Basic Sequence Of Operation In Response To A Press On The Start Key (Book) - Canon Color imageCLASS MF9170c Service Manual

Chapter 4

4.2.2 Basic Sequence of Operation in Response to a Press on the Start Key (book)

imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
Reader motor
(M12)
Document lamp
(LAMP1,2)
Reader HP sensor
(SR717)
*1 Gain correction: The gain ratio of the analog video signal output from CCD is adjusted to be a fixed value.
*2 Move shading correction: Even when the document density is constant, the CCD output level does not become constant due to the following reasons.
- Variation in pixels for CCD
- Difference of the transmitted light intensity between the center and the surrounding of the lens
- Difference of the light intensity between the center and the surrounding of the document lamp
- Deterioration of the document lamp
Shading correction is performed to correct unevenness of the CCD output level.
1. Document lamp ON
(At lamp OFF only)
2. Gain correction
3. Move shading correction
4. Original scanning
* Book Position: the position at which the motor is accelerated to prepare for reading.
4-4
Move shading correction *2
HP shift
Book Position shift
Scan movement
Start key ON Gain correction *1
STBY
HP Book Position
F-4-5
Home position
(Shading position)
Book Position *
F-4-6
HP shift
SREADY
Read end position
: Motor forward
: Motor reverse
: Document lamp ON
: Reader HP sensor ON
Read start position Read end position
0019-8966
HP