Optical disk for use in optical memory devices
CA 1303740 C · Owner: Takemori, Hirotoshi · Inventors: Ohta, Kenji; Van, Kazuo; Inui, Tetsuya
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An optical disk for use in optical memory devices comprises guide grooves and pits on one surface thereof, wherein the depth of the guide grooves is different from that of the pits and the distance from the bottom face of each of the guide grooves to the other surface of the optical disk opposite to the one surface of the optical disk on which the guide grooves and pits are disposed is the same as the distance from the bottom face of each of the pits to the other surface of the optical disk opposite to the one surface of the optical disk on which the guide grooves and pits are disposed, a method for the production of optical memory master plates that are used for the production of the …
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 June 16, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 16, 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.