Ricoh A-P4, Service Manual

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polygon motor rotation speed, reduces noise generated by the polygon motor, and reduces the frequency
of the image data clock.
The two laser beams follow the path: collimating lenses [C] > prism [D] >polygon mirror [E].
The two laser beams arrive on the drum surface about 2 mm apart in the main scan direction and about
0.06 mm apart (at 400 dpi) in the sub scan direction. The two-mm difference in the main scan direction
allows the machine to detect the laser synchronization signal for each beam.
Laser Beam Pitch Change Mechanism
When the LD positioning motor [A] turns, the metal block [B] in contact with the LD unit housing [C] moves
up and down and changes the position of L2 (L1 does not move).
6. Details
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