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Expired Canadian patentCanada

Radiation-sensitive record with protected sensitive surface

CA 1094685 A · Owner: North American Philips Corporation · Inventors: Yuan Kong Lou, David; Kenney, George C.; Balas, Charles

CIPO record

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

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Abstract From the Canadian patent

PHA.20.742, 28-4-1977, ABSTRACT:, A record structure for recording with a radiation beam uses a transparent disc or drum a coaxial, backing disc or drum and two coaxial resilient ring-shaped seals to provide an enclosure between the discs or drums. Radiation-sensitive recording material on the side of the disc or drum within the enclosure is thereby protected from ambient dust particles and other contaminations while the gaseous or solid by-products of the inter-action between the recording material and the radiation beam in the area around which the beam impinges are substantially contained between the disc surfaces and cannot produce deposits on an objective lens used to focus the …

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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 January 27, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 27, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 11, 1977
GrantedJanuary 27, 1981
Term endedJanuary 27, 1998
Patent numberCA 1094685 A
Classification (IPC)G11B7/00 +1 more

Timeline

Timeline From CIPO dates

1978198119841987199019931996Application filedMay 11, 1977Patent grantedJan 27, 1981Term endedJan 27, 1998

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