Laser Exposure - Ricoh Aficio MP2550B Service Manual

Laser Exposure

6.6 LASER EXPOSURE
6.6.1 OVERVIEW
The optical path from the laser diode to the drum is shown above.
The LD unit [A] outputs a laser beam to the polygon mirror [B] through the cylindrical lens
[C]. The shield glass [D] prevents dust from reaching the polygon mirror.
Each surface of the polygon mirror reflects one full main scan line. The laser beam goes to
the F-theta mirror [E], mirror [F], and BTL (barrel toroidal lens) [G]. Then the laser beam
goes to the drum through the toner shield glass [H].
The laser synchronizing detector [I] determines the main scan starting position.
The speed of the polygon mirror motor is 35,433 rpm for 600 dpi.
SM 6-29 D017/D018/D019/D020