Method and apparatus for preventing parasitic electrical discharges in magnetic disk drives
CA 2001392 A1 · Owner: Hewlett-Packard Company · Inventors: Gailbreath, Samuel H.; Hilton, Richard L.; Shelton, Boyd N.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The pole pieces (40, 42) and other components of a magnetic head (10) of a disk drive and an adjacent disk drive surface (26) are biased to approximately the same DC voltage level (+5v) in order to prevent any unwanted electrical discharge therebetween. This method thus prevents the generation of spurious signals at the output of a read amplifier (32) to which the magnetic head (10) is electrically connected.
Read the whole patent
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 October 24, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 24, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 24, 2011.
- 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
Timeline From CIPO dates
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.