Epson Stylus Color 980 Service Manual page 70

EPSON Stylus Color 980
Unlike previous EPSON ink jet printers, the number of 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 phases A and 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 the 4W1-2 phase excitation using the hardware and is
equipped with the necessary number of input ports (8 ports) for current
setting signals. Among these input ports, 4 ports 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 2-16 shows the excitation modes used for the CR motor and their
usage.
Table 2-16. CR Motor Excitation Mode and Usage
Excitation mode Usage
2-2 phase drive LQ print mode
1-2 phase drive Not used
Sort skipping
W1-2 phase drive
SLQ print mode
Wiping
2W1-2 phase drive
Capping
Moving from the
capping position
4W1-2 phase drive
Uncapping
Operating Principles
Minimum step
1/120" (0.212 mm)
1/240" (0.106 mm)
1/480" (0.053 mm)
1/960" (0.026 mm)
1/1920" (0.013 mm)
Electrical Circuit Operation Principles
Revision A
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