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Organic LED Could Replace Light Bulbs?
egrinake writes to mention a BBC article about a 'natural' replacement for lightbulbs. From the article: "The organic light-emitting diode (OLED) emits a brilliant white light when attached to an electricity supply. The material, described in the journal Nature, can be printed in wafer thin sheets that could transform walls, ceilings or even furniture into lights. The OLEDs do not heat up like today's light bulbs and so are far more energy efficient and should last longer."
There's only one question every time. How much light/W does it produce (lm/W)? And what is the price for the 'OLED bulb'.
:)
h tmlu/lightdintro2.htmlh tmlu/lightdintro.html0 4_LED_Paper.pdf
And... do not compare it to traditional light bulbs. Traditional light bulbs are dead.
Of course, LEDs have achieved a lot in producing more and more light, but currently it is some 10s or 100s fold differends between the price of the
fluorescent light sources and a LED based one, and the fluorescent light source (mostly) produces more light than the LED.
Yes, I hope that OLEDs will be the ones who can reach the barrier, but until that this article is very-very optimistic
check
(figure:)
http://europa.eu.int/comm/energy_transport/atlas/
articles:
http://europa.eu.int/comm/energy_transport/atlas/
http://www.lumileds.com/pdfs/TP40_IESNA_July%2020
1. Light bulbs heat around where they are, the ceiling and not where people usually are (closer to the floor).
2. Heating allows for fine tuning of the temperature.
3. In the summer, the excess heat from the light bulb must be negated by your cooling system, causing even more energy drain.
^_^
Most of us aren't stupid enough to live in Alaska. See, there's this little thing called "Summer"...
Plus, a heat pump is about 300%-400% as energy efficient as resistive heating. Excepting a handful of latitudes, anyone who can afford a heat pump and doesn't get one ought to do the rest of us a favor and just off themselves right now, instead of using up oxygen while waiting around for the inevitable Darwin Award.
OLED's are nice for displays, but not enough lumen/watt efficiency for general illumination.w Article.jhtml?articleID=181503227/
LED's are improving much faster - 100Lm/W from Nichia to hit market soon:
http://www.eetimes.com/news/latest/technology/sho
I work for an electronics company with a world leading lighting divsion, and I can tell you we're moving to solid state lighting (of which OLED is a form) as fast we can. It's clearly the way of the future.
Obviously we're worried somebody else will take away our lighting market share by bringing out the killer-led-app. However, there's no question of "buying up IP and sitting on it". This playing field is as open as it gets in the industry.
Replace the light switch with a dimmer and your bulb will last MUCH longer, even if you always use it to max. That's because the kick the filament receives when turned on is aliviated. Even if you turn it to maximum very fast, it's still a lot slower then the switch. I used to buy replacement bulbs every now and then. Since I put dimmers all around the house, and that was five years ago, just two bulbs died.
factor 966971: 966971
No no no.
First of all, PLEDs (that's POLYMER based light emitting diodes) are a liquid, so they can actually be printed using existing inkjet technology - it's incredibly cheap to manufacture because you don't need special equipment, just modify existing plants. Instead now of printing paper, you're printing lightbulbs/screens.
Secondly, each of these is minutely small. The emissive layer is LIQUID. The resolution is absolutely fantastic, just as good as liquid crystal.
Thirdly, LCD screens are dependant upon polarisation. You have a really strong backlight, you pass currents through the liquid crystal layer and it blocks out certain frequencies of light. No matter what you show on screen, whether it be completely black or completely white, it's consuming the same electricity, it's just that in one, the liquid crystal is letting you see it, in another it's not. Have you ever wondered why the screen gets its darkest ONLY when you turn it off? That's because the backlight gets turned off. OLEDs naturally produce the light from the off, and only use the energy required to make the frequency you need. Not only does this mean you get a more natural colour, you get REALLY good contrast because you can render black properly.
Forthly (I should really stop this list): because you can tailor make a film of OLED to produce a particular frequency of light, it WILL look natural. If you're asking why, think back to some basic physics - you remember that when an electron descends an energy level, it emits a particular frequency of light? The sun has a pattern of frequencies produced this way, but it's with hydrogen, which is quite hard to replicate, with say, neon and flourescant bulbs. With OLEDs it's easy to tailor make molecules that'll replicate the same frequency spectrum.
I had to do a presentation about OLEDs a few months ago mate: I know my salt.
I've got the spirit, lose the feeling.
It's much more down to earth: there's a simple relationship between light yield and lifetime (from wikipedia:
- Light output is approximately proportional to V^3.4
- Power consumption is approximately proportional to V^1.6
- Lifetime is approximately inversely proportional to V^16
More light for your watt means the bulb burns out more quickly. They are now tuned for 1000 hours, which -mind you- means about $10 in electricity during the lifetime. If you want to increase the lifetime, put it on a dimmer.Avantslash: low-bandwidth mobile slashdot.
For those of you that do not know what an OLED is, or want an better explanation of 'em: http://science.howstuffworks.com/oled.htm
The main reason is that the power supply can be much smaller when running at 10 kHz or so compared to 50 Hz. In the latter case, it is a ballast in series with the tube, consisting of a big and heavy induction coil. In the former, it is more like a switching power supply. More expensive components (at least if you only need to convert a few watts), but also much smaller. RF can mean anything between 3 Hz and 300 GHz.
Avantslash: low-bandwidth mobile slashdot.
OLEDs are not going to replace light bulbs anytime soon. According to this article OLEDs are putting out about 25 lumens per watt of energy input. Compact fluorescent bulbs currently put out about 40 - 50 lumens per watt, and HID lighting (e.g., mercury vapor and metal halide) put out from 70 - 150 lumens per watt. So, if New Scientist is correct, HID lighting is up to 600% MORE efficient than OLED. The thing that makes OLED interesting is that it can be applied to any surface, but they are not more efficient than light sources we already have.
Light-up outerwear is already easy and cheap. You can power 10 feet of EL wire with two AA batteries and a tiny portable inverter. That's more than enough to light up a jacket.
Your 4th point is simply wrong. The sun emits light as a dark body, and it is a very hot dark body. It is hard to emulate the sun light with LEDs because LEDs have a very narrow emission spectrum, and a dark body's emission is continuos. Also, because the sun is very hot, it emmits light at very hight frequencies (blue and violet), that are hard to abtain on LEDs.
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Hemp is even cheaper and more readily renewable than wood. Personally I think it makes higher quality paper. Why doesn't the US smarten up and start pushing this as an alternative to clear cutting acres and acres of land. It also makes an excellent rotation crop because of the lack of pests.