The Truth Behind Led TVs

[rajanmehta 4,056]

LED backlighting in TVs has been a real boon for end users, while manufactures have been able to create stunningly slim televisions. It also keeps the environmentalists happy since there is no mercury used in LED backlit TVs there by giving you a greener product. We tested quite a few LED based LCD TVs in the past and the difference in power consumption is certainly visible while still maintaining a good brightness level.

The problem with the term "LED backlit LCD" is that it's a bit too long, which does not look good in advertisements and posters. Manufacturers have conveniently eliminated LCD and simply highlight "LED", duping customers into thinking they are LED TVs, which they clearly aren't. Today we'll have a look at the different types of LED LCD TVs currently available that offer improved picture quality over the other or even traditional LCD TVs.

All LED Backlit TVs are not created equal

The first thing that you should know is that not all LED LCD TVs are created equal. Just because the TV may have a sticker that says "LED" on it does not mean you'll get the same performance as the flagship model. Stop and think for a moment, if companies used the same technologies in their high-end and low-end products, no one would look at the higher end models, right?

There are predominantly two types of LED backlighting technologies; Edge-lit LEDs and Full array LEDs. The first batch of LED TVs that came out in 2009 were based on this technology and was first showcased by Samsung. Today you'll find everyone using this technology in their "cheaper" LED LCD TVs. Edge-lit typically means the LEDs are placed around the edge, which allow companies to make slimmer TVs. There are no major advantages in this type of LED LCD over conventional LCDs when it comes to picture quality. In fact there are many uniformity issues with edge-lit LEDs, like certain areas of the TV tend to be brighter than others, which we noticed when we reviewed the Sony ZX1. This is cheaper to produce than Full array LED LCDs, since they use a fewer number of LEDs.

The other technology that can be found on most of high-end TVs of today is Full array LEDs. As the name suggests, there is a full array of LEDs (see pic) sitting behind the LCD panel. This obviously gives you a more even backlighting with little or no uniformity issues. Mid-range to high end models typically have this sort of backlighting, like the Samsung UNC6500 series. In terms of picture quality, there is no real perceptible difference when compared to an LCD. The only advantage here is lower power consumption and again a slimmer profile. The latest crop of LED LCD TVs feature Local Dimming LED technology, which changes the game altogether.

What is Local Dimming LEDs?

LG was the first to push out this technology in India and today almost all major brands have Local Dimming (LD) in their flagship models. LD on Full array LED TVs give you the better picture quality compared to the LD on Edge-lit TVs, which was introduced this year in the Samsung UNC8000 series and LG LE5500 series. The LEDs used here are similar to the Full array models except that the array is broken into different zones and the LEDs in each zone can be dimmed or brightened depending on the scene at hand.

This gives you very good black levels that rival plasmas, since the LEDs in the dark areas can be completely turned off. There is a little catch here though. The side effect of this is a slight blooming effect noticed up close when a brighter image appears suddenly over a dark background. This happens because when displaying a dark background, the LEDs in that area are mostly off and when a bright object suddenly comes into that area, the LED's light up to full brightness and then dim down to the current selected picture mode. This happens very quickly and isn't very noticeable when watching a movie, but if you connect a PC to it with a static background, it's visible.

Despite this, these TV's are capable of delivering the best picture quality among LCD TVs.

Commercial true LED TVs don't exist yet

How would one define a LED TV? It's when a single LED is responsible for illuminating a single pixel on the screen, which is when you could do away with the LCD panel altogether. Today's high-end LED LCD TVs pack in around 1500 LEDs and a typical full HD panel will have around 2 million pixels. So in order for a TV to be classified as a true LED TV, we would have to have 2 million LEDs powering individual pixels, which is simply not possible today, and probably won't be commercially viable for some time.

So you see, no matter how companies try to spin and twist words and create fancy slogans, if a TV uses an LCD panel, it's still an LCD TV and not a LED TV. Sony and LG clearly mention this on their site as LED LCD TV, but Samsung seem to have conveniently dropped the "LCD" from all of their LED TVs, which would easily fool the misinformed.

Aren't LED backlit TV's supposed to be cheap?

Technically LEDs should be cheaper to produce compared to CCFL based LCDs, but our guess is that manufacturers seem to be cashing in on the hype and buzz generated by none other than them. Everybody wants a slimmer TV for easier installation, more bragging rights, etc. and we seemed to have conditioned ourselves into thinking the extra price is justified.

Another reason for LED LCDs being expensive could very well be the manufacturing process not being that mature as yet compared to LCDs.

It's probably cheaper to manufacture an LCD, since this technology has been around for a while now and manufacturing units are more wide spread as compared to LED LCDs, which just started hitting selves a year back.

