Panasonic Panafax UF-4000, Service Manual

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6.1.4. Laser Unit
Laser
A 5 mW Laser Diode, with a wave length of 780 nm (±20 nm), provides a modulated beam controlled by
nVIDEO. The beam power on the drum surface is approximately 0.20 mW, and is controlled by the
monitor circuit.
Collimator Lens
This lens converges and focuses the laser beam, converting it to parallel light.
Aperture
This controls the size of the laser beam.
Polygon Mirror and Motor
The polygon scanner consists of a 6-sided mirror, directly driven by a polygon motor, revolving at 15,867
rpm (400 dpi) or 16,235 rpm (600 dpi). Scanning speed for 400 dpi and 600 dpi are controlled by motor
clock supplied from LPC PCB. Motor clock for 400 dpi is 1,588 Hz and 600 dpi is 1,624 Hz. The laser
beam is reflected against these mirrors and swept over the recorded width in the scanning direction. This
unit features a stable line scanning speed, a precision mirror reflection angle, a reflection free surface,
and instant start.
Beam Detection (BD) Lens and Beam Detection (BD) Sensor
The BD Lens receives the reflected light from the Polygon Mirror and redirects it into the BD Sensor,
which converts the laser beam into electrical signals and sets the start timing for the scanning line.
Polygon Motor
Polygon Mirror
F
θ
Lens
Laser Diode
LD PCB
Beam Detection
Sensor
Beam Detection
Lens
Cylindrial Lens