Scanner Drive; Scanner Drive Mechanism - Ricoh FT4430 Service Manual

SCANNER DRIVE

1. Scanner Drive Mechanism

This model uses a dc servomotor [A] to drive the scanners.
The first scanner [B], which consists of the exposure lamp [C] and the first
mirror, is connected to the scanner drive wire by the wire clamp [D]. T h e
second scanner [E], which consists of the second and third mirrors, is
connected to the scanner drive wire by a movable pulley (the second scanner
pulley [F]).
The pulley moves the second scanner at half the velocity of the first scanner.
This is to maintain the focal distance between the original and the lens during
scanning. This relationship can be expressed as:
V1r =
where: r =
V1r =
V2r =
VD — —
The wire clamp for the first scanner also works as the actuator of the home
position sensor. The CPU controls both the registration and return timing.
2(V2r) = VD/r
Reproduction ratio
First scanner velocity (when the reproduction ratio is "r")
Second scanner velocity (when the reproduction ratio is "r")
Drum peripheral velocity (150 mm/s)
2-13
16 April '88