Data recording medium, recording medium recording and/reproducing apparatus, and recording or reproducing method
CA 2420221 A1 · Owner: Kihara, Takashi · Inventors: Kihara, Takashi; Sako, Yoichiro; Kazami, Shinichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical disc (1, 4) on which encrypted data is recorded. The optical disc includes a first recording area (3b, 4b) where encrypted content data is recorded and a second recording area (3a 4a) having a first area portion (6) , provided in a position from which data is read out prior to the read from the first recording area, for recording encryption key data for decrypting the encrypted data and a second area portion (7) for recording identification data for identifying a recording medium which has been modulated by a modulation method different at least from the first area portion.
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 June 24, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 24, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 24, 2024.
- 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.