Canon CiRC2550, Service Manual

Page: 260 / 774

Chapter 7
7-37
scraping spring and the toner feed screw are activated, and the toner on the hopper assembly is feed to the drum unit.
The above operations are controlled by the DC controller. The DC controller computes the amount of toner used from the ATR control results, uses this
information to judge how long the toner refill motor should be driven, and thus supplies the required amount of refill toner to the drum.
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[1] Stirring plate
[2] Agitating plate
[3] Scraping spring
[4] Sensor flag
[5] Toner feed screw
[6] Toner feed motor drive signal
[7] Toner feed motor error detection signal
[8] toner container
[9] drum unit
[10] Hopper assembly
M8 and M11: Toner feed motor
PS3 through PS6: Toner feed level sensor
2. Toner level detection
To execute correct toner feeding, this machine has a toner feed level sensor (PS3~PS6).
This sensor detects the sensor flag mounted on the shaft of the feed screw. This sensor flag executes reciprocating movement by the drive of the toner feed motor.
It is the structure that the toner feed screw rotates and the specified amount of toner is fed to the drum unit when the sensor flag moves back and forth once.
At the time of the toner feeding, DC controller monitors this sensor while driving the toner feed motor. The toner feed motor is stopped when the toner feeding is
completed. By executing this, the toner feeding is correctly implemented.
The following is a timing chart depicting when 4 A4 full-color prints are made (with an image ratio of 40%):
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[1] Drum supply
[2] Hopper supply
PS3 through PS6: Toner feed level sensor
M8 through M11: Toner feed motor
Error code:
E025-0000: Y developing assembly supply error
E025-0001: M developing assembly supply error
E025-0002: C developing assembly supply error
E025-0003: Bk developing assembly supply error
Any of the foregoing errors is identified when there is no change in the output of a specific sensor (PS3 through PS6) used for a particular developing assembly.
Reference:
While toner is being supplied, the toner supply motor (M8 through M11) is rotating counterclockwise (CCW). In other words, if all is normal, the toner supply
feedscrew will rotate, thus causing the output of PS3 through PS6 to change.
CW
CCW
[10]
M8 11
[8]
[9]
[1]
[2]
[4]
PS3 PS6
[5]
[6] [7]
M-CON
D-CON
[3]
250ms 250ms 250ms 250ms 500ms 100ms
[1] [2]
PS3 PS6
CL1 CL4
M8 M11
M2 M3
CCW CW