Canon imageRUNNER 2270 Service Manual page 180

5.3.2.2 Analog Control Inside the Contact Image Sensor
The contact image sensor (CIS) is used to control analog image processing in the following
flow of work:
The light reflected by the original is collected by the rod lens array;
the light is then collected by the CCD array;
the light is converted into an electric signal by the CCD array (photo-conversion) for output.
The CCD array consists of a total of 8 channels (units). Each channel possesses its own
output correction table used to process an input intensity signal for gain correction for
output of an image signal.
Ideal output characteristics
Output
F-5-14
Be sure to correct the output among the channels using the following service mode items:
-if you have replaced the contact image sensor (CIS) and, as a result, a discrepancy occurs
in the output of image density among channels; or
-if the setting of CCD-LUT is other than '0' and you have replaced the reader controller
PCB.
Actual output characteristics
Input
Chapter 5
0006-5928
CCD channel x 8
5-15