C. Controlling the Scanner Lamp
1. Outline
Figure 4-103 shows the circuit used to control the intensity of the scanning lamp, and
the circuit has the following functions:
q
Turning on and off the scanning lamp.
w
Detecting the activation of the scanning lamp.
Figure 4-103
CHAPTER 4 IMAGE FORMATION SYSTEM
COPYRIGHT © 1997 CANON INC. CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
4-3
IC115
IC104
IC109
D/A
converter
-2A
-12A
-1
-3
LDT
-10A
LINT
-5
-8A
-6
-7A
-4
-9A
LMPON
-2
-11A
ZRCS
J103
J117
J603
±24VA
±24VA
DC controller PCB
Lamp regulator
(CVR)
Switching
circuit
Phase
control
Zero-cross
detection
circuit
Arc
circuit
Differential
amplifier circuit
Power supply voltage
fluctuation detection circuit
Scanning
lamp
(LA1)
FU1
Power supply
Power
switch
(SW1)
PWOFF
*
Q147