Panoramic periscope

Claim 1

A panoramic periscope with daylight viewing and heat-picture optical systems, comprising (a) a front window (2) for incoming rays, said front window being transparent both to rays of a visible spectral region for daylight-viewing and to rays of a spectral region for producing a thermal image, (b) a reflector mirror (3) behind said window in position to receive and reflect entering rays in both of said spectral regions, said mirror being movable both in elevation and in azimuth, (c) a daylight-viewing optical system, (d) a heat-picture optical system selectively shiftable to at least two different magnifications, (e) said heat-picture optical systems having a front lens (4) effective at a first magnification of said heat-picture system, said front lens having a central hole, (f) said hole serving as an entrance pupil when said heat-picture system is operating at a second magnification, (g) said hole also allowing passage of light in a visible spectrum during daylight-viewing, (h) observation means including two oculars, (i) means for directing rays of said visible spectral region into one of said oculars (15) for daylight-viewing of a scene, and (j) means for directing rays of said thermal image spectral region into the other of said oculars (23) for viewing a heat-picture image produced by said rays.