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Technology

Lighting The Future: Lasers And (Wild) LEDs 109

Posted by timothy from the just-landed-in-my-bookmark-file dept.
Effugas writes: "Thank Memepool for pointing everyone towards The LED Museum, an absolute geek haven if there ever was one. The Museum archives, tests, and describes the multitude of LED types out there, from Ultraviolet to Turquoise to Infrared--and, most amazingly, true full color LEDs! Apparently, I wasn't the only tech drooling over the possibilities that these devices could be put to use towards: Color Kinetics threw 75 of 'em into a spotlight can and added a surprisingly versatile digital controller with external interfaces. The result: A 16.7 Million Color Programmable Spotlight, for $500US." This is an incredible site; I look forward to when the full color LEDs (and that spotlight - Yow!) are a lot cheaper. And unaccountably, Effugas has linked that "A" to something awful.

mindpixel writes: "Sandia National Laboratories is reporting the demonstration of the first UV microcavity laser which could be used to replace gas-filled fluorescent tubes in home and commercial lighting applications. Successful penetration of the lighting market by this and LED technology by 2025 "should translate [globally] into cost savings of $100 billion a year, power generation capacity reductions of 120 gigawatts, and carbon emission reductions of approximately 350 million tons per year (assuming that all the savings come from coal-fired plants)."

"
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Lighting The Future: Lasers And (Wild) LEDs More

Lighting The Future: Lasers And (Wild) LEDs

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  • I rigged up a color-programmable fishbowl full of Christmas lights (RGB) through three dimmer switches for the same effect, much cheaper... I have noticed, however that there is a bit of a heat problem. I wonder whether LEDs would be any better in that regard.

  • From the bit about the spotlight:

    If the diffuser window were removed, you would see a hexagonal array of LEDs sitting in the bottom of the can. ... To protect the LEDs and microprocessor board inside, the fixture should not be operated without the diffuser, and please don't monkey around with either the LEDs or the circuit board itself. I won't disassemble this one any further, and you shouldn't either.

    Somehow I don't think that's going to stop the current audience :)

  • This another example how solid-state lighting is beginning to establish itself in the world lighting market. At first it will be niche products like those described above. Soon however, they will begin to replace the standard lighting fixtures we have in our homes and offices. Being someone who works in development of these technologies I find it exciting to here about these applications all the time. GO SOLID-STATE!!!!
  • The result: A 16.7 Million Color Programmable Spotlight, for $500US.

    Definately something I'm showing to my theater friends. Considering what regular spotlights (plus all the gels) cost these days, and considering their electric bills, I think they would be willing to shell out $500 to try one of these things...
  • On the LED subject, I was at a Fossil store the other day and they were selling LED watches -- the ones with red numbers that you had to press a button to see...what was that, 1978 or so?

    Twenty bucks, and it was even about the same size as the old ones (must have put lead or something in there to simulate the weight :-)
  • LEDs work at a much lower power than other light sources. This of course depends on the particular wavelength you are looking for. Some LEDs still have some work to do in the efficiency department but most high brightness LEDs would be perfect for that application.
  • I've got a few flashlight bulbs made from big LEDs - they're only red and orange, but they're pretty bright, and they can last about a week with a pair of D batteries, if you accidentally leave it on the whole time. (Of course, now I need to get new batteries...) Instructions to make your own are Here [x5ca.net].
  • there's a link on the "A" in the article that point to a Q2 map, God is fun :)
    --
  • Some major cities are starting to replace their regualar old bulb and coloured lens traffic lights with the newer solid state trafic lights the contain LED's. The new light are way more expensive but come with the added bonus of not having to change the bulb every year.

    If you want your own personal LED flashlight, you can check out Photonlight [photonlight.com]. Way cool LED flaghlights that are visible for one mile and not much bigger around that a quarter.
    ----------

  • I purchased a bunch of CREE full color LEDs from DigiKey a few years ago for only $7ish each. Cool things. To bad they don't sell them anymore. I'd like to get some more, but I'd prefer surface mount instead of pins.
  • Truth be told, I got the idea for my project from a light bar of LEDs featured in Wired for around $10.00.

    The cool thing about Christmas lights is you can choose between lamp-style lighting (with the fishbowl I am using) or indirect lighting up the wall. I would just have to put a rail up near the ceiling to hide the lights themselves--my wife won't let me hang Christmas lights in our living room for some reason. I wonder why.
  • There are plenty of night clubs that will appreciate these things. Not only does the C-75 [att.net] provide a greater range of colours than conventional disco lights, they also don't have plastic films that need replacing from time to time.
  • I wonder if you arranged 800x600 of these things on a grid (assuming the price drops significantly) we could actually see LED projectors in the future! Sounds like a promising alternative to LCD, huh? Then maybe I can watch projected movies on my big loft wall without spending US $10,000.

  • More New LED Technology (Score:3)

    by Lita Juarez ( 201217 ) on Tuesday October 24, 2000 @04:49AM (#680928)
    Those LED sites were interesting, but they fail to mention another form of LED technology which has recently been developed by researchers at MIT. This new form of LED is able to produce a sound output, as well as the more usual light output.

    These SLEDs (Sound and Light Emitting Diodes) work in much the same way as a normal LED - spontaneous emission of photons from a forward biased p-n junction. But in the SLED, some of the photons of light are redirected through a resonant liquid crystal cavity, which causes vibrations of the resonant cavity at harmonics of the photon frequency. By changing the voltage applied to the liquid crystal cavity, different resonant points can be found and thus the frequency of the sound can be altered.

    The researchers believe that this technology can be used to produce laptop screens which produce sounds from the screen itself, without the need for unwieldy speakers. They are also working on using lower frequencies, so that touching an image on the LED screen will produce a tactile sensation, as if you were touching the object in the image itself.

    There's more stuff about SLED technology at the website of the journal Science. [sciencemag.org]

  • $500 is a steal for what you get in the C-75. Yeah it can't push the candle power of the big boys, but it doesn't cost that much for what it does. What I wouldn't have given to have a couple of these when I used to do lighting work back in the 80's.
  • Cadillac now uses these in some of its vehicles for brake lights; they light up 5 times faster than an incandescent bulb, they're resistant to breakage (those trunk lids are a bit hefty), and they're much brighter and give a more uniform appearance.

    As for that spotlight, I think it would make a very attractive bundle with a higher-end DV camcorder. Maybe toss in a copy of Final Cut Pro and a good microphone and you've got a very nifty little movie studio for $4000 or so. Sweeeet.

