Controlling The Scanning Lamp; Outline - Canon GP405 Service Manual

CHAPTER 3 EXPOSURE SYSTEM
III. CONTROLLING THE SCANNING LAMP
A. Outline
The scanning lamp is a fluorescent lamp, and is turned on and off by the composite power
supply PCB using the control signals from the image processor PCB. The PCB has the following
functions:
• Controlling the scanning lamp pre-heating mechanism
• Turning on/off the scanning lamp
• Controlling the scanning lamp intensity
J706
Intensity control (PWM) signal
J714
J113
Error detection signal
J714
J113
Pre-heat control signal
J714
J113
J714
J113
3-4
Shading correction data
Composite power supply PCB
AC power supply voltage input
J103 J209
OFF signal
J103J209
J103J209
J112
Figure 3-301
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Scanning lamp
activation control
Pre-heating control
J301
CCD PCB
Scanning lamp (FL1)
Scanning lamp
J208
intensity sensor
J208