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Expired Canadian patentCanada

Specifically configured sheet members or articles for use in improving sound or image quality

CA 2111815 C · Owner: My-T Onken Co. Ltd. · Inventors: Tanaka, Tatsuo

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 sheet member adapted for attachment to an acoustic or imaging apparatus to improve the acoustic or imaging performance thereof. The sheet member is generally circular including a plurality of generally W-shaped cut-outs and a like plurality of generally V-shaped cut-outs both formed alternately and equi-angularly in the outer circumference thereof. The sheet member improves the acoustic or imaging performance by reducing the interference caused by electromagnetic radiations emitted from the acoustic or imaging apparatus or their components to which the sheet member is attached. The reduction of such interference can be attained also by forming a compact disc a laser disc, a magnetic tape, …

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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

  • Filed December 17, 1993 and granted November 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 17, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 2015.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 17, 1993
GrantedNovember 2, 1999
Term endedDecember 17, 2013
Patent numberCA 2111815 C
Classification (IPC)H05K9/00 +2 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedDec 17, 1993Patent grantedNov 2, 1999Term endedDec 17, 2013

Sources & verification

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