Disc-shaped optical recording medium and reproduction limit method thereof
CA 2440052 A1 · Owner: Sabi, Yuichi · Inventors: Sabi, Yuichi; Iwamura, Takashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A disc-shaped optical recording medium which prevents unauthorized copy to protect a digital content and a reproduction limit method thereof. There is provided a CD that can be reproduced by an ordinary audio CD player but cannot be read out by high-speed reproduction of a CD-ROM drive belonging to a computer. The CD (10) has a clam hole (14) formed at a position shifted from the center position with respect to the outer diameter of a disc substrate (12), so that the center of gravity of the disc substrate (12) is located at a position shifted from a rotation center of the clamp hole by a predetermined amount. Moreover, paint (16) is applied as an eccentric load to the label …
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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
- Filed January 20, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 20, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 20, 2025.
- 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.