Laser/Scanner Section - Canon PC-D320 Service Manual

4.1 Laser/Scanner Section

This section comprises a Laser unit, cylindrical lens, 4-faced polygon mirror, scanner motor,
imaging lens, reflection mirror and BD sensor. The Laser is driven in accordance with the Laser
drive signals that are sent from the SCNT board. This Laser light passes through the cylindrical
lens to fall on the 4-faced polygon mirror that is rotating at a fixed speed. The Laser light is
reflected from the 4-faced polygon mirror and passes through the imaging lens, and reflects
from the reflection mirror to scan the photosensitive drum in the toner cartridge.
BD Malfunction
The CPU on the ECNT board determines a BD malfunction if the /BDI signal
is not detected within 0.1 second after the scanner motor is forcibly driven.
NOTE
Or, if the detected cycle of the /BDI signal has not reached the specified value
within 2 seconds after the scanner motor reached its specified rotation
number.
Laser/scanner unit Malfunction
If the /BDI signal is not detected within 1.5 seconds after the scanner motor is
forcibly driven, the CPU on the ECNT board extends the time to 120 seconds,
the CPU determines a scanner malfunction.
The Laser/scanner unit contains parts that require adjustment that cannot
adjust in the field. Never disassemble the Laser/scanner unit.
PC-D320/PC-D340/FAX-L400 Chapter 2: Technical Reference
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