  • two MIT alums built a 25' tall LED tower [hydrochloride.net] for Burning Man 2000 [burningman.com]. very impressive, both technically and artistically.
  • It's not just major cities... Any new traffic light seams to be a prime candidate for LEDs. Something about maintence costs alown call for the switch. At a cost of about $250 to change a traffic light, a light that lasts 20 times longer quickly pays for it's self even if it is a $500 light. To make matters worse, the worst LED traffic lights use only 18% of the energy of a regular traffic light. One city alown was figuring they would save $250,000 a year on electricity once fully converted to LED traffic lights. The current problem is production numbers. Not enough are being produced so they can't go hog wild replacing them. Some still need to get the old lights.

  • Cold LED Stagelights, Windows and Fishbowls (Score:5)

    by BigBlockMopar ( 191202 ) on Tuesday October 24, 2000 @05:07AM (#680933) Homepage

    I rigged up a color-programmable fishbowl full of Christmas lights (RGB) through three dimmer switches for the same effect, much cheaper... I have noticed, however that there is a bit of a heat problem. I wonder whether LEDs would be any better in that regard.

    Incandescent bulbs (Christmas lights) use a tungsten filament heated to white hot inside a vacuum.

    A natural by-product of this is heat.

    (Actually, truth be told, a natural by-product of an incandescent bulb is *light*; most of the energy is wasted as heat.)

    A Light Emitting Diode is based on the concept that when some semiconductor PN junctions (ie. diodes) are forward-biased, they convert the energy lost to their forward voltage drop into light.

    LED light actually comes from the semiconductor junction itself; it's highly efficient (85% or more), highly color-stable (the color emitted depends on the doping of the junction), has none of the thermal inertia issues associated with tungsten filaments (ie., look at a car with tungsten tail lights and an LED third brake light), and is virtually impervious to mechanical shock.

    The LED is the way of the future. Your fishbowl would benefit.

    I'm not sure about stagelights, though. I used to work in the sound/lighting/professional video field; I don't know how I'll like stagelights that don't feel *warm* when they shine on you!

    Although, I'd never have to dig out the asbestos gloves and climb a ladder to change a hot quartz bulb during the 10-minute intermission or fart around swapping gels...

    Hey, is there a Linux version of the Color Kinetics software out there? I'm just wondering, when Windows blue-screens, do their cans change to blue in sympathy?

    Either way, these guys are set to give Intellibeam, RoboScan, etc. a run for their money. Most of the times I ever used those, it wasn't for the tacky little gobos or the fact that they'd follow a target: it was because they changed color *quickly*, certainly faster than conventional cans with a gel reel setup.

  • Back when I was in high school (around the time of the IBM PC, FWIW) I would play with TTL chips like they were Legos, and make all sorts of cheezy projects with them, from silly LED flashers to hacking on the video generator section of my TRS-80.

    Anyhow, twice I accidentally ran the power from my 5V 1A power supply directly through them. Their tops popped off instantly. The first one was a jumbo, and the top of it bounced off my glasses. Good thing I was nearsighted and had to wear glasses or it might have gone into my eye! (The second one was just an itty bitty, and nothing memorable.)

    So if you're bored of microwaving AOL CDs, then get out those old junk 2400 baud external modems, rip out the LEDs, and hook 'em up to a 5 volt power supply!


  • On the LED subject, I was at a Fossil store the other day and they were selling LED watches -- the ones with red numbers that you had to press a button to see...what was that, 1978 or so? Twenty bucks, and it was even about the same size as the old ones (must have put lead or something in there to simulate the weight :-)

    Cool! I've always wanted one of those!

    I *hate* analog watches (the whole idea of moving parts on my wrist...), but I want a *tasteful* and *neat* digital watch. (Calculator watches need not apply.) Do they at least have the really nice cases and wristbands that I remember them having in my childhood?

  • Some major cities? Here (sweden) they no longer install anything *but* LED traffic lights and the old ones are getting replaced as quickly as the funding allows.

    The best thing about them is not the power consumtion or their life span. Old style traffic lights have a large reflector behind the light bulb. That reflector does a very nice job reflecting, not only light from the bulb, but from a low sun during morning rush.

    If you have a low sun behind you it is almost impossible to see if the light is red or green. With a LED traffic light there may be reflections from the green light when the light is red, but the reflections are white/clear not green.

    Does a thing or two for road safety, don't you agree?

  • I *hate* analog watches (the whole idea of moving parts on my wrist...), but I want a *tasteful* and *neat* digital watch. (Calculator watches need not apply.) Do they at least have the really nice cases and wristbands that I remember them having in my childhood?

    No, it was that kind of chintzy looking gold band. The watch itself was about 1 inch by 1 inch and about 3/4 of an inch high. Looked almost exactly like a watch I had back in high school.

    Neat? Yeah.

    Tasteful? Not by a long shot.

  • LED's are already used in video arrays with fantastic results. NASDAQ has a huge, curved LED array covering their building in Times Square. Purportedly the "largest" (by what measure I am uncertain), it is awfully impressive. ABC has a pretty big one next door to NASDAQ and of course, also claims to be the largest. There is also a new monitor (probably 12' x 20') done in LED's by the Manhattan entrance to the Holland Tunnel.

    Check it:
    NASDAQ LED Array pix [smartvision.com]
    NASDAQ LED Array Article [etecnyc.net]
    ABC LED Array PR [techmall.com]

  • White LED Flashlight Bulbs (Score:3)

    by raygundan ( 16760 ) on Tuesday October 24, 2000 @05:35AM (#680939) Homepage
    are available from www.theledlight.com [theledlight.com]. They make single and multi LED bulb replacements that fit into standard flashlight bulb sockets. Get 10X the battery life, plus ridiculously long bulb life (100,000 hrs). They will even fit maglites. I have no idea why companies are still making flashlights with traditional bulbs-- there doesn't seem to be any downside at all! (These bulbs cost $20 more than other bulbs, but if you've ever used a maglite regularly, you know how often the bulbs burn out-- why else would they have a spare in the handle? You'll get your money's worth by saving on batteries and replacement bulbs.)
  • All I can say is... DAMN! Now give me these things in a 6x9 instrument with out put quivilent to a 750 w bulb and it'll revolutionize the theatre lighting industry. No more gels, now you could programatically change your gels for every scene, you could even cross fade gels throughout a scene. You could also reduce heat, which actors and makeup artists will LOVE. Not to mention us spot monkeys that spend hours in the beams. God imagine the light shows Pink Floyd could have done if they'd had these instruments.

  • 800x600 LED Color TV Sets! (Score:5)

    by BigBlockMopar ( 191202 ) on Tuesday October 24, 2000 @05:42AM (#680941) Homepage

    I wonder if you arranged 800x600 of these things on a grid (assuming the price drops significantly) we could actually see LED projectors in the future! Sounds like a promising alternative to LCD, huh? Then maybe I can watch projected movies on my big loft wall without spending US $10,000.

    Uhhh... No. If you made an array of LEDs and wanted to project them, you'd still need a lens.

    To do it more reasonably, just make the 800x600 grid direct-viewable in whatever size that you want.

