Epson LQ 1050 - B/W Dot-matrix Printer - Page 105

REV.-A
Printhead Drive Pulse Width Control
The width
of the printhead drive pulse is controlled by the CPU (~PD78 10HG). The CPU monitors
printhead drive voltage VP (+24 V) at ANO, kand controls the width of the printhead drive pulse (output
from PC6 of the CPU) by making it longer or shorter according to changes in the drive voltage, so as
to keep the drive voltage constant in order to stabilize print quality. (See Figure 2-50.) Figure 2-51 shows
the relationship between
printhead drive voltage and print drive pulse width.
350
Print Drive 340
Pulse Width 330
(M s)
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21.6
24
Drive Voltage
Figure 2-51. Print Drive Pulse
320
310
300
26.4
V DC
(Vp)
Width
2-61