Canon IR3300, IR2800, IR2200 manual Controlling the Primary Charging Roller Bias, F04-201-01

CHAPTER 4 IMAGE FORMATION SYSTEM

2 Controlling the Primary Charging Roller Bias

2.1 Outline

Part 2>Chapter 5>4.4 “Controlling the Primary Charging Roller Bias”

The machine’s primary charging is a direct charging method that uses a charging roller. In addition to a DC bias, the charging roller is subjected to an AC bias to ensure stable charg- ing.

The following items relate to the control of primary charging:

[1]Turning on/off the bias.

[2]Controlling the DC bias to a specific level of voltage.

[3]Controlling the AC bias to a specific level of current.

[4]Controlling the photosensitive drum resistance detection mechanism (APVC control).

[5]Controlling the AC bias based on the readings of the environment sensor (humidity) and the soft counters.

[6]Controlling the DC bias based on the reading of the drum sensor (temperature).

DC controller PCB

		Composite power supply PCB
24 VDC input from			+24V
main power supply		J135
	Primary charging			Transformer	Primary DC
J301		J136		drive signal
	output enable
					charging high-
-B4	signal	-B9		DC bias
						voltage
				output ON
						transformer
				signal
						(T502)					Primary
				DC bias
										DC bias	charging roller
				output		Output	Voltage
				control signal						output	J130-4
	Serial communication					control	detection
			CPU-PW	Current level
				(APVC measure-
Print/standby mode signal				ment)		Current
	AC bias level signal					control
	DC bias level signal										Photosensitive
APVC measurement data				Voltage level
											drum
J301		J136				Primary AC			AC bias
									output
				Transformer		charging high-
-A3		-A10
				drive signal		voltage trans
-A1		-A12									Drum sensor
						former
				AC bias output		Drive		Current			(temperature)
				control signal		control	detection
											Environment
											sensor
J311-A2				Measurement result							(humidity)

J302-B14 Measurement result

F04-201-01

The primary charging output enable signal is used as the AC pulse ON sig- nal when the developing bias is being controlled.

Memo

4-4 P COPYRIGHT © 2001 CANON INC. CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001