Ricoh IS450S Service Manual page 25

22 December 1998 SCANNER MECHANISMS
Original Feed and Separation
[D]
[E]
[F]
[A]
[C]
[B]
G411D520.WMF
To feed the original, the paper feed motor and the paper transport motor (which
drives the paper transport drum) turn on. The paper feed motor drives the pick-up
roller [A] through a train of gears and the pick-up clutch [B]. The pick-up clutch
turns on to feed the top sheet of the original. If the pick-up roller feeds multiple
pages of the original, the separation roller [C] and the feed roller [D] separate these
pages (the separation mechanism is friction-based).
When the leading edge of the original activates the feed sensor [E], the paper feed
motor and the pick-up clutch turn off, then the paper transport drum [F] feeds the
original to the scanning position.
Image Scanning
The scanner starts to scan the image when the leading edge has passed the read
sensor by a certain distance (measured by motor pulses).
When the CPU has fed the trailing edge of the original 30 mm past the feed-out
sensor, the transport motor turns off.
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