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Toward Micro-Diode Display Panels?
VernonNemitz asks: "Light-Emitting Diodes (LEDs) have been around for decades, and they come in all colors. Here are the basic principles behind their operation, information on what's currently in production , and other practical info. Now, you would think it obvious that video displays should be made from LEDs, to take on the various competitors. Certainly this has been done on a large scale, and I am not the first to be interested in LED display technology for home viewing. The apparent goal of silicon LEDs these days seems to be tied up with optical communications between circuits, have they forgotten the possibility of making high-resolution display panels?"
"Achieving a good image will require smaller pixels, and now I have a better understanding of what has been holding it up, so would like to share what I found out. Basically, unlike a lot of electronic technology, LEDs are mostly -not- made from silicon. So, while silicon diodes are common, and large arrays of them are also made (for sensors), LEDs are not easy to incorporate into standard integrated-circuit manufacturing. Nevertheless, researchers have been pursuing and steadily making progress toward integrating silicon-based LEDs. Even whole arrays, 'suitable for large two-dimensional areas', of silicon laser LEDs have been made, as far back as three years ago."
We need some technology that makes it all CHEAP. Because I spent over $1,000 on a 20" LCD, and although its a kick-ass monitor, its still too pricey.
I can say that this technology is at LEAST 25 years away due to the lack of precision in nanostructure topology lithographic processes. The author seems to be ignorant of a few of the fundamental laws of nanotech, namely that: 1) Maxwell's equations must be obeyed in light of quantum gravity. Yes, quantum gravity is CRUCIAL to the process. This prevents the inadvertent bonding of junction pairs and 2) The superposition principle does NOT apply to these non-inertial frames of reference! Trust me, this technology is pretty much canned until we can solve a few engineering problems in the litho. area.
The largest problem with this technology isn't that it can't be done on a larger scale (it can). The problem is more financial. With all of these companies having geared up for LCD production and building huge plants while downsizing CRTs, it's unlikely that the shift to LED tech is going to happen anytime soon - no matter how cheap it is.
As always, you have to find a way to pay for the R&D that you use - even if it becomes outdated beforehand.
"...Well, there's egg and bacon; egg sausage and bacon; egg and spam; egg bacon and spam; egg bacon sausage and spam..."
Between the skin cancer and the glare off my tin foil hat..er I feel a song coming on...
Roses are red
Violets are blue
I'm a schizophrenic
And so am I.
Back to the LED's, I always apply a generous of SPF 45 when I see one shining my way.
--
I think we're barking up the wrong tree using light-emitting technology for displays. I think that we would be far better off having a very high-res, paper-white display that was 100% reflective. Indeed others have called this "digital paper" and it has become a holy grail of display technologies. However the technology to do this is just about here now. I'd much rather see that kind of display. Give me a reflective, 600 dpi display and then I'll read books on a computer. Light-emitting displays are much harder on my eyes than a magazine or newspaper.
Neither is to the point of making that concept practical.
Unless you got an extra 10grand to spend on a 5" screen that needs a small nuclear power plant to run..
( ok a slight exaggeration, but you get the point )
They would be pretty thou..
---- Booth was a patriot ----
Any time, as soon as the costs goes down to a manageable level, and the light level remains consistent throughout the display.
Just keep getting OLED displays larger and larger...
http://www.kodak.com/US/en/corp/display/
It uses an thin organic film between conducting layers rather than electronic components, but OLEDs are just a few years away. They're self-luminous and more efficient than a backlit LCD. Lots of /. stories about them too.
It does seem to me though that using silicon LEDs (ie. enough silicon wafer to coer a display) could get pricey.
Engineering is the art of compromise.
Red leds have been around for decades, but the higher you go in frequency (orange, yellow, green, and recently blue), the more expensive they get. Since you need many many triads of them to make a display, that may not be the cheapest one in town.
