EPSON Stylus Color 900 Revision C
Operating Principles Electrical Circuit Operation Principles 72
Table 2-18 shows the excitation modes used for the pump/ASF motor
and their usage.
Table 2-18. Pump/ASF Motor Excitation Mode and Usage
2.3.6 Printhead Driver Circuit
The printhead driver circuit consists of 2 circuits: the common voltage
production circuit (a trapezoid waveform production circuit) on the C265
main board and nozzle selector on the printhead. The pre-driver
CXA2128 (IC15, 16) produces trapezoid waveform and the transistors
(Q3 - Q6) output it. Unlike previous products, data (serial data) is
independently transferred to each nozzle row to enable reduction in
data latch time required to form one dot, while nozzle selection is
performed by ASIC, which sends serial data directly to the nozzle
selector on the printhead synchronizing with the clock signal. (A block
diagram and the circuit diagram for the nozzle selector are not included
in this manual.) The printhead driver circuit block diagram is shown in
Figure 2-18.
Excitation phase
Usage Minimum step
2-2 phase drive
Fast absorption
Semi-fast absorption
Fast feed
1/720" (0.035 mm)
1-2 phase drive Micro absorption 1/1440" (0.018 mm)
W1-2 phase drive Not used 1/2880" (0.009 mm)
2W1-2 phase drive
Normal absorption
Normal feed
1/5760" (0.004 mm)
4W1-2 phase drive
Constant drive
Slow feed
Slow absorption
1/11520" (0.004 mm)