What the Future holds

In the next three to five years we should be able to see a considerable drop in prices as we adopt newer technology for cheaper and better LED LCD TVs. QD Vision is a company that claims to have developed a breakthrough technology called Quantum dots based on nano technology that is capable of delivering up to 40% more power efficiency and a color gamut over 100% of the NTSC spectrum. This is achievable due to the use of nano sized semiconductor crystals capable of emitting pure red, green and blue light.

You should see this technology hitting LED LCD models of 2011, which isn't far away. If you were on the fence on getting an LED LCD TV then we'd say get the one with Local Dimming LEDs if you can afford it, or else simply stick with a cheaper LCD TV, as the color reproduction will be better than the "cheaper" Edge-lit models. Better still, if you have a well functioning CRT at home, stick with that and take the plunge maybe next year when prices go down south.

SOURCE: Techtree

[parin 857]

Nice Info Rajan Thanks

[Greatest 55]

Thats really news for me buddy.. I wasnt aware of this... +1 for you...

[amitnsonu 72]

Nice info

thanks for sharing Rajan ji.

[ami1 237]

Thanks a lot. +1 for the info. I've been trying to decide between LCD & LED. Will go for LCD now. Couldn't see much difference anyway between them. And both look worse than CRT unless you are really far away. But people tend to think of CRT as really old fashioned these days so i am forced to replace !

[srk006 21]

very useful article. +1

[dkaile 1,051]

Sony doesnt manufacture TRUE LED TV's still... you can call theirs pseudo led's... just remember this.... Samsung is the market leader in true LED for now...

[vll 1]

nice info +1

[ipkonfig 10]

The OP is quite informative. I wish I had seen this before making that purchase of Samsung 42' LED TV last month

[CaptSD 0]

Very useful.

[Harshal 11]

good share.

[sumitnda 6]

thats a wonderful post! thanks for helping me decide to go for a LCD (and NOT a LED), and thus saving me quite a few thousand rupees!!!

[HetalDP 947]

@Ranjan

There must be 3 Technology Comparison

1. LCD with CFL Backlit = Normal LCD
2. LCD with LED Backlit
3. True OLED or True LED

[rajanmehta 4,056]

@Ranjan

There must be 3 Technology Comparison

1. LCD with CFL Backlit = Normal LCD
2. LCD with LED Backlit
3. True OLED or True LED

True OLED or True LED is just a theoretical debate right now. In December 2007, Sony started selling an 11" OLED TV priced at $ 2500 and now has stopped production and sale altogether. LG has EL9500 which is a 15" OLED TV which is in sale in Korea for $ 2600. Samsung and Panasonic has prototypes of 40" and 37" OLED but not available for sale.

Just look at the exorbitant prices and sizes less than a typical PC Monitor for available OLED Tv. This are just technology demonstration and has no real world value for an end user as of today.

And in India, none of them is available. OLED will take atleast next 5 years to mature into an affordable, mass market technology. Untill then, there is no question of a real life practical comparison between OLED and True LED.

And we still don't have True LED also at each Pixel Level. Right now there is at the most 1500 LED Pixel in a typical Full HD Panel with around 2 million pixels.

Differences between LCD with CFL backlit and LED Backlit is what is important right now and it is there for everyone to see and understand.

Edited November 10, 2010 by rajanmehta

[Mufaddal 678]

good share by Rajan

[kshah 452]

Very goo d info.

OLED is still may be year and a half away and OLED / AMOLED seems to be future.

[gauravjc 47]

Good Share my friend !!

[MGR 18]

thanks for useful info

[KumaarShah 143]

@ Rajan, Terrific info as usual from all your topics!!!! Keep it up... Thanks for sharing.

[chintan1 6]

Good info Rajan Bhai ... well now have decided to go for LCD TV only instead of LED ..

[Honest 836]

+1 dear Rajan Brother.

[KAPILKDEV 68]

Very useful article, +1 for you dear Rajan Mehta

Edited November 11, 2010 by KAPILKDEV

[raccoon 53]

+1. Thanks for posting Rajan. We have a "well functioning CRT" but were considering a replacement. Will stick with that for now.  

[kkdeep 6]

IMO the biggest advantage of LCD over the "well functioning CRT"

1) is aspect ratio (16:9)

2) LCD is thinner

3) Full HD support in LCD and hence better picture quality.

if these things don't bother you, stay with CRT.

Edited November 12, 2010 by kkdeep

[raccoon 53]

if these things don't bother you, stay with CRT.

They do! Not to mention the higher power consumption of a big CRT. Thats why we were considering a change. But I guess it may be better to wait a bit.

Edited November 12, 2010 by raccoon