Lamp Lighting Circuit - Canon CANOSCAN D1230 series Service Manual

CHAPTER 2
B. Lamp Lighting Circuit
1. Scanning Lamp Lighting Circuit
When the scanner is powered on, or the host computer sends a scan command, ASIC turns
the scanning lamp lighting signal (LAMP) ON to light the scanning lamp.
The reflected light from the document is focused on the light-sensitive device CCD (charge-
coupled device) via the five mirrors, lens and FARE unit.
The scanner is provided with a lamp OFF function for energy saving. A built-in timer to be set
by the device driver is counted during lamp ON and turns the scanning lamp OFF when no
scan command is sent for a certain period.
Host
Computer
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COPYRIGHT
Lens
Main PCB
LAMP
ASIC
Figure 2-7
©
2001 CANON INC. CANOSCAN D1230U/D2400U REV.0 MAR. 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Document Glass
Scanning Lamp
CCD
FARE Unit
Scanning Unit
CCD
PCB
GND
GND
Inverter
PCB