View Full Version : How are plasma displays different than standard flat panels?


gregdavidson
02-14-08, 02:16 AM
I'm pretty much a novice in the technology world. How are plasma tvs better than standard flat panels? This is probably a stupid question but you have to start somewhere.

Tympani
02-14-08, 08:33 AM
Not sure what you mean by "standard" flat panel, but I presume you mean LCD. Plasma and LCD are both considered standards. You can find a very detailed discussion of the 2 technologies, including pros and cons, by exploring the FAQ section of this forum. Be aware though, that these FAQ pages were written in 2005 and prior, and significant progress has been made in both categories such that distinctions may not be as profound. To say one technology is "better" than the other is too simplistic. There are advantages of both, and personal preference may dictate one or the other. Practical issues like window reflections, viewing angles, weight, altitude etc. may also direct a decision. Then by all means, go look at some sets and compare. Be sure to look beyond "brightness" to more subtle issues of picture quality, and remember any set can be adjusted to look "better" or "worse" (often deliberately) in a store line-up. Ultimately, don't get too wrapped up in the process and succumb to "paralysis by analysis" With a little bit of homework, almost any nicely set up quality contemporary flat panel (other than bargain-basement quality) will provide a satisfying viewing experience for HD broadcast and DVD. Enjoy!

http://archive2.avsforum.com/avs-vb/showthread.php?p=6106845&&#post6106845

joemama127
02-14-08, 10:59 AM
Like most people, for the longest time I assumed that plasma was a relatively new technology developed in the early 90's and reaching retail in the late 90's.....I was wrong. Of course crt is the oldest, and then front/rear projection but plasma was invented in 1964 which iirc pre-dates lcd by about 10 years.;)

I'm not even going to try and explain the differences between lcd/plasma...there are people on this forum who can do so however.

gregdavidson
02-23-08, 09:58 PM
It seems like there's always going to be something new coming out. Is mankind ever going to reach the pinnacle on any kind of technology? Sooner or later we're going to have talking tvs and robots are going to operate everything. Kind of scary if you'd ask me.

s2mikey
02-24-08, 12:38 AM
I'm pretty much a novice in the technology world. How are plasma tvs better than standard flat panels? This is probably a stupid question but you have to start somewhere.

Well, just quickly, plasmas work by charging a "plasma"(xenon gas, I believe) substance that gives off light when "excited". This is what makes the image. LCDs on the other hand work by liquid crystals "twisting" to variably open and close allowing different amounts of light through the pixels to make the image.

Thats kind of it, in a laymans nutshell sort of way. Gurus...please correct me if I am way off here. :D

gregdavidson
03-01-08, 05:02 AM
I'm still lost but thanks for the input.

itigap
03-01-08, 10:09 AM
I'm still lost but thanks for the input.
Greg,

The first post here was really good. To add, I would say there are differences in the way each technology generates an image which in turn leads to generally agreeded upon differences in the way their images are perceived.

LCD is transmissive whereas plasma is emissive. That is the light coming from an LCD panel begins in the back of the panel, normally as a white florsent bulb. The red, green, and blue LCDs which represent the pixels act like a camera's iris by opening and closing to varing degrees in response to the signal thus letting either more or less of the light through. No matter how much they close, LCDs cannot block 100% of this backlight and so cannot go completely black.

Plasma pixels on the other hand are cells of plasma (think gas). Each cell (like LCD there are actually three cells per pixel one each for red, green, and blue) gives off levels of ultraviolet radiation in response to the electrical signal. These are like mini explosions hundreds of times per second. The inside walls of each cell are coated with a phosphor which emits a color when struck with the ultaviolet radiation (like a CRT gives off light when struck with an electron beam). In order to be able to "explode", each cell needs to be precharged (think idle) and even if there is no signal for that cell this idling will give off a little radiation so plasma cannot go completely black either. However, in general, plasma does a better job of going darker e.g. blacker than LCD, which is a distinct advantage in producing a better image. (In a year, Pioneer displays will get around this and be able to go completely black!)

In general, plasma also allows the cells to respond to fast motion better than LCD and so action has little or no blur with plasma while LCD exhibits more blur.

Plasma screens are generally polished glass e.g. very shiney while most LCD screens have a matte finish that diffues light. Reflections, therefore, in a bright room can be more problematic with plasma. However, matte screens do IMO (and many others) degrade somewhat the picture quality (PQ). Some plasmas now offer a strong filter that deals well with bright rooms and some LCDs (Samsung 71 series) offer a polished screen. The 71 series is the best LCD I have seen perhaps partly due I suspect to its reflective screen (Sony has a good LCD too).

In general, stores are terrible places to look, although we have no other. This is because of the extreme lighting that is seldom like a home setting. Once past the lighting, the picture you get for a given set will be determined most by its picture adjustments. Unfortunately, in stores the displays you see on a wall are not properly adjusted (not even close). Without having the remotes in hand and adjusting the displays at least by eye to a reasonable picture you can't tell much about PQ.

Both technologies in the right setting can provide enjoyment. Most here, as am I, are biased toward plasma based on ultimate PQ particularly in well light controlled environments e.g. darker rooms.

I am sure others can provide more comparisons betwen the two as well as contrast their differences.

Cheers,

Gary

Jim Burns
03-13-08, 02:32 PM
The gas is neon

greenland
03-13-08, 02:40 PM
The gas is neon

I though that it is supposed to be a mixture of noble gases. Neon and Xenon?

Of course that will all change once I patent my new Green Plasma concept using gas collected from flatulent fireflies.