Objective lens having constant focal length in visible and ir range
CA 2267692 C · Owner: Raytheon Company · Inventors: Noyes, Gary R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The focal length of an objective lens system is substantially equal at two wavelengths: one within the visible spectrum and one within an eyesafe IR spectrum centered about 1.54µm; the lens is essentially achromatic throughout the entire visible spectrum (0.45µm-0.70µm) and is well-corrected for other monochromatic aberrations (spherical aberration, coma, astigmatism, field curvature and distortion). By, having an objective lens (12) that is common to both optical paths (visual 36 42 and laser 36, 44) and has the property of having essentially the same focal length and essentially the same angular deviation for the two optical paths upon lens decentration, then a practical mechanism can …
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 2, 1998 and granted November 5, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 2, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 2, 2020.
- 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.