CRT, LCD, LED, OLED, ... OCD? - TV Technology and You.

In today's world of rapidly developing technology, it would seem as though there's a new TV display technology coming out every year accompanied with its own alphabet to add to the soup. What is the difference between LCD and LED? Or CRT and Plasma? More importantly, what does it mean to -you- and your TV-watching preferences?

1.0: The Basics.

An entire book could be written on the history of display technologies and the electronics behind them. Suffice to say that TVs started out as an expansion of Radio. The electronics were nearly identical, spare for some additional stages used to isolate the picture. This signal, effectively, told the TV how to reproduce an image on its screen.

For several decades, a Cathode Ray Tube was -the- display. This blast from the past creates a stream of electrons that are then deflected by magnetic coils along a 'track' (a series of horizontal lines, coated in phosphorus) that makes up the front of the display. When the beam hits the phosphorus, the electrons excite the phosphorus, causing it to glow. By breaking the beam's movement into discrete steps, the screen can be treated as a grid of cells, each assigned their own brightness. This is, more or less, what a "pixel" is - one of the cells within this grid that makes up the screen.

This was pretty cool, and all, but but you could only have one 'color' (white). It didn't take too long for more complex Cathode Ray Tubes to be developed that could support multiple electron beams and hit smaller sub-pixels made to glow specific colors. This remained the top display method for many decades to come, with advances in technology making them lighter, more efficient, and larger in size.

1.1: So, what happened? Why do we have so many different displays, now?

Cathode Ray Tube (CRT) technology has its limits. It's a vacuum tube, something people my age never really had to mess with. Vacuum tubes only work in a vacuum, as the name would suggest. This requires thick, heavy glass to hold the vacuum, as well as thousands of volts to operate. They are big, heavy, and leave their mark on your electric bill.

As people got accustomed to radios that could fit in their pockets and computers that sat on a desk; all things made possible by solid state technology (the transistor... there was a day when radios used to be marketed by how many transistors they had in them); it was only a matter of time before display technologies took a similar route and migrated away from vacuum tubes.

2.0: Who's Who in Whoville?

There are several types of TV displays marketed. There are even more that are or have been in research, that I will not bother covering at this point in time.

CRT: Cathode Ray Tube. The CRT is becoming much more rare in today's market, but is popular in the 'bargain' markets and gaming enthusiasts. CRTs still possess some of the fastest display capabilities, which minimizes 'ghosting' and other blurring effects when displaying fast-paced environments, such as games.

Rear Projection TVs: You don't see these very often, anymore. For the most part, an image is generated and then projected onto a screen. The display technologies inside has varied widely, from CRT-bases to PDP and some others. The displays are slimmer than CRTs of comparable size, and usually lighter. The front screen is often quite fragile and care should be taken to avoid damage. There is also considerable 'glow' or 'halo' to many displays of this type.

PDP: Plasma Display Panel. To be honest, I've never seen "PDP" used in the marketing or labeling of a Plasma TV. The Plasma display is, essentially, a gridded system of colored florescent/neon lights. Plasma is, basically, never seen in displays smaller than 32 inches, as production is not cost-effective. Plasma displays are popular with display enthusiasts as they currently offer the greatest color range, contrast, and response time (speed of the display) of mass-marketed displays. However, the screen is susceptible to burn-in and will dim over time.

LCD: Liquid Crystalline Display. The prime competitor to PDP technology. LCDs operate by manipulating the properties of crystals with electric current. Electricity can be used to disrupt the structure, allowing for light from a back-light to be passed/blocked by the cell. While light and affordable, LCDs have long endeavored to improve response time and true contrast ratios (the back-light must be blocked in order to create dark scenes). Exactly how severe these discrepancies are varies by individual preferences. It is also worth noting that LCD encompasses a number of sub-varieties not discussed here - for example, my laptop's LCD display is a little different from your TV's LCD display - but the fundamental technology is still the same.

