Sharp MX-4100N Service Manual page 485

2. Operational descriptions
A. Transfer
(1) Transfer operation
a. Transfer operation
PTC
Toner images on the OPC drum are transferred to the primary
transfer belt by applying the positive high voltage to the primary
transfer roller.
Negative charge is generated by the PTC unit, and this weakens
positive charges on the transfer belt, reducing the attractive force
between the primary transfer belt and toner.
By this operation, the transfer efficiency in the secondary transfer is
improved.
Next, the positive high voltage is applied to the secondary transfer
belt, and toner images on the primary transfer belt are transferred
to paper. In the monochrome mode and the color mode, the black
(K) transfer voltage is selected.
b. Cleaning operation
In the cleaning operation, the polarity of the applying voltage of the
secondary transfer belt is made negative, and unnecessary toner is
transferred to the primary transfer belt, and it is cleaned by the pri-
mary transfer belt cleaning blade, and transported to the waste
toner section.
(2) Primary (intermediate) transfer roller separation
The primary transfer roller operates pressing all the rollers, sepa-
rates all the rollers, or presses only black depending on the opera-
tion mode.
When the roller separation clutch (1TURC) turns ON, the transfer
cam rotates to shift the primary transfer link and the primary trans-
fer arm linked with the cam in the arrow direction, performing sepa-
rating operation of the roller.
All pressing
All separating
Constant
current
Pressing only black
It also performs all pressing, all separating, or pressing only black
with the roller separation sensors (1TUD_CL, 1TUD_BK) and the
separation detection arm.
All pressing
All separating
Pressing only black
The primary transfer drive and the secondary transfer drive are
commonly used with the black developing motor.
Constant
voltage
MX-5001N TRANSFER SECTION L – 3
mechanism and contents
1TUD_CL
ON
OFF
OFF
1TUD_BK
OFF
ON
OFF