Displays That Harvest Light Instead Of Creating It 73
mach10 writes: "An article here shows that a scientist has been able to create fibers that collect ambient light, strong enough to power a dotted matrix for display. It can reach 30 times ambient light, and they are soon hoping to expand the area to replace signs on roads. Hrm ... But my sundial watch still doesn't work in the dark =\" Add this to some ultra-efficient light source (like white LEDs?), a low-power processor, human power and some solar cells, and most of my requirements for portable computing happiness would be met.
Re:Ambient light? (Score:1)
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Re:Cheap night vision? (Score:3)
They're already here (kinda). Binoculars (with large lenses) collect more light than the unaided human eye and can serve to amplify the light- you just need to find binoculars that have large lenses and low magnification. This works especially well in low light (dusk, not dark) situations.
Re:My cock (Score:1)
Re:Obvious problem (Score:1)
Light Fibre possibilities (Score:2)
Re:Ambient light? (Score:1)
I'm imagining a handheld with several thousand flourescent fibers sticking out. I think it would look like a troll doll. It'd look pretty funny in your pocket.
Re:Not a power source (Score:1)
Woah... duuude! (Score:2)
I always enjoy that ol Harvest light (Score:1)
Re:Not a power source (Score:1)
Solar cell heat problems (Score:1)
Re:I can't help it, (Score:1)
Re:Wow, those LEDs are a ripoff (Score:1)
See if the LED Museum's purchasing information page [att.net] has pointers to better prices for the LEDs you want. I very much recommend checking out Craig Johnson's LED Museum [att.net].
re: light (Score:1)
Combining many of these (Score:1)
____________________
So... (Score:1)
Does it ABSORB light? (Score:1)
Do these threads use light, or absorb it?
Because if they absorb it, this technology will make a room darker as it works. I don't see how it's possible to actually absorb light (instead of deflect or refract it).
But then, I am rusty on my physics.
Vesuvius
Re:Ambient light? (Score:1)
Janos Hajto of Napier University in Edinburgh says the screen is so efficient at harvesting light from the environment, that it even works at night.
Seems it works at night as well!
Why yellow LEDs? (Score:1)
Do you mean that yellow/green LEDs should be used to provide the ambient light for the fibers? That doesn't make sense, because even if (which I doubt) the dyes the fibers use will flouresce from just yellow/green wavelengths, you end up getting different colors out the ends of the fibers anyway. I suspect the fibers work best with either full-visible-spectrum ambient light, or with predominantly low-wavelength light, like blue/violet/ultraviolet light, because those wavelengths have enough energy to make things flouresce very well.
Or do you mean that we should all look at screens in colors that are close to our peak of vision, because they will appear brighter to us? Wait, I thought we wanted full color screens....
LEDs are mad cool, but if you're going to use them to illuminate these fibers, you'll probably want either white ones, for full spectrum color, or blue ones, for sheer energy to make the dyes in the fibers flouresce.
Only need a few cm, works under any light level (Score:5)
A similar technique is used in light-gathering spotting sights. These are popular with bowhunters, and are essentially a rod of fluorescing plastic (~5cm long, ~0.5cm in diam) that you mount on your bow to help you sight on the target. The end is tapered and set at a right angle such that the incident light that hits the side of the rod makes the tapered little point (~0.2cm in diam) glow really brightly. Based on my rough estimates of the dimensions, I'd say that the area of the side of the rod (capturing incident light) is ~100X the size of the glowing tip. As with the narrow fibers, it works under any light level except complete blackness, and remember, under very dim conditions, even a faintly glowing dot looks bright.
Hmmm (Score:1)
Everytime that little light bulb appears above my wifes head I could use this to suck the light energy away from it and I'd be right!
Whoohoo, I'd be right! That'd be a first!!
Trevor.
brakelights etc (Score:1)
LEDs (nearly) never need replacing, are fairly shock insensitive, are bright. I can't wait till they're cheaper for the colors besides red (which is free, thanks to Radio Shack!:) )
simon
Oh really? Go to a gun store. (Score:2)
At any rate, this is nothing new.
Jon
Solar work (Score:1)
Heard About A Similar Thing... (Score:1)
It was a panel formed in a way that light coming in perpendicular to its surface would cause light to come out one or more edges, kinda like the invention(s) described in this forum, except I don't know if his used fibre.
His device was comparatively inexpensive to manufacture.
But, turns out it'd stop working after awhile. Thinking about it later, I wondered if maybe it was kinda chaotic internally, except with only one path for light to leave. Maybe that meant the light would bounce around a lot. And maybe there's no such thing as a "perfect" reflector, so each "bounce" cost not just a bit of energy, but a bit of thermal transfer to the imperfect reflectors.
