AR-C150 (serv.man5). ARC150-Basic Manual - Sharp Copying Equipment Service Manual (repair manual). Page 48

Correction of the image forming section is performed to maintain stable and high quality print even though there are some changes in the tempera-
ture, the humidity, the characteristics of consumable parts, and the operating conditions of the engine. 
In concrete, correction is performed by changing the control parameters related to the image forming section (process) and the image process opera-
tions. 
The above correction operation prevents against deterioration in the print qualities on color balance, gradation, background copy (dirty background),
due to changes in operating conditions.
It also reduces the necessity of servicing, reducing the number of service calls.

There are following correction items.

Item

NO.

Correction items

Factors

Purpose and effect

Change item

NOTE

1

Image density
sensor sensitivity
correction
(Calibration)
(Gain
adjustment)

Sensitivity change due
to dirt on the sensor
and temperature
change

Sensitivity change due to image
density sensor dirt or
temperature change is
corrected to assure correct
image patch density detection. 

LED drive
current (voltage)
for the sensor

2

OPC drum
marking sensor
sensitivity
adjustment
(Calibration)
(Gain
adjustment)

Sensitivity change due
to dirt on the sensor
and temperature
change

Sensitivity change due to OPC
drum marking sensor dirt and
temperature change is
corrected to assure correct
recognition of the OPC drum
type and control of the image
forming position (phase). 

LED drive
current (voltage)
for the sensor

3

OPC drum
deterioration
correction

Laser beam
power correction 

Photo sensitivity
decrease due to OPC
drum membrane
decrease and electrical
stress and photo stress

Photo sensitivity decrease due
to OPC drum membrane
decrease and electrical and
photo stress is corrected to
maintain the proper print density
and prevent against
background copy. 

Laser beam
power

Reset by SIM 24-7.

4

High density
(saturation
density) image
correction 

Developing bias
voltage
correction 

"OPC drum/developing
section
(developer/toner)
characteristics change
(Temperature/humidity
change,
developer/toner
deterioration)"

Density change and
background copy due to the
image forming section
characteristics change are
prevented. (High density section
is corrected.)

Developing bias
voltage

The factors of the
developing section
characteristics change
include the effects of
temperature and
humidity as well as
developer deterioration.

Main charger
grid voltage
correction 

Developing bias
voltage change due to
developing bias voltage
correction (change)

Correction for correction
(change) of the developing bias
voltage.  It is performed in order
to maintain the constant
difference between the
developing bias voltage and the
main charger grid voltage.
(Prevention against background
copy)

Main charger
grid voltage

If the difference
between the
developing bias voltage
and the main charger
grid voltage is not
maintained at constant
level, improper density,
background copy, or
carrier drop may be
resulted.

5

Transfer
capability
correction 

Transfer voltage
correction 

Transfer belt
characteristics change
(temperature/humidity
change)

Influence on the change in
transfer capability (transfer
conditions) is reduced to assure
stable transfer operation. 

Transfer voltage

"Paper kind (thickness,
material)"

Correction for change in
transfer efficiency due to paper
kind

Transfer voltage

Back print

Correction for change in
transfer efficiency due to
change in paper surface
conditions

Transfer voltage

AR-C150

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