Optical recording and reproducing apparatus
CA 2013836 C · Owner: Imai, Hitoshi · Inventors: Tadokoro, Michihiro; Imai, Hitoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical recording and reproducing apparatus for optically recording and reproducing information on and from a disk comprises: a light source for generating a Parallel beam; a movable optical system adapted to condense the parallel beam from the light source on the disk, to split the beam into two different beams, and to move in the radial direction of the disk; a split-beam detecting device having two light receiving surfaces which receive part of the two different beams obtained in the movable optical system; and a control device adapted to effect tracking control by moving the movable optical system in the radial direction of the disk in accordance with respective detection signals …
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 April 4, 1990 and granted July 26, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 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.