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LED Evolution Could Spell The End For Bulbs

Zonk posted more than 9 years ago | from the in-my-day-we-had-heated-filaments-by-cracky! dept.

Science 482

An anonymous reader writes "USA Today is running a story discussing how LED lamps were unthinkable until the technology cleared a major hurdle just a dozen years ago. Since then, LEDs have evolved quickly and are being adapted for many uses, including pool illumination and reading lights, as evidenced at the Lightfair trade show here this week. More widespread use could lead to big energy savings and a minor revolution in the way we think about lighting."

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482 comments

I want bulbs (-1, Redundant)

Anonymous Coward | more than 9 years ago | (#12253714)

LEDs are inferor looking. Bulbs are clearly better cause they are older. :-)

xuseme (-1, Troll)

Anonymous Coward | more than 9 years ago | (#12253722)

collar

Bought some today! (1)

stoanhart (876182) | more than 9 years ago | (#12253723)

I just bought a keychain LED flashlight today, because they last forever on one of those little watch batteries. I wouldn't want them for home lighting though. It's such a weird shade of white, like blue-white. It would drive me nuts!

Re:Bought some today! (1)

Ruud Althuizen (835426) | more than 9 years ago | (#12253774)

I don't think LED's are very usefull in homes. Because they only have one shade, and not a whole spectrum. Meaning that colors would even be much duller compared to TL-lights. It is probably going to cause a lot of people getting depressed because of the absence of colors in their lives.

Re:Bought some today! (3, Interesting)

Adult film producer (866485) | more than 9 years ago | (#12253792)

I've heard of this before, having the odd bluish tone to it, maybe this will help.. I dont know, I dont have a lot experience with leds.

"Q: I want to use white LEDs for photographing or videotaping insects, plants, electronic parts, and other close-up subjects, but all of the white LEDs I've tried have this blue circle in them that ruins the picture. Any suggestions?

A: Try using Nichia's rectangular white model, NSPWF50S. This LED has a very wide, even beam that doesn't have that obnoxious blue ring in its beam. Since all white LEDs tend to have a bluish cast on film or videotape, you may need to adjust your camera's white balance or even use an orange-tinted filter to compensate.
The beam angle is very wide, around 140 by 120 degrees, so they won't be very good much over 1-2 feet away from the subject. They should work great for close-ups (a foot or less) though.

You will probably have to buy these directly from Nichia, since electronics places don't seem to carry them yet. I have some info on my Where To Buy LEDs page. "

Thats from the led musem (find it through google if you want or here ya go

http://ledmuseum.home.att.net/reserved.htm#q7

http://ledmuseum.home.att.net/ (the led museum homepage.. very cool stuff, he's been around for a long time. check out his rigged up wheelchair.)

Someone else here can probably provide an explanation for why there's a bluish tone to some white leds.

Re:Bought some today! (0)

Anonymous Coward | more than 9 years ago | (#12254000)

I can adjust the white balance on my camera for almost any kind of lighting, but I CAN'T adjust the white balance on my eyes.

Photography isn't the only thing humans do. Lighting needs to be as close to natural light as possible for things like painting, cross-stitch, and quilting.

Re:Bought some today! (0, Informative)

Anonymous Coward | more than 9 years ago | (#12253793)

White LEDs have at least three LEDs in them, Red, Green and Blue. You can in a "home" setting adjust the invidual LEDs to achieve the exact colour temperature you want.

Look at http://www.lumileds.com/

But the problem with LEDs today is that they are not more efficient than halogen bulbs.

A good halogen bulb give about 15-20 lumen per watt. A good LED doesn't give more than maybe 10 lumen.

Re:Bought some today! (4, Informative)

Yokaze (70883) | more than 9 years ago | (#12253929)

I thought white LEDs are usually blue LEDs, which are coated with a scintillator, which converts parts of the blue light to yellow. Wikipedia seems to support my impression [wikipedia.org] .

Regarding efficiency, I refer once more to Wikipedia: "In 2002, 5-watt LEDs were available with efficiencies of 18-22 lumens per watt. [...] In September 2003 a new type of blue LED was demonstrated by the company Cree, Inc. to have 35% efficiency at 20 mA. This produced a commercially packaged white light having 65 lumens per watt at 20 mA, [...]".

Re:Bought some today! (2)

wanderingstan (812124) | more than 9 years ago | (#12253807)

From the article:

The feature of LEDs likely to propel them into homes is aesthetic, not practical. Arrays that mix red, green and blue LEDs can produce any color of the rainbow. Instead of a dimmer, you might have three sliding knobs that let you mix color.

"On a very hot day you might want blue light to cool it down a bit, or on a winter day you may want to simulate sunlight," said Steve Landau of Lumileds Lighting, an LED-making joint venture of Agilent Technologies Inc. and Philips Lighting.

So just choose any shade of light that you want.

LEDs do not evolve (5, Funny)

keesh (202812) | more than 9 years ago | (#12253726)

I know that this is true because I read it in the Bible. They did not evolve, they were created by God.

Ob Simpsons quote (1)

wootest (694923) | more than 9 years ago | (#12253804)

There's your answer, fishbulb.

Re:Ob Simpsons quote (0)

Anonymous Coward | more than 9 years ago | (#12253852)

Hens love roosters, geese love ganders, everyone else loves LED Flanders.

But it's warmer.. (5, Funny)

Dancin_Santa (265275) | more than 9 years ago | (#12253730)

I guess we are going to start having "illumiphiles" who will try to tell us that the incandescent lightbulbs of yesteryear are somehow "warmer" and that humans can tell the difference between LEDs and vacuum tubes.