    Problem 1: Average current to each LED is, let's say, 15mA. 800x600x0.015A = 7,200 amps. Evidently, this is going to have to be multiplexed somehow. (Oh, yeah, that's 7,200A *per color*, since I didn't multiply that number by three for each of the primary colors. (I assume you want each pixel to be three color.)

    Assuming the average forward voltage drop per LED is 2.0V, that's a total consumption of 14.4kW. With the cost of a kWh of electricity where I am hovering around $0.06, watching the X-Files would cost me $8.64 in electricity. Per color! ("Maw, we's is goan' hafta winna lottery before we is can afford ta turn on th' whole TV set... 'ntil then, it's Jerry Springer 'n green only.") And that's just for the LEDs, not the support electronics.

    Problem 2: Let's say these are three-color T-1 3/4 LEDs. And let's say that you've somehow figured out a way of wiring them to each other that doesn't occupy any display real estate.

    A T-1 3/4 LED is about 1/4" in diameter. If you have 800 of them in a row, that's gonna be 200 inches long. 16.66 feet. 600 LEDs tall: 150 inches; 12.5 feet. A 16.6 x 12.5 foot screen. Or, using Pythagorean Theorum to figure out how they'd advertise it if it were a TV set, 20.78 feet diagonally. 249.36 Viewable Inches! On Sale Now! (Got space for it?)

    LEDs vary from lot to lot, factory to factory. Blue on one side of your display with be different from the blue on the other side. At the same time, it'll be difficult to get your driver system to be adjusted flat across the entire color spectrum. You will have color purity issues. Look at a big LED display board in a public place now; few of them even approach the scope and resolution that you're talking about. And they're all spotty. There's a gorgeous example on the Paramount Theater at Toronto's Richmond and John Streets.

    Finally, 800x600 is 480,000 LEDs. Each one is gonna cost you at least a buck (three color T-1 3/4), even in quantity. Each one is going to take you at least 30 seconds to solder into place (realistically, doing it by hand). Got 240,000 minutes (that's 4,000 hours; 166 days)? And we haven't even looked at the support electronics.

    Just wait another 20 years or so until a stadium somewhere is being demolished, and scoop the JumboTron out of it. They're not LED-based, they don't have the same resolution, but they're pre-built and they look really good.


  • Fort Hood started the conversion back in 1998, and they're quite pleased...
    In a typical group of 100 signal lights with 120-watt lamps, the electrical load is 12,000 watts (12 kilowatt, kW). If the operating hours are 6,132 hours per year, the electrical consumption will be 73,584 kilowatt-hour (kWh), resulting in an annual electrical cost of $3,776. The use of LED technology reduces this cost by 85%. The lamp rating of the LED lamp is 17 watts, resulting in an electrical load of 1,700 watts (1.7 kW). Using the same operating hours, the electrical consumption will be 10,425 kWh, resulting in an annual electrical cost of $534 (thus the 85% savings).

    The normal lamp-life of a 120-watt lamp is 8,000 hours. For the traffic signals described above, the lamps would have to be replaced every 1.3 years. At this time, the replacement cost and the maintenance cost are realized. The lamp life for LED technology is 100,000 hours. Therefore, the replacement period extends to 16.3 years, resulting in a significant cost savings for lamps and maintenance cost.

    Check it:
    Fort Hood Converts to LED's [pnl.gov]

  • Since I don't really know that much about this stuff, a question. If they can have a few of these in a "can" to make a multicolor spotlight, what would be the chances of using 3 of these just like the 3 individual colored lamps used in front projection TV's? Would it be cost effective if it could be done?
  • Its actually become popular for outdoorsmen (women too). ;Prince ton Tech [rei.com] has been doing this for about a year. You trade off the brilliance of a regular bulb (which lasts for 2.5 hours) for 40 hours of life - this from 2 AAs...

    Before, the only way to get long lasting light was to take a big and heavy battery pack (usually 4 or 6 D cells). It may not sound like much but it made a headlamp relatively impractical for backpacking (where an extra pound. means an awful lot). I can use my headlamp for multiple trips (usually about 10 days total) and not have to bring replacement batteries -though I usually do, because 1 extra AA (I'll bring one spare) still weighs less than the old battery pack

    Headlamps are fantastic though, because it frees your hands so you can do stuff like - set up a tent, see what your doing while you cook dinner, and even change a tire (not that I change tires while backpacking, but I do use my headlamp for other things as well).

    Plus, LEDs are way more sturdy than regular bulbs - and while Headlamps and such are built sturdy, it becomes a worthy investment the first time you break your replacement bulb while changing it... not to mention you don't have to replace LEDs...

    I think I've seen this for a few regular flashlights too - for those of you who don't want to look like the three-eyed monster while you use a flashlight.
  • Also of interest may be this project [uk.net] to build a white LED front light for your bicycle

  • Um, that shouldn't make any difference, should it? The heat you feel from a spotlight is down to all the electromatic waves [be it visible light/ir/etc] hitting you and transferring energy. Provided the LED lamp is of the same intenisty then it shoulkd be just as warm

    No, it's not the light that makes you feel warm. It's the radiant heat that gets thrown off the bulb that makes you feel warm. Of couse, the radiant heat is electromagnetic energy - IR at that - but the difference is that a more efficient lighting technology throws off less IR and more visible light.

    Compare a fluorescent desk light with an incandescent desk light. They may both put out the same amount of light, but the incandescent will warm the stuff around it more (since it wastes more energy as IR, surface temperature and convective heat).


  • White LED's...
    • Aren't as bright as regular LED's
    • Are 2-3x less energy-efficient than regular LED's (comparable to blue)
    • Are much more expensive (now)

    I'm not dissing them, but yellow or blue-green LED's I've seen as bright as 36,000mcd, but all the whites I want to buy are only 6,000mcd at most. They're also a novelty and a little too expensive now for my taste.

  • I've always wanted to get three big SCSI drives, each with their own LED connections, and hook each positive terminal to one of the three positive ones on the full-color LED. Then I wanted to wait until 7:40 AM for a little light show.

    It would have been lame, but cool.

    - A.P.

    --
    * CmdrTaco is an idiot.

  • My blue-LED Dreamcast [min.net] is running scared, as we speak.
  • I'm trying to figure out how I could replace the indicator ('flasher') bulbs with LEDs, as my motorbike runs on 6V and the indicator lights suck 2*21 Watts which then isn't very bright during daytime. If I find a good source, I go shopping for some high-performance yellow ones, soldering 9 of them onto a bulb socket.

    (3 x (3 in series)) Any hints?

