Driving And Controlling The High-Voltage System; Outline - Canon iR2020 Series Service Manual

[1] Between sheets
- At the end of printing
To prevent fogging of the drum, the developing DC bias is held higher than usual except during image formation.
To prevent the toner remaining on the photosensitive drum from sticking to the transfer charging roller, the transfer roller bias which is lower than that applied
during printing the is applied at the prescribed timing.
[1] Time until post-rotation

6.4 Driving and Controlling the High-Voltage System

6.4.1 Outline

iR2016J / iR2016 / iR2020 / / iR2016i / iR2020i
The voltage generated by superimposing the DC voltage over the AC voltage is applied to the primary charging roller and developing cylinder, and a positive or
negative DC voltage is applied to the transfer charging roller according to the instruction of the CPU on the DC controller PCB.
The primary DC bias and developing DC bias are changed according to the image density information sent from the image processor PCB, thus adjusting the image
density.
A negative DC voltage is applied to the electrostatic discharge needle and fixing film.
Print command
is received
STBY
Main motor
(M204)
Scanner motor
(M203)
Primary charging
AC bias
Primary charging
DC bias
Developing
AC bias
Developing
DC bias
Transfer bias
Static eliminator
bias
Fixing film bias
PRINT
Main motor
(M204)
Scanner motor
(M203)
Primary charging
AC bias
Primary charging
DC bias
Developing
AC bias
Developing
DC bias
Transfer bias
Static eliminator
bias
Fixing film bias
INTR PRINT
F-6-4
[1]
LSTR
Cleaning bias
F-6-5
[1]
PRINT
STBY
Chapter 6
0011-0650
6-3