Process for production of glass preform for optical fiber
CA 2116701 C · Owner: Ohga, Yuichi · Inventors: Ito, Masumi; Ohga, Yuichi; Danzuka, Toshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to an improved process for providing the production of a glass preform for an optical fiber which includes substantially no bubbles therein and also which has a substantially uniform shape. The process for the production of a glass preform which comprises at least silica for an optical fiber is comprised of producing a body comprising a rod on which fine glass particles are deposited preferably by a vapour phase reaction and heating the body to vitrify the body under a reduced atmosphere or a vacuum so that the glass preform is produced. The process includes a first heating step of degassing the body at a first heating temperature, a second heating step of …
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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 March 1, 1994 and granted December 30, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 1, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 2016.
- 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.