EXP Computer C4077-90960 - Manual (Page 92)

High Voltage Power Distribution
The High Voltage Power Supply (HVPS, see Figure 5-4) applies a DC biased
AC voltage to the primary charging roller and the developing roller, and a
programmed DC voltage (depending upon the phase of the printing process)
to the Transfer Roller. Refer to the General Timing Diagram (Figure 5-22)
at the end of this chapter for HVPS timing information.
Toner Cartridge Detection
A toner level detector inside the toner cartridge is connected to the HVPS
when the toner cartridge is installed. If the toner level drops below a
predefined level, the TONER LOW message will appear on the display panel. If
the toner cartridge is missing, INSTALL TONER CARTRIDGE
will be displayed.
Print Density Adjustment
The HVPS also controls the image density by varying the voltages applied
to the developing cylinder in the toner cartridge. These voltages determine
the amount of toner applied to the photosensitive drum. Print density is
adjusted from the control panel (Print Quality Menu), or from the driver
software.
High Voltage Power Supply Contacts
Drum Ground
Transfer Roller
Post Transfer Bias
Toner Registration/
Toner Sensor
Developing
Roller Bias
Primary
Charging Roller
Fuser Bias
Figure 5-4
5
Functional Overview
Functional Overview 5-7