Registration Control (Color Shift Correction) System - Konica Minolta magicolor 8650 Service Manual

Theory of Operation Ver. 2.0 Nov. 2007
7.2.6

Registration control (color shift correction) system

A. Overview of the registration control
• In a tandem engine, in which an independent image reproduction process is provided for
different colors, incorrect color registration, or color shift, is more likely to occur due to
individual PH assemblies being out of correct position or the relevant parts being out of
accuracy. Due to the registration control system that automatically detects the color shift,
the color shift in both main scan and sub scan directions can be corrected.
• The color shift detection sequence proceeds as follows. A color shift detection pattern in
the sub scan direction is created at the front and rear sides on the transfer belt. The IDC
registration sensor/YC and IDC registration sensor/MK read the corresponding pattern to
calculate the amount of color shift in the sub scan direction and save the data. A color
shift detection pattern in the main scan direction is created at the front and rear sides on
the transfer belt. The IDC registration sensor/YC and IDC registration sensor/MK read
the corresponding pattern to calculate the amount of color shift in the main scanning
direction and save the data. Based on the data representing the amounts of color shift,
the machine calculates how much each of the different colors should be corrected. The
correction data is further stored in memory. Based on the data stored in memory, the
machine controls each dot during production of image outputs, thereby correcting the
color shift (varying the timing at which the LD is turned ON).
• The color registration control system is activated at the timing when the image stabiliza-
tion sequence gets started.
Detection pattern for sub
scanning direction
Transfer belt
7. Write section (PH section)
Detection pattern for main
scanning direction
4038T2C007AA
IDC registration sensor /YC
(IDCS/YC)
IDC registration sensor /
MK (IDCS/MK)
17