What's more, more often than not, LED colors aren't pure primitive colors, so it's even harder to get accurate RGB mixing with them.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
...But not with Silicon. Silicon LED's may be (relatively) cheap for red and green models, but the blue ones are insanely hard to make, and thus are quite pricy (just look at the DigiKey catalogue). Also, Si LED's are very ineffecient (I don't remember the number, but it's like 20%ish I thought). The next "wave" of things are going to come from OLEDs (Organic Light Emitting Diodes). These are easier and chaper to make for screens and such, and eventually can be made in a "roll to roll" production type deal since these things are "grown." They're already being used in some cell phones, I believe.
A problem with these is that they decay if they're not protected, so currently they use a glass-substrate and a glass coating for some, which can make them bulky. Also, OLEDs have a shorter life span than LCD's, but that's being worked on too. So hark, have patience, OLED screens are coming. Another interesting technology to look into is Light Emitting Quantum Dots... those little suckers are cool, and could also replace LCDs and lights as we know it (from what I remember, they're also quite efficient... I think around 60%).
Display in a can (shake can vigerously till ball rattles, then spray)
or
CRT on a roll (wallpaper floral, or oceanic).
or
Moldy madness (smear some on wall, then leave it alone to grow)
or
Memorex (as in, is it live, or did one of your walls just fall down?)
I suspect that the technical limitation is that of delivering enough current across the span of the array. Unlike plasma displays, LEDs are low voltage beasties. And unlike LCDs, LEDs are high current devices. To get say 20 W of brightness, you will need to inject on the order of 10 Amps in (and that 10 Amps only gives you 11 microamps per LED in a 640 x 480 x 3 color display). Routing that much current along the array conductors(which are probably plated or grown on the glass substrate) with acceptably small voltage losses would seem to be very tricky.
That's just my guess as to the technical hurdles for high resolution LED displays. I'm sure some bright young soul will solve the problem, however.
Two wrongs don't make a right, but three lefts do.
some new tech
Reflection based displays, like eInk, are great for displaying text. But when it comes to representing graphical concepts they fall far short, since they're limited to greyscale.
It's fairly simple to adjust the amount of light reflected to make greyscale images. What is very hard to do is adjust the wavelengths reflected to make different colors. Until there is an easy way to do that discovered, light emitting displays is pretty much the only option for computing chores that rely on color.
I hope this will lead to flat panel displays that aren't so touch sensitive cause cleaning my LCD is a pain when crud gets stuck to it, also i would imigine this could lead to shaped displays and eventually being able to skin devices such as cell phones rather than buying a cell phone faceplate just downloading a cool design and being able to switch designs like ringtones (and even being able to photoshop your own designs) I'm waiting untill i can have a winamp vis that will animate my entire Case
Snowden and Manning are heroes.
... it sucks to be you.
Yeah, I would really like to try to play games or do anything at night - holding a flashlight in one hand!
Seriously, uniform lighting and color are a necessity for a decent display (at least in terms of laptops). There is no way you would get one from a paper-white display.
I had but a simple dream, to destroy all humans.
I have experience in the industry, and can tell you that inorganic LEDs HD displays are not gonna happen. The inorganic LEDs cannot be deposited on silicon wafers. The inability to deposit means no way can it be cheap, or feasible. Not to mention the heat output by that many LEDs. I created a test box to evaluate LED's for lighting systems. Using the latest mass produced ones, I still had a significant heat output with 100 tiny ones. A HD inorganic LED panel would simply melt. Organic LEDs remain viable, yet still not ready. OLEDs can be deposited and can use much of the same wafer design. They have many issues, most dealing with lifetime and color shifting, but it works for HD. Kodak is spending a lot of effort on the technology, and I was allowed to use two of the OLED displays and gotta say they have a good design, but just need more help in the material science.
I'd say more, but my guild is raiding.
Check this out. Highlights (emphasis mine):
The cost of the $13 million, four-year project will be shared among NIST, GE and ECD Ovonics. The program goal is to create a cost-effective system for the mass production of products such as flexible electronic paper displays, portable TV screens the size of posters, embedded sensors, solar powered cells and high-efficiency lighting devices.
