Sharp SF-1120 - Manual (Page 43)

(4) Transition of photoconductor surface potential
(5) Photoconductor drum sensitivity correction
In this model, fall in sensitivity due to long use of the photoconductor
drum is corrected by the copy lamp light intensity to prevent against
considerable change in copy quality.
The photoconductor drum sensitivity fall correction is performed as
follows:
(6) Process control function
[Summary]
The process control function detects the density of the standard toner
image formed on the photoconductor, the density of the initial image
and controls the charging grid voltage so that the same level as the
initial image density is provided.
That is, the process conditions are established and the high voltage
output and exposure level are controlled to stabilize the toner density.
In this model, the density sensing level is automatically set.
D L BL Charge Exposure Develop Transfer Separate Clean
Dark area
Developing bias voltage
Light area
Residual potential
-730V
-215V
Cleaner
OPC drum
Develop
CTL
CGL
CTL
CGL
Sim46
CLV
0
1step = 0.33
(Sim46)
(NEW) (USED)
Time (min)
R
F
MAin control PWB
High voltage PWB
(Light quantity
correction)
CPU density
judgement
I/O MC grid
output selection
MC grid bias
output (density
correction)
in each mode
Mark
5 – 14