LED-LCD: Light Emitting Diode back-lit Liquid Crystalline Display. Typically marketed as "LED" - this display type is virtually identical to LCD TVs except the florescent back-light has been replaced with white Light Emitting Diodes. It is important to note that each pixel is not a miniature LED (much to my disappointment when doing my research on the display). Some of the higher-end sets have segmented back-lighting that can be individually varied to further improve contrast (let's say you have one corner of the display that needs to be dark but the middle needs to be bright-as-day). This display generally represents a marked improvement over plain-Jane LCDs.

OLED: Organic Light Emitting Diode. This form of display has only -just- seen market activity. Essentially, organic compounds are used to create tiny light-emitting diodes on ... just about anything, really. Each cell is its own cache of light-emitting diodes. As such, there is no back-light. The display can be made flexible (IE: "roll up") and is the thinnest, lightest display technology currently offered. While currently the most expensive of displays in its class, it offers the greatest color range, contrast, and response times of all displays. Its primary drawback is the volatility of the organic compounds, which break down in Ultra-Violet light and degrade over time (particularly the blue). It is, however, expected to succeed both Plasma and LCD technologies in the future. QD LED (Quantum Dot Light Emitting Diode), or QLED is yet a further enhancement to OLED technology that will likely appear in the coming years (though whether or not it will be marketed as QLED or just quietly phased in under the OLED banner cannot be known).

2.1 So... What's best for me?

You are really only going to be able to decide that for yourself. However, here are some things to consider:

The size of your room. I've not met many people who like having to turn their head to see something toward either side of the TV. I've also not met many people who like to feel like they are 'reaching through space' to focus on the TV. This is also going to relate to what you have available in regards to stands/mounts. While a CRT may be cheaper to put into your room for personal use - you may find it far more practical to place a more expensive LCD that takes up far less room.

What you plan to do with your TV. If you're just watching the news, Discovery, History, etc - you don't really need to have top-of-the-line color gamut, contrast, and screen response. Further, displays susceptible to burn-in should not be used in applications where they are going to be displaying static images for long periods of time (such as security displays or programs with static borders). Gamers and video enthusiasts will likely go for the faster, higher-contrast displays (such as Plasma) - sports fans will likely find they prefer similar displays.

The times. OLED is poised to succeed both Plasma and LCD display technologies. It may very well be that, in a couple years, there will be little/no sense in purchasing realistically obsolete technology. Sometimes you may be better served by holding off on a purchase for a few months to a year in order to take advantage of new market offerings.

See it for yourself. It is almost always preferable to actually see what the display looks like before actually buying it. It's even better if you can see what it will look like when displaying the types of scenes you will most often use it for. If you notice - most stores run slower, calmer scenes on their TVs - this is likely due to many reasons, not the least of which being an attempt to avoid vexing customers wandering by a wall of displays showing vertigo-inducing sequences. In many cases, this may be less than practical. However, you should at least check out reviews of that particular model. Chances are there are some people who are using it similar to how you would, and have said a thing or two about how satisfied they are with it.

3.0 The Future?

Basically, the future is shaping up to look like OLED and variations thereof. However, we are seeing some pretty interesting developments in lasers and holographic display technologies. I don't expect we will see any of those come to market within the next 5 years, but you never know. CRTs will likely still be around in their current market segment.

Projectors are seeing much wider use in fields of education and industry, and we may see some spill-over into the home entertainment market. That's one I don't see being particularly wide-spread, but may certainly have some interesting applications (turning a wall into an alternate scene of some sort, for instance - perhaps not a TV-related use, but more of an atmospheric/decorating tool).

E-ink displays being used by a number of specialized reading devices (Kindle, Nook, etc) may see some spill-over into the portable market. I can't help but imagine my laptop with a large E-ink display on the cover (back of the screen) displaying my course-book or some other reading material. For those interested - those displays are -very- similar to paper-and-ink. I generally do not like to read much on the computer as it tends to strain my eyes in ways that reading from a book does not. These displays are electronic, but much easier on most people's eyes. I won't get into how they work - but if you do a lot of reading, they are worth looking into.

