Scanning Lamp/Fau Lamp; Computer; Circuit; Lighting Circuit - Canon CANOSCAN D660U Service Manual

CHAPTER 2
C. Scanning lamp/FAU lamp lighting circuit
When the scanner is powered ON, the "LAMP ON" signal is set to "H" and turns ON the lamp
control circuit to provide +12VI to the inverter PCB to light the scanning lamp.
The scanning lamp exposure control is performed by scanning white calibration plate which
is placed outside the image area to feedback on the output. ASIC inputs the pulse signal
(LAMP ON) according to the feedbacked signal to the lamp control circuit to generate +12VI.
FAU lamp exposure control is performed by directly feedbacking the output from the FAU
lamp. When the host computer commands to use the FAU, ASIC sets "FAU INV" signal to "H".
The lamp control circuit provides +12VI to FAU inverter PCB to light the FAU lamp.
LAMPON
Host
ASIC

computer

FAUINV
2 - 14
Lamp
control

circuit

GND
12VI
GND
Main PCB
Figure 2-12
COPYRIGHT © 2000 CANON INC.
Scanning
CCD
Inverter
drive
PCB
PCB
FAU lamp
FAU Inverter
PCB
CANOSCAN D660U REV.0 JULY 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
lamp
Cold cathode
fluorescent
lamp
Cold cathode
fluorescent
lamp