  • Not quite. The heat is due to IR radiation, not visible light nor UV. A (tungsten) filament is basically a black body radiator, i.e. it emits the complete spectrum, from IR to UV (with different intensities though, according to Planck's Law, determined only by the temperature of the filament). A LED is not an blackbody radiadtor, it emits light of a rather tight spectrum, determined by the band gap of the semiconductor. So, indeed, LED lamps should emit less heat than filament lamps (in the ideal case none). This is also the reason, why LEDs are more efficient light sources than filaments.

  • . I have no idea why companies are still making flashlights with traditional bulbs-- there doesn't seem to be any downside at all! (These bulbs cost $20 more...

    I think you answered your own question. Yes, the long life bulb is better. However, if you put these on a retail shelf, and consumers compare the cost, what do you think most of them are going to do?

    Of course, a lot of this depends on how much you use a flashlight. The only time I ever use one is during a blackout, and those have become increasingly rare over the years. So, the LED just doesn't make sense for me, because I might burn out one flashlight bulb every 20 years. By then, the flashlight will probably have been lost anyway. I'm not sure where they go... probably the same place as the socks in the dryer.

  • You know what's really cool? That someone actually credited Memepool [memepool.com] for a link. Check back through the quickies and you'll notice that entire chunks of Memepool turn up.


    It's an uncommon courtesy for folks to attribute their links.

    - technik
    (not affilliated with memepool)
  • I found digital watches rather unpractical. You have to look at the exact numbers while with analog watches you can see the time with a glance. Plus, analog watches look much better usually, but that was your point.

  • Hennepin County, Minnesota has done a cool pilot project on using a LED traffic flasher powered by solar for an amazing savings... They have some great graphs on the cost savings (79% down for LED on the grid, 99% for LED w/solar), and the only limitation on the tech was during the coldest winter months there was a charging issue with the lead-acid battery. Very interesting stuff.

    check it:
    Solar LED Traffic Light Project - Hennepin County, MN [hennepin.mn.us]

  • gee you're so 1999

  • Programmable spotlight great for darkrooms... (Score:3)

    by SuperKendall ( 25149 ) on Tuesday October 24, 2000 @06:28AM (#680957)
    The programmable spotlight looks like it'd be great as a darkroom light - you can turn it to red whenever you're ready to work, and back to a more natural light when you're finished.

    Also, at 11 years of rated bulb life it might make a really good home lamp! Plus you have the bonus of whatever lighting color suits your mood.
  • For more info you can check out CREE's website [cree.com] They are a huge LED manufacture.
  • Incidentally, why do theaters and stage staff insist on colored lights? Why can't you simply illuminate actors and musicians with white lights? It's distracting having people with one side of their head blue and the other side red -- or their whole head blue, except when it's Blue Man Group.

    Mood. :)

    For example, a Negative Green Filter makes standard florescent lights appear more light 'natural' daylight.

    Other filters provide different moods, red for rage or jealousy, green for envy (or seasickness), and so on.

  • Notice in the season premiére when Cap'n Janeway was turned into a Borg she had a blue LED implanted in much the same way that Cap'n Picard's cheesy red laser was?
    That was cool.
  • Huh?
    <p>
    I looked though the web page. White LEDs <b>are</b> blue LEDs with some sort of chemical coating.
    <p>
    Erik Z
  • The 30 watt (equivalent) bulb is $190. I was going to scoff about how that was WAY to expensive but then I did the math:

    Assume I live for 50 more years. Further assume that I have the light on 8 hours/day, 365 days/year. That's 2920 hours/year * 30 watts = ~87kWh/year. Times 50 years is 4380kWh. Multiplied by, say, $.06/kWh is $260! Add the money for the bulbs themselves (which keep burning out) and we are talking about $300 for lifetime use of a single bulb! (unless someone points out the sure-to-exist flaws in the above)

    The LED bulb uses 1/10th the power so the 50 year cost must be $26 added to the $190 one time cost is just $220.

    Problems, though:

    1) I couldn't find anything higher than a 30 watt (equiv) bulb on their site. Does nothing higher exist?

    2) The cost isn't amortized over my lifetime. This causes two subproblems:
    a) If I move, I better take the bulbs with me or I don't reap the savings
    b) The cost is all upfront--meaning I have to buy costly bulbs when I am young and (certainly) poor so I can save money when I am old and (hopefully) rich.

    Therefore, prediction: Until using LEDs becomes either cheap or mandatory, only ultra-enviro's will be using them.
    --
    An abstained vote is a vote for Bush and Gore.
  • "And unaccountably, Effugas has linked that "A" to something awful."

    linked what to what??

    • Uses patented Chromacore (tm) technology for additive color synthesis
    Oh, my god!!! they have PATENTED ADDITIVE COLOR SYNTHESIS!!!!

    My CRT monitor as well as my COLOR TV are surely infringing on that patent!!!!

    What am I gonna do???

    --
    Americans are bred for stupidity.


  • If they can have a few of these in a "can" to make a multicolor spotlight, what would be the chances of using 3 of these just like the 3 individual colored lamps used in front projection TV's? Would it be cost effective if it could be done?

    No. The issues again are resolution, the physical size of the LEDs, the current required t feed them, and the cost of the LEDs and their driver logic.

    Considering first off that an LCD display is basically a large integrated circuit, if LEDs were made as large ICs like this, it would be possible. But an LCD pixel really uses no current: like CMOS logic, it's a potential-operated high-impedance device. There's actually very little energy used; it just passes light from the backlight selectively. However, an LED matrix panel like you'd need for this would still be a current-operated device. The device would generate its own light - and heat. While an LED is a very efficient way to make light, they need a certain threshold current to be useable. This threshold current is sufficient that the display would guzzle huge amounts of power.

    There are ways to multiplex the display to get around that, but by the time an LED array is big enough in resolution to compete with today's technologies, the driver circuits are incredibly large, with huge component counts. While CRT drive circuits are unweildy (flyback, deflection, cathode drives and stuff), they're nothing compared to what this thing would require. Sure, the LED matrix wouldn't need a 30kV power supply to drive an accelerating anode (like an CRT does). Instead, the LED matrix would require drive circuits that were capable of supporting 307,200 LEDs. And that's for a paltry 640x480 display in only one color. You'd need 921,600 LED junctions for 640x480 with RGB.

    The only way it would be practical to build this would be a large LED matrix as a single array. Production yield rates, current requirements and cooling are the issues that I see with that. If you think a PIII Xeon is a pig, wait 'til you see a single chip that big.

    Alternate video projection technologies are far more refined:

    CRT projectors (like Sony's venerable VPH-1040 and 1270, Zenith/Aquastar, some Barco models) offer excellent resolution, good brightness and are flexible to a wide variety of different input signals. Downside: cost, size, limited lifespan of expensive projection CRTs, limited portability due to need to adjust convergence with each time they're moved relative to the screen.