4.0 Research, "lost," and Just-over-the-Horizon technologies?

Those interested can discuss and share below, as well as elaborate upon the running display technologies. There are simply too many branch and 'would have been' technologies to practically cover.

star for you, im looking into buying an hdtv atm, going with a 32" led...problem is im having a hard time finding one at 120Hz for a decent price. 120hz only really matters for high end gaming i believe but i keep hearing 60Hz is fine for 32" and below.

you didnt mention IPS panels and TN panels IPS is pretty usefull for people who work with photos and digital animation. I believe the diffence is IPS panels use each color individually while TN panels will mix colors to get whats wanted. IPS is generally an amazing picture.


LG totally makes an IPS panel TV, I hear its really awesome, however acquiring one is kinda like winning a lottery since some of the same model are IPS and others are not.

it seems like internet being integrated into TV is next to come... googleTV appears to have many downfalls like certain websites block it from streaming video and the android app it runs on crashes often, netflix works though.

hey i like what i read so far i kinda just skimmed it. What i am curious whith all these changes is?

Is ther some kinda of subliminal message tech. Built in to these new t.v.'s?

I mean it is called programing for a reson now it could be taken to the next ldc, led, plasma and high motha franken DEF son! Level

i also herd wild acusations that thay have listening devices built right into the cable boxs

dont worry thou Big Brothers is watching very closely he will make shur we are all "safe"

keep your heqd down and stay in line
lol

hey i like what i read so far i kinda just skimmed it. What i am curious whith all these changes is?

Is ther some kinda of subliminal message tech. Built in to these new t.v.'s?

I mean it is called programing for a reson now it could be taken to the next ldc, led, plasma and high motha franken DEF son! Level

i also herd wild acusations that thay have listening devices built right into the cable boxs

dont worry thou Big Brothers is watching very closely he will make shur we are all "safe"

keep your heqd down and stay in line
lol

hey i like what i read so far i kinda just skimmed it. What i am curious whith all these changes is?

Is ther some kinda of subliminal message tech. Built in to these new t.v.'s?

I mean it is called programing for a reson now it could be taken to the next ldc, led, plasma and high motha franken DEF son! Level

i also herd wild acusations that thay have listening devices built right into the cable boxs

dont worry thou Big Brothers is watching very closely he will make shur we are all "safe"

keep your heqd down and stay in line
lol

reply to post by gougitousakusha

you didnt mention IPS panels and TN panels IPS is pretty usefull for people who work with photos and digital animation. I believe the diffence is IPS panels use each color individually while TN panels will mix colors to get whats wanted. IPS is generally an amazing picture.

These are subsets of LCD and I generally don't consider them to be much different to the vast majority of end-users. Most of the time, the display is tuned to its market fairly well and the end-user doesn't really have to get into the dirt with it. Further, the distinction tends to be mostly in monitor technologies as opposed to TV displays (though I could be wrong).

www.pchardwarehelp.com...

S-IPS/H-IPS panels are generally considered the best all around panel type, but they are more expensive and very few are made. High end, expensive.

S-PVA/MVA panels offer better color reproduction and viewing angles than TN panels, have slightly worse response times than TN or S-IPS, offer the best contrast ratios, may suffer from color shifting or input lag and have higher availability than S-IPS panels. Mid range, fair price.

TN panels are very cheap and have the fastest response times, but suffer from inferior color reproduction, contrast ratios and viewing angles. Low end, inexpensive.

H-IPS seems to be regarded as the penultimate in LCD display technology.

[Quote]it seems like internet being integrated into TV is next to come... googleTV appears to have many downfalls like certain websites block it from streaming video and the android app it runs on crashes often, netflix works though.

A number of -interconnect- technologies are going wireless or have adapters to go wireless. I would be surprised if there aren't TVs coming with wireless connectivity on the market. Personally, I'm a perfectionist and would prefer everything went to fiber optic cable - if I'm moving my TV around enough to justify wireless, there's a problem.

