XJ128 and XJ128 Plus Printhead
XJ128 Guide to Operation
Xaar Document no: D031010302 Version A
Page 8
2 General Product Information
2.1 The XJ128 printhead
The XJ128 inkjet printhead consists of a piezo based, 128-channel actuator with ink-supply filter and
drive circuitry mounted on a metallic chassis. The printhead is available in three different models.
Each model operates in a
‘
binary
’
mode, thus ejecting a single sized drop upon demand.
2.2 Xaar technology
As with all Xaar technology products the
printhead utilises Xaar
’
s patented shear
mode,
shared
wall
piezo
based
technology.
2.2.1 Xaar piezo technology
Xaar
’
s printhead technology is based upon a piezo
ceramic material (PZT). When a voltage is
applied across this material the material distorts or bends. Xaar uses this phenomenon by machining
rows of parallel channels into a PZT block. An electrode is then placed onto the sides of the channel
walls allowing a voltage to be applied across it. The way in which Xaar makes the wall bend due to
the applied voltage is known as
“
shear mode
.
”
Two channels share the wall, and hence the term
“
shared wall
.
”
These channels are filled with ink and a pressure wave inside the ink is generated due to the
distortion of the PZT walls. This pressure wave forces ink out of the end of the channels via the
printheads nozzle.