Separation Mechanism; Separation Charging Mechanism; Outline; Correcting The Output To Suit The Environment And The Toner Deposit - Canon ImageRunner iR8500 Series Service Manual

Chapter 8

8.8 Separation Mechanism

8.8.1 Separation Charging Mechanism

8.8.1.1 Outline

iR105i/iR105+ / iR9070 / iR85+ / iR8070
The separation mechanism is controlled for the following:
[1] DC bias constant current
[2] AC bias constant current
[3] output correction to suit the environment and deposit of toner (fuzzy control)
[4] output correction upon detection of leakage
Figure shows the construction of the control system for the separation charging mechanism.
When '1', the high-voltage
DC output is ready.

8.8.1.2 Correcting the Output to Suit the Environment and the Toner Deposit

iR105i/iR105+ / iR9070 / iR85+ / iR8070
The separation current output is controlled to an optimum level to suit the environment (conditions identified by the data from the environment sensor)
and the toner deposit (low, average, or high based on the count of black pixels).
8-36
Relay PCB
J723
J510A
0 V
1 16
HVDC-EN
15
2
14
3
4 13
When '1',
5 12
high-voltage
11
6
AC output is
7
10
ready
8
9
9 8
HVAC-EN
10 7
11
6
SPDC-CNT
12 5
PT/SP-ERR
13 4
HVAC-CNT
14 3
15
2
1
16
When an overcurrent
or an under current is
detected, '1'.
A voltage input between 0 and 12 V, used to control
the current level of the separation bias.
The level of the DC bias varied to suit the
SPDC-CNT potential.
500µA
J721
1 2 3 4
Separation
charging wire
J734
5
4
3
2
1
HVAC-CNT
1 1
HVAC-ON
2
2
24VP
3 3
GND
4 4
GND
5 5
J722
J741
When '1', high-
The AC bias voltage level varies
voltage output
according to the HVAC-CNT potential.
turns on.
12KVPP
8KVPP
F-8-49
3V
11V 12V
SPDC-CNT
AC+DC
J742
3V
11V 12V
HVAC-CNT
0006-9791
0006-9795