Auto Power Control (Apc) - Ricoh G031 Service Manual

LASER EXPOSURE

2.2.3 AUTO POWER CONTROL (APC)

LD Drive Board
C N 1 - 7
5 V
L D P D
V C C
A P C
LD Driver
V I D E O
DPI select
L D O F F
G031D508.WMF
To prevent the intensity of the laser beam from changing because of temperature,
the machine monitors the laser beam with a photodiode (PD). The PD is enclosed
in the laser diode. The PD passes an electrical current to the LD driver IC and this
IC adjusts its output level to keep the laser diode output constant.
The laser diode power level is adjusted on the production line. Do not touch the
variable resistors on the LD unit in the field.
G031/G032 2-8 SM