D. To prevent emission of light from the eyepiece.
To prevent light escaping from the night sight eyepiece, a
security shutter is installed. (Page 6, Figure 1-5.)
B. Optical, electrical, and mechanical.
The AN/TAS-4A Night Sight is designed with three functional
groups: optical, electrical, and mechanical.
A. Visual collimator.
The visible light is collimated onto the scan mirror by the
visual collimator in the AN/TAS-4A Night Sight.
C. Objective lens/roof mirror assembly.
In the AN/TAS-4A Night Sight, the objective lens/roof
mirror assembly images the visible light on the reticle for
viewing. (Page 8, Figure 1-7.)