There are, however, a number of media players going to internet and NetFlix/Hulu/etc compatibility. A lot of blu-ray players come with wireless networking available and can load up your user profiles. It is certainly interesting, but if I've got a blu-ray player (something I refuse to do because I don't like Sony and their history with proprietary formats) - I am going to want the full high-def quality that is not subject to compression artifacts and pixelation that can be found in streamed HD media.

That said - the internet will play a large role in the future of your TV experience... I was merely focusing on the displays, themselves.

star for you, im looking into buying an hdtv atm, going with a 32" led...problem is im having a hard time finding one at 120Hz for a decent price. 120hz only really matters for high end gaming i believe but i keep hearing 60Hz is fine for 32" and below.

www.lcdtvbuyingguide.com...

This may be of some help.

It does a great deal to cut down on motion induced artifacts – especially with fast motion scenes. It decreases motion lag and judder. However, there are nasty side effects you should know about. When viewing film and broadcast programming in 120Hz/240Hz we see unwanted background noise introduced. Many of the tricks movie producers and programmers employ to create depth and give background information a background look are unraveled and what results is a distracting lack of depth. Cinematography is impaired. In some film reproduction, the background set becomes so clear that you can see the cheap tricks used in the studio to create an effect of say stones in the background. With 120Hz/240Hz you can see that they are plastic. It causes unnatural appearance of the image popping out of the background especially in when foreground characters are moving slowly.

... I can't help but feel they need an editor on that site.

Literary distractions aside - it echoes what I've heard from some other people who say that the faster TVs make everything look "CG" or "fake."

Personally, I've played a number of games on a run-of-the-mill 60hz LCD TV and was not disappointed. That said - I was merely happy to have an HD TV - and may have noticed the difference if I was transitioning from a plasma TV.

A lot of LCD stats, though, can be pretty tricky to cut through. There are few industry standards regulating what, exactly, defines the screen response time (and a number of other statistics related to a screen). This article (on the same site) kind of highlights the issue:

www.lcdtvbuyingguide.com...

Manufacturers of LCD TV are keenly aware of this weakness in response time compared to other technologies such as Plasma, or DLP (LED TV is being touted as a new technology but since it is based on an LCD panel with LED backlighting response time is still a factor). As a result, the best of the manufacturers have improved response rate times considerably – nearly to the point of non-consideration. Some lower tier manufacturers are finding more creative ways to measure response time in order to be or stay competitive. Originally, LCD TVs and monitors were listed with TrTf (Time Rising, Time Falling – sometimes referred to as average). Now, many manufacturers are using a GTG (Gray to Gray) measurement, which is a different average and can measure quite a bit lower than the TrTf time on the same set. Some manufacturers even find it acceptable enough to list just one half of the TrTf time. The problem is there is no industry standard for measurement in response time. There are only liberal interpretations already in use for luminance and contrast ratio.

You should be pretty decent with your good brands; Sharp, RCA (do they make displays, anymore?), etc. It's when you get into your bargain bin that you really have to perk an eyebrow at the claims on the box that rival the stats of something twice the price.

reply to post by jplaysguitar

Is ther some kinda of subliminal message tech. Built in to these new t.v.'s?

Subliminal messaging has many connotations and an interesting history worthy of a completely separate thread.

As far as display technologies are concerned, Subliminal Messaging 'started' as a form of advertising in movie theaters (one of the earliest forms I'm aware of). Going back to the days of film projectors, the movie theater would replace one slide (of the many playing each second) with an image of popcorn, soda, or some other concession offered at the theater. The theory was that the audience would not consciously perceive the image, but subconsciously trigger a desire for popcorn, soda, etc.

This practice eventually hit the media and many states passed laws to make such advertising illegal.

Now, to expand upon the concept of subliminal messaging, I don't think we should look at secret codes within a signal and, instead, look at the social suggestions within many media programs.

Take a TV show popular a few decades ago - Lassy - and compare it to any popular kids program today - like i-Carly. Where are the parents? How do the kids behave? Who "wears the pants?"

