Canon iR7086, Service Manual

Page: 268 / 735

Chapter 7
7-22
F-7-29
7.7.5 Detecting the Toner Level and Controlling the Toner Supply Mechanism
0010-8067
iR7105 / iR7095 / iR7086
The following shows the components associated with the machine's toner supply control system:
F-7-30
DC controller PCB
J510A J723
J721
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0 V
24 VH 24 VH
HVDC_REMOTE
DEV_DC_CNTR
DEV_AC_ON
GND
GND
1 2 3 4
Relay PCB
Developing cylinder
J732
Voltage input between 0 and 12 V,
used to control the voltage level
of the developing DC bias.
500V
Image area
Non-image
area
The developing DC bias varies as follows
according to the potential of DEV_DC_CNTR:
3V
11V 12V
DEV_DC_CNTR
De
v
eloping DC bias
AC output: 1200 Vpp
When '1', high-voltage
output is ready.
When '1', the developing
AC bias is generated.
2
1
17
18
High-voltage DC PCB
Magnet roller
Developing assembly toner sensor TS3
Toner sensor TS1;inside the buffer
Buffer toner lower limit sensor TS2
Purpose: to keep the toner inside the developing assembly to a specific level.
Operation: upon detection of the absence of toner, the machine rotates the magnet
roller to supply toner to the developing assembly.
Purpose: to detect the absence of toner inside the buffer.
Operation: upon detection of the absence of toner,
the machine stops the ongoing operation, and
indicates a message to that effect.
Purpose: To keep the toner inside the hopper to a specific level.
Operation: If the absence of toner is detected, the toner feeding screw
inside the sub hopper is rotated to supply the buffer with toner.
Sub hopper toner sensor (TS4)
Toner bottle
Sub hopper
Purpose: to keep the toner inside the sub hopper to a specific level.
Operation: upon detection of the absence of toner, the machine rotates
the toner feedscrew inside the sub hopper to supply toner to the buffer.