Canon BJC-55 Series, Service Bulletin

Page: 116 / 249

The HEAT ENABLE signals control the ejection of small and large ink droplets as
follows:
For each color, (Y, M and C), HENB B and A signals drive the front and back nozzle
heaters respectively. For black, HENB C and D signals drive the front and back
nozzle heaters respectively.
The HEAT ENABLE signal consists of the pre-pulse and the main pulse that optimize
ink ejection by constantly monitoring the head rank, the printer inner temperature
and head temperature. The ink is ejected by varying the HEAT ENABLE pulse
width.
Part 4: Technical Reference
BJC-50
4-6
HLATCH
0 1 2 3 4
128 or 136
1(0) 0(1)
1(0) 0(1)
1(0) 0(1)
1(0) 0(1) 1(0) 0(1)
1(0) 0(1)
1(0) 0(1)
HDATA
HCLOCK
Odd ENB
Even ENB
B ENB 0
B ENB 1
B ENB 2
H ENB A, B, C, D
Odd ENB
Even ENB
B ENB 0
B ENB 1
B ENB 2
H ENB A, B, C, D
Data transmission to shift resistor
Head Drive in HQ Mode (Divided into 16)
Head Drive in HS Mode (Divided into 8)
164
µ
s (6.43kHz)
164
µ
s (6.43kHz*)
92
µ
s (7.82kHz)
HQ
720dpi/smoothing
HS
Pre-Pulse
Main Pulse
1(0) 0(1) 1(0) 0(1) 0(1) 1(0) 1(0) 0(1)
1 Block
Variable Pulse
Width
1 Block
When using a black BJ cartridge, HENEB A and D are drive signals. When using the color BJ
cartridge, HENEB A and B drive yellow, magenta and cyan, and HENEB C and D drive black.
Odd ENB
Even ENB
B ENB 0
B ENB 1
B ENB 2
H ENB A, D
H ENB B, C
1 Block
Head Drive in 720dpi (Divided into 8)
Large and small dot printing
Figure 4-4 Print Signals