surface roughness of each solid body which the outer layer of the running coated optical fiber contacts is 0.8 &mgr;m or less. When the temperature of the outer coating layer is a room temperature or the Young's modulus of the outer coating layer is higher than 500 MPa, the surface roughness of each solid body, which the outer layer of the coated optical fiber contacts during drawing or rewinding, is 1.2 &mgr;m or less.
    Type: Application
    Filed: October 25, 2002
    Publication date: July 24, 2003
    Applicant: COATED OPTICAL FIBER AND MANUFACTURING METHOD AND APPARATUS THEREFOR
    Inventors: Koji Tsurusaki, Koichi Harada, Munehisa Fujimaki
  • Publication number: 20030110811
    Abstract: An optical fiber is formed by performing vapor phase deposition of SiO2 on the outside of a glass rod comprising a core section and a first cladding section and drawing a glass preform which formed by a second cladding section. Also, a single mode optical fiber is manufactured so that the ratio of the diameter D of the first cladding section and the diameter d of the core section is in a range of 4.0 to 4.8, and OH concentration is 0.1 ppm or less. Also, an optical fiber is manufactured so that a value of D/d>4.8, and the OH concentration is 0.1 ppm or less. It is thereby possible to maintain an initial loss in the 1380 nm wavelength range even if hydrogen diffusion occurs.
    Type: Application
    Filed: November 26, 2002
    Publication date: June 19, 2003
    Applicant: SINGLE MODE OPTICAL FIBER AND MANUFACTURING METHOD THEREFOR
    Inventors: Tomohiro Nunome, Hiroshi Kutami, Manabu Saitou, Kenji Okada, Munehisa Fujimaki, Koichi Harada
  • Publication number: 20030049006
    Abstract: This dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber and which has an adhesive property of 10 g/mm or less. Alternatively, the dispersion compensating optical fiber comprises an uncovered dispersion compensating optical fiber which contains a core and a cladding and a resin coating which is disposed around the uncovered dispersion compensating optical fiber, which has an adhesive property of 1 g/mm or less, and which includes a single or double coating layer and an outer coating layer formed on the surface of the single or double coating layer to have a thickness of 3 &mgr;m or more.
    Type: Application
    Filed: March 21, 2002
    Publication date: March 13, 2003
    Inventors: Kazuhiko Aikawa, Yutaka Nagasawa, Shogo Shimizu, Takaaki Suzuki, Masakazu Nakayama, Kuniharu Himeno, Ryozo Yamauchi, Keiji Ohashi, Munehisa Fujimaki
  • Publication number: 20020124600
    Abstract: The present invention provides a drawing method for optical fiber, which is capable of reducing attenuation at 1.55 um due to Rayleigh scattering, even if the drawing speed is high. The reduction of the attenuation of the optical fiber 3 is realized by conducting a preliminary cooling in a first cooling zone 4, which has a low convection heat transfer coefficient, for reducing the temperature of the as-drawn optical fiber just before entering into a second cooling zone 5. The optical fiber is obtained after being cooled in the second cooling zone 5, which has a higher convection heat transfer coefficient.
    Type: Application
    Filed: January 22, 2002
    Publication date: September 12, 2002
    Inventors: Takahiro Hamada, Munehisa Fujimaki