Rear projection screen incorporating diffuser
CA 2285047 A1 · Owner: Minnesota Mining And Manufacturing Company · Inventors: Moshrefzadeh, Robert S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A rear projection screen (10) including a plurality of refracting beads (1) bound in optical contact with a substrate (12) is disclosed. The beads are surrounded by an opaque matrix (2). A diffuser (28) is positioned such that light traveling through the screen (10) will pass through the diffuser (28) after passing through the beads but before exiting the screen (10).
Read the whole patent
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 20, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 20, 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.