Auto Power Control (Apc) - Ricoh B245-62 Service Training

The LD board controls
the laser diode.
The APC circuit adjusts
laser power for
temperature changes.
The laser diode power is
adjusted on the
production line.
Do not adjust the
variable resistors on the
LD unit in the field.
See the notes for details.
Slide 44
The LD driver IC drives the laser diode. To prevent the intensity of the laser beam from
changing because of the temperature, the machine monitors the current passing through
the laser diode (LD). The machine adjusts the current to the laser diode by comparing it
with the reference level from the reference circuit.
This auto power control is done just after the machine is turned on and during printing.
The laser diode power is adjusted on the production line.

Auto Power Control (APC)

44
B245-62 / PD-C4