Optical head in an optical memory device
CA 1278860 C · Owner: Ohta, Kenji · Inventors: Fujii, Yoshikazu; Inui, Tetsuya; Deguchi, Toshihisa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In an optical system of an optical memory device which records, reproduces or erases information onto or from a recording medium by applying a laser beam to the recording medium, a beam splitter is disposed in an optical path to conduct a portion of the laser beam emitted from a laser device to a light detector. In accordance with a detected value from this light detector the influence of a stray beam generated in the optical system is removed from a servo error signal.
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
- Granted January 8, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 8, 2008.
- 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.