Re:But it's warmer.. (0)

Anonymous Coward | more than 9 years ago | (#12253740)

I'm sure incadecent vs flourecent has been raging scince the 1930s. Personaly, I don't care, except maybe for mood lighting where incadecents win out (at least for me).

Re:But it's warmer.. (2, Informative)

jacksonj04 (800021) | more than 9 years ago | (#12253822)

Most incandescent bulbs are 'warmer' than most flourescent for things which matter. I think this is due to the fact they actually rely on heat to generate the light.

However, as with all things, you can get flourescent tubes which have a really warming glow, and the halogen bulbs in my room have a much cleaner light than ordinary bulbs.

Additionally, they don't have mains flicker. When I went to the US the flicker from flourescent tubes drove me insane (in the UK they flicker at 50Hz, what is it in the states?).

Re:But it's warmer.. (1)

Filiks (578065) | more than 9 years ago | (#12253865)

60Hz, so if anything the flicker should have been less noticeable. Maybe you're just used to the 50Hz flicker?

Re:But it's warmer.. (0)

Anonymous Coward | more than 9 years ago | (#12253867)

Additionally, they don't have mains flicker. When I went to the US the flicker from flourescent tubes drove me insane (in the UK they flicker at 50Hz, what is it in the states?).

In North America it is 60 Hz, so it should have been less visible than it is in the UK.

The other big difference between LED/fluorescents and incandescents is the spectrum: the former have bright emission lines, the latter don't. I don't know if this would bother anyone, but it's visible in various prismatic effects. (Wait a minute, this is /.: I'm sure there's someone here who is extremely bothered by this.)

Re:But it's warmer.. (1)

Given M. Sur (870067) | more than 9 years ago | (#12253872)

Additionally, they don't have mains flicker. When I went to the US the flicker from flourescent tubes drove me insane (in the UK they flicker at 50Hz, what is it in the states?).

60Hz [google.com]

And it's spelled fluorescent :P

Re:But it's warmer.. (4, Informative)

ComputerizedYoga (466024) | more than 9 years ago | (#12253989)

I'm in the US, I perceive flicker on 70hz and below refresh rate monitors, and on some old fluorescent lighting (but I've gotten used to it and can deal with it). But the thing is, a properly ballasted fluorescent lamp doesn't flicker at 50 or 60 hz. It flickers at 100 or 120 -- the ballast doubles the frequency from the mains frequency. Which is faster than most people perceive. However, solid state ballasts go WAY faster than that ... Wikipedia's entry on ballasts [wikipedia.org] is pretty informative.

So, pretty much, newer better lamps shouldn't flicker perceptibly. I know my CFL's don't, and ever since we got the ballasts replaced the tubes at work don't either. But I guess YMMV.

Re:But it's warmer.. (1)

kf6auf (719514) | more than 9 years ago | (#12253858)

You obviously aren't an "illumiphile." To an "illumiphile" the ideal is natural light. You know, the stuff we get from our Sun's blackbody radiation. While incadensent lights are close because they also use blackbody radiation (unlike LEDs and flourescent lights), they aren't perfect so real "illumiphiles" like windows. That's not to say that I wouldn't use LEDs, I'd probably use some LED, some flourescent, some halogen, and so on in addition to incandescent and good, old-fashioned windows since a good mix of light sources is what makes the light look more natural at night.

Re:But it's warmer.. (1)

zakezuke (229119) | more than 9 years ago | (#12253901)

I guess we are going to start having "illumiphiles" who will try to tell us that the incandescent lightbulbs of yesteryear are somehow "warmer" and that humans can tell the difference between LEDs and vacuum tubes.

But vacuum tubes are warmer. The first time I put my hand into a HAM radio set I got a blister. I'm telling ya a blind man could tell the difference.

Re:But it's warmer.. (2, Informative)

Temporal (96070) | more than 9 years ago | (#12253923)

In fact, there is a major difference, even in theory. A white LED light is produced by combining red, green, and blue LEDs. If you were to take this white light and run it through a prism, you would not see it defract into a rainbow. Instead, you'd see a red beam, a green beam, and a blue beam.

Now, technically our eyes only have receptors for red, green, and blue. So, what you would see would look mostly the same as under true white lite. However, the way light reflects off of surfaces can be more complex than that. Imagine a surface which only reflects light in the yellow range (that is, it does not simply reflect red and green, but in fact reflects only the yellow wavelength of light). This surface might appear yellow under natural light, but would be black under this LED light!

In general, you won't see such extreme differences. But, there will be subtle differences between colors viewed under these white LEDs vs. an old-fashion light bulb. Will you care? Maybe, maybe not. Fluorescent light has the same problem, and personally it never bothered me. But, yes, I can certainly imagine there being "illumiphiles" who are bothered by it.

Oh yeah... and if you're one of those mutants with a fourth color receptor, you'll hate these lights.

Re:But it's warmer.. (0)

metlin (258108) | more than 9 years ago | (#12253964)

Oh yeah... and if you're one of those mutants with a fourth color receptor, you'll hate these lights.

Fourth color receptor?

Re:But it's warmer.. (2, Informative)

Internet_Communist (592634) | more than 9 years ago | (#12253967)

AFAIK, this is incorrect. I was disctinctly under the impression a white LED is created by using a special coating on a blue led.

Re:But it's warmer.. (5, Informative)

Anne Thwacks (531696) | more than 9 years ago | (#12253981)

if you're one of those mutants with a fourth color receptor, you'll hate these lights. Reply to This

Yes, I am. You might be too ...

