XEROX DFC165 & DWC 165c Service Manual
2-17
2.3.5 Printer Unit
The facsimile machine has a bubble ink jet system which uses a special head and prints
on plain paper.
The bubble ink jet print head consists of an interchangeable cartridge, which
contains a sponge soaked with liquid ink, which is ejected from 50 nozzles made of a
nickel and gold component, under the control of the signals that reach an electrical
circuit consisting of 50 resistors (Fig. 2-13).
cartridge
nozzles
electrical
circuit
sponge
Each nozzle generates a drop of ink
when the corresponding resistor is pow-
ered (+24 Volt) for a few microseconds.
The resistor is heated and the ink that is
in direct contact with it evaporates, ex-
panding like a bubble and pressing the rest
of the ink against the nozzle.
nozzle
+24V
+24V
ink
Fig. 2-13 Composition of the print head
resistor
bubble