Technology Behind Plasma Displays

digg writes "CoolTechZone.com has an in-depth article that gives an overview of how Plasma Displays work. From the article: 'So, what exactly is plasma? Plasma by definition is one of the four states of matter (apart from solid, liquid and gas) and consists of positively and negatively charged particles, which are added in roughly the same quantity.' This obviously makes the gas more or less inert but ensures that the charged particles are free to conduct electricity. Plasma can be produced if a gas is energized enough to split the molecules into positive and negatively charged ions. Mostly, the plasma displays use a mixture of noble gases like Neon and Xenon."

Comments

Obligitory Wikipedia Link

[Xandu]

Of course, you can get all this (and more) at Wikipedia's Plasma Display page.

[I realize this is probably karma whoring, but I hate it when there's only one link in summary and it doesn't even have much info, and is littered with ads, and you have to look at 3 pages to get the whole article. That and run on sentences.] ;-)

Amateurish

[Mapultoid]

I hate to be totally pedantic (mildly pedantic is usually sufficient), but I read the first two paragraphs of this and had to stop. It reads like a creative writing exercise in poor writing. Too many words that need to be cut, laden with cliches. I rarely read the articles around here, are they really this bad? I'll stick to scanning the comments for "+5 Funny", thanks.

Re:Amateurish

[deglr6328]

Yeah seriously, its horrible. I mean honestly:

"Each time a different colored cell is charged, this charges the atoms and converts them to ions and facilitates the release of UV photons due to the ionic collision. The inside wall of the cell is meted with a special treatment of a phosphor coating. This is done to exploit the phosphors property of giving out light when it comes in contact with other light."

Ughh, barf, don't even bother to RTFA, not worth it. This is a FAR more fascinating and in depth view into the workings and history of plasma displays.

Only 4?

[drewbradford]

4 states?

What is this? 1990?

We've actually doubled the number of states of matter in the past half century.

Re:Only 4?

[Timesprout]

We've actually doubled the number of states of matter in the past half century.

Yes but apathy is still the one true state of matter.

Re:Only 4?

[Ann Elk]

I'm waiting for the new Bose-Einstein condensate displays to arrive. They should be really cool.

Re:Only 4?

[Jeff DeMaagd]

Well, the four are the ones most accessible to the average person. Many of those states aren't even made in labs right now, and some of the ones listed in Wikipedia seem to be theoretical at best.

Lots of solids (maybe liquids too) have sub-phases based on bond and crystal alignment based on temperature, pressure and percentage of different atims, I'd be interested in knowing where those fit in.

Re:Only 4?

[satanami69]

It'll be nice to change the outcome of football games simlpy by observing them.

LCDs vs Plasma

[Snoolas]

I'd personally be more interested in reading a comparison of Plasma and LCD. Preferably one that I could stand reading without my attention immediately turning to something else.

light photons thus released Ultraviolet

[Anonymous Coward]

"Now the problem in plasma (unlike OLED) is that the light photons thus released belong to the Ultraviolet band and are therefore invisible to human eyes. This was where researchers got hitched until someone came up and suggested that they use these UV photons to incite visible light photons. Now to better understand this concept, lets look at how a normal plasma display is constructed."

Now call me chicken and fry me in Kentucky, but isn't that exactly how fluorescent tubes work (and even to some extent cathode ray tubes).

HTF did the 'researchers' managed to get hitched on the problem, it plain fucking obvious.

My discreet math professor

[Anonymous Coward]

My discreet math professor, Dr. Bitzer showed us some of the original designs he had of the plasma screen (which was originally was developed for his distance learning program) he told us that the original problem most designers were having was that they were trying to put the capictors (resisters for the alternating current) inside of the plasma chamber which made the displays too clunky

he showed us his original working model

Re:My discreet math professor

[kavau]

If your math professor really was so discreet, he would never have shown you his model...

There's more than four phases of matter

[BlueStraggler]

Make that "one of at over a dozen known phases of matter" , not "one of the four phases".

Re:There's more than four phases of matter

[Tlosk]

>>Make that "one of at over a dozen known phases of matter [wikipedia.org]" , not "one of the four phases".

You might have a point if they had said what you said they did, but they didn't. They referred to four states of matter. As explained in the very article you link to people often confuse state with phase, but they are not the same thing.

Have they fixed the broken pixel problems yet?

[Shanep]

Every long-term plasma display installation I have seen (train stations, malls, building foyers), have lots of broken, noisy pixels. As if a burn-in effect had occured. I took this problem into account when designing a display about 4 years ago, by randomly placing images/text (within constraints) and this still occured.

I would be really pissed off if this happened to me on one of these super expensive displays. What's more, have they made plasma look good yet? I've never seen a plasma display which looked good. Even when opperated at their native resolution through digital interfaces.

To me, they seem way overpriced for the quality and durability you get.

Mirrordot Link

[Gadgetfreak]

If only chicks went down as easy as that server.

Who stole the BE-condensate?

[pbhj]

Four states of matter?

