Projection lens system
CA 1257124 A · Owner: Koninklijke Philips Electronics N.V. · Inventors: Clarke, John A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
12, ABSTRACT:, Projection lens system. A lens system is provided which is suitable for back-projecting an enlarged image of a TV cathode ray tube (CRT). To achieve a compact cabinet design 1 for such a projection television set a, short projection throw and a wide projection angle are required to-, gether with a wide aperture (F/1) for a bright projected picture and with a definition which may need to be good enough to resolve 1249 line television pictures. The lens system comprises a concave CRT faceplate FP and three lens elements L1, L2 L3. L2 and L3 are each of, positive power and L1 most remote from the CRT, is a weak lens. At least one of the element surfaces is aspheric. The powers …
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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 July 11, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 11, 2006.
- 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.