So I wonder whether the problem was that the heat would build up inside, due to all the excess reflections, and finally break down the structure itself.
Anyway, it sounded pretty interesting. He said the people who helped him look into what it'd take to "fix" it felt it'd cost so much more to manufacture it to not fail that it'd no longer be a cost-effective element of a system.
What I'm suggesting here is that the invention itself, functionally speaking, is probably not very new or exciting...but if it can be profitably manufactured and sold, that might be pretty exciting!
Re:Oh really? Go to a gun store. (Why?) (Score:1)
Human power, solar and collection systems (Score:3)
So, the human powered option is out for many applications.
The fibers *MAY* have applications in solar systems. What kills the cells is heat buildup more than anything else, and the concentrator *MIGHT* not allow infra-red to pass, but allow the other parts of the bandwidth to pass.
A company called (methinks) marathon solor used to have a light conentration system for its cells to boost output. Such a method is economical *IF* the cells are expensive and the fiber is cheap. (oh, and they are now bankrupt)
Given that you can now buy solar cells as shingles to go on your roof, I have to question if the economics are right to use fiber concentration on silicon cells.
Home power [homepower.com] is a nice place for figuring out how to get off the grid, and this gent [redrok.com] thinks the future for cheap solar is heliostats. Combine a heliostat with a helium-as-working-fluid sterling cycle prime mover, and you may just have a winner!
Re:Light Fibre possibilities (Score:2)
Everlasting light (Score:2)
Richy C. [beebware.com]
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Re:Not a power source (Score:1)
Um... Okay. Well, actually, the article says, "Hajto started by mixing fluorescent dyes into a transparent polymer called polycarbonate. He then stretched the polymer into fibres."
The flourescent dyes actually do amplify the light, albeit only UV light if I'm not mistaken. So LEDs still wouldn't really work (unless there are UV LEDs?) but still. I think that's actually the major thing that this thing has over plain fibre-optics (besides the fact that plain fibre-optics wouldn't really accept any new light from the sides... or maybe I'm mistaken again).
Just thought I'd add my $0.02.
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No worries.
Re:Everlasting light (Score:1)
Re:Everlasting light (Score:1)
The loosers will yell and send killers to shoot you.
____________________
What the real breakthrough is (Score:1)
A miracle! (Score:1)
It's very promising. But I wonder how many years untill it is available/affordable for us, common mortals. ASAP, I hope.
Hugs
Re:Incompatible with Liouville's theorem? (Score:1)
Ambient light? (Score:1)
Still, maybe its a useful idea to combine with existing LCD tech? Imagine a handheld that no longer had the dissapearing-screen-in-bright-sunlight effect we all know and love! Perhaps add these fibers in addition to a backlight and we'd be talking big-time potential for improvement.
-s
Re:inaccuracy in the article (Score:1)
between
MY STIFFY and my HARD COCK
Re:Everlasting light (Score:1)
JDWilso2
Re:Everlasting light (Score:2)
If you're not wasted, the day is.
Re:I can't help it, (Score:1)
Cheap night vision? (Score:1)
And perhaps a surveilance system that needs no power? Just some "old cables" lying around in the back yard, and I know if it is the kids, the wife, the mistress or the IRS that is coming. .
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Size issues? (Score:2)
I've a feeling that this may also be fundamentally limited by the amount of light around. 30 x 0 is still 0, so for night work, you may need some more severe amplification.
Grab.
Always the right brightness (Score:3)
This would solve a lot of my problems with my TFT-screen.
Re:inaccuracy in the article (Score:2)
switching the voltage on liquid crystals requires a lot less power than backlighting
Re:Does it ABSORB light? (Score:1)
What do you think the color black is? It is what we see when we look at an object that absorbs all the visible light that hits it instead of reflecting or refracting it.
Saw something similar years ago (Score:1)
The take they had on this was to place efficient but expensive solar cells on the edges of the plastic for more cost effective electricity production.
Wouldnt the fibers need to be open to the ambient light to work. If they are contained within a screen wouldnt this stop the required light from reaching them in the first place.
Thought: Does this just work for visible light or would it work for other wavelengths? (x-ray, etc)
Could this be used as radiation shielding with the fibers intercepting, for example, a laser and re-radiating the energy harmlessly away from the shield.
Re:Everlasting light (Score:1)
very rusty. (Score:1)
any surface that isn't a perfect mirror will make a room darker just by sitting there. light can most certainly be absorbed by objects- how else would you be able to heat things by radiation? when the sun shines on you, you feel warm because you are absorbing some of the energy in the sunlight, and it raises your skin temperature.
