Canon Color iR C3480, Service Manual

Page: 249 / 774

Chapter 7
7-26
F-7-30
[1] Color displacement detection signal
UN16: color displacement sensor A
UN15: color displacement sensor B
D-CON: DC controller
M-CON: Main controller
A. Start-Up Timing
- at power-on
- when the front cover is opened/closed
- during recovery from sleep
- during initial rotation upon detection of a change in the environment (condition 1)
- between sheets upon detection of a change in the environment (condition 2)
- When new drum unit is installed
Condition 1:
as a result of comparison against the previously detected machine inside temperature, a change of 4 deg C or more exists
Condition 2:
- the standby time has lasted 10 min or more and the machine inside temperature has changed 1 deg C or more
- during continuous printing, the machine inside temperature is different from the previously detected temperature by 4 deg C or more
B. Main Scanning Write Start Correction
1. Particulars of Control
The machine writes a main scanning position detection pattern of each color on the ITB, and compares the measurement value (A) and the reference value (B) stored
in the DC controller to find out the degree of color displacement (C). If displacement is detected in main scanning direction, the machine changes the timing at
which writing starts in main scanning direction.
D-CON
M-CON
Video Data
UN16
UN15
ITB
Y
M
C
BK
Y
M
C
BK
Laser Scanner Unit
[1] [1]