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Expired Canadian patentCanada

Automatic servo gain calibration system for a disk drive

CA 1318975 C · Owner: Groll, Frederick K. · Inventors: Scaramuzzo, John A. Jr.; Watt, Charles R.; Groll, Frederick K.

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Abstract From the Canadian patent

A method for automatically calibrating gain parameters of a servo control including a track position detector for a computer disk drive. The method generally comprises the step of encoding AB bursts on at least one special calibration track of a disk surface in accordance with a known off center pattern signal having a preselected frequency. Servo correction number information is also encoded on the calibration track to compensate for the off center pattern of the AB bursts. A digital signal processing technique is performed on a correction signal derived from the AB bursts and servo correction number information to detect a residual signal at the preselected frequency of the off center …

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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 June 8, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 8, 2010.
  • 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 8, 1989
GrantedJune 8, 1993
Term endedJune 8, 2010
Patent numberCA 1318975 C
Classification (IPC)G11B5/59 +1 more

Timeline

Timeline From CIPO dates

1990199319961999200220052008Application filedJune 8, 1989Patent grantedJune 8, 1993Term endedJune 8, 2010

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