Protection from unauthorized use of a recorded digital signal
CA 1329654 C · Owner: Nagashima, Satoru · Inventors: Shirai, Tatsuro; Yoshida, Shiro; Nagashima, Satoru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A digital signal recording and reproducing apparatus for recording an input digital signal on a recording medium to reproduce it therefrom, comprising first means for recording the same identification code as an identification number particular to the digital signal recording and reproducing apparatus when the input digital signal has a specified sampling frequency at the time of recording, and second means for reproducing the recorded identification code at the time of reproduction thus permitting the digital signal recorded on the recording medium to be reproduced only when the reproduced identification code is coincident with the identification number particular to the apparatus.
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 May 17, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 17, 2011.
- 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.