Kyocera KM-4230 Service Manual page 46

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1 Laser diodes: Generate the laser beams that form the latent image on the drum.
2 Collimator lenses: Collimate the diffused laser beams emitted from the laser diodes into
cylindrical beams.
3 Beam splitter: Refracts the laser beam emitted from one of the laser diodes so that it
becomes parallel to the other laser beam, and sends those two beams to lens 1.
4 Polygon mirror: 6-faced mirror that rotates at approximately 29527 rpm. Each face
reflects the laser beams toward the drum in the horizontal (main) scan direction. The
motion of the beams across the drum forms one scan line.
5 Lenses 1, 2, 3 and 4: Maintain scanning speed across the drum and beam diameters
constant. These lenses also correct the vertical alignment of the polygon mirror so that
the focal plane of the laser beams are always on the drum.
6 Object mirror: Reflects the laser beams onto the drum surface.
7 BD sensor mirror: Directs a laser beam to the BD sensor to generate the horizontal sync
signal.
8 Cylindrical correcting lens: Corrects for the deviation of the laser beam reflected by the
BD sensor mirror.
9 BD sensor: Detects the laser beam reflected by BD sensor mirror, and sends the
detection signal to the main PCB (MPCB). The main PCB (MPCB) uses this signal to
determine the horizontal scanning signal timing.
0 Glass dust filter: Prevents dust from entering the unit.
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Drum
Figure 1-3-20 Laser scanner unit (2)
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2A3/4
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1-3-23
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