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Expired Canadian patentCanada

Data file directories and methods

CA 2045948 C · Owner: Rolfe, Randy Keith · Inventors: Friedl, Theodore John; Gregg, Leon Edward; Rolfe, Randy Keith

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 data storage medium having the ability to recover from media errors includes a directory located at any desired region of a data storage area with redundant directory pointers at reserved locations. A unique file token is included in the directory entry for each data file and is also included in each extent list where the locations of parts of a fragmented data file are stored. Multiple extent lists are chained in two directions to facilitate reconstruction of the chain if part of the pointer information is lost.

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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 June 28, 1991 and granted November 17, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 28, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 28, 2013.
  • 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 28, 1991
GrantedNovember 17, 1998
Term endedJune 28, 2011
Patent numberCA 2045948 C
Classification (IPC)G11B20/12 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedJune 28, 1991Patent grantedNov 17, 1998Term endedJune 28, 2011

Sources & verification

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