21 Jan
2002
21 Jan
'02
1:31 p.m.
On Jan 21, 10:45, Mark Tapley wrote:
..."heater?" IIRC, Pete said these
transistors work up to 100 MHz and
they
are being used to drive *heaters?* Does that mean the
other 17 or so
connections to the print head carry the which-pixel information and
whatever (piezoelectric?) pulse it takes to actually send out the squirt
of
ink? Oy. Or are there 8 heaters and one for the jet
pulse, and the thin
17
carry the jet-selection info? Maybe I am going to be
be interested enough
to trace this whole circuit out. Or maybe I should just shred one of the
print heads to see what's inside it.
The 100MHz just means it's possibly over-specced -- but probably not by
much. The head travels at a fair speed over the paper and the dots are
small, so you want the jets to turn on and off fairly fast; and you want a
nice square wave (or at least fast rise and fall times) while you're doing
it, not some ragged aproximation to a bent sine wave. I don't know much
about inkjets, but isn't the very rapid and very localised heating part of
what generates the jet?
--
Pete Peter Turnbull
Network Manager
University of York