    LCD projectors (most of the little table-top projectors being offered in computer magazines) offer portability because of small size and weight, as well as the fact that they're no tougher to set up than a slide projector. Disadvantages: limited resolution, don't adapt very well to being used at varying resolutions, limited brightness due to technological limits on how hot you can make an LCD sheet, uses conventional projector bulb which usually fails at the worst possible time.

    Finally, the Hughes/JVC Image Light Amplifier video projectors. These things are nuts. They combine the best features of a CRT projector with more conventional projection technology. They were developed for NASA to use at Mission Control in the 1960s, and have been continually refined ever since. Can display huge images visible in full sunlight. Very flexible as to resolution of the incoming image. Problems: cost over $500,000. The last one I set up took a 240V 200A power drop. Has a large xenon projector light that takes 20 minutes to warm up, relies on expensive and limited-life projection CRTs to draw an image onto special LCD "image light amplifiers". Fragile optics to split light from xenon projector bulb, pass it through three ILAs which serve as the screens for the projection CRTs, filter it into primary colors and then shoot it out three separate lenses to the screen. Weighs over 600 lbs. Requires convergence and purity adjustments to align it to the screen. Causes severe eye damage if you accidentally look into any one of the lenses. Suitable only for long-term installation in very large facilities.

    Even so, to put the LED projector into perspective, the Hughes/JVC projector is far better adapted to your living room.

    Biggest I've ever had in my living room was a Sony VPH-1272. And that was a gorgeous floor-to-ceiling movie. Too bad it was before the DVD came out, and I had to cope with VHS.

  • You're right about colored LED's being more efficient than the white ones. You can also get colored LED replacement bulbs for your flashlights at www.theledlight.com. Their prices and stats are unusual too-- they have white LEDs at 18,000mcd, green at 30,000, and blue at 9,000. Additionally, the white, blue, and green LED replacement bulbs they sell cost exactly the same ($24.35). I know that at your local electronics shop they will charge you an arm and a leg for blue LEDs-- these are possibly (although I couldn't find the info he mentioned) blue LEDs with some sort of coating on them. Anybody got more info?

  • Indeed. The old style whites were four chips giving roughly equal output of red, green and blue. The new whites are blue chips with a yellow phosphor coating. Depending on how much you pay for them you can avoid the bluish ring or yellowish center some of these new whites can be heir to.
  • I'd probably say that the largest (although it drops resolution to a few leds per feet in parts) is the Luxor in Vegas. Not a screen on the Luxor... the Luxor itself.

    Of course, it's rather abstract, only displaying various washes and plasma fractals across the majority of the surface (but hawking Sarah Brightman and Sigfried and Roy in places).

    Vegas in general is home of bright eyegrabbers, and there are plenty of screens, most of the new ones being LED matrices.

    --
    Evan

  • > Hey, is there a Linux version of the Color
    > Kinetics software out there?

    According to their website, their products
    support DMX512 protocol, so yes, there is
    Linux software (free!) that can support it!

    Just do a freshmeat.net search on "DMX"
  • For the bulbs in your house, the best way to go (right now, anyway) is compact fluorescent bulbs. The light they produce is nearly indistinguishable from that of incandescent bulbs, but they're about 4X as efficient. (13W is equivalent to 60W) They cost from $15 to $30, and last from 5 to 12 years, depending on brand. You can buy dimmable, R30 and R40, bulb-shaped, 3-way, etc... and you can get them at normal stores (i got a lot of mine at Meijer). By the time they burn out, LEDs ought to be affordable and more widely available. I cut more than 10% off my electric bill by replacing all my bulbs. As to the amortization problem, I saved all the crappy old ones to put back in when I move out. They're coming with me, all right!

  • It's been some time since I've done theater lighting, but I have my $0.02 to throw in anyways.

    Is this really a true "spot" light? It doesn't appear to be focusable. It is more of a directed fill, it seems to me.

    And did they stick it in a traditional can because it was cheaper? I mean, does it really *need* the heat-sink fins around the outside?

  • Something Awful [somethingawful.com]
    I belive the actual link was to a QuakeII map called 'This Map is Good Fun', which really has to be seen to be believed.

    --K
    ---
  • There are SEDs, too. That's for Smell Emitting Diode.

    Basically, that's a GaAs diode tuned for 420 nm emission on which a voltage of about 200 volts is applied for 300 ms.

    The result is a foul stench of burned epoxy. The only problem with the design is that it's a single use. But I hear that the researchers are busy looking for a solution...

    --
    Americans are bred for stupidity.

  • I used to work in an electronics supply shop about ten years ago (Electro Supplies, Stockport, UK). I used to like to mess about with various LEDs to make window displays. Some of my favorite simple ones:

    -Spelling things out using 7 segment displays.

    -We used to sell a simple kit that ran seven LEDs off a digital counter IC that produced an effect like the front of KITT from Knight Rider, or a Cylon from Battlestar Galactica. A cool variation on this was to replace the visible-light LEDs with infra-red ones and have the kit hidden somewhere in view of a CCTV camera - you couldn't see anything when looking around the shop, but the camera, being IR sensitive, showed it up brilliantly - we confused a lot of people with that one! :)

    -Wiring a bunch of flashing LEDs (built-in flasher ciruit, operates off 12vdc) in parallel and mounting them in a line. Because none of them flash at exactly the same rate, you get a great 'visual beats' effect (I don't know the proper term). They would flash at seemingly random rates, and then patterns would emerge - alternate flashing, all flashing at the same time, lights running from one end to the other, running from the centre to the ends - I still like to trance out to that effect (you get the same thing with a line of cars with their indicators flashing, or a line of those flashing bollards around roadworks).

    The Memepool entry that this /. is taken from has a link to a pretty cool LED oscilloscope:

    http://www.geocities.com/SiliconValley/Lakes/7156/ articl3.htm

    I remember reading how to build an even cooler one that used a vertical strip of LEDs, and a mirror mounted on a motor that reflected the LED strip. The speed of the rotating mirror was the timebase and the LED strip showed the amplitude! :)

    [Happosai]
  • At the Guggenheim museum of modern art i Bilbao, Spain, there's five huge columns that have bright blue LEDs on one side and bright red LEDs on the other. Poetry is constantly streaming either down- or upwards the 10 meter (33 ft) high columns. The words are in english, spanish and basque. Really, really, really, really cool! I remember that I was mighty impressed when I saw it for the first time, and even more impressed when I saw it the second time.

    Also, at the Gardermoen Airport outside Oslo, Norway, there's a one meter wide, two meter high LED board. The LEDs are amber, and all are lit or dimmed to illustrate a figure jumping up and down in ultra-slow motion. It's always cool to see the figures when arriving from a long flight... :)
  • Moderate parent as Funny.

    This comment looks like a hoax. It contains fake url in it. It claims nonsence clear to enyone knows that light frequency's 1E12 times greater than one of sound. Nevertheless it's moderated Interesting and Insightful, by two different moderators I suppose.

