EPSON AcuLaser C9200N Revision D
OPERATING PRINCIPLES      Operating Principle of Main Unit Mechanism 40
Confidential
REGISTRATION CONTROL (COLOR SHIFT CORRECTION) SYSTEM
 In a tandem engine, in which an independent image reproduction process is 
provided for each of the four different colors of toner. Incorrect color 
registration, or color shift, is therefore more likely to occur due to each of 
the PH Units being out of correct position. The color shift correction 
system automatically detects any misalignment among the different colors, 
correcting it both in the main scanning and sub scanning directions.
 The color shift correction is made when the Front Door is opened and 
closed, the Transfer Belt is removed and reinstalled, the Main Power 
Switch is turned OFF and ON, or "Calibration" is carried out from the 
Control Panel.
Figure 2-8.  Registration Control (Color Shift Correction) System
SKEW CONTROL MECHANISM
 When the PH Unit is mounted on the main body installation plate, image 
distortion (skew) occurs due to mounting error. Therefore the PH Unit 
adopts the correction system.
Figure 2-9.  Skew Control Mechanism 1
 The main body skew can be corrected by adjusting the dial of the 
corresponding PH Unit (Y, M, C).
Figure 2-10.  Skew Control Mechanism 2