Hacking An Inkjet Printer

[MMS]

I have an old inkjet printer and was taking it apart (an old Lexmark).
I looked at the back, and there looks like there is a matrix of copper
connections back there. Just tinkering, I took a 9V batter with two
wires, and tried touching a few of these pads to see if I could get it
to fire....some sputtering, but not much.

Does anyone know about inkjet printers and cartridges? Is there a good
website that might help me out (I am googling this idea as well)? I
would love to be able to figure out how to make the cartridge fire with
some simple electronics (its part of a much bigger curiosity I have
festering in my mind)...thanks!

-M-

 

[Bob Myers]

I have an old inkjet printer and was taking it apart (an old Lexmark).
I looked at the back, and there looks like there is a matrix of copper
connections back there. Just tinkering, I took a 9V batter with two
wires, and tried touching a few of these pads to see if I could get it
to fire....some sputtering, but not much.

Thermal inkjet print heads deliver the ink in TINY
droplets (on the order of picoliters), and have to be
driven with carefully-timed-and-limited pulses. They way they
work is through a very rapid, very high temperature, and very
localized heating of tiny resistive elements which essentially
cause the ink to "explode" out the nozzle and thus be
transferred to the paper. Trying to drive those heads
with a 9V battery will do very little (outside of likely burning
out the resistive elements).

Bob M.