Controlling Separation Charging; Outline - Canon GP605 Service Manual

CHAPTER 6 IMAGE FORMATION SYSTEM
F.

Controlling Separation Charging

1.

Outline

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 6-313 shows the construction of the control system for the separation charging mecha-
nism.
When '1', the high-voltage
DC output is ready.
J510A
1
HVDC-EN
2
3
4
5
6
7
8
9
10
11
12
13
HVAC-CNT
14
15
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.
Figure 6-313 Construction of the Control System
6-32
COPYRIGHT © 1999 CANON INC.
Relay PCB
1 2 3 4
J723
0 V
16
15
14
13
When '1',
12
high-voltage
11
AC output is
10
ready
9
8
HVAC-EN
7
6
SPDC-CNT
5
PT/SP-ERR
4
3
2
1
When '1', high-
voltage output
turns on.
The level of the DC bias varied to suit the
SPDC-CNT potential.
500µA
J721
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
The AC bias voltage level varies
according to the HVAC-CNT potential.
12KV
CANON GP605/605V REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
3V
11V 12V
SPDC-CNT
AC+DC
J742
PP
8KV
PP
3V
11V 12V
HVAC-CNT