Printer Control Section; Printing Data And Control Signal Flow - Canon S6300 Service Manual

S6300

1. PRINTER CONTROL SECTION

The printer control section converts the data created and input by the printer driver into
printing data and printer operation signals and it also controls the driving of the print
head and electrical mechanisms while referring to feedback from various sensors.

1.1 Printing Data and Control Signal Flow

The signal flow starting with the printer receiving the printing data and ending with the
execution of printing is explained below.
a) The printer driver in the computer creates a print file from the image data and
compresses the print file. When the printer driver creates the print file, it obtains
data concerning the amount of ink to be ejected from the print head. The printer
driver refers to this ink ejection amount data. The printer driver can thereby create
an optimum print file for the print head.
b) The print data, including control signal output from the host computer, moves from
the interface controlled by the printer controller (on the logic board) and is captured
by the printer controller. The printer controller and DRAM are dedicated buses, and
the print data is stored in the DRAM's receiving buffer (ring buffer).
c) The print data stored in the receiving buffer is sent to the MPU. The firmware stored
in the control ROM is divided into the control command and print data. The control
command is processed in the MPU.
d) Since the print data is compressed by the printer driver, it is controlled by the
printer controller and uncompressed in the DRAM.
e) When the printer controller receives a printing start request from the MPU, it obtains
the print data in the DRAM print buffer.
f) The printer controller converts the print data into serial data and transfers it as the
printing signal to drive the print head. In the print head, the print data is converted
from a serial signal into a printing data signal and the printing is executed.
Printing Driving Method.
g) The MPU controls the printer controller, control ROM, and various motor drivers.
While monitoring the status of the print head and printer, it also executes overall
control of print driving. (See
)
Sensors and Their Functions and Feedback.
a
Host
computer
Printer
controller
f
c
Print head
g
MPU
: Print signal
: Control signal
Figure 3-1 Printing Signal Flow
DRAM
b
Receiving
c
buffer
d
Print buffer
e
Logic section
b
Control ROM
g
Motor driver
g
Sensors
3-1
Part 3: Technical Reference
(See
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