Has the author been living in a hole? Even being conservative I think you'd have to plump for there being 5 states of matter.

http://en.wikipedia.org/wiki/States_of_matter

That's aside from the poor wording which suggests that there are 7 states (or perhaps that's what he meant??).

"In-depth article"? No. It's an ad troll.

[Animats]

That's not an "article". It's just a troll to drive traffic to the site.

'So, what exactly is plasma? Plasma by definition is one of the four states of matter (apart from solid, liquid and gas) and consists of positively and negatively charged particles, which are added in roughly the same quantity.' This obviously makes the gas more or less inert but ensures that the charged particles are free to conduct electricity.

"Makes the gas more inert?" Those guys should stick to writing about case mods.

Plasma panels have actually been around since the 1960s, as neon-red displays. The early concept was that a sustaining voltage applied to all pixels kept them lit if they were on, and an X/Y array of wires could be used to turn individual pixels on and off. Thus, the display itself had memory, back when having enough memory to refresh the display was expensive.

Color, intensity variation, and speed took a long time to achieve. Now there are transistor drivers behind every pixel, and the panel is built in what's effectively a big wafer fab. But that's not the toughest part of the manufacturing problem. All the electronics is on the back glass, while the phosphors are on the front. These two big pieces of glass have to be welded together with subpixel precision, held in contact only by millions of tiny ridges that have to match up. That's the most difficult step, and the one that limits display size.

Etching

[tsa]

In our cleanroom, we use plasmas for etching silicon. Plasma etching is a standard process that is used in the manufacturing of just about every chip. The plasma in TV-screens is generated in the same manner as the plasma in our etching machines. Therefore I have to conclude that plasma screens will suffer from the etching, and will not have a long lifetime. Add to that the amazing energy consumption, and my choice for my next TV is made: LCD, or maybe even another CRT. I still think CRT monitors give a better poicture than LCD, and for TV's the difference is even greater.

CRT is too low-res?

[SanityInAnarchy]

consider that even the lowest resolution that you can get on the computer monitor you are viewing is 640x480 whereas the best resolution that the finest analog TV can give you is a maximum of 480 horizontal lines

WTF does this have to do with Plasma vs. CRT? This is a limitation of analog vs. digital, not of any one display type.

Seriously, think for a second. You're whining that your TV doesn't have great resolution when monitors are usually at least 1024x768. Um. Most monitors are still CRTs! I had a CRT that did 1600x1200 for years!

Remember, plug a plasma TV into a coaxial cable plugged into standard analog cable TV, and you're going to get 640x480, no matter what the plasma is capable of.

I'm not sure if I even want to finish reading the article after that.

DLP still better for me

[ruiner13]

I have a 50" Samsung 3rd Gen DLP TV ($1600 at Best Buy a few months ago, 0% APR for 2 years). I could not be happier with it. Not only does it have more HD ports than any TV I found in its price range (VGA, DVI, HDMI, 2 x Component), the color and contrast ratio are outstanding (1500:1 claimed) using a 7-segment color wheel (and no, I do not see the rainbow effect, I believe partly die to the higher rotation rate of the 7 segment wheel). Not only that, but it does not suffer from burn-in or fading the way plasma does (important for me for gaming). The only part that needs periodic replacing is the lamp unit itself, which you can find online for around $200, and according to other people with similar sets to mine, each lamp lasts 2-3 years, depending on use. The power savings of DLP over plasma or CRT more than makes up for it, I believe the set I have uses 60-70 W during normal use. In the long run, I don't see plasma sticking around. I see technologies like DLP and LCoS (or D-ILA as JVC calls their version) being the market leaders in 5 years. Plasma always looks over-saturated and grainy to me, not to mention the heat that comes off those things. They might be a little brighter than most DLPs, but I do not believe they are worth it. The only plus side is their depth, 4" versus 14" or so for my DLP.

Re:DLP still better for me

[larryj]

It's a personal preference thing. I'm glad you like your DLP and I'm even more glad that we have a lot of options when it comes to display technologies. I've had the opposite experience, DLP doesn't look as good to me as LCD or plasma. Judging by what's on display at stores isn't a fair comparison though, so I'm sure I would like DLP better if I saw a calibrated display.

I've been gaming a LOT on my plasma for 13+ months now. No sign of burn-in or fading at all. I haven't noticed an excessive amount of heat either.

I needed something to hang over a fireplace. At the time, LCD wasn't that impressive although I think LCD has come a long way since I was seriously shopping (13-15 months ago).

Re:OLED...

[meta-monkey]

The OLED situation isn't quite THAT rosy, but it is promising. OLED lifetimes are lower than plasma right now, although it is getting better. And that whole "roll up the screen" business is a bad idea for anything you want to survive long-term, because any sealing problems that let in water will destroy the organics in the screen. I don't think you'll actually see large screen OLED displays on the market until 2008 or 2009. In the meantime, I bought a plasma.

Sci-facts [OT]

[minginqunt]

To pedantically correct the original poster, there are *at least* six states of matter, possibly more.

