2.5. PCBs AND THEIR FUNCTIONS
2.5.1. SBU (Sensor Board Unit)
The light reflected from the document is picked up by the CCD (Charge
Coupled Device) and converted into an electrical signal. The CCD sends both
odd and even pixel video signals to the multiplexer, where these signals are
merged. The signal is amplified and digitized then sent to the SCU.
SCU
CCD
Sample
hold
Sample
hold
Multiplexer
Gain
control
A/D
converter
Ref.
White level
selection
Relative
Absolute
G404D505.wmf
DETAILED SECTION DESCRIPTIONS
October 9th, 1995
PCBs AND THEIR FUNCTIONS
2-20