Exposure; Overview - Ricoh FW780 Service Manual

3.

EXPOSURE

3.1 OVERVIEW

Light from the exposure lamp [A] reflects off the original and through the fiber
optics [B] to the OPC drum [C]. During exposure, the original moves across the
exposure glass at the same speed as the drum's peripheral velocity.
The platen plate [D] presses the original [E] flat against the exposure glass [F]
just above the fiber optic array. This ensures that the image is properly focused.
(The original must be within 0.2 mm of the exposure glass surface.)
The exposure lamp is a 140 V, 26 W fluorescent lamp.
The original registration sensor [G] detects when the original leading edge passes
the front of the exposure glass. The original flattener [H] holds the leading edge of
the original to ensure that original registration sensor detects the original at the
correct time. The light sensor [I] monitors the intensity of the exposure lamp
output.
SM
[F] [D] [H]
[I]
[A]
2-6
[E]
[G]
[B]
[C]
A163