Making a hole in a flat panel display (literally)

On Tue, 20 Jan 2004 07:03:12 -0800, DIAMOND Mark R. wrote (in article ):

But you still haven't told us the application. Is it really that secret?

Thia might just work if you used an LED display ; there are areas on these which have no wires so you could probably drill a hole through it if you were careful.

-A

I found it pretty reasonable even if a bit naive. Care to tell the world what was so unbelievable? Or were you just setting yourself up to walk all over a beginner for kicks? Inquiring minds want to know.

- YD.

probably to mount a camera, like this;

interesting for video conferencing to have the camera 'in' the screen so you can make eye-contact.

Alex.

No ... it's not a secret. ... studies on insect vision. Question is how to construct a display of an experimental stimulus (artificial flower is a good analogy, even if the stimulus is nothing like a flower) that also provides a honey bee with a sugar reward. That is the reason for wanting to have a display surrounding a tube. Typically, a feeder tube comes through a stimulus pattern drawn on paper, but having a dynamic display, rather than paper, would be much more useful.

The person who commented on those funny joke flowers which squirt unsuspecting people in the face was not that far off the mark!

-- Mark R. Diamond

I also didn't think it was naive. But then it might be naive not to think so. I guessed that all pixels immediately below and to the right of the "hole" would stop working, but I wasn't sure of just how the internal circuitry is organized. The part that never occurred to me was that the liquid of the LCD is continuous across all pixels and would leak. I still actually don't see how the liquid can be a continuous layer AND allow independent driving of the pixels.

-- Mark R. Diamond

through a

working ...

the

I read in sci.electronics.design that DIAMOND Mark R. wrote (in ) about 'Making a hole in a flat panel display (literally)', on Wed, 21 Jan 2004:

The liquid is an insulator and the electrodes are pixel-sized. Only the bit of liquid between the pixel electrodes responds to that pixel's voltage.

Could this 'sugar reward' be a liquid? I would think you could have a thin straw from the edge to the center of the display. Another concern is what the insect is really responding to. I read many years ago of such an experiment of insects being able to reliably discriminate between two very close shades. It was later discovered that the two shades were made/printed with different processes, and had very different reflectivities in the infrared band, which was what the insects were actually responding to.

Those poor, unsuspecting insects...

-----

I have real doubts as to how an insect will percieve a colour display. Anyway, the vastly simpler way to do this is to use a thin tube (clear tubes are available with diameters of well under a millimeter) going across the display, and a tube at right angles poking out.

Yup, color vision for bees extends into what we call "invisible" UV; they look for UV-reflective patterns on flowers that your average LCD isn't designed to replicate. Or is the OP planning to use the LCD as a selective shutter with a UV source behind it? I don't think the glass they're made of will transmit enough to be worthwhile, nor will dark pixels block enough to make the right patterns even if the glass transmits UV. Besides, what about aliasing/moire patterning due to the mismatch of the rectangular-array LCD image and the hexagonal-array eyes of bees?

Sounds good to me, if the LCD is UV-capable.

Mark L. Fergerson

I read in sci.electronics.design that Ian Stirling wrote (in ) about 'Making a hole in a flat panel display (the reason!!!!!)', on Wed, 21 Jan 2004:

Bees have excellent colour vision, extending into the UV, and can detect polarization, to which we are quite insensitive.

Consequently, their resistor colour code includes two extra colours that we can't see. They need them, because they count in twelves, of course.

Shouldn't that be "they count in Bs" :), that would be base 11 not 12

sci.electr>

Reminds me of my daughter's second grade science fair project. As everyone knows, hummingbird feeders are red and are filled with red sugar water because hummingbirds are attracted to red - wrong! She set up an experiment with identical feeders colored red, blue, yellow and green and logged the levels over a period of three weeks or so. The rate of consumption was virtually identical for all colors, in fact, the red was slightly less popular than the other three. Not bad for a seven year old.

Bob

sci.electr>

to

good

provides a

than

Consider projection. You can get LCD screens designed to be used on overhead projectors, and a similar projection system could be used to project the image of a screen onto a normal sheet of frosted plastic. Also has the advantage of keeping the electronics away from the insects.

Best Wishes

Or a sheet bonded to the display with a very narrow groove in it. If the index of refraction of the sugar solution and the sheet are identical it will be totally invisible...

But indeed be aware of the 'designed for human eyes' aspect of the displays.

Thomas

I read in sci.electronics.design that Roger Hamlett wrote (in ) about 'Making a hole in a flat panel display (the reason!!!!!)', on Wed, 21 Jan 2004:

The trouble usually arises from the converse effect.

I read in sci.electronics.design that Mjolinor wrote (in ) about 'Making a hole in a flat panel display (the reason!!!!!)', on Wed, 21 Jan 2004:

Only the very old ones have 5 and a half legs.

That's another consideration: LCD displays of ANY type are strongly polarized - Unless I've completely misunderstood everythign I've ever learned about them, it's the basic principle of how they work, in fact. When not energized, the "crystal"'s polarization is "twisted" 90 degrees to the light source's polarization, blocking transmission. When energized, it's "untwisted" to match the polarization of the light source, allowing the light to pass through. This is hinted at in the name of the old "Supertwist" displays, which used a liquid crystal compound that, if memory serves correctly, had a *MUCH* wider range of "twist" available - Something like triple the "range" of normal LCD material.

I'd say chances are *VERY* high that a bee would see an LCD display much like we see a piece of flat black paper: A monochromatic, practically featureless surface.

That's not quite correct on a couple of points - not ALL types of LCDs rely on polarization (some work via a switchable light-scattering effect, for instance), and the way the standard twisted-nematic (TN) or "supertwist" (STN) types operate isn't quite as described above. But it's certainly close enough with respect to the vast majority of color displays that might be used in this application, with regard to the fact that they DO pretty much all output polarized light. (Using an LCD display with polarized sunglasses can be interesting, to say the least...:-))

Better to go with a plasma panel, if it MUST be a "this flat screen" - or what's wrong with the good ol' color CRT?

Bob M.