Konica Minolta bizhub C658 Service Manual page 1795

bizhub C658/C558/C458/C368/C308/C258
[2]
[3]
[1] Void image area at edge of paper
[3] Void image area at trailing edge of paper
3.3.6 Color registration control (color shift correction) system
(1) Overview of the registration control
• In a tandem engine, each four different color has an independent image reproduction process. Color shift may occur because of
variations in part accuracy. The color registration control system automatically detects color shift and correct color shift in the main and
sub scanning directions.
• The color shift detection sequence proceeds as follows. A pattern each is produced at the front and rear on the transfer belt. Each of IDC
sensors at the front and rear reads the corresponding pattern. The amount of color shift in each of the sub scanning and main scanning
directions is then calculated and stored in memory.
• The amount of color shift in the sub scanning direction is read from the pattern falling within the sub scanning detection range. The
amount of color shift in the main scanning direction is read from the pattern falling within the main scanning detection range.
• From data readings, the machine calculates how much the position of each of the different colors should be corrected. Based on the
calculated data, the machine controls each dot during image output, thereby correcting the color shift amount.
[1]
[4]
[1] Transfer belt
[3] Detection area for sub scanning direction
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 3. WRITE
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[4]
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[2] Void image area at leading edge of paper
[4] Laser emission area
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[2] Detection area for main scanning direction
[4] Movement direction of the transfer belt
O-20
SECTION (PH SECTION)