Most people have another type of receptor, called a rod, which is not colour sensitive, unlike the three kinds of cones which are colour sensitive. However, my rods have a much wide spectral response than the normally accepted colour range of white light. I have known for a long time that light without significant ultraviolet content makes it hard for me to accurately resolve edges. I find technical drawing very difficult by incandescent light. Others may be the same too.

Remember 10% of men lack one kind of cone, and are partly colour blind. A lot more lack fashion sense, but you can't blame that on LEDs

Certainly (4, Funny)

Dorsai65 (804760) | more than 9 years ago | (#12253731)

an illuminating article...

Re:Certainly (1, Funny)

Anonymous Coward | more than 9 years ago | (#12253868)

whoever modded this as troll needs to get their lights punched out.

I like the color-mixing aspect.. (4, Interesting)

jcr (53032) | more than 9 years ago | (#12253732)

I'd buy them for that capability alone.

I wonder when we might see LEDs with enough brightess to serve as a projector lamp?

-jcr

Re:I like the color-mixing aspect.. (1)

Ruud Althuizen (835426) | more than 9 years ago | (#12253816)

There are already some of those

Re:I like the color-mixing aspect.. (3, Informative)

metlin (258108) | more than 9 years ago | (#12253925)

Actually, rock climbers & spelunkers who do lots of caving have been using LED based headlamps [rei.com] for a while now.

They have excellent focus and can illuminate pretty darned well, projecting the light to a good distance as well as a very effecient battery usage.

I do not even remember the last time I used a lightbulb based headlamp.

So, to answer your question - current LEDs can probably do that already.

Re:I like the color-mixing aspect.. (2, Informative)

jcr (53032) | more than 9 years ago | (#12253982)

current LEDs can probably do that already.

I'd think you'd need considerably more brightness for a projector lamp than you need to see where you're going in a cave.

-jcr

Re:I like the color-mixing aspect.. (1)

metlin (258108) | more than 9 years ago | (#12253992)

Even in the minimal setting of just one LED powering the headlamp, it can be quite blinding. If you made a cluster of slightly more powerful versions of these LEDs, making a projector would not be hard at all.

Re:I like the color-mixing aspect.. (1)

ForestGrump (644805) | more than 9 years ago | (#12254001)

there are also LED lights for cars now too.

like for parking lights, not your main headlight.

But from what i've heard, they are more trouble than they're worth. The quality is low, so they go out often. they draw less power than normal bubls, and so blinkers blink too fast, or the car thinks the bulb is out because it's "not drawing power"

crap, 5am

In other news... (5, Funny)

Nichotin (794369) | more than 9 years ago | (#12253733)

the lightbulb industry lobbies the congress to ban LED technology that will ruin the market for lightbulbs.

Re:In other news... (1)

jcr (53032) | more than 9 years ago | (#12253741)

Too late. There aren't enough voters in the US whose living depends on manufacturing lightbulbs to get the congress critters to knife the baby..

-jcr

Re:In other news... (0)

Anonymous Coward | more than 9 years ago | (#12253754)

I thought that this was outsouced to China already?

Re:In other news... (1)

jcr (53032) | more than 9 years ago | (#12253995)

Lightbulbs aren't a terribly high-tech manufacturing problem, and they're manufactured locally in most of the third world. I don't know where the bulk of the light bulbs consumed in the USA come from, though. With shipping costs, it might still be cost effective to make them here.

-jcr

Re:In other news... (1)

Trejkaz (615352) | more than 9 years ago | (#12253777)

Sounds like a plan.

But I don't see LEDs being serious competition until you can buy a bulb which looks like an incandescent, but uses LEDs internally. Just look at fluorescent bulbs... you still don't see so many of those around, possibly because they are awfully ugly. :-/

Re:In other news... (1)

ComputerizedYoga (466024) | more than 9 years ago | (#12253913)

bare incandescents are just as ugly as fluorescents. Maybe uglier! Those filaments are such a small point, and such an intense light source that it's pretty unpleasant to look at them. I'd rather have one of my 14 watt fluorescents shined in my eyes than the 60 watt incandescents they replaced.

I think the main reason there's not widespread adoption of those fluorescent bulbs is that people don't think in the long-term. In the short term, a pack of walmart brand bulbs costs 75 cents and there's 4 of them, great! Or hell, splurge and get the $1.50 GE bulbs or whatever. Those crazy fluorescents are like $7.00-$12.00 for a two-pack.

A quick cocktail-napkin calculation based on my last power bill ($80 for the month) and usage level (980kwh), and estimating bulbs that are on for about 6 hours a day (which is probably an underestimate in my case, since I'm pretty much only at home at night, and usually spend more like 8-10 hours with at least some light on) ... those fluorescents save me about $1.00/month each in comparison with the bulbs they replaced. Meaning in the course of 5 months, instead of having to discard 2-4 burned out incandescents and spend another 75 cents to get another pack, I've saved the cost of the fluorescents, and they've effectively cost me nothing. Now they continue to save me a few bucks a month on the bills, which is nothing spectacular, but it's pretty nice, and it adds up. In the short term, my checkout cost could have been 9 bucks lower than it was, but in the longer term, I'm pretty much winning out over everyone who didn't pay that up-front cost.

Re:In other news... (2)

hackstraw (262471) | more than 9 years ago | (#12253942)

the lightbulb industry lobbies the congress to ban LED technology that will ruin the market for lightbulbs.

No, they would probably sue the last of the die hard lightbulb users because they prefer the yellow glow of an incandescent bulb.

