HP Color LaserJet Professional CP5220 Service Manual - Page 51

ITB unit presence detection, ITB cleaning mechanism, All rollers disengaged, Only black roller engaged

Page 51 highlights

The primary transfer roller engagement and disengagement control engages the ITB with the photosensitive drum or disengages the ITB from the drum depending on the requirements of the print job. There are three states of the primary transfer rollers. ● All rollers disengaged: The ITB disengages from all the four photosensitive drums. This is the state during a standby period, and it is the home position for the primary transfer rollers. ● All rollers engaged: The ITB engages with all the four photosensitive drums. This is the state for full-color jobs. ● Only black roller engaged: The ITB engages with only the black photosensitive drum. This is the state for the black-only jobs. The operational sequence of the primary transfer roller engagement and disengagement control is as follows: 1. The fuser motor drives the primary transfer disengagement solenoid to rotate the primary transfer disengagement cam. 2. As the cam rotates, the YMC slide plate or the Bk slide plate moves to right or left. This causes the primary transfer roller to move up or down. 3. The ITB engages with or disengages from the photosensitive drum depending on the movement of the primary transfer rollers. The DC controller determines an abnormal primary transfer roller disengagement mechanism and notifies the formatter when it does not detect a specified signal from the primary transfer disengagement switch even though the primary transfer disengagement solenoid is driven. ITB unit presence detection The DC controller detects the ITB unit presence by monitoring the primary transfer disengagement switch. The DC controller drives the primary transfer disengagement solenoid for specified times during the initial rotation period of the following: ● The product is turned on ● The product exits Sleep mode ● The door is closed The DC controller determines an ITB unit absence and notifies the formatter when it does not detect a specified signal from the primary transfer disengagement switch. ITB cleaning mechanism The cleaning blade in the ITB cleaner scrapes the residual toner off the ITB surface. The ITB motor drives the residual toner feed screw and the screw deposits the residual toner in the toner collection unit. The DC controller detects whether the toner collection unit is full by monitoring the ITB residual toner full sensor. When the DC controller determines the toner collection unit is full, it notifies the formatter. ENWW Image-formation system 39

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The primary transfer roller engagement and disengagement control engages the ITB with the
photosensitive drum or disengages the ITB from the drum depending on the requirements of the print
job. There are three states of the primary transfer rollers.
All rollers disengaged
: The ITB disengages from all the four photosensitive drums. This is the
state during a standby period, and it is the home position for the primary transfer rollers.
All rollers engaged
: The ITB engages with all the four photosensitive drums. This is the state for
full-color jobs.
Only black roller engaged
: The ITB engages with only the black photosensitive drum. This is the
state for the black-only jobs.
The operational sequence of the primary transfer roller engagement and disengagement control is as
follows:
1.
The fuser motor drives the primary transfer disengagement solenoid to rotate the primary transfer
disengagement cam.
2.
As the cam rotates, the YMC slide plate or the Bk slide plate moves to right or left. This causes the
primary transfer roller to move up or down.
3.
The ITB engages with or disengages from the photosensitive drum depending on the movement
of the primary transfer rollers.
The DC controller determines an abnormal primary transfer roller disengagement mechanism and
notifies the formatter when it does not detect a specified signal from the primary transfer disengagement
switch even though the primary transfer disengagement solenoid is driven.
ITB unit presence detection
The DC controller detects the ITB unit presence by monitoring the primary transfer disengagement
switch. The DC controller drives the primary transfer disengagement solenoid for specified times during
the initial rotation period of the following:
The product is turned on
The product exits Sleep mode
The door is closed
The DC controller determines an ITB unit absence and notifies the formatter when it does not detect a
specified signal from the primary transfer disengagement switch.
ITB cleaning mechanism
The cleaning blade in the ITB cleaner scrapes the residual toner off the ITB surface. The ITB motor
drives the residual toner feed screw and the screw deposits the residual toner in the toner collection
unit.
The DC controller detects whether the toner collection unit is full by monitoring the ITB residual toner
full sensor. When the DC controller determines the toner collection unit is full, it notifies the formatter.
ENWW
Image-formation system
39