More often than not, in programs popular today, the children are running rampant while being portrayed as more intelligent than the parents (present mostly as a figure to conflict with). While I don't believe this is some kind of focused effort to disrupt society - I believe it is simply a shift in marketing. Teen programs are written to appeal to eight year olds wishing they were teens. Adult programs are marketed to teens wishing they were adults. Children's programs are marketed to elderly who wish they were kids again (I jest). I believe it has lead to a number of unhealthy trends that will negatively impact our society for years to come, but there is little to suggest a conspiracy.

I mean it is called programing for a reson now it could be taken to the next ldc, led, plasma and high motha franken DEF son! Level

It's called programming because there is a program that the station follows. You air shows at scheduled times, or you kind of lose viewership and your advertising space loses value.

If you're curious about using patterns of lights and sounds to influence human behavior... that's a pretty tough one. First - Neurology is a very unique property to each individual. We think, learn, and remember in different ways because our brains process information in different ways. I'm somewhat rare in my possession of what would appear to be Type A ASMR - en.wikipedia.org... - and neuroatypical with a number of characteristics similar to those with Asperger's (though I have never been clinically diagnosed).

What it all amounts to is that, even if you could 'hack' one person's brain using patterns of lights and sounds - it would most likely not work on any other person. Thus, it would have very little to no value in broadcast television (supposing you could work around the complexities of displaying those patterns, effectively, between other bits of broadcasting without triggering suspicion).

i also herd wild acusations that thay have listening devices built right into the cable boxs

While not entirely impossible, it is simply impractical to deploy such devices on a wide range. You would have tens of millions of devices recording hundreds of millions of hours' worth of audio. If there were such devices, and teams of people were listening to them, it would literally be like playing the lottery to find anything of practical use to them.

I've taken apart my fair share of electronic devices, and never once found a camera or listening device that made me say: "hey, something fishy is up..." I've only ever found cameras and microphones in devices marketed for their ability to record audio/video (IE - you buy them to record stuff).

dont worry thou Big Brothers is watching very closely he will make shur we are all "safe"

keep your heqd down and stay in line

I have military and factory experience, making a decent name for myself in both - I've learned how to stay in line when necessary and rock the boat to make things happen.

Back on topic - I know this is a conspiracy forum and we all like to believe in some omniscient power... but I think this is really all that needs to be said about the idea of subliminal messaging in television. "It's not the monsters under your bed, it is the man next door." - Bonus points if anyone can tell me what song and band those lyrics come from.

reply to post by Aim64C

Great thread Aim64c. I recently had a TV die and went through this education process myself and I think you explained it pretty well.

The only other thing I'd add that might matter to some enthusiasts is display resolution.

Generally the largest displays will tend to have higher resolution, and the smallest displays tend to have lower resolution, though there are certainly exceptions. Case in point was a small TV about 20-21" at Wal-Mart that had 1920x1080 pixels of resolution. I was looking for something closer to 30" but surprisingly there was a gap at Wal Mart where none of the TVs in that size range had 1080 resolution, after the 21", you had to go well over 30" to get the 1080 again. Since they also call 720 "HD", and I can see the difference between 720 and 1080, it's safe to say not all HD is created equal. I thought it was really odd that there was such a gap in the availability of 1080 sets (and they had dozens available).

In the end I ended up buying another used 32" CRT for $50, for the time being at least. Yes it uses more electricity, but I don't use it that much so that's not a big factor for me. I would have bought a 30" 1080 modern TV, if I could have found one, but I couldn't find one, I could only find the 1080 resolution in sets much smaller or much larger than 30".

One last thing, is reliability. You mentioned the burn-in of static images on some screens like plasma, which could also happen to CRTs, and is sort of a life/reliability issue. From anecdotal reports from friends and family members, the more modern technologies seem to not last as long as the CRTs which can last for decades. Perhaps that's because CRT tech was mature and the modern technologies aren't mature yet? I don't know the reason the CRT TVs, nor have I seen robust statistics, but from my small sample of friends and family statistics, that was another reason I bought the used CRT, I know it will last..

I'll be happy when OLED gets a little better and they expand on the platform a little more.



I want an invisible TV!

Put it in the wall and you don't see it until you turn it in. Now that's technology...