Canon MultiPASS C50 Service Manual page 103

5.3 Printing Signal
a) Black BJ cartridge drive control
The black BJ cartridge driving control is executed by dividing the head's 128 nozzles into 8 blocks (16
nozzles each). These blocks are further divided into odd and even blocks (8 nozzles each). The odd
blocks eject ink simultaneously, and the even blocks do so as well. The control signals for the former are
the block enable 1, 2, and 3 signals (BENB 1, 2, 3), and for the latter the signals are the even/odd enable
signals (Even/odd ENB).
The heat enable 0 and 1 (HENB 0, 1), which are the heater drive control signals for ejecting the ink,
comprise the pre-pulse and main pulse. To constantly achieve optimum ink ejecting, the internal
conditions such as the head's rank, printer temperature, head temperature are monitored, and the heater
drive pulse width is varied before the pulse is output. Also, the printing drive signal from the printer
controller is transferred to the BJ head's shift resistor according to the HLATCH timing.
The printing drive signal (HDATA) is latched and when the printing control signal and heater drive
control signal are output together, the heater for the applicable nozzles is driven, and the ink is ejected.
b) Color BJ cartridge drive control
The color BJ cartridge head's nozzle configuration differs from that of the black BJ cartridge. (The black
has 64 nozzles while the color has 24 nozzles each for Y, M, and C.) Therefore, the number of nozzles in
each control block is different from that of the black BJ cartridge. Also, since the heaters are driven
simultaneously for each color, the heater drive control signals used are the heat enable (HENB) 0, 1, 2,
and 3 signals. Otherwise, everything else is the same as with the black BJ cartridge.
For heat enable, the HENB 0, 1, and 2 signals drive the nozzle heaters for Y, M, and C. The HENB 3
signal drives the nozzle heater for black ink.
O
A
BE1
E A
O
A
BE2
E
A
O
A
BE3
E
A
O
A
BE4
E
A
O
A
BE5
E
A
O
A
BE6
E
A
O
A
BE7
E
A
O
BE8
E
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1718 19 20 21 22 23 24 25 2627 28 29 30 31 32 33 34 3536 37 38 39 40 41 42 43 4445 46 47 48 49 50 51 52 5354 55 56 57 58 59 60 61 6263 64
Figure 2-17 Printing Sequence (Black BJ Cartridge/HQ Mode)
B A
B
B
B
B
B
B
B
B
B
B
B
B
B
A B
A B
2-23
Chapter 2: Technical Reference
B
A B
A B
A B
A
A
A
A
A
A
A
A
A
A
A
A
BE1 to BE 8 : Block Enable 1 to 8
E : Even Enable
O : Odd Enable
A : Heat Enable 0
B : Heat Enable 1
B
B
B
B
B
B
B
B
B
B
B
B