4-9
FS-1800/1800N | FS-3800/3800N
Figure 4-1-7 F-theta lens
Primary f-theta lens
Laser diode
Polygon mirror
Secondary f-theta lens
Drum
Laser beam
Name Description
5 Primary f-theta lens See figure 4-1-7 below.
6 Secondary f-theta lens The primary (above) and secondary f-theta lenses equalize focusing
distortion on the area on the drum closer to the edge. The effective
length of line (A, B in the figure below) the laser beam draws on
the drum becomes longer as the laser beam hits closer to the drum
edge. In the figure 4-1-7 below, distances represented by A and B
are not the same (A > B) until the f-theta lenses are provided between
the polygon mirror and the drum (A = B).
7 Diversion mirror Diverts the laser beam vertically onto the drum. Note the diffused
laser beam finally pinpoints on the drum.
8 Protective glass Prevent dust, debris, etc., from entering the scanner assembly.
9 Sensor mirror Bends the very first shot of a laser scan towards the pin photo sensor
(below).
0 Pin photo sensor When shone by the sensor mirror above, this pin photo sensor
generates a trigger signal.
To Next Page
Loading...
