Figure 4. Projector PH-637( * )/PFP, case.
of the housing is a groove that holds a grease pencil used for marking
cellophane or plastic held on the stage. On the right side of the hous-
ing next to the support-post hole is a clamping knob used to lock the
post in position. The housing contains an optical system composed of
the reflector, projection lamp, glass condenser lens, rear surface mirror,
Fresnel condenser lens, and glass cover of the projection stage. T h e
housing of the PH-637A/PFP also contains a cellophane roll attach-
ment (d below).
b. Head-support Post and Projection Head Assembly.
(1) Head-support post. The head-support post is made of
stainless steel and has a rack secured to the upper end by
three screws. The post fits through a hole in the top of the
housing (a above), and a notch at the bottom of the post fits
over a locating pin on a plug at the bottom of the housing.
(2) Projection head assembly. The projection head assembly
consists of a front surface-mirror housing, lens, and sup-
port arm. The mirror housing is a black, crackle-finish,
aluminum casting that contains the mirror and a window.