Canon ImageCLASS MF4690, Service Manual

Page: 35 / 182

Chapter 2
2-1
2.1 Construction
2.1.1 Function Configuration
0016-1809
The functions of this host machine are mainly composed of the 7 blocks: System
Control System, Scanning Control System, Printer Control System, Laser Scanner System, Image Formation System, Fixing System, Pickup/Feeding System.
Below is the block diagram.
F-2-1
2.2 Basic Sequence
2.2.1 Basic Operation Sequence
0016-1810
The operations of this host machine are controlled by CPUs of the SCNT board within the Reader Controller System and the DCNT board within the Engine Control
System. The table below shows the purpose of each interval and the outline of the operations of reader unit and the engine from turnon of the power supply to stop
of each motor after printing.
T-2-1
interval name definition of interval purpose remarks
WAIT (wait) Interval between turnon of the
power supply and the end of the
initial drive To clear the drum surface potential
and to execute the cleaning of
transfer charging roller Presence/absence of cartridge is detected during this interval.
STBY (standby) Interval between the end of WAIT
or LSTR and input of print
command from SCNT board, or
interval between the end of LSTR
and turnoff of power supply To make the host machine ready for
printing
INTR (initial rotation) Interval between the input of print
command from SCNT and turnon
of the pickup solenoid To stabilize the photosensitive drum
as a preparation for printing
Also to clean the transfer charging
roller
PRINT (print) Interval between the end of initial
rotation and turnoff of the primary
high-voltage output To form an image onto the
photosensitive drum based on the
video signal input from the SCNT
board and to transfer the toner image
onto media
LSTR (last rotation) Interval between turnoff of the
primary high-voltage output and
stop of the main motor To fully deliver the final sheet
printed
Also to clean the transfer charging
roller On input of print command from the SCNT board, host machine
enters INTR immediately after LSTR. However, depending on the
conditions shown below, the host machine may not start INTR
immediately.
-media size
-temperature of the fixing assembly
System Control
System
Laser / Scanner System
Printer Control
System
Pickup / Feeding System
Fixing System
Image Formation System
Scanning Control System