Laser Exposure; Laser Scanning - Ricoh G092 Service Manual

6.3.3 LASER EXPOSURE

Laser scanning

[A]
[A]: Laser diodes
[B]: Collimator lens
[C]: Polygon mirror
[D]: Synchronization sensor
Laser path
The laser diodes [A] (one for each color and black) generate the laser beams used
to "expose" the OPC's surface.
The collimator lens [B] ensures the beams are parallel, and directs them to the
polygon mirror [C].
The toroidal correction lens [F] corrects the vertical registration errors of the
beams.
Mirrors direct the beams to the primary lenses (at the bottom of the unit). The
lenses ensure that each beam scans across the drum at a constant speed.
Laser synchronization
At the start of each horizontal scan, the horizontal synchronization mirror [F]
deflects the laser beam to the horizontal synchronization sensor [D].
Synchronization is done for the black laser beam only. The other lines depend on
the line position adjustment.
SM
[B] [C]
[G]
[F]
[E]: Horizontal synchronization mirror
[F]: Toroidal correction lens
[G]: Laser optics housing unit
6-11
PRINT PROCESS
[D]
[E]
G081D105.WMF
G081/G092