Actually, the LED makers might lobby congress for their non-use because they last so long, but they will be so blinded by the new profits that they will not probably think that far, and instead just make shittier ones so people will buy more.

All sarcasm aside. LEDs are one of my favorite electronic components that exist. They were before the newer lightbulb types came around. They are probably the most reliable, simple, yet useful electronic devices ever. A positive and negative voltage, the silicon or whatever substrate that the device sits on, and the glass or plastic part that projects the light. Thats it. And they are inexpensive (at least the lower power ones).

LEDs are vital for many electronics to indicate status. One server I worked with had various LEDs scattered in the box and each subsystem was routed to the front of the box via a plastic light conduit thingy. If everything was a go, all were green. If one component was bad, it turned red, and you would have to open up the box to see which LED turned red.

In my area, the cities are starting to convert all of their stop lights to LEDs. They are bright as hell, and they last something like 7x as long as the other bulbs. I've seen LEDs as brake lights on busses as well. And not to mention the ever cool headlamps.

LEDs are cool, and welcome in my book.

Is this true? (3, Interesting)

Anonymous Coward | more than 9 years ago | (#12253738)

For starters: LEDs aren't as efficient as many people seem to think, iirc they're a bit more efficient than normal lightbulbs, but TL-lamps and other gas-ionisation-type lamps are still way more efficient. Secondly: While LEDs may emit light for 6 years continuously, they have a certain half-life that's way shorter than that; at the end of the 6-year life span, the leds probably only emit 1/4th of what they did when they were new.

Did you read the article? (5, Insightful)

egosum (758988) | more than 9 years ago | (#12253869)

Just this week, researchers at the Lighting Research Center at Rensselaer Polytechnic Institute in Troy, N.Y., said they had boosted the light output per watt of a white LED to almost six times that of an incandescent light bulb, beating even a compact fluorescent bulb in efficiency.

Re:Is this true? (2, Insightful)

BaatZ (850474) | more than 9 years ago | (#12253996)

Excuse me, but iirc you are wrong about this.

LED's use the fact that at the P/N junction (that's what LED's actually are), electrons flow into a lower energy state, emitting the excessive energy as light. Since there hardly is any resistance in a ligt (typically less than 10^-14 Ohm), almost all electric energy is converted into ligt. You can also feel for yourself; led's won't get hot even after long operating times.

Gas ionisation tubes, however, are quite primitive. It's just accellerating some gas in an electric field, much of the energy dissipated by the field becoming kinetic energy of the gas ions, but there is also some energy needed to ionize the atoms.
When the ion strikes the fluorescent wall, most of it's kinetic energy indeed becomes ligt, but then again, some of it is lost just because the particle isn't massles. Not mentioned that starting up a tube costs significant amounts of energy.

LEDs are definitely becoming more powerful (4, Interesting)

Motherfucking Shit (636021) | more than 9 years ago | (#12253749)

I used to think of LEDs as cute little indicator lights. A nice tiny, soft green LED light tells me that my monitor is on, or blinkenlights let me know that packets are flowing through my router. An orange LED might alert me to standby mode on a device. None of them were really all that visible unless I was looking directly at them, and certainly none put out any ambient light.

Then I got my newest computer. This thing has a single blue LED backlighting an area the size of a dime, behind the power button on the case. When I turn off all the lights, after a minute or so of my eyes adapting, the single blue LED gives off enough light to illuminate half the room. For the first week or so, I had trouble getting to sleep because of the light... From one blue LED.

As the technology gets better I can imagine LED lamps coming in vogue. I seriously doubt that the end of the bulb will come anytime soon, though. Probably not in my lifetime.

Re:LEDs are definitely becoming more powerful (0)

Anonymous Coward | more than 9 years ago | (#12253765)

When I got my newest computer. This thing has a single blue LED backlighting an area the size of a dime, behind the power button on the case. When I turn off all the lights, after a minute or so of my eyes adapting, the single blue LED gives off enough light to illuminate half the room. For the first week or so, I had trouble getting to sleep because of the light... From one blue LED.

Easy fix: Turn off your computer when you go to bed.

Re:LEDs are definitely becoming more powerful (0)

Anonymous Coward | more than 9 years ago | (#12253775)

Or use a peice of electrical tape. Worked back
in the day to stop that 12:00 from blinking on
my VCR!

Re:LEDs are definitely becoming more powerful (4, Insightful)

ShaunC (203807) | more than 9 years ago | (#12253803)

Ugh. Blue LEDs are, without a doubt, the most annoying new fad in consumer gadgetry. The problem is they're suddenly showing up in everything, replacing green LEDs as the default.

A couple of months ago I bought an all-in-one VCR/DVD deck that plays and records to both tapes and DVDs. Hell of a convenient unit, except that when you power this puppy up, it has four blue LEDs on its face. One for "power on," one for "disc in," one for "tape in," and one down by the controls which I guess is there for the hell of it. The clock is a matched-color blue LCD display.

The blue LEDs are absolute distractions. Even during the day, with the lights on or the sun coming in the windows, my eyes want to focus on the blue lights instead of on the TV screen. I'm not sure whether it's the intensity of the LEDs, or the fact that the eyes are more sensitive to blue light. Probably some combination of both - they chose blue strobes on cop cars for a reason I guess - but whatever, it's damned annoying.

Give me a soft green LED any day. Enough with these bright blue ones.

Blue LED-hidden danger? (0)

Anonymous Coward | more than 9 years ago | (#12253862)

I notice when I look directly at a blue light
source, my pupils dialate to the point that the
surrounding enviroment looks noticably dimmer.
Dosen't happen with most colors on the lower end
of the spectrum.

