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Expired Canadian patentCanada

Projection screen

CA 1279781 C · Owner: Laine, Curtis S. · Inventors: Laine, Curtis S.; Dow, Ronald G.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A slide projection screen is disclosed which is designed to facilitate video recording of projected images. To accommodate for varied light intensity levels, the screen resulting from the optic projection by a slide projector, a compensating layer is provided on the screen. The compensating layer is made by preparing a master film image corresponding to the average light intensity pattern from a slide projector and using the master film image to expose a photo emulsion layer on the screen being made. Certain embodiments include a light absorbing layer to compensate for light scattering halation effects.

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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 February 5, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 5, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 1, 1987
GrantedFebruary 5, 1991
Term endedFebruary 5, 2008
Patent numberCA 1279781 C
Classification (IPC)G03B21/56

Timeline

Timeline From CIPO dates

1988199119941997200020032006Application filedJune 1, 1987Patent grantedFeb 5, 1991Term endedFeb 5, 2008

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.