electroluminescent displays (was Re: fluorescent displays

[Steve Baldwin]

> << maybe I'm looking for electroluminescent displays ???
> 
> Do you mean something like those indiglo faces that are used on watches?
I've
> been hoping that someone would make gauges using indiglo-type
faces...they
> are super bright and also very cool looking!  :)
> (Is it just plastic with a neon light shining through it?)

There are vacuum fluorescent displays and there's an electroluminescent
backlight. The two are quite different and not owning anything with a
cockpit, I'm not sure which you are after.

Vacuum fluorescent displays are commonly used on video recorders and
microwaves. They have a green or blue-green character and emit light, so
they are visible at night. They can have graphical logos and symbols and
are encased in glass. They work on a similar principle to neon bulbs or the
old nixie tubes, where you put about 90V on the digit that you want on.

Electroluminescant backlighting uses a phosphor coating like that used on
oscilloscope CRTs and monitors. When it's in an AC electric field of a
couple of hundred volts, it glows with a blue/white light. The light is
quite broad spectrum, so it can have filters over it to provide a range of
colours. Because it just needs a thin phosphor coating and a couple of
electrodes, it is very thin, like a mylar film. It's usually used to
backlight LCDs (like the indiglo watches) although there is a company here
in New Zealand that can now screen print it any way you like. (Not cheap)

There are several other ways to backlight LCDs. The cheapest and most
common uses LEDs but this requires a bit of space behind the LCD. Another
is to use a fiberglass matt with continuous strands. One axis of the matt
has the strands extended out to form a fibre-optic bundle and that is
pointed at a light source. Where there is a bend in the strand (ie. the
weave), light is emitted so you get an even illumination under the LCD and
it doesn't need much height.

Steve.