Question on general feasibility:
I've had the idea that I would like to use end glow fiber optic cable to essentially create a seven segment display. I would drill pin holes in a material (ie wood or drywall) and line up the fibers of one cable in a straight line to create one segment, repeat this 6 more times with six more cables to complete the makeshift seven segment display, repeat all that 2 more times to be able to display 3 digits. Could I rig up a way to illuminate a bunch of small cables using something like this LED matrix shield http://www.adafruit.com/products/494 as the illuminator?
Example small cable: http://www.fiberopticproducts.com/store/product_info.php?cPath=8_19&products_id=819)
Or do I generally need pretty powerful LED's to illuminate? (I could always make my own LED matrix) Each cable, from end to end, would probably be between 2 to 4 feet.
Edit: I wouldn't require it to be visible during the day or in brightly lit area, just clearly visible in the dark/dusk.
You can make a start at estimating how good it could be by looking at overlaps between the area of original lcd and capture area of plastic optical fibre, multiplied by the solid angle of original lcd output overlap with the solid angle of fibre capture (which can be about the same as you can measure in its output if the input is held against a flat light source or very close to a bulb filament).
I'd expect that you'll find that
i) the source illuminated elements are not the same size as the fibre
ii) the source solid angle has about 1/4 overlap with the capture solid angle of plastic optical fibre, maybe less.
Worth your time poking it for an hour to get some idea of the solid angles, but I'd expect too much loss so not a great project.
I've got a car with dashboard illumination that works on a similar principle. It's surprisingly simple and works well enough at night. It just has an ordinary incandescent lamp as a light source, in a holder with several fiber optic strands pointing at it. The strands are routed to the dashboard where they are push fitted into translucent plastic housings. The whole housing glows when the lamp is on.
ad2049q:
You can make a start at estimating how good it could be by looking at overlaps between the area of original lcd and capture area of plastic optical fibre, multiplied by the solid angle of original lcd output overlap with the solid angle of fibre capture (which can be about the same as you can measure in its output if the input is held against a flat light source or very close to a bulb filament).
I'd expect that you'll find that
i) the source illuminated elements are not the same size as the fibre
ii) the source solid angle has about 1/4 overlap with the capture solid angle of plastic optical fibre, maybe less.
Worth your time poking it for an hour to get some idea of the solid angles, but I'd expect too much loss so not a great project.
So I just watched this video, this guy just takes a bunch of filaments and hot glues it to the end of an LED: How to attach fiber optic filament to an LED - YouTube Light was visible at the end of the fibers, I guess by what you'r saying it's more complicated than that? Or just really sub-optimal? What if I were to use a different type of led to attach to the fibers http://www.o-digital.com/uploads/2226/2231-1/Flat_LED_472.jpg for example.
I'm only probing your opinion because I don't want to spend $$ ordering this stuff to test theories with low potential.
Very much suboptimal, rather than impossible.
My day job a few years back was designing connections between optical waveguides (very tiny fiddly things) and optical fibre. 50% losses there would have been a showstopper. In your application though, just to want to see it, you probably can tolerate such losses.
The flat ended LED in the picture might be ok for getting the fibre near to the source, but I might prefer to buy roundtops and clamp or glue the fibre at some best distance away. It is a probem of conventional lens design to get that right. The other way to get it might be to cut the tops off cheap roundtop encapsulated LED and polish the flat until it looks more like your picture but with less than 0.2mm of solid plastic between the LED inside and the new flat surface which you might glue to. You might also want a look at surface mount LED types. Though they mostly make less light, if there is no obstruction from encapsulation, you can get the fibre closer to the chip, and end up with same or greater light out of the fibre.
If you can find plastic optical fibre 0.6mm diameter or larger, that might do what you want.
The choice of glue is really important for long term. Avoid anything which might yellow with age, especially in the light from that LED.
Even if you chicken on the project, it would not cost much to buy a pack of LED's and observe on cardboard at 30cm the pattern of light which comes out. The best match to the pattren which comes out of your fibre will have possibility, all else at best, of getting the best possible light capture. The roundtops which I have all let out a ring pattern which is not the best.
With a "big" optical fibre, it is ok to have an LED smaller than the fibre.
