Track access control system in rotating disc devices with eccentricity correction
CA 2014172 C · Owner: Fujitsu Limited · Inventors: Yanagi, Shigenori
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A track access control system in a rotating disc storage device including: a data writing/reading head which is movable in a radial direction of a rotating disc; and an impinging beam moving mechanism is mounted on the data writing/reading head, for moving am impinging position of the optical beam for the data writing/reading, on the data writing/reading head. A relative position of the impinging beam on the disc from an optimum position is detected. The position of the head is controlled responding to a low frequency component of the above detected deviation and the, operation of the impinging beam moving mechanism is controlled responding to a high frequency component of the above …
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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 April 9, 1990 and granted November 1, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 9, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.