    I believe Sig11 is right: /. moderation is broken.
    ---
    Every secretary using MSWord wastes enough resources


  • Just stay away from the Lights of America brand.

    They have a system where the bulb and the ballast are separate, unlike most compact flourescents. That's a good thing, because the ballast has a longer life than the bulb portion in most flourescent configurations. With typical CF bulbs, you throw away a perfectly good ballast when the bulb goes. I originally bought Lights of America CFs for that reason.

    The problem was that the bulb portion was crap!
    It burned out almost as quickly as an incandescent. Some savings!

    Go to the library and look at the Consumers Report issue where they rate CF bulbs. Lights of America regularly comes up at the bottom of the list.

  • As a side note... remember that the article (which you obviously did not read) created a lamp using WHITE LEDs. Not Red, Green, and Blue, but WHITE, because the RGB PN junctions are inside the LED itself. Each one costs about $20. Power usage is rated at 120mw maximum, and unless you're watching a pure white screen you will never use that much for every LED, so let's assume 1/2 that power under normal operating circumstances. That totals up to (I believe) only 28.8kW... about 1/3 less than you estimated for a full color screen. And the total to watch that for an hour is only $1.72 for a full color screen. As for construction, this wouldn't be a hobby project. With a premade backplane designed for these, probably build in 32x32 chunks, the cost and complexity could be minimised. Overall you end up with a super high resolution, full color, full animation billboard that puts all others to shame and has an extremely low maintenance cost... for a mere 10 million at worst. :-)


    And my soul from out that shadow that lies floating on the floor
  • Does this mean I can get true color images in my LiteBrite?
  • Basically, that's a GaAs diode tuned for 420 nm emission...

    I would've thought GaAS diodes would be smelly enough in their own right.

  • . .

    Okay this may already be redundant, but can someone tell how to equate foot candle infomation provided by Color Kinetics into an equivalent for 100 Watt 240 volt 30deg tungsten halogen output?

    I'm sorry if I've missed something obvious here but just trying to work out *how many* of these I need ;-)

  • The spec sheet (PDF Format) [colorkinetics.com] lists the C-75's light output (white) at only 40.5 lumens. Compare that to a 100 Watt 120 Volt standard household bulb which puts out 1690 lumens. Even the big C-200 only puts out 250 lumens (white).

  • Traffic lights aren't the only application.

    The EXIT signs for most buildings these days have a handful of red LEDs inside for illuminating the letters.

    This is an even better example because they are more ubiquitous than even stoplights, and you'd only notice they are burned out when the power goes out.

  • has none of the thermal inertia issues associated with tungsten filaments (ie., look at a car with tungsten tail lights and an LED third brake light),

    I don't understand. Do you mean that hot things stay hot?
    __
  • has none of the thermal inertia issues associated with tungsten filaments (ie., look at a car with tungsten tail lights and an LED third brake light),

    No, they're saying that LEDs don't have to get hot before they start to emit light - They start emitting light much sooner than a light bulb, once you apply power to them.

  • Check out SLOAN optoelectronics they have a .PDF outlining LED replacement for incadescent light INCANDESCENT REPLACEMENT LED LAMPS [sloancorp.com]. I found these thru Allied Electronics catalogue, page 679 [alliedelec.com]. They retail for around $10
    This is one example out of many, I don't work for Allied nor Sloan; Feel free to look this up in any electronic component shop like Future-Active etc...
    ---
    Vote Inanimate Carbon Rod in 2000
  • It contains fake url in it

    That looks suspiciously like the URL for the world renowned journal known as Science! Why's that fake?

    It claims nonsence clear to enyone knows that light frequency's 1E12 times greater than one of sound

    I suspect the laws of physics are different in your part of the world (as well as the rules of English spelling and grammar).
    Where I live, the speed of sound in air is of the order of 3e2 m/s, and the speed of EM radiation (light!) is 3e8 m/s. That's a factor of 1e6, not 1e12!

    I don't know whether or not the original post is a hoax or not. But your logic is certainly spurious.

  • Therefore, prediction: Until using LEDs becomes either cheap or mandatory, only ultra-enviro's will be using them.


    Don't forget Lazy people!!! I use those incredible long life low power bulbs because I hate having to bother to change the light bulbs. So I get the longest life bulbs I can find in order to avoid that. I've also found that you can get compact flourescents for as low as 4$ a bulb and they are good quality. I usually get mine from Ikea...

    Kintanon
  • Well, the old LED watches were very impractical - I had one in 1977 (in jr. high school). They required two hands to operate... one at the end of the arm it's strapped to, and the other to push the buttons to light up the display.

    I loathe the symbolism of strapping my body to a clock, so I seldom ever wear a watch. But when I do, I prefer a watch with both an analog face and an LCD digital display. If you can have both, why not?

  • As cool as it would be to use something like this in a theatrical production. I don't think it's feasable until they pump up the output.

    The specs read as: 46 footcandles at 3ft
    15 footcandles at 6ft
    6 footcandles at 9ft.

    A 23 degree source four (from ETC, one of the best theatre lights around)
    does 15342 footcandles at 3ft
    3835 footcandles at 6ft
    1704 footcandles at 9ft.

    So as much as infinite color control would be nice, I need more power or no body in the audience is going to see it.
  • It claims nonsence clear to enyone knows that light frequency's 1E12 times greater than one of sound

    I suspect the laws of physics are different in your part of the world (as well as the rules of English spelling and grammar). Where I live, the speed of sound in air is of the order of 3e2 m/s, and the speed of EM radiation (light!) is 3e8 m/s. That's a factor of 1e6, not 1e12!

    I suspect there are other more serious problems in your part of the world (perhaps localized to your frontal lobe). Nowhere in his post did he mention the speed of sound or light through air.
  • One of the coolest uses of LED's I saw was in the tunnel from Honshu to Hokkaido. The walls had LED panels that synched to the speed of the train and would display animated ads and such as the train sped by in the dark. Took a lot of panels I must say.
  • Frequency of Visible Light = 10^14 Hz Frequency of Sound = Maximum of 30,000 Hz. (Audible) Hmmmm....

  • I own the PrincetonTec LED headlamp, I've read the LED article in Technology Review recently, and I've followed many links on the web about white LED's, and the following seem to be the relevant facts for headlamp and homelamp applications:

    The current efficiency for a white LED is limited to about 20 lumens/watt (see the Technology Review article or www.misty.com/~don/led.html#w [misty.com].

    The reason that they do not put out much heat is that they do not put out much light either (though enough for some tasks).

    Compact Fluorescents currently run about 50 lumens/watt (a 15 W, 750 Lumen unit costs $5-10), so it is clear that if you have access to AC power, you can forget LED's unless a drastic change in efficiency happens.

    Halogen flashlight bulbs (state of the art Xenon) run about 10-20 lumens/watt (more for the higher power ~4W bulbs). Sorry, I lost the reference for this one.

