Refractive index profile type optical fiber
CA 2297159 C · Owner: Kawarada, Yasushi · Inventors: Miyauchi, Haruko; Oishi, Norizi; Kawarada, Yasushi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
54, Disclosed is a graded index type optical fiber having a multilayer structure comprising a plurality of concentrically arranged non-blended layers LNB1 to LNBm formed of (co)polymers P1 to Pm selected from the group consisting of two or more homopolymers HP1 HP2, ... and, HPn composed of units of vinyl monomers M1 M2, ... and Mn, respectively (provided that the refractive indices of the homopolymers decrease in that order), and one or more binary copolymers CPs composed of units of vinyl monomers M1, M2, ... and Mn, each of (co)polymers P1 to Pm having a glass transition temperature (Tg) of 80°C or above wherein, the refractive index is highest at the center of the multilayer structure …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed July 27, 1998 and granted September 2, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 27, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 27, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.