Scince blue lighting is real popular in consumer
devices these days, incuding car detailing, I
wonder how much of a hazard this is for night time
driving, or any other risky places where these LEDs may be showing up?

Re:LEDs are definitely becoming more powerful (1)

lachlan76 (770870) | more than 9 years ago | (#12253975)

Your eyes aren't more sensitive to blue light. Human eyes are most sensitive to green, red, and then blue light (in that order).

Re:LEDs are definitely becoming more powerful (1)

AsOldAsFortran (565087) | more than 9 years ago | (#12253990)

Here's what I remember about the perception of light. Not a professional in the area.


The color receptors (cones) are least sensitive to blue light. Ever see a blue firetruck?


The green receptor is most senstive (hence the new greenish firetrucks), the red second and the blue third.


The b&w low-light receptors (rods) are least sensitive to red light, hence the use of soft red illumination in WWII pilot briefings before night flights. If you're buying one of those small led flashlights to use at night when you want to still be able to see effectively in the semi-dark when the flashlight is off, buy a red version.


Those blue leds just must be putting out lotsa lumens.

Re:LEDs are definitely becoming more powerful (1)

Yaotzin (827566) | more than 9 years ago | (#12253999)

I don't know if you have them but I spotted a lot of blue light-coils (or whatever they're called) around christmas and you could not focus on them at all. Even if you try they're still blurry.

Re:LEDs are definitely becoming more powerful (1)

jacksonj04 (800021) | more than 9 years ago | (#12253830)

Same with my box, until I replaced it with a far nicer green one.

Starwars at 3am (0)

Anonymous Coward | more than 9 years ago | (#12253946)

Torrent hashes get cranky. LEDs start projecting patterns of dementia across the laundry pile on your floor.

All you can do is role over , face the other wall and wonder if those LEDs you purchased on Ebay really are DOT approved.

Not new (4, Interesting)

The Tyro (247333) | more than 9 years ago | (#12253752)

This is no surprise... it's been this way in flashlights (hand torches, to you brits) for a while, particularly the higher-end ones and those designed for specialty applications.

As an example, some of the weapon-mounted lights being used by the military are also going to LEDs. Some of the regular incandescent bulbs just don't hold up as well to the punishing recoil of most weapons... you were forever changing bulbs. The higher end incandescent lights like the Sure-Fire lights [surefire.com] could take the shock, but forget mounting anything like a mag-lite [maglite.com] on a weapon.

Best thing about them: they're easy on the batteries. Batteries are heavy, and there's nothing worse than having to carry too many spares. Every ounce counts when you're carrying it on your back.

Re:Not new (5, Funny)

Anonymous Coward | more than 9 years ago | (#12253844)

"but forget mounting anything like a mag-lite on a weapon"

YOU SEE!!! Doom 3 had it right all along!

Re:Not new (0)

Anonymous Coward | more than 9 years ago | (#12253894)

A: "hand torches"? Been watching Band of Brothers this week?

B: Doom 3 did not have it right. Sure you might not be able to mount a light on many large-caliber weapons. But weapons like pistols and submachine guns are widly accpeted with tactical frames, that allow the mounting of lights, including mag lights.
And doom 3 is far enough in the future to have a research base on Mars. I think we will have fingured out how to hold a light and a big gun at the same time by then.

Re:Not new (4, Funny)

a whoabot (706122) | more than 9 years ago | (#12253905)

Your sig reminds me of a conversation two people I knew/know had.

One was just a regular guy. One was a girl that knew taekwondo and I guess was pretty good at it. He would bug her that even though she knew a deadly art of self defense he could still beat her, just because she was a girl. This would tick her off and eventually it escalated one day into seriously discussing setting up a "no holds barred" fight between the two.

At one point of the discussion he was like, "Wait wait wait wait wait. If she gives me a compound fracture, am I allowed to stab her with my exposed bone?"

It only made it funnier that he was serious.

They never got to fighting because eventually she became convinced of his psychosis when he started agressively arguing that even biting and the gouging of eyes were not be barred:

"Well, it just so happens that I think my stomach for, and skill in, gouging eyes are my greatest abilities. If I'm barred from such an act then I can't imagine how this fight would not be a handicap fight in your favour. It's tying my hands behind my back."

Re:Not new (5, Insightful)

theonetruekeebler (60888) | more than 9 years ago | (#12253978)

I have a Petzl 3 LED headlamp , the size of half a golf ball, with a retracting headband. I keep it in my motorcycle tank bag---and use to hike to the the deer stand. Incredibly light, good for reading in a tent, for roadside map consultation (back before I invested in a GPS). Three LEDs, sips battery power, a good, natural color of light.

The absolute best use for new-generation LEDs I have seen is for brake lights. Many high-end cars, and even some delivery trucks, use LEDs now, and the advantages are clear: they are damned bright, highly directional, don't burn out, and best of all, they reach full brightness a tenth of a second faster than an incandescent bulb. That may not sound like much, but at 60MPH, 0.1 second is 8.8 feet extra feet for the car behind you to start reacting (100km/h ==> 2.8m in 0.1s). I have blinky LEDs on my motorcycle and they solve all sorts of problems with tailgaters.

Not Convinced (3, Funny)

Paris The Pirate (799954) | more than 9 years ago | (#12253753)

Not convinced I'd want that style of lighting everywhere around my house as it stands it'd be like living in a large supermarket.

I'd have to invest in some hardcore lift music to complete the 'still out shopping' effect. And perhaps pay a young relative to scream and be slapped periodically in the middle distance.

