Erasing of information signal from an optical disk
CA 1308482 C · Owner: Kawamura, Shinobu · Inventors: Kawamura, Shinobu; Nagai, Tadao
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 erasing of an information signal recorded on an optical disk such that the information signal is erased except for the vertical blanking interval and for the interval corresponding to the address signal of the informations on the disk. The rest of the information signal including the horizontal synchronizing signal is erased either continuously or intermittently or is not erased. The circuit produces a control signal which assumes a first logical state for enabling the erasing and a second logical state for disabling the erasing responsive to a horizontal synchronizing signal, a vertical synchronizing signal and a command signal commanding the erasing …
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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 October 6, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 6, 2009.
- 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.