Itb Speed Control - Ricoh B132 Service Manual

IMAGE TRANSFER AND PAPER TRANSFER

6.12.8 ITB SPEED CONTROL

[B]
[A]: MUSIC sensors
ID Sensor – K
[B]: ITB position sensor 1
[C]: ITB position sensor 2
[D]: ITB encoder strip
For full color and black-and-white printing on plain paper, and for thin paper, the
ITB speed is 282 mm/s.
For OHPs, and Thick Paper 1 and 2, the speed is 141 mm/s (1/2 speed).
NOTE: For OHPs, the fusing unit line speed is 100 mm/s (1/3 speed). (16.14.1)
The machine uses three MUSIC sensors [A] to control the speed of the drum motor
to prevent color registration errors during full color printing. (See section 6.7.4.)
There are two ITB position sensors Sensor 1 [B] and Sensor 2 [C] above the
encoder strip scale [D] on the rear edge of the ITB.
• ITB position sensor 1 monitors the belt speed. The CPU uses this information to
adjust the speed of the belt to account for eccentricity of the image transfer roller,
differences in the thickness of the belt, belt slippage, and the load placed on the
ITB by friction between the rollers at paper transfer.
• ITB position sensor 2, located 20 mm from sensor 1, ensures that the number of
gradations on the edge of the ITB in this 20 mm gap remain constant. This
detects stretching or shrinking of the belt, and the ITB drive motor speed is
adjusted to compensate.
B132/B200
[D]
[C]
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(
, ID Sensor Y, M, C
[A]
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(16.7.4, 6.11.3)
6-100
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B132D308.WMF
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