US Patent 9069172 Multi-mode sight

A multi-mode sight includes an optical sight that provides a direct view image of an aiming point or reticle superimposed on a target scene. The optical sight includes a single optical path defined through the sight comprising a direct view and overlay path. A thermal imager provides a monochromic thermal image of the target scene. A single combiner is located in the optical path and passes the direct view image and reflects the thermal image to overlay the thermal image onto the direct view image for an operator to see as a superimposed thermal and direct view optical image of the target scene together with the aiming point or reticle.