of opaque material. The arrow can be moved to any position on the
screen. Improper alignment of the optical path of the pointer system
may result in the operator not being able to project the arrow to all
parts of the screen. Incorrect focus of the aperture plate will result in
a fuzzy, indistinct image.
(1) Set the projector up (par. 10) about 15 feet from the pro-
jection screen, so that it faces the screen squarely.
(2) Turn the ON-OFF switch to the ON position. Insert copy
and focus the image on the screen.
(3) Position the pointer control knob until the arrow appears
on the screen. Swing the knob so that the arrow moves to
all portions of the projected picture area.
(a) If the arrow can be moved to all portions of the projection
area, optical alignment of the pointer system is correct.
Do not attempt to readjust it.
(b) If the arrow can be seen over only a portion of the picture
area, optical alignment is necessary. Open the side access
door by loosening the two knurled captive screws. Loosen
the screw that holds the rear mirror and aperture plate
bracket in adjustment, and swing the bracket (fig. 16)
from one side to the other until the light strikes the front
surface mirror as centrally as possible. Tighten the screw
when the correct adjustment is obtained.
Note. When adjusting the optical alignment of the pointer system,
do not change the adjustment of the aperture plate. Conversely, when
adjusting the focus of the arrow, do not change the adjustment of
the rear surface mirror.
(c) Close the side access door and tighten the two knurled
(4) Examine the projected arrow on the screen.
If it is in sharp focus, do not attempt to refocus it.
If the arrow is fuzzy or indistinct, focusing of the aperture
plate is necessary. Open the side access door by loosening
the two knurled captive screws. Loosen the screw that holds
the rear surface mirror and aperture plate in adjustment
and move the aperture plate forward or backward until
the arrow is focused sharply on the screen. Tighten the
screw when the correct adjustment it obtained.
Close the side access door and tighten the two knurled