Data carrier optically read out by transmission, and method of manufacturing said data carrier
CA 1066801 A · Owner: Thomson-Brandt · Inventors: Le Carvennec, Francois; Dubois, Jean C.; Carre, Bernard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure The present invention relates to the protection of relief impressions formed in order to store information on a data carrier which can be optically read out by transmission. The invention relates to a data carrier the relief impression in which is protected by at least one layer transparent visa-vis the read-out radiation. The protective layer has an index of refraction that differs from that of the data carrier per se. Thus, a refractive boundary at the relief impression is maintained and the information encoded in the diffractive relief pattern is preserved.
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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 November 20, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 20, 1996.
- 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.