Epson Stylus Color 740 Service Manual

EPSON Stylus COLOR 440, 640, and 740 Chapter 2 Operating Principles
37
The followin
g
fi
g
ures show sectional drawin
g
s of the printhead while
waitin
g
to print and durin
g
printin
g
(
normal state and e
j
ectin
g
state
)
.
 Normal State:
Durin
g
the normal state, the PZT elements do not move and ink fills
the ducts between the ink cavit
y
and the nozzles.
(
Refer to Fi
g
ure
2-3.
)
 Ejecting State:
The printhead is desi
g
ned to operate at a hi
g
h fre
q
uenc
y
, and
g
oes
throu
g
h thousands of print c
y
cles each second. Durin
g
each print
c
y
cle, the main board transmits data to the nozzle selector IC
(
IR2C72C
)
, which is located on the printhead. This data determines
which PZTs are to be actuated in the current c
y
cle. At the same
time, the main board
g
enerates a hi
g
h-fre
q
uenc
y
drive volta
g
e.
Durin
g
each print c
y
cle, the nozzle selector applies this drive
volta
g
e to specific PZTs, as determined b
y
the print data. This
causes ink to e
j
ect from the nozzles in a specific pattern.
(
See
Fi
g
ure 2-4.
)
Figure 2-3. Printhead - Normal State
Figure 2-4. Printhead - Ejecting State
Nozzle
Nozzle Plate
Cavity
PZT
Ink Course

Epson Stylus Color 740 Specifications

General

Brand	Epson
Model	Stylus Color 740
Category	Printer
Language	English