Table of Contents
Advertisement
2. Operation
a. Primary charging high-voltage generation circuit
This circuit is controlled by the three signals (PRIMARY CHARGING AC BIAS DRIVE signal,
PRIMARY CHARGING DC BIAS DRIVE signal, and PRIMARY CHARGING BIAS VALUE CON-
TROL signal) sent from the DC controller PCB. The primary charging DC bias and primary
charging AC bias are generated in this circuit and applied to the primary charging roller.
The PRIMARY CHARGING AC BIAS DRIVE signal (/HV1AC) controls ON/OFF of the AC bias
applied to the primary charging roller. The PRIMARY CHARGING DC BIAS DRIVE signal
(/HV1DC0, /HV1DC1) controls ON/OFF of the DC bias applied to the primary charging
roller. It also shifts the voltage value of the DC bias.
The PRIMARY CHARGING BIAS VALUE CONTROL signal (HV1PWM) changes the value of the
primary charging DC bias in the image area. (See note)
PRIMARY CHARGING AC BIAS
DRIVE signal (/HV1AC)
PRIMARY CHARGING DC BIAS
DRIVE signal (/HV1DC0, /HV1DC1)
DC controller PCB
PRIMARY CHARGING BIAS VALUE
CONTROL signal (HV1PWM)
Note: The primary charging DC bias value in the image area changes with the developing DC
bias in each color according to the video data sent from the Video controller or the density con-
trol command.
b. Developing high-voltage generation circuit
This circuit is controlled by the four signals (DEVELOPING AC BIAS DRIVE signal, DEVEL-
OPING DC BIAS DRIVE signal, DEVELOPING BIAS VALUE CONTROL signal, and DEVEL-
OPING BIAS COLOR BLACK SWITCH signal) sent from the DC controller PCB. Developing
DC bias and developing AC bias are generated in this circuit and applied to the developing
cylinder.
DEVELOPING AC BIAS DRIVE
signal (/DEAC)
DEVELOPING DC BIAS DRIVE
signal (/DEVDC)
DC controller PCB
DEVELOPING BIAS VALUE
CONTROL signal (DEVPWM)
DEVELOPING BIAS COLOR
BLACK SWITCH signal (DEVACSEL)
The DEVELOPING AC BIAS DRIVE signal (/DEVAC) controls ON/OFF of the AC bias applied
to the developing cylinder. The DEVELOPING DC BIAS DRIVE signal (/DEVDC) controls
ON/OFF of the DC bias applied to the developing cylinder.
Primary charging
high-voltage
generation circuit
Figure 2-2-14
Developing
high-voltage
generation circuit
Figure 2-2-15
CHAPTER 2
Primary charging roller
Drum cartridge
AC+DC
Toner cartridge
AC+DC
Developing cylinder
2 - 21
Advertisement
Chapters
Table of Contents
Troubleshooting
