EPSON Stylus Color 900 Revision C
Operating Principles Electrical Circuit Operation Principles 70
Unlike the previous EPSON ink jet printers, the number pf the phase
excitation input ports in the motor drive IC of this printer has increased
to 8. The previous micro step system used total of 4 phase excitation
input signals for both Phase A and Phase B. (Stylus COLOR, Stylus
PRO series, and Stylus PRO XL series are exceptional, since they
transfer 4-bit serial data from ASIC to the motor driver.) This is because
the micro stepping was controlled by the software only. On the other
hand, LB1847 enables 4W1-2 phase excitation using the hardware and
is equipped with the necessary number of input ports (8 ports) for
current setting signals. Among 8 input ports, 4 are allocated to each
phase, A and B. Therefore, 16 types of current setting data can be
constantly sent to the driver IC. The LB1847 controls the micro stepping
system by exciting the corresponding phase based on the combinations
of the setting signals sent from the ASIC.
Table 2-17 shows the excitation modes used for the PF motor and their
usage.
Table 2-17. PF Motor Excitation Mode and Usage
Excitation phase
Usage Minimum step
2-2 phase drive Not used 1/720"(0.035 mm)
1-2 phase drive
Fast feed 1
Fast feed 2
Special fast feed
1/1440"(0.018 mm)
W1-2 phase drive Not used 1/2880"(0.009 mm)
2W1-2 phase drive Middle-speed feed 1/5760"(0.004 mm)
4W1-2 phase drive
Normal feed
Micro adjust feed
Slow feed
1/11520"(0.004 mm)
