🚀 go-pugleaf

"Cory Seligman" <coryms+google@azazel.eng.monash.edu.au> wrote in message
news:a64581c0.0309242126.7a4fe4ee@posting.google.com...
> Hi all.
>
> I've successfully made a linear optical encoder with a stroke of about
> 25cm using a flattened steel rod with a nice shiny surface, and gluing
> on a laser printed transparency with a pattern of stripes. This works
> find with a 1mm pattern, and a homemade detector. The detector is an
> IR LED, a small lense and a Honeywell HLC2701 encoder detector
> chip/opto thingy.
>
> No worries, except it's fiddly. The lense and detector and pattern
> have to be adjusted just right, and it's hard to put together.
>
> So I got some Agilent HEDR-8100 detector chips. they have the lenses
> built in and do all the hard work for you. The only problem is that
> they're 150 lines per inch, which is more than I can do reliably on a
> laser printer. So I'm looking for alternatives.
>
> Does anyone know of somewhere I can get stripes like that printed
> directly on the steel? Or etched?
>
> Any thoughts on producing a clear strip with black stripes
> photographically?
>
> Or maybe a replacement reflective optical encoder detector that works
> on a 1mm stripe spacing? As far as I can tell, the Agilent one is the
> only device of its type.
>
> Thanks in advance,
>           Cory


Have you tried using a high quality ink jet type printer with ink jet
transparency?  Even the local Walmart will sell Lexmark printers that claim
up to 2400dpi or up to 11ppm capability and only cost $35.  2400dpi aught to
be way more than adequate for the job.  You have to use the right type of
transparency though (a laser transparancy or the wrong type of ink jet
transparency will yeild terrible results).

Using my ordinary Epson ink jet printer I regularly develop etched copper
PCBs with line sizes sometimes as small as say 5 mils wide.  I haven't
extensively tested smaller features because I haven't really had much need
for it, but I think it is certainly possible given todays ink jet
technology.  If you aren't going to be using any photoresist and copper
etching I should imagine the quality would be a fair amount better as well
(with just the plain transparency).