It isn't because it can't be done. It is because the Veruca Salt money managers on Wall Street can't tolerate a four year return on investment. GE's stock went down when they announced this.
Life is the leading cause of death in America.
So you need a red, green and blue to make one pixel just like a phospher display, and the circuitry to provide a precise analog current to all three LED chips and every pixel. And you have to avoid crosstalk between pixels.
Still, I use blue LEDs on my front panels a lot as simple indicators. They am kool. :-)
--- Ban humanity.
I know that I have wondered about making a large display with LED's.
My thought was to build it with a standard block sections, then you just use the number of blocks to create your screen size.
Wise men speak because they have something to say, Fools because they have to say something!!!!
If you google around the web, you'll see that LEDs are poised to become the primary source of lighting in coming years; they already last longer and can produce powerful lighting more easily than bulbs, so all that's left is for the cost to come down.
My thought is, monitors out of LEDs can wait until they're already tested and used in the mass market for lighting. Until then they'll be a poor choice for pretty much anything below Jumbotron proportions, and there's still a good lifespan for LCD technology besides.
But then, I'm thinking economically here.
Also, there's a huge pile of shit between the and tags.
Please remove them also.
Here's a link for CmdrTaco:
the near future for large screen displays is thick-film dielectric electroluminescence. it is an inorganic electroluminescent display technology developed by iFire (from www.ifire.com). i've been following their story and have seen prototypes. very cool indeed. sometime next year they are going to be producing 34" panels. they are cheap to produce too.
These devices are a more natural successor to the CRT based systems - excellect contrast and brightness (as good as existing CRTs), flat panel design, lower power consumption (as compared to plasma). The technology is essentially one cathode per pixel.
From IEEE Spectrum, September 2003:
Samsung and Motorola are aggressively pursuing field-emission display technology using nanotubes. Samsung, for example, has already demonstrated a full-color 38-inch field-emission display capable of handling normal video frame rates. What's more, a Japanese government-funded consortium was announced earlier this year to develop similar displays, and Sony Corp. (Tokyo) is developing its own nanotube display technology as well.
Just found something... OSRAM is producing a
LED-Package not to form a display as itself, but
rather a backlight for common displays (presumably
LCD, but they say nothing about it specifically).
The good thing they say is, that the colour
temperature can be adjusted with that technique.
As far as I am informed this is not the case with
current LCDs? Or am I wrong?
Could be somewhat in between the both technologies.
Sort of bringing "the best of both worlds" together.
Link to the Osram Website:
http://www.osram-os.com/news/news_multiled.html
Meme of the day: I browse "Disable Sigs: Checked". So should you.
A number of companies including Kodac and Universal Display are already manufacturing OLED, or Organic LED's. These have the advantage over solid state LED's that they are cheaper to produce over large areas because they do not need to be etched like silicon but can be painted on.
First, each led must have a wire on it. This limits the led to the size, that a ball will fit on. This is usually about 25 microns. (approx 1 mill)
;)
So now the led must be bigger than that, so now you would have a die, normally around 10 mills, to be nice and bright. Now space them out with say 7 mills in between, and do an array, with perfect dimensions between die, (remember, you have to have a spacing big enough to place the wire down to the pcb, and you will end up with a spacing of around 17 mill centers or so.
So you see, the pitch is rather large, then you add some optics, so you can make the whole thing look good, and a 1024 x 768 to be pretty clear.
Then throw in some optics to change the view, to a smaller pitch, and walla you have the viewing scope used on so many tanks
This has been built for along time, and is VERY expensive.
Why not connect them in series ?
;-)
Start with 960V at the top and drop 2V with each pixel to get 0V at the bottom.
With a glass substrate (effectively, an SOI-process), Isolation should not be a problem.
If you want to make a touch screen, then you might want to put them on the back side, though
If you insist on vertical control lines, feed in a control current and have each pixel cell drop 2V on that, too.
I, for one, welcome our new Micro-Diode Display overlords.
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White LEDs provide the backlight in every cell phone with a colour display. Now.
Schizophrenia and Multiple personality disorder are two completely different disorders.
