Optical head control circuit for optical tape recording/reproducing apparatus
CA 2025213 C · Owner: Miyoshi, Hiroshi · Inventors: Ohsato, Kiyoshi; Miyoshi, Hiroshi; Kamatani, Yoshiteru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A control circuit for controlling the position of a head in an optical tape recording/reproducing device having a rotary optical head controls the position of the head at the instant that it faces the tape based upon a desired head position derived from a preceding period in which it was facing the tape. A head position error signal is sampled and added to a sample head position signal during a period when the head is facing the tape and is held during the time the head is not facing the tape. The instant the head begins to face the tape once again this, desired value that has been held is applied to the head in order to reduce the pull-in time of the control circuit and provide more time …
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 September 12, 1990 and granted December 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 12, 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
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.