Process Correction System - Sharp SF-2314 Service Manual

(5) Process correction system

1) Outline of the correction system
This model is provided with the correction system for the optical unit
and the photoconductor drum unit. The combination of the two cor-
rection systems provides stable clear copy.
These functions are to maintain the copy quality for a long time and to
correct the characteristics of the parts, and are controlled by the
software and invisible from the outside.
2) Correction operation
1. Photoconductor drum unit correction (Photoconductor
drum sensitivity correction)
Cleaner
Fig. 2
VCL
Correction level
(CL voltage)
Fig. 3
The photoconductor drum is subject to mechanical stress by the
cleaning blade, resulting in wear in the OPC layer. In addition to that,
the photoconductor drum receives optical stress from the copy lamp.
These stresses reduce the photo sensitivity of the photoconductor
drum, producing unnecessary dirt copy. This trouble is removed by
adjusting the copy lamp voltage. For this model, however, to reduce
the number of service calls, the copy lamp voltage is automatically
dropped according to the reduction in the photo sensitivity of the
photoconductor drum to correct it.
Develop
OPC drum
Fig. 1
(NEW)
CTL
CGL
Correction level is initialized by Simulation 46 or
by replacing the photoconductor drum.
0 100
Change the tickness of the carrier transport layer (CTL).
By the developper.
By the cleaner blade.
(USED)
CTL
CGL
Manual mode exposure 1
200 300
Drum rotating time
The drum rotating time from installation of a new photoconductor
drum is counted by the timer and the copy lamp voltage is corrected
in every mode. (Refer to Fig. 3.)
The correction is performed within the range of the max. supply volt-
age of the copy lamp. (The rotating time of the photoconductor drum
can be checked with Simulation 44-4.)
* The correction level is initialized by Simulation 46 or by replacing
the photoconductor drum.
* Replace the OPC drum for every 40K copies. After replacement,
be sure to reset the drum count value to "0" with SIM 24-7.
The replacement timing of the OPC drum is indicated by lighting
the OPC drum replacement lamp. The copy count of the OPC
drum can be checked with SIM 22-12.
5 – 12
Wear down
Photo mode exposure 1
Manual mode exposure 5
Photo mode exposure 5
min
400 500