Ricoh M C250FW, Field Service Manual

Page: 273 / 324

7.Detailed Descriptions
261
Laser Exposure
Overview
No. Part name
1 LDB (C/M)
2 F Lens
3 Polygon mirror motor
4 Synchronizing detector board
5 LDB (K/Y)
Mechanism
Composition
This machine uses two LDB units and one polygon mirror motor [A] to produce latent images on four
OPC drums [B] (one drum for each color toner).
There are two hexagonal mirrors. The polygon mirror motor rotates the mirrors clockwise and each
mirror reflects beams from LDB unit.
The laser beam from the LDB (C/M) is directed to the F lens at left side by the polygon mirrors. The
laser beam from the LDB (K/Y) is directed to the F lens at right side by the polygon mirrors.
Laser exposure for magenta and cyan starts from the left side of the drum, but for yellow and black it
starts from the right side of the drum. This is because the units for magenta and cyan are on the other
side of the polygon mirror from the units for yellow and black.