Specifications

Rev. A Outline of Operation 2-5
TM-J8000/J8000P Technical Manual
Confidential
Data Input and Printing
Figure 2-7 shows a block diagram of the driver IC. Each driver IC receives input through its DI
(data) and XSCL.(sync) lines. These inputs are implemented separately on each of the two driver
ICs (so that each receives data independently).
The serial print data enters through the DI and moves into the SHIFT REGISTER in sync with
the XSCL signal. The data then moves into the LATCH in accordance with the LP timing signal.
The latched data passes through the inverter and sets the appropriate bits of the segment
driving, causing the nozzles to operate.
To control actual printing, the driver IC feeds the V3 terminal voltage waveform selectively to
the COM and SEG outputs. (See Fig. 2-8.) Ink ejection is generated when there is a difference
between the COM and SEG output voltages. To print a segment, the IC produces a positive
difference for the first pulse followed by a negative difference for the second pulse. To withhold
a segment, the IC maintains a zero difference.
The level and width of the applied pulse is adjusted according to the head rank (specific to each
head), the gap rank, and the temperature as detected by the thermistor. On the Main circuit
board, the head rank read information indicated by short-land setting. The gap rank sets DIP
switch on the Main circuit board to match the gap-rank marking on the head board.
Figure 2-7 Block diagram of driver IC