Re:Everlasting light (Score:1)
Actually, where I live they have started using LED's in stop lights and such because they've found that they last for a longer period of time and seem to be more noticeable to people.
Also of interest is that the rear brake lights of a Chevy Impala now use LED's. Just a random fact...
Re:suplementary light (Score:1)
Re:Obvious problem (Score:1)
Thing I love about google is that you can click "cached" next to the search result, and get a copy from google's cache, of pages that have been deleted. And quite often it's quicker! :-)
White LED efficiency that of parent LED (Score:1)
A truly efficient backlight for this fellow's screen would be three colors of LED (RGB), not a white one.
Re:suplementary light (Score:1)
Re:Light Fiber possibilities (Score:1)
Re:White LED efficiency that of parent LED (Score:3)
Interestingly, the blue Nichias has quite a lot of UV output, which can be used for blacklight applications with a filter.
Unfiltered CCD cameras hate the blue Nichia light, probably because of the UV stuff. They think the (rather pretty) deep blue light is tinted magenta or cyan.
3000% energy efficiency (Score:3)
It's a great idea, but the problem is that you're getting more energy out of the system than you put in. Energy efficiency doesn't go over 100%, so either these phosphors have energy hidden in them (and they'll run out over time, like batteries), or this system collects a lot of ambient light and concentrates it into a small space.
No true color (Score:1)
I can't help it, (Score:5)
Never mind...
--
Vote Homer Simpson for President!
Obvious problem (Score:3)
But it doesn't say how long each fibre needs to be to produce its two dots of light. I assume that (up to a point) as you increase the lenght of the fibre, the ends get brighter. So for 30x ambient do you need a 1 meter fibre? 5 meters? 100 meters?
Let's see if we can find some real linkage...
If you're not wasted, the day is.
Re:3000% energy efficiency (Score:5)
If you're not wasted, the day is.
Human Power? (Score:1)
//Humming
Re:inaccuracy in the article (Score:2)
Re:inaccuracy in the article (Score:2)
As I recall, there is a small transient current during switching (basically, it's like charging a capacitor), but practically no continuous current draw. That's why LCDs are low in power.
--Joe--
Wanna program the Intellivision? Get an Intellicart! [schells.com]
suplementary light (Score:2)
If there's no ambient light to be had (and you don't want to waste your high-power flashlight, which creates a strong beam using lots of battery juice), you switch on the small bank of LEDs (or are there even more efficient light sources? I don't want to drop in cyalume sticks all the time;) )which fit in your portable computer analogous to the backlight in a normal notebook
What I wonder is how long a fiber has to be, and in what configuration, to capture enough light to be useful (For instance, will it collect efficiently if a good portion is coiled? That would seem important in a space-saving screen
Also, what is the tightest resolution that could be achieved with these little dots? Lite-bright? 15" SXGA?
The article doesn't really address those issues, unfortunately.
simon
Yellow LEDs are better in this case (Score:1)
Kids toy of the future (Score:1)
Even the samurai
have teddy bears,
and even the teddy bears
9 "small calories", not "large calories" /gram (Score:1)
not 9000, as he says. He's thinking of "large calories.
Quick reality check, burn a gram of fat (1/28th oz - or a fingernail-sized blob). Does he really think that this will raise the temperature of a liter (quart) of water by 9 C (16 F). Even with the inefficiencies of combustion and heating, it's clear he's a few orders of magnitude off
Please adjust his calculations accordingly when you read the article.
Re:Light Fiber possibilities (Score:1)
With regards to "fiber plumbing" you'd be better of actually reading the article before posting. It is fairly clearly stated that these fibers produce only a single color(a wavelength) of light whereas white light is a combination of several colors in right proportions. And were not even talking about trying to recreate natural(sun) looking light, which is a lot more difficult.
Re:Not a power source (Score:1)
Wow, those LEDs are a ripoff (Score:2)
Not a power source (Score:5)
Some folks are misunderstanding the principle here. These fibers are collecting ambient light, not amplifying it. Like all things in the physical world, there is a power loss through the fiber, so you are not getting something for nothing.
Think of this invention as analogous to a rain gutter where light is the water and the gutter is the optical fiber. When it rains, water is "collected" along the length of plumbing that edges the roof. No extra water is created, but the volume of water at the end of the pipe is an amplification of what would have been there without the gutters.
The innovation here is that no one has created a fiber that easily collected ambient light along its length before. The only other way I know of to focus ambient light is to use mirrors or lenses. Clearly the fiber sounds cheaper, less bulky, and less fragile.
Re:Everlasting light (Score:1)
Therefore the intensity of the light produced by the fiber when the only light source is itself (if you can get it kick started) will not increase. So this is not really an infinite power supply
Cost? (Score:1)