Print Drive; Printing Drive Control - Canon BJC-1000 Service Manual

BJC-1000

1.3 Print Drive

To eject ink from the head for printing, the printer controller generates control signals
to the BJ head.
The control signals consist of the drive control signal for ejecting ink from the head's
nozzles and the temperature control signal for adjusting the head's temperature so that
the amount of ink ejected is uniform.
To achieve optimum printing, both these control signals are optimized by the printer
controller and sent to the BJ head through the carriage ribbon cable.
The drive frequency varies depending on the printing mode and BJ cartridge type.

1.3.1 Printing drive control

a) Black BJ cartridge drive control
The driving control of 64 nozzles in the black BJ cartridge is executed by the matrix
structure of 8 COM signals and 8 SEG signals. The COM signal connects the COM1
to COM8 circuits to the head drive power supply (VH) in order that the 64 nozzles
are ready to print in units of eight nozzles. While the COM signal is connected to the
head drive power supply, the SEG signal connects the SEG circuits (SEG1 to SEG8)
for the even- and odd-numbered nozzles to the ground, and applies the heater
voltage to the heater plate. The load on the AC adapter is reduced and ink charging
delay is prevented by driving the head in steps.
The SEG signal has two pulses, pre-pulse and main pulse. The pre-pulse does not
eject ink, but increases the head temperature to the appropriate value, and the main
pulse ejects ink. The printer controls each pulse width to obtain the optimum print
density according to the print speed and temperature.
b) Color BJ cartridge drive control
With exception of the following points, the head drive control of the color BJ
cartridge is the same as that of the black BJ cartridge.
The nozzle configuration of color BJ cartridge is different from that of black BJ
cartridge, and the COM 1 and 2 signals are used for driving the nozzle heaters for C,
COM 4 and 5 signals for M and COM 6 and 7 for Y.
The color BJ cartridge has 16 nozzles each for Y, M, and C, whereas the black BJ
cartridge has 64 nozzles for black only.
Nozzle 64
Nozzle 1
Mechanical Nozzle Arrangement
Figure 4-3 Nozzle Arrangement
4-3
Part 4: Technical Reference
1 25 41 49
9 17 33
2 10 18 26 34 42 50
3 11 19 27 35 43 51
4 44
12 20 28 36 52
5 13 21 29 37 45 53
54
6 14 22 30 38 46
23 31 39 47
7 15 55
16 24 32 40 48 56
8
* Nozzles not used in color BJ cartridge
Electrical Nozzle Arrangement
SEG 1
57
SEG 2
58
59 SEG 3
SEG 4
60
SEG 5
61
SEG 6
62
SEG 7
63
SEG 8
64