    The reason LED flashlights have become popular is that, for low power applications, halogen lights don't scale well and normal incandescent bulbs are not very efficient (~5 lumens/watt).

    That being said, I must say I like my PrincetonTec lamp - it does go about 40 hours and is bright enough to comfortably read and walk on reasonable trails. I (along with others) reviewed this lamp on outdoorreview.com/reviews/Headlamps/product_2333.a sp [outdoorreview.com].

  • The C-Series lamps by Color Kinetics would be great for mood lighting, and probably within reach of people wishing to experiment with DMX. Although, as mentioned in other posts, not really good for high output applications. Pity they're running IIS over there as I can't get to the 'how to buy' page on colorkinetics' site. Time to change their web server platform, methinks.

  • The Something Awful Connection (Score:4)

    by Sangammon ( 100874 ) on Tuesday October 24, 2000 @10:00AM (#680997)
    It took me a second, but I think that Effugas (the guy who sent in the story) made a tremendously funny metajoke by linking the word "A" to one of Something Awful's Cranky Steve's Whorehouse map reviews. The infamous This Map is GoodFun [somethingawful.com]

    For those know in-the-know, Something Awful is an often hilarious page of humor written by one Rich "Lowtax" Kyanka, and is somewhat game-oriented in much of its humor. One featured page is "Cranky Steve's Whorehouse" which reviews Quake (and its descendants, relatives) maps that are truly and hellaciously awful. One hallmark of bad maps, and this [somethingawful.com] one in particular is the overuse of colored lighting.

    So imagine what happens when everywhere you go, the same type of people who write these godawful Quake maps get the bright idea to use these multicolored lights in real life?

    Right

    -Tal

  • The revoloution is still in development... At the moment these lights are not bright enough, and the range of colours that they produce is quite limited. They tend not to do white very well. On the last tour Pink Floyd used a lot of VL5's, made by Vari*lite [vari-light.com]. These fade between colours by spinning plates of coated glass in front of the lamps. Some readers may find Vari*lites approach to patents distressing. I belive they use cold light mirrors that reflect light but not heat.
  • LED != LCD

    Science_mag.find( "SLED" ) == -1; // for that matter

    An LED laptop screen would be interesting, though. Just not very good resolution-wise.
  • Maybe you should check out the details of the patent first before commenting. Who knows what they have done, maybe they have a truly innovative patent that has nothing to do with your TV or Monitor. Maybe this is another Dumb Patent(tm). Oh well, it won't be known unless you look the bloody thing up.
  • Actually, a friend of mine works at ColorKinetics and the patent they have is on the specifc process they use to control the color of the LED, not the full color LED itself. To me, this seems to be a reasonable patent, as the process was a new concept a few years ago, and are now focusing their business on developing the applications of this technology, partiuclarly in te entertainment and retail industry. If I'm not mistaken, this is the sort of thing that patents are supposed to allow new companies to do. If you've ever actually seen on of their rigs in action, I think that you would agree that they have come up with a clever device. What this will do to the process of color application is pretty amazing.
  • A friend of mine was designing a DSP-based video effects system that was never completed.

    He used one or more of these DSPs, a whole lot of 'spotlight' LEDs and an infrared port to build a mirror-ball like LED light bulb that plugged into a regular house light bulb socket.

    The OS (etc) was beamed to it via IR, and since the LEDs were multi-level (ie grey-scale) he could dynamically project bitmaps onto the surrounding walls, as well as doing other special effects. I think it had a small mic so it could pulsate effects to music.

    Way cool, but too expensive (at the time), so only the prototype got built.


    [Antispam] Kill the x in my email address to reply

  • What? The Luxor has a matrix of spotlights coming out the top pointing straight up, and a series of animated flashbulbs running up and down the edges of the pyramid. No displays on the actual building (unless it's changed in the two months since I was at Vegas last.)

  • You forgot one:

    Indeed I did, thank you.

    Digital Light Projector - brand name for a technology developed by TI. Basically, you have a chip with an array of micro-mirrors that you use to deflect light from a projector. These are a lot brighter than LCD displays.

    Yeah; I've heard of them, but I've never actually seen one. It sounds like it takes the best of the Hughes/JVC (xenon bulb for the main projection), arrayed video device like an LCD display (oh well, can't be perfect), and adds to that the fact that the display element neither creates the light (like a CRT projector), nor does it have to transmit it (like an LCD projector). It strikes me that the fact that the light doesn't actually pass through the imaging element would save it from a lot of heating. Even if it does heat up, since it's reflective, you could spackle a huge heatsink or even a liquid cooling system to the back of the reflective imaging device, if you need to pass a lot of light across it. This is an exciting projector.

    They were kind of pricey ($50k), but are starting to make inroads in the portable presentation projector market.

    $50k is about what a new VPH-1270 was going for, last time I was involved with them. (Yeah, I'm sure they've been discontinued now.) So, that sort of money doesn't seem to be too badly out of line. I assume it's a single imaging system, too, meaning that you wouldn't have to do convergence of the individual colors.

    Last time this came up, I found some models for $9k-$5k.

    It sounds to me like these things are basically in competition with the LCD projectors, but are brighter because the imaging device would be less concerned with heating. I'd expect they'll still have many of the same resolution problems as an LCD display (ie. ever try to run 640x480 on your 800x600 notebook screen?), but with a few advantages that will make them take over. Eventually. There's inertia to overcome.

    It's stuff like this that reminds me why I've always loved Texas Instruments.

  • If anyone is interested, ColorCorp [litemeup.com] is selling Used Color Kinetics C-200s [litemeup.com] (the biggest model) for $525, including the power supply. (They go for ~$1,100 new)

    The person I spoke with at ColorCorp said they have been in use as rental lamps for ~2 years... they should have plently of life left, considering that the LEDs supposedly last for 11 years of continuous usage.


  • You wouldn't necessarily have to have all the LEDs on all the time though. You could strobe the LEDs at 60Hz and persistence of vision would give the impression of a nice stable image. This could reduce the cost of electricity (and also the amount of heat generated) by a huge factor.

    True, yes, and I did mention the technique of multiplexing display elements. It's easily done, and it yields terrific results. But, anything that you would be displaying on a system like that would be multiplexed anyway - VGA images? TV pictures? They're all scanned, one line at a time. Unless you were to build the circuitry to hold that in video RAM of some sort rather than just building a passive monitor, it would remain that way.

    And you needn't solder the LEDs by hand, or solder them at all. You could probably (with some practice) manufacture a monolithic array of LEDS, with the majority of interconnects already done.

    Sure. Then you get into the same issues of lot-to-lot and even diode-to-diode inconsistencies. This is how newer large electronic billboards and stuff are already being done. Notice their patchy color purity?

