Toshiba e-STUDIO2330C Service Manual page 371

The test patterns for the 4 colors illustrated below are regarded as one set. Several sets are printed
directly onto the transfer belt, and the pitch of the test patterns is measured by the color registration
sensors.
Corrections will be made after four types of deviation are calculated according the measurement:
parallel deviation in the secondary-scanning direction; deviation of write start position in the primary-
scanning direction; deviation of reproduction ratio in the primary-scanning direction and tilt deviation
Image position
aligning sensor (rear)
Transfer belt
rotation direction
Image position
aligning sensor (front)
Deviation
Parallel deviation in the secondary-
scanning direction
Deviation of write start position in the
primary-scanning direction
Deviation of reproduction ratio in the
primary-scanning direction
Tilt deviation
Because the color registration control of the equipment optimizes the laser write start position to correct
the deviation of 4 colors that appears uniformly on the paper, it cannot correct the following deviations
that fluctuate.
• Deviation caused by drum rotation errors
Deviation in the secondary-scanning direction of approximately 94 mm pitch caused by eccentricity
of the driving parts from the drum motor to the drum, or etc.
• Deviation caused by fluctuations in transfer belt speed
Fluctuating deviation in the secondary-scanning direction resulted from fluctuations in transfer belt
speed caused by eccentricity of the driving parts from the transfer belt motor to the transfer belt
drive roller, as well as by slippage between the transfer belt and the transfer belt drive roller
• Deviation caused by meandering of the transfer belt
Fluctuating deviation in the primary-scanning direction caused by meandering of the transfer belt
e-STUDIO2330C/2820C/2830C/3520C/3530C/4520C
TRANSFER UNIT
[Pk-c] [Pc-m]
[Sk]
[Wk-r]
K C
[Wk-f]
Fig. 14-2
Measurement/Calculation Pitch
(x=m, c, k)
[Pk-c], [Pc-m], [Pm-y]
[Wx-r]-[Wy-r]
([Wx-r]+[Wx-f])-([Wy-r]+[Wy-f])
[Sx]
© 2008, 2009 TOSHIBA TEC CORPORATION All rights reserved
14 - 8
[Pm-y]
Test pattern
[Wc-r]
M Y
[Wc-f]
Object of Correction
Laser write start position
(secondary-scanning direction)
Laser write start position (primary-
scanning direction)
Image writing frequency
Angle of reflection mirror in the
laser unit