Laser Emission Timing; Color Registration Control (Color Shift Correction) System - Konica Minolta BIZHUB C3100P Service Manual

[5]
[1] Index board
[3] Semiconductor laser
[5] Index mirror (K)
Y
[1] [2]
[10]
[1] G2 lens (Y)
[3] Return mirror (M)
[5] Return mirror (C)
[7] Return mirror (K)
[9] G1 lens

2.2.3 Laser emission timing

• When a ready signal is detected after the lapse of a given period of time after the print cycle has been started, a laser ON signal is output
from the MFP board.
• The laser ON signal triggers the firing of each laser light, which illuminates the index board via the polygon mirror, G1 lens, index mirror (K),
and Index lens. This generates an Index signal.
• This Index (Start of Scan) signal unifies the timing at which the laser lights are irradiated for each main scan line.
• The Index signal is generated only from the K laser light. For the other colors, the emission timing is determined with reference to K.

2.2.4 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. That in the
main scanning direction is read from the entire pattern.
• 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]
[2]
[3]
[4]
M C
[4]
[5]
[3]
[9]
O THEORY OF OPERATION bizhub C3100P > 2. WRITE SECTION
[2] Return mirror (light source)
[4] Polygon mirror
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K
[6]
[7]
[8]
[2] G2 lens (M)
[4] G2 lens (C)
[6] G2 lens (K)
[8] Polygon mirror
[10] Return mirror (Y,M,C,K)
O-3