Objective Lens/Roof Mirror Assembly/Eyepiece.
The objective lens/roof mirror assembly (Figure 2-22) directs the
scan mirror image onto the optical reticle for viewing through the
The objective lens is part of a 2.67X
telescope. The optical elements consist of a double-objective lens.
One element of this lens is moved by a bimetallic annular disc to
effect temperature compensation, a roof mirror which orients the
scene, a field lens to control exit pupil location, an optical
reticle, and a three-element eyepiece lens with diopter adjustment.
Objective Lens/Roof Mirror Assembly.