Print Signal Sequence - Canon QY8-1360-000 Service Manual

BJC-7100

1.3 Print Signal Sequence

The following describes the sequence of signals from the time the host PC sends the
print signals to the printer up to the point at which printing is performed.
a) The host PC sends print signals to the printer.
The print signals consist of print data and control commands.
b) The printer controller receives the print signals and temporarily stores them in the
DRAM receive buffer.
c) The MPU fetches the print signals from the receive buffer and separates the print
data from the control commands based on the program in the control ROM.
The MPU processes the control commands based on the program in the control ROM.
d) The MPU expands the print data in the DRAM print buffer.
e) The printer controller receives the request to start printing from the MPU and the
print data is sent from the DRAM by DMA to the printer controller.
f) The printer controller converts the print data into serial data for the respective BJ
heads and outputs this data to the BJ heads with control signals.
The drive circuits in the BJ heads convert the serial data to parallel format and
control the output of inks onto the print paper as indicated by the control signals.
g) The MPU and printer controller sense the status of the BJ heads and printer and
control the printer as a whole, including the motor drivers, etc.
Host PC
Drive
Circuits
BJ Head
• Black Head
• Ink Optimizer Head
• Color Head
• Photo Head
: Print Data
: Control
a
Controller
f
c
g
Commands and
Signals
Figure 4-3 Print Signal Sequence
The BJC-7100 supports the Canon extended (native) mode, but not
emulation. The print signals sent from the host PC are therefore Canon
extended mode signals converted by the printer driver.
b
c
Printer
d
e
d g e
c
g
MPU
g
4-3
Part 4: Technical Reference
DRAM
Receive
Buffer
Print Buffer
Control ROM
Motor Driver
Sensors
Logic Board