Re:Not Convinced (1, Funny)

Anonymous Coward | more than 9 years ago | (#12253779)

no way im ever gettin lightbulbs in my house. night is s'posed to be dark, ya dern whippersnappers

Psychological effects? (0)

Anonymous Coward | more than 9 years ago | (#12253788)

I wonder what the effect would be on people if
their home enviroment didn't look much different
from their work place, supermarket, etc. I'd
like to think of home as a refuge away from those
places, and sometimes, even the flourecent
ceiling fixture in my living room reminds me
too much of the "real world". When that happens,
I shut it off, and just use the much dimmer
incadecent lamps built into the ceiling fan.

I also tend to feel more relaxed when the
flourecent is off.

Re:Not Convinced (1)

gatkinso (15975) | more than 9 years ago | (#12253984)

Put them behind a shade.

bullshit (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#12253760)

Leds aren't even near to the most efficient light sources. Check wikipedia for W/lumen readings. In addition to that, they have a creepy 1-3 component spectrum.

Re:bullshit (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#12253786)

but they don't give off a bunch of bullshit heat do they?

Re:bullshit (1)

Yr0 (224662) | more than 9 years ago | (#12253798)

Its a cost/performance trade-off dickwad. LEDs have reached that point where bulk resale is possible.

This is news*? (1)

l0b0 (803611) | more than 9 years ago | (#12253773)

Hasn't this been obvious for years? I mean, even though the first white LEDs were hugely expensive, and the public seems to be as clueless as always, this must be one of the most important technology revolutions outside the silicon industry for decades.

*Directed at the USA Today article, not the /. reviewers

Re:This is news*? (1)

l0b0 (803611) | more than 9 years ago | (#12253796)

[...]outside the silicon industry[...]

Urrh, that is, outside the semiconductor^H^H^H^H^H^H^H^H^H^H^H^H^Hcomputer industry.

Marketing is pushing it. (4, Funny)

Anonymous Coward | more than 9 years ago | (#12253782)

"On a very hot day you might want blue light to cool it down a bit."

And if street noise is distracting you, a green LED will quiet that right down.

Re:Marketing is pushing it. (0)

Anonymous Coward | more than 9 years ago | (#12253824)

I wish :\

There's nothing like the sound of a nearby
freeway to get your mood down. Even if it
does sound like a (very bastardized version) of
a rushing stream.

Re:Marketing is pushing it. (2, Interesting)

jacksonj04 (800021) | more than 9 years ago | (#12253874)

Nope, marketing have a point here. The colour of light does affect your mood, why do you think hospitals concentrate on the cleanest light they can for operating theatres and general wards, whereas maternity wards have warmer lighting?

Starbucks use warm lighting because it makes you want to stay there, especially if it's raining outside.

I have some super-bright ones.. (1)

Tjoppen (831002) | more than 9 years ago | (#12253790)

Like this one [lumileds.com] .
The three watt variant. Runs on two AA batteries.
It lights up the entire room with a somewhat cold white light. Can be fixed by adding some red and yellow I recon.

Also, looking directly into it is very nasty, but a clear bulb probably does that aswell.

How I think about lighting (1)

Realistic_Dragon (655151) | more than 9 years ago | (#12253795)

Wow, I never noticed that the room light is out, guess I have too many displays and boxes with status LEDs in here or something.

Need to fit normal lamp-sockets. (5, Insightful)

jdonnis (115371) | more than 9 years ago | (#12253801)

I think one of the main issues with LED lights is the incompatibility with existing lamps.

Sure you buy new lamps every once in a while, but a real breakthrough will come when you can get LED 'bulbs' that fit in a normal 220/110V socket on a normal lamp.

The same thing happened with those energy-saving bulbs, it seems they only really took off (at least here in Denmark where electricity is expensive) when they became available in versions that looked like normal bulbs and fit most lamps.

Another example is the wire spot halogen lights, once they became available in 220/110V versions they took off. Nobody seemed to want those bulky 220->12V transformers around.

Re:Need to fit normal lamp-sockets. (1)

rusty0101 (565565) | more than 9 years ago | (#12253911)

You will see them in standard (what is it, 1 1/2"?) socket bulbs within the next year or so. That won't mean they will be cheap. In all likelyhood the screw in portion will be a transformer that will drop the voltage to a level that is suitable for the LED array.

Possibly an array will be set up so that rows are in series, and columns are parallel. Though you may see flicker with that method as well.

Most of the 'fix' in both the florescent bulb and the hallogen bulb solutions came about from similar systems, so most of the ground work is done. It's just a new implementation.

My personal gripe with the compact florescents is that they do not match up dimension wise (outside of the socket itself) well with other bulbs. I have harps on table lamps that don't work well with them, as well as shades with wire spring clamps that are supposed to mount on the bulb, that are a pain to use as well.

Then again that's just my own experience.

-Rusty

Re:Need to fit normal lamp-sockets. (4, Informative)

zakezuke (229119) | more than 9 years ago | (#12253940)

Sure you buy new lamps every once in a while, but a real breakthrough will come when you can get LED 'bulbs' that fit in a normal 220/110V socket on a normal lamp.

They've been out for some time.

http://store.sundancesolar.com/ledlibu12acl.html
http://www.smarthomepro.com/97314.html
http://w ww.ccrane.com/120-volt-led-light-bulb.aspx

The technique is simple. Use a rectifier to convert AC to DC, and use enough LEDs in series and glue them all together. Sure if one LED burns out you loose a whole series, but don't expect that for a few years.

