Method for optical information recording
CA 1285332 C · Owner: Matsushita Electric Industrial Co. Ltd. · Inventors: Ohno, Eiji; Nishiuchi, Kenichi; Yamada, Noboru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for erasing and recording information on an optical recording member of the type wherein a new signal is overwritten on a previously recorded track by means of a single laser spot passing only once thereon. The method comprises the steps of modulating a recording laser power to a recording power level (PW): maintaining the laser power at the recording power level (PW) for a time corresponding to data to be recorded: lowering the laser power to a cooling power level (PC) which is lower than the recording power level (PW); and maintaining the laser power level at the cooling power level (PC) for a predetermined period, to thereby record information. By modulating the recording laser …
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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
- Granted June 25, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 25, 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.