Canon IR2800 Turning On/Off the Bias, Controlling the Current Voltage/Current to a Specific Level

CHAPTER 4 IMAGE FORMATION SYSTEM

2.2 Turning On/Off the Bias

The primary charging roller bias is turned on/off as follows:

2.2.1 DC Bias

[1]When the primary charging output enable signal from the DC controller PCB goes ‘0’, the DC bias output control signal (pulse signal) is generated.

[2]The DC bias is sent to the primary charging roller.

2.2.2 AC Bias

[1]When the primary charging output enable signal from the DC controller PCB goes ‘0’, the AC bias output control signal is generated.

[2]The AC bias is generated to the primary charging roller.

2.3 Controlling the Current Voltage/Current to a Specific Level

The output level of the DC/AC bias applied to the primary charging roller is controlled by the DC/AC bias output control signal from the PW-CPU.

2.3.1 Controlling the DC Bias to a Specific Level

[1]The output voltage level of the DC bias is fed back to the PW-CPU, and the DC bias output control signal is varied as needed to suit the level when driving the transformer.

[2]The DC bias is made to assume a specific voltage level.

2.3.2 Controlling the AC Bias to a Specific Current Level

[1]The output current level of the AC bias is communicated to the drive control circuit and is compared against the reference current level; the result is used to vary the AC bias output control signal as needed to drive the transformer.

[2]The AC bias is made to assume a specific current level.

COPYRIGHT © 2001 CANON INC. CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001 4-5 P