Whether you'd actually want to own one is a different story.

Slightly off-topic, but... (1)

CosmeticLobotamy (155360) | more than 9 years ago | (#12253806)

I don't know much about the tech side of LEDs. I know they're pretty. So this might be a stupid question.

Why haven't I ever seen two of the little light junctiony dealies inside one little plastic bubble? Whenever they make products like those LED flashlights that they want to be brighter, they add more individual LEDs, but is there a technical reason why you can't just make the little plastic bubble bigger and put 50 of the light sources inside it to save space? Or is it a manufacturing cost issue?

Re:Slightly off-topic, but... (1)

BrynM (217883) | more than 9 years ago | (#12253884)

but is there a technical reason why you can't just make the little plastic bubble bigger
Because all it would do is make the LED focus differently possibly making it dimmer. The "bulb" doesn't do much but protect the pins inside, protect the layer of aluminum-gallium-arsenide between the pins and focus the light produced. There are colored LEDs that have clear casings even. Here [howstuffworks.com] 's a good explanation.

By the way, that wasn't off-topic at all.

Re:Slightly off-topic, but... (1)

CosmeticLobotamy (155360) | more than 9 years ago | (#12253944)

Yeah, it was going to be more off-topic, but I forgot what I was originally going to ask, and then I forgot that I forgot.

But what I was asking wasn't just to make the plastic wad bigger. I was wondering why no one has consolidated like 10 of the emitting bits into one of those plastic bubbles (or at least hasn't put them into tiny flashlights available on Think Geek) instead of using multiple discrete plastic chunks. I don't know if the individual light emitters would have to have seperate leads, but even if you had to expand the plastic chunk to get more leads on it, you'd still save space. But I wasn't sure how important the focusing would be if you had more of them and I didn't know if having a bunch too close together would somehow screw something up.

Basically I just want somebody to glue a bunch of LEDs together and sell them that way. Preferably using the same plastic that they make the bulbs out of as glue.

a 1000 watt led lamp? (1)

xlyz (695304) | more than 9 years ago | (#12253812)


you can really say a beowulf cluster of leds :)

Why LED lighting isn't taking off yet (2, Insightful)

atomic noodle (814905) | more than 9 years ago | (#12253817)

The problem is theft.

Over their long lifetime, even existing LED lights are much cheaper than incandescents (factoring in electricty and replacement costs). So they should be attractive to places like hotels, shops and so on.

One of the most serious problems is that the high intial cost makes the LED a very attractive target for thieves. Nobody's going to bother stealing incadescent light bulbs from, say, a hotel room - they're bulky, delicate and almost worthless. LEDs on the other hand, are compact, easily hidden, and quite valuable.

Could be solved with RFIDs (0)

Anonymous Coward | more than 9 years ago | (#12253972)

Nobody's going to bother stealing incadescent light bulbs from, say, a hotel room - they're bulky, delicate and almost worthless. LEDs on the other hand, are compact, easily hidden, and quite valuable.

Just put a little RFID tag inside of the bulb (tm). When you check out they will simply add it to your bill. The lady behind the counter will tell you you with a smile on her face: "an ash tray, two towels, a pyjama and -ohh- 12 light bulbs. That makes $218, the room charge is offered by the hotel."

Re:Why LED lighting isn't taking off yet (1)

bots (671566) | more than 9 years ago | (#12253980)

Raoule Duke disagrees.

Future of Lighting Design (5, Interesting)

maino82 (851720) | more than 9 years ago | (#12253820)

I'm a lighting and electrical systems design student and a lot of talk has been going on about LEDs these past few years. One thing people seem really excited about is the color mixing capabilities. While it may be true that a single white LED might not provide the kind of white you want, you can mix RGB to any color temperature of white you want (from a warmer incandescent color to the cooler color of the sun). I went to Lightfair a few years ago and saw an LED parking lot light that had an array of various color LEDs that mixed to white on the workplane, and an added bonus was that because there were so many colors in the array, the color rending was amazing.

Unfortunately, like the article says, the first cost is still prohibitive in a lot of cases, although the savings in energy would seem to make it worthwhile. LEDs also tend to get very, very hot in large quantities if they're used for a long period of time, so air circulation is a common problem as well.

Hopefully some of you computer engineers and programers can come up with a cheap way to produce and control LED arrays so I can start using them in practice! Building owners would be extremely happy if power consumption in buildings would go down significantly and if they had the ability to control the color and brightness (they are easily and cheaply dimmable, unlike flourescents) of any room individually.

Hold On Now (5, Funny)

Rie Beam (632299) | more than 9 years ago | (#12253835)

This article contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things (and light sources). This material should be approached with an open mind, studied carefully, and critically considered.

50000 hours lifetime? (2, Insightful)

Anonymous Coward | more than 9 years ago | (#12253839)

Current white LEDs will last up to 50,000 hours, about 50 times as long as a 60-watt bulb. That's almost six years if they're on constantly.

Erm. Weren't LEDs supposed to have (virtually) unlimited lifetime?

LEDs are only nice... (1)

Psychic Burrito (611532) | more than 9 years ago | (#12253840)

...when you use them to be seen directly be the human eye, like for displays, or car brake lights. As soon as you use them to "light something", like a room, a book with a reading light, or a film set, their property of irregular spectrum makes them only second choice, because the LED light changes the colors in ways ranging from subtle to irritating. Give me flat-spectrum LEDs and I'll use them any day!

