Toshiba DP120F Service Manual page 278

At the actual printing, the laser beam scans across the rotating drum, the drum surface moves
42 micromillimeter when the laser beam completes one scanning operation and returns to a
position to be ready for next scanning. That is, the printing is done by the laser beam scanned
at this pitch (600 dpi).
Polygon mirror
Following shows an example of the laser beam raster scanning to form a character "A."
DP120F/DP125F Mechanical Description
Fθ lens
Drum
Fig. 5-3-14
Fig. 5-3-15
5-18
Reflecting mirror 2
Reflecting mirror 1
05-03-14
05-03-15
March 2000 © TOSHIBA TEC