1) Solid
2) Liquid
3) Gas
4) Plasma
5) Bose-Einstein condensate
6) Fermionic condensate

I now take my Physics-pedant hat off and apologise.

CRT array techology

[plusser]

I see no mention here of a technolgy that was delveloped about 10 or 15 years ago to produce large flatscreen television based on CRT technology.

The idea is this. Remember back in the 1980's when all you had was basically CRT screens and nothing else. Somebody then realisied that you could arrange a large number of CRTs in a grid array and produce a much bigger picture by sending a segment of the video signal to each screen.

It was then noticed that this large array of CRT had a much thinner profile than having on very large CRT. What happened was that one of the CRT manufacturers of the time decided to construct a large panel screen by using several thousand small CRTs in an array, each one emulating a function of a pixel.

Looking at the description of large plasma displays, the technology in arranging pixels very similar (the only different being the method used to generate the charge to generate the phosphor glow). It may be that using CRTs was too expensive, and plasma was cheaper to use.

Any body else know about this technology?

Re:CRT array techology

[Miamicanes]

They were/are called "Field Emission Displays" (FED), if I recall correctly. The idea was to take a flat plate of glass (or equivalent) with normal CRT phosphors, but behind each phosphor put multiple tiny solid-state electron emitters. In other words, instead of taking a single electron beam and sweeping it repeatedly across the screen, put multiple weak electron beams behind each subpixel. The rationale for using multiple beams was avoidance of dead pixels. If there were, say, six emitters behind each subpixel, one or two of them could fail outright or progressively, and the viewer would likely never notice the difference... and the few that WERE bad enough to be noticeable could be programmed around by simply increasing the intensity of that specific subpixel.

I first found out about FED displays (yeah, I know "FED Display" is redundant) when I went to CES in Orlando in 1996(?). I thought for sure FED would rule the day (not for laptops, of course, because they used too much power... but for home TVs). I'm not really sure whether the concept proved to be unfeasible, or whether FED actually mutated something else. My guess is that cheap, hi-res DLP, far bigger and cheaper TFT panels than anyone dared to predict a decade ago, and cheaper & less-fragile plasma all chipped away at the manufacturers' motives for funding it, and they all went after one or more of the other technologies instead.

IMHO, it's a pity. DLP has good intensity, is indestructable, and high resolution, but suffers from either rainbows or high cost & convergence problems. TFT has high resolution, but is limited in brightness when used with projectors, and both size & pixel-perfection in direct displays. Brand new plasma sets look impressive, but they're the lowest-rez sets of all, and I'd personally rather watch a 34" CRT than endure ugly stretched images necessitated by plasma's vulnerability to burn-in due to pillarboxing instead. CRT... well, CRT has probably the best overall color saturation, but is size-limited by the tube itself (unless, of course, your living room is big enough to drive a forklift in).

Sigh. I really, REALLY like the concept of FED displays... they have/had the potential to give us the best features from all the other alternatives (though possibly at a staggering cost).

Plasma Universe

[bluevector]

Plasma physics not only governs the operation of your plasma television, it may also dominate the large scale structure and behavior of the universe (star formation, galaxy formation, intergalactic structures . . .); though most scientists are either unaware that this is so, or are not ready to admit it.

Check out the following:

Plasma Cosmology .net

Plasma Universe

Guided Tour of the Plasma Universe

Electric Currents and Transmission Lines in Space

Immense Flows of Charged Particles Discovered Between the Stars

Interesting quote from Hubble regarding redshift:

Edwin Hubble. "Humason assembled spectra of the nebulae and I attempted to estimate distances." So wrote Hubble of his colleague Milton Humason in 1935 by which time spectra had been obtained for over 150 nebulae. Hubble was a stern warner of using the Doppler effect for galaxies and argued against the recessional velocity interpretation of redshift, convincing Robert Millikan, 1923 recipient of the Nobel Prize for Physics and director of physics at the California Insitute of Technology, that the redshift interpretation as an expanison of the universe was probably wrong, the year before both of their deaths in 1953.

Hubble ended his book Observational Approach to Cosmology with the statement:..."if the recession factor is dropped, if redshifts are not primarily velocity-shifts, the picure is simple and plausible. There is no evidence of expansion and no restriction of time-scale, no trace of spatial curvature, and no limitation of spatial dimensions. Moreover, there is no problem of internebular material. The observable region is thoroughly homogeneous; it is too small a sample to indicate the nature of the universe at large. The univers[e] might even be an expanding model, provide[d] the rate of expansion, which pure theory does not specify, i[s] inappreciable. For that matter, the universe might even be contracting."

Taken from:

http://public.lanl.gov/alp/plasma/people/contribut ors.html

Thuderbolts.info

Thunderbolts' Picture of the Day

Picture of the Day Archive

A few very interesting selections from the archive:

The Picture that Won't Go Away

Quasars in Infrared are Still Nearby

Predictions on "Deep Impact"

Electric Stars

Of Pith Balls and Plasma

Space Shuttle Struck by Megalightning?

The website of Halton Arp

The Observational Impet