Heat treatment of flat photochromic sheet glass
CA 1329038 C · Owner: Corning Glass Works · Inventors: Drake, Patricia Ann; Kerko, David Joseph; Ball, Edith Mary
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention is directed to a method for heat treating a sheet of a potentially photochromic glass to cause the growth of silver halide crystals therein which impart photochromic properties thereto wherein the heat, treated sheet will be essentially free from thermal deformation and surface defects, and the photochromic properties exhibited therein will be essentially uniform across the area of the sheet. The method involves first placing a sheet of potentially photochromic glass on top of a sheet of carrier glass that exhibits a softening point at least 50°C higher than the temperature at which the potentially photochromic glass will be heat treated and thereafter, subjecting the stacked …
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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
- Granted May 3, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 3, 2011.
- 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.