Riso RP-255, Technical Manual

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FB ORIGINAL SCANNING SECTION
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B C F
J
K
P
1206
2-2. Original Scanning Mechanism (RN20/21 Series)
The FB read pulse motor [J] drives the front and rear wire spool pulleys [G] via the 2-stage reduction
pulleys linked by the timing belts [H] and [I]. The front and rear wire spool pulleys are configured
symmetrically.
The wire [S] has one end secured to the frame via coil spring [A], and is wound onto sliding pulley 2 [E]
mounted on the mirror carriage [B]. It is wound approximately 6.5 times around the rear wire spool pulley
[G] via the fixed pulley [F] secured to the frame. It is then attached to the lamp carriage [C] and then
secured to the frame via sliding pulley 1 [D] mounted on the mirror carriage [B]. The lamp carriage [C]
carries two original illumination lamps [K] (and lamp inverters) and mirror 1 [M], and the mirror carriage
carries the two mirrors [N] and [O].
The mechanism uses a “full/half-rate mirror scanning” system, in which the mirror carriage moves 1/2 L
mm as the lamp carriage moves L mm in the same direction. This means that when the FB read pulse
motor [J] is activated, the original surface can be scanned while maintaining a constant distance
between the original and the center of the lens mounted on the frame. The original on the scanner table
illuminated by the lamp is reflected via mirrors 1, 2, and 3, and is then focused onto the CCD [R] by the
lens [Q] in the lens ass’y [P].
A: Spring
B: Mirror carriage
C: Lamp carriage
D: Sliding pulley 1
E: Sliding pulley 2
F: Fixed pulley
G: Wire spool pulley
H: Scanner timing belt 1
I: Scanner timing belt 2
J: Flatbed read pulse motor K: Lamp
L: Stage glass
M: Mirror 1
N: Mirror 2
O: Mirror 3
P: Lens ass’y
Q: Lens
R: CCD
S: Wire