LEDs take way too much power to be effective for displays.
TT
The ROPOD.
"Sic Semper Tyrannosaurus Rex."
Are organic-LED based projectors a viable future direction? I have an NEC DLP unit - which is nice and all, cost around $2000 and is rated 2000l (and a 20' LCD screen). Both of course would have cost far more three years ago (and the projector replaced a Barco 1208s CRT model - at 180lbs these things were no joke, especially in a club...) - but both seem to be near the limit of the current technologies. Or will nanoscale micromirror devices allow for increased resolution and decreased response time (and maybe less pixel edge visibility) from next-generation DLP devices?
Why is the parent post modded down? who wasted their mod points? ... btw, I'm soooooo drunk. seriously. I am typing this with one hand...
The, Problem, With, Your, Post, Is, You, Don't, Know, How, To, Punctuate, Your, Sentenaces, So, They, Make, No, Sense, At, All!
Gee, Before, Taking, On, Tech, Research, It, Would, Be, Good, To, Finish, Primary, School.
...has uncovered some loss technology your lame post may be interested in. at this url
But first LEDs will be used as a backlight source. They are vastly more efficient than the most incandescent sources. The best incandescent lights can achieve an output of 40 lumens/watt and these tend to be halogen lamps, too hot for your lcd panel. Discharge lamps run at 50-60 lumens per watt but the colder versions (fluorescent tubes) produce horrible light. The best white LEDs can produce over 120 lumen/watt; vastly more efficient.
Combined with an infinitely variable colour (within the gamut of the LED) they make an exceptionally good light source, not only for LCDs but also in architectural situations. Already a large number mobile phones and some PDAs use a white LEDs as a backlight source. I'm sure laptop LCDs will be next.
OLEDs provide the next evolution in display technology and hopefully the next jump in efficiency. A black pixel is a very inefficient thing on an LCD panel, think of all that wasted light absorbed into the pixel, much better to be able to switch off the light for that pixel.
(Recapping what some other people have said but I hope I've said something new of note)
25 microns = 0.025 millimeters
Are there inch-based microns too or something?
Opportunity knocks. Karma hunts you down.
This is News for Nerds [TM].
Thanks for all the responses!
I should mention that it has been my understanding (perhaps mistaken) that OLEDs are not actually diodes, but "devices", based on electroluminescent phenomena.
I confess I posted the Question mostly out of curiosity: the technology SEEMS so obvious....
I personally agree that reflective-light display technology is potentially inherently superior. My personal favorite (so far) can be found here.
... and the cost for 2GB of ram in those good old days would have been: Somewhere in the range of a brand new luxurious Mercedes.
send + more == money?
I can watch my computer without needed an extra desk-top. I believe that a refractive or reflective display would require an external light source?
Not directly related to display panels, but since we're talking about LEDs here, something I've been curious about...
A few years ago LEDs were these dim little lights that might come on to tell you that your hard drive is being accessed or your caps lock is on. Lately we see products like LED traffic lights, LED brake lights on cars, LED flashlights , etc. that are vastly brighter than the old LEDs we've seen for years. What sort of breakthrough or advances did the LED industry make to allow such bright, daylight-visible LEDs to become possible?
Take the LED's put them on a wand that spins at 3600 rpm, make the LED's super bright and able to update at 120 (to eliminate flicker, or faster), then you could make a round full color monitor for less than 2000 dollars that never runs out of juice.. You might even try using some of that phosphorescence material that slows down the translucense of light to control the speed of the transfer from the LED's to the screen.. The monitor would last forever would never deteriorate in quality.. However pixels would not be square everywhere on display, at the edges it would be more skewed than at the center..
Just say no to license servers!!
I honestly don't think Bush lied, but I don't think he had all the facts either, more of an assumption based on past experience and facts. Saddam has been playing cat and mouse games with the world for years. It's kind of like getting mad after the cops shoot someone who was pretending they had a gun. If he had come clean the first time around it would have never have come to this.
Getting way of topic by continuing this thread if you want to continue this conversation drop me an email.