The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 12, 2024
Filed:
Mar. 06, 2019
Bae Systems Plc, London, GB;
Mark Edgar Bray, Chelmsford, GB;
BAE SYSTEMS PLC, London, GB;
Abstract
An optical devicecomprises an objective lensdefining a focal plane FP and an eyepiecespaced apart therefrom, defining an optical axis OA therethrough. The optical devicecomprises an optical memberhaving a first planar face, arranged on the optical axis OA proximal the focal plane FP, wherein the first planar faceis arranged to oppose the objective lens. The optical devicecomprises a filter assemblycomprising a first notch filterarranged to attenuate transmission of electromagnetic radiation having a first wavelength λ, wherein the first notch filteris arranged in front of the optical member. The first notch filteris arranged at a first oblique angle θto the optical axis OA whereby, in use, incident electromagnetic radiation having a predetermined wavelength λpropagating along the optical axis is reflected by the first notch filteraway therefrom, wherein the first wavelength λand the predetermined wavelength λare different. In this way, retro-reflection of the incident electromagnetic radiation towards a source thereof is reduced, thereby better detection of the optical device