Canon imageRUNNER 2270 Service Manual page 191

Chapter 5
-CCD drive
-CCD output gain correction, offset correction
-CCD output A/D conversion
2) Digital Image Processing
-shading correction
Contact image sensor CIS)
CCD(1 line)
Analog
image
signal
Analog image
processing
-gain correction
-offset correction
CCD/AP circuit
5.3.6.2 CCD Drive
The machine's CCD sensor is a 1-line linear image sensor consisting of 7488 photocells.
After completion of photoelectric conversion in the light-receiving block, the signals are
output to the AP circuit in the reader controller circuit board in parallel for each channel
(total eight channels) of the CCD array.
5-26
CCD
control signal
CCD
drive control
Gain
correction
data
A/D
conversion
Digital
image signal
10
F-5-26
Reader controller PCB
EEP-ROM
Target value
CPU
SRAM
Digital
image signal
Shading
correction
8
J502
0006-5931