    You could also reduce the size of each LED element (how big does a pn junction need to be?) in the array. Just a thought.

    I don't know how big the PN junction has to be to produce light, but as far as I know, it's no bigger than any other PN junction - the critical issue with them becomes the chemicals doped. (Ie. what makes a P type region a P-type region, what makes N type N-type, etc.)

    But this would be no more relevant than it is in, let's say, the cache on an Athlon, which has way more PN junctions in a tiny area than this whole gargantuan display would have.

    The problem is that we're used to the cooling issues surrounding very large highly-integrated CMOS logic. Remember, too, that the perfect CMOS gate has an infinite input impedance and therefore the stage before it needs no current to drive it and therefore no heat can be produced... but we all know that's not true.

    Now, as if that weren't bad enough, an LED is *not* a high impedance device like CMOS, which relies only on the presence of a charge to operate. LEDs are current-operated devices. They won't light up at all until you're passing more than their threshold current through them. Once they're lit, they operate fairly linearly from barely on to their absolute limits - the more power they dissipate, the more brightly they light.

    As far as I know - and I'm not a semiconductor physicist - the minimum threshold current is what it takes to actually break down the PN junction and make current flow in forward-biased mode. On most LEDs, that's an energy of about 0.5mA at 1.2-1.6V (or 0.0006W), but it seems to depend more on the LED's designed wavelength (and therefore PN doping) than its junction size or rated brightness. 0.0006W per LED across a 640x480 display is still an imperceptibly black screen, by the way. And one that's taking almost 200W for that blackness. If this is a small display, you have to get rid of that (approx) 200W of waste heat just at idle.

    I doubt that the cache on an Athlon has to get rid of 200W of waste heat at idle, and yet they're fairly well heatsinked...


  • As a side note... remember that the article (which you obviously did not read) created a lamp using WHITE LEDs. Not Red, Green, and Blue, but WHITE, because the RGB PN junctions are inside the LED itself.

    Actually, I did read it. These are *not* white LEDs, which actually have a phosphorous coating on a blue LED die. These are RGB LEDs.

    They were encased in T-1 3/4 cases with 4 pins (as opposed to the usual two) sticking out. A T-1 3/4 is approximately 1/4" in diameter. (Not close enough for drilling panels, but close enough for napkin calculations like these.) 800x600 in T-1 3/4 LEDs (of any color, RGB, or white) would be 200 inches wide by 150 inches tall.

    Do the math if you wanted to build that using discrete red, green and blue LEDs....

    Each one costs about $20. Power usage is rated at 120mw maximum, and unless you're watching a pure white screen you will never use that much for every LED, so let's assume 1/2 that power under normal operating circumstances

    Until you watch MTV and someone does put up a completely white screen. You cannot count on that. And those LEDs are not rated to full power for all three junctions continuously.

  • Re:More New LED Technology (Score:1)

    by Anonymous Coward
    as I recall, they were called Smoke Emitting Diodes...
  • Heheh...

    Analog and Digital Electronics... I'm bored in lab one day, I look over to my partner, holding up a nice green wire, "Let's see what happens if we plug this in ... here, and this one..." *BANG* A transistor explodes. A much bigger explosion than one might believe could come out of a transistor, as well... My teacher was on the other side of the lab having a meeting, he just looks up, makes sure no one is dead, and keeps on with the meeting...

    Lots of fun that class was...
  • Get a normal torch and mount a LED and resistor in the old bulb's base... and good luck using up the batteries :)
    Been there, done that, and it took a week. Some day I'll try it with actuall new batteries, instead of the year-old ones I used that time.
  • Just dropping by to see why my little LED website is so much on fire today.
    Now I know why - I've been slash-dotted!!

    Yup, I'm the one responsible for crowding the internet with The LED Museum that seems to be the hot topic of the day. I knew I wasn't the only one who was "turned on" by LEDs, but for the love of Pete, there really are a LOT of people out there who dig 'em, if the people who are using slashdot.org to find my site are any indication.

    Thanks Timothy (mailto:timothylord@mindspring.com) and Effugas (mailto:effugas@best.com) for posting the article!

    This is better than TV!
    Thanks Slashdot.org, you've made my day!

    Regards,
    Craig Johnson
  • What's really cool is somebody *noticed* I credited Memepool. I discovered the site from one of the rare times they were credited, and I've been impressed beyond words ever since.

    Mind you, I didn't flat out copy the Memepool story--but I'd have never found out about the Color Kinetics product line without 'em.

    --Dan
  • The Luxor has a matrix of spotlights coming out the top pointing straight up

    Err... I think it was actually the MGM. It decidedly wasn't the Luxor, as earlier this evening, my girlfriend was reading Slashdot, and pointed out that we hadn't visited the Luxor, but she also remembers the display. I'm seriously guessing MGM, as I think it was the casino with Studio 54.

    Again, the resolution wasn't all that hot, but it was displaying very definate and discernable patterns across the entire building visible from where we watched. The display came down to the where you could walk up and look at the individual LEDs. If an early Atari counts as a graphic display, this did as well.

    For those who haven't been on the strip, Vegas has lots of lights. Lots and lots of lights. Everything is connected, and it's hard to remember specifics on minor details - but I'm leaning towards MGM.

    --
    Evan


  • For those of you have been to Las Vegas, you've seen just such a thing in action. I have no idea what the resolution of them is (I'd imagine something like 320x200 or MAYBE 640x480 tops). I actually got a chance to get up close to one while it was operating (it was about 6 feet tall), mounted into a wall. Examing it more closely there were indeed little triads of R-G-B LEDs, which when viewed at a range necessary to actually make out that fact were extremely bright.

    Very cool. Yeah, actually, you don't need to go to Vegas to see that. Times Square has a couple, and Toronto's Gardiner Expressway are peppered with advertising billboards that use LED video. There's also one at Richmond and John Streets on the Famous Players Paramount Theater. Not really practical for the masses, but once they work out color purity issues, they'll cease to be a poor man's Sony JumboTron (which actually uses tiny little 3-pixel CRTs called "Trinilites").

    That, and much like putting your nose against a projection tv, it was impossible to make out much detail.

    Just imagine if the resolution were essentially infinite, if you never saw pixels or scanning lines. How cool would porn be then, huh?

    What's interesting about 'Vegas is the fact that cruising the strip you can actually see several generations of technology, from the monochrome incandescent bulb displays, all the way up to the state-of-the-art LED full-color animated displays that are viewable in direct sunlight.

    You know, some of the old incandescent signs were cool, too. Back in the days before microprocessors, banks of lights would be turned on and off by a cam wheel, much like hitting the address line on a suitably-programmed EPROM turns on whatever data lines you've chosen. And the cam outputs usually fed relays, which did the gruntwork. Thank god for CMOS logic, optocouplers and triacs; if you want a retro incandescent sign, that's the only way.

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