Disc-shaped recording medium
CA 2049767 C · Owner: Yoshida, Tadao · Inventors: Tsurushima, Katsuaki; Yoshida, Tadao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A disc-shaped recording medium for storing compressed audio data which have been recorded thereon by an optical recording apparatus. The inner diameter of a data recording region of the disc-shaped recording medium is in the, range from 28 mm to 50 mm. The outer diameter of the data recording region is in, the range from 58 mm to 62 mm for an inner diameter of 28 mm and is in the , range, from 71 mm to 73 mm for an inner diameter of 50 mm. The disc-shaped recording medium may be used with a small-sized portable disc recording and reproducing apparatus, and can record compressed audio data for playback with a playback time, substantially as long as that of a standard compact disc having …
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 August 23, 1991 and granted October 31, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 23, 2013.
- 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.