Reflection type diffraction grating
CA 2357607 A1 · Owner: Nippon Sheet Glass Co. Ltd. · Inventors: Nakama Kenichi; Kawamoto, Shinji; Kunisada, Terufusa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Areflection type diffraction grating according to the present invention has a structure in which a metal film as a first layer with reflectance not lower than 30 % with respect to the wavelength of incident light and a transparent dielectric film as a second layer are laminated successively on the surface of the reflection type diffraction grating. With respect to the wavelength of incident light, the metal film has a refractive index selected to be not higher than 1.5 and an extinction coefficient selected to be not smaller than 6Ø The transparent dielectric film has a refractive index selected to be in a range of from 1.30 to 1.46, both inclusively, with respect to the wavelength of …
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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 20, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 20, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 20, 2023.
- 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
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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.