Chapter 6 Principles of Operation
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7.5 Color Registration Control
The printer uses a tandem system where the drums and developers ex clusively for yellow, magenta, cyan,
and black are arranged respectively. The images are formed on the drums of respective colors and they
are overlapped to form one image, and in this case a color shift may occur. The color registration control
calculates how much the registration is shifted, and adjusts the ROS write ti ming.
The color registration control is made from a change in inside temperature an d the print count at the
execution of the process control.
The control is outlined below:
1) With no toner put on the BTR, the output value of SENSOR ADC ASSY is measured to determ ine
the threshold value.
2) The patches for color registration control are generated on the BTR. These patches are composed
of 10mm lines of K, C, K, M, K, and Y in this order by the amount of four disp ense counts, led by a black
trigger.
3) The density of patches generated by the SENSOR ADC ASSY is read.
4) The adjusting amount of registration shift is calculated from the threshol d value determined in 1)
and the patch density measured in 3).
5) The ROS write timing is changed from the adjusting amount of registration shift.
10mm
About one turn of BTR
engine principle0045FA
K
K
C
K
M
K
Y