A big advantage: fast switchable (3, Insightful)

eMago (267564) | more than 9 years ago | (#12253849)

A big advantage of LEDs over standard lightbulbs is, that they are quickly switchable without reducing lifetime that much. For lightbulbs you need expensive flashlights, but for LEDs a standard 5mm High Power LED - or if you want more power, a flux - can be used for fast switching applications.
Additionally you can use many LEDs together without much effort to create nice structures and designes in different colors - as mentioned in the article.

Since I discovered not so long ago, that the blue and white LEDs of today with e.g. 8000 and 20000mcd are another dimension compared to the LEDs I used in my electonic experimenting set as a child, I hacked together an XMMS-Plugin serial lightshow with a uC-backend and use some blue and red high-power LEDs to illuminate some parts of the room. With standard lights that fast-switching beat-detection would not be possible in such a cheap way.

Of course if you really want to illuminate the room in a standard, really bright manner, you need even more powerful and expensive LEDs, however it is a good start and I expect my main, ordinary illumination to be "lightshow compatible" in 10 years ,-).

Hrm... (5, Interesting)

Duncan3 (10537) | more than 9 years ago | (#12253851)

So which way am I better off? Just using lower wattage "classic" lightbulbs, or with dozens of 120V AC->5V DC converters wasting energy everywhere.

The adapter for my iBook puts out more heat then the iBook. More of the heat from my AMD64 is from the power supply vs. the CPU and Gfx.

Almost nothing I own needs over 12V anymore. When will I be able to just have one nice 120->12V spaceheater and run everything else in the room off 12V?

Re:Hrm... (1)

zakezuke (229119) | more than 9 years ago | (#12253917)

So which way am I better off? Just using lower wattage "classic" lightbulbs, or with dozens of 120V AC->5V DC converters wasting energy everywhere.

I would *think* that one would use a rectifier and hookup enough LEDs in series to accomidate 120V, or 240v for that matter.

Re:Hrm... (1)

DaveV1.0 (203135) | more than 9 years ago | (#12253998)

Actually, one would think that the power converter would be built in to:
  • the LED "bulb" if one were to use legacy lamps
  • the lamp made for LEDs
Another point: With DC, there are issues with high power devices and circuits involving heat and current carrying capacity of wiring.

As for a single 120VAC - 12VDC converter for a room, you can purchase high amp converters and do just that. Granted, it may not be cheap and there will be a large number of devices that use other than 12VDC which will still require engery-wasting power converters, but it can be done.

Most white LEDs work using a different method (5, Informative)

Andy Mitchell (780458) | more than 9 years ago | (#12253857)

The article says:

They haven't been used as sources of illumination because they, for a long time, could not produce white light -- only red, green and yellow. Nichia Chemical of Japan changed that in 1993 when it started producing blue LEDs, which combined with red and green produce white light, opening up a whole new field for the technology.

This is certainly one way to produce a white LED but it is not the common method today. Most white LEDs use a phosphor to convert a blue or ultraviolet LED into a white one. A quick google found the following page that talks about this in more detail:

http://www.marktechopto.com/engineering/white.cfm [marktechopto.com]

I would speculate that for normal home lighting using a phosphor will give better results as:

  • Using separate red, green, and blue emitters increases complexity. Different colour LEDs are often made using different semiconductors.
  • Using 3 separate LEDs will produce a light that looks white, however as LEDs only produce a very narrow range of frequencies (determined by the band gap as I recall) this may cause some colours to look a bit off. Fluorescent lighting also works by converting UV to visible light and can produce an excellent reproduction of daylight. Providing of course you buy the right tube that uses the approprite magic combination of phosphors.

Re:Most white LEDs work using a different method (1)

t_allardyce (48447) | more than 9 years ago | (#12253983)

But dont forget with 3 LEDs you have a variable colour light, it might sound novelty and useless but you can make a lot of difference to a room just by subtly changing colours - just look at the difference between crappy energy saving bulbs and old-fashioned ones?

Drag Racing (3, Informative)

Skraut (545247) | more than 9 years ago | (#12253873)

The drag racing industry has moved from incadecant to LED lights for the starting "Christmas Tree"

Re:Drag Racing (1)

zakezuke (229119) | more than 9 years ago | (#12253890)

The drag racing industry has moved from incadecant to LED lights for the starting "Christmas Tree"

Note to self... don't take interior design tips from people who spend good money putting off center stripes on cars.

.feature of LEDs likely to propel them into homes. (2, Funny)

Anonymous Coward | more than 9 years ago | (#12253881)

The feature of LEDs likely to propel them into homes is aesthetic, not practical.

I want to have Natalie Portman propeled into my home. She is aesthetic pleasing, but this would not be practical.

Of course! (1)

phobos13013 (813040) | more than 9 years ago | (#12253889)

Its not like you could make a dance floor [slashdot.org] out of LEDs can you now....

Didnt think so!

Re:Of course! (1)

phobos13013 (813040) | more than 9 years ago | (#12253900)

heh, i mean you couldnt make a dance floor [slashdot.org] out of LIGHT BULBS could yah now..

Didnt think so!

Cartoon Physics (0)

Anonymous Coward | more than 9 years ago | (#12253954)

Does this mean that when Wile E. Coyote has an idea, an ACME LED cluster will switch on above him? I'm not sure I could handle that sort of iconography.

Been there... (2, Interesting)

Arrepiadd (688829) | more than 9 years ago | (#12254003)

A few years ago (actually, a lot) when fluorescent lamps were invented someone said that regular lamps would be dead in 10 years. Fluorescent lamps where invented still in 19th century, so I guess it didn't come true.

I'd hope it gets through this time, but people still by those energy consuming lamps, so I'll just wait and see...

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