Patent Yard Sign in
Expired Canadian patentCanada

Optical disk

CA 2540441 C · Owner: Dainippon Ink And Chemicals, Inc. · Inventors: Fujii, Koichi; Murakami, Kazuo

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

An optical disk comprising a first substrate a first , reflective layer for reflecting laser beams for information reading formed on the first substrate, and a resin layer made of a cured film of an ultraviolet curable composition formed on the first reflective layer, wherein the first reflective layer is a reflective layer made of silver or an alloy containing silver as a main component, and the ultraviolet curable composition contains (a) a radical polymerizable compound, (b) a compound represented by the following formula (1) and (c) a radical photopolymerization initiator. (see formula 1)

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 September 28, 2004 and granted November 19, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 28, 2024.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 28, 2026.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 28, 2004
GrantedNovember 19, 2013
Term endedSeptember 28, 2024
Patent numberCA 2540441 C
Classification (IPC)G11B7/25 +2 more

Timeline

Timeline From CIPO dates

2005200720092011201320152017201920212023Application filedSep 28, 2004Patent grantedNov 19, 2013Term endedSep 28, 2024

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.