Brother DCP-7030 Service Manual page 57

(2) Exposure
The laser beam radiated from the laser diode inside the laser unit are concentrated into a
constant width by a slit in the CO lens cell and then reflected by a polygon mirror rotating at
high speed. The evenly charged drum is irradiated with reflected light and exposed. The
surface potential is lowered by such exposure and a latent image is formed.
Laser diode CO lens
Polygon mirror
Laser unit
Exposure drum
Fig. Ref. 2-21
Ref. 2-22
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