Canon Color Bubble Jet BJC-2000 Series, Service Manual

Page: 72 / 136

Part 4: Technical Reference
4-4
BJC-2000
b) Color BJ Cartridge (Multi-Drop) Drive Control
The multi-drop type color BJ cartridge's printhead has 136 nozzles and each nozzle
has two heaters located one in front of the other. The printing operation using this
multi-drop type color BJ cartridge is (dependent/influenced) by how these heaters
are controlled.
The sequence of ink ejection is as follows. The 136 nozzles has 8 function blocks (16
nozzles/block) and each block is separated into two functional units. Hence, each
functional unit has 8 nozzles. Ink is consecutively ejected from each unit.
Selection of the nozzles to be ejected is done by BLOCK ENABLE signals 1, 2 and 3
(BENB 1,2,3) and the EVEN/ODD ENABLE signal (Even/Odd ENB). HEAT ENABLE
(HENB 0,1,2,3) is the heat drive control signal for ejecting ink.
The HEAT ENABLE signal controls ink ejection as follows:
HENB 0: signals the nozzle (black) at the back
HENB 1: signals the nozzle (black) at the front
HENB 2: signals the nozzle (color) at the front
HENB 3: signals the nozzle (color) at the back
The HEAT ENABLE signal is made up of the prepulse and the main pulse. To
optimize ink ejection, the head rank, printer's inner temperature, and head
temperature are constantly monitored. The ink is ejected by varying the HEAT
ENABLE pulse width.
HLATCH
0 1 2 3 4
128or136
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 1
B ENB 2
B ENB 3
H ENB 0,1,2
H ENB 3
Odd ENB
Even ENB
B ENB 0
B ENB 1
B ENB 2
H ENB 0,1,2
H ENB 3
Data Transmission to Shift Resistor
Head Driving in HQ Mode (Divided into 16)
Head Driving in HS Mode (Divided into 8)
1 Block
154
µ
s (6.51kHz)
77
µ
s (13.02kHz/9.76kHz*)
109
µ
s (9.19kHz)
HQ
720dpi
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
*9.76kHz: Color/1pass:
Figure 4-4 Printing Signals