Before the invasion of the flat screen, flat panel displays in our lives, the only real question when purchasing a CRT (cathode ray tube) TV was how big did you want it and how much space did you have in your room to house it ? Yes there were definitely some quality issues but mostly it was dictated by how many diagonal inches you could get buy. The 14″ and 21″ being the most popular at least in India. While size still matters to add to complexity of buying a TV includes Plasma vs LCD displays. Just when people were getting their mind sets ready for one or the other, Samsung jumped everyone with the ultra thin awesomely thin looking LED TV. And like most electronics that get the oohs and aahs from the public, everyone else followed suite.

People are now thinking what is this new animal in the TV world. To put it simply it is another form of the LCD TV that uses LED lights to provide the required back light and thats about it.

[ad#Adsense Wide] All LCD Television panels require a back light to work as the LCD itself cannot generate its own light. The light is transmissive so the back light is essential to the working of the TV, thus producing the image. Currently, most LCD TVs used CCFL technology (cold cathode fluorescent lamps) as their backlight source. These lamps provide very good colors, brightness and contrast. But the biggest problem for these screens is the blacks which the Plasma TV excels in. I can hear you saying, “but I see Black all the time ! “. Well, the best way to explain the point is to have no source on the LCD screen i.e disconnect your TV receiver / DVD etc, and you will see that the screen turns black. Well is it really black, is something you need to answer for yourself.

LED TVs utilizing brighter LED back lighting can achieve much better blacks, as well as brighter colors and even greater contrast ratios (Toshiba Regza 55X1 is boasting 5,000,000:1). LCD TV Contrast is measured from the darkest lit area of the screen to the brightest area to give a ratio. Just when you are getting comfortable with LED TV’s the manufacturers throw at us 2 options with LED TV’s as well. Full Matrix LED and Edge Lit LED TVs. I am here to help you with it.

So is it really an LED TV?

An actual LED TV is actually those huge screens that we see at the cricket matches or for advertisements. Where in we can really see each dot that is transmitted in the screen. They are made up of thousands of extremely bright LED lights. All of us have seen LED’s the ones used to indicate working position in your TV receiver, DVD player, Play station that is red or green showing if the device is operational. But because the size of LEDs are mostly too big and chunky to use in TVs, but they are an ideally suited as a light source for back lighting LCD crystals.

So, what was this business about Edge lighting and full array lighting ?

Edge lighting

Edge lighting is pretty much as self described. In this method, a series of LED backlights are positioned along the outside edges of the screen. From there, the light is dispersed across the screen, which means the LED/LCD TV can be made very thin. And while the results may be better than CCFL screens, the black levels in edge lighting are not as deep and, if you look closely, the edge area of the screen tends to be brighter than the middle viewing area.

Full-array backlighting

To take full advantage of LED lighting, some manufacturers use full-array LED backlighting, where many rows of LEDs are placed behind the entire surface of the screen. Although this makes for a thicker TV panel, the LEDs provide more even, brighter colors and greater contrast. A measurable benefit of full-array lighting can be seen when “local dimming” is utilized, meaning that each LED (or more common, a selected “zone” of LEDs) can be turned on and off independently within the screen, thus providing greater control of the brightness and darkness for each of those areas. Greater contrast levels are achieved by diminishing the effects of light from brightly lit neighboring areas seeping into blackened areas of the screen, which is one of the downsides of LCD screens. In other words, the greater level of dimming control, the better the picture quality.

A number of manufacturers are preferring this technology with impressive results. They include: Samsung, Toshiba and LG. Currently, most LED backlighting is provided by white LEDs that are plentiful and cost less than red, green, blue (RGB) versions. In the near future, expect to see RGB LEDs, that provide a much greater color range and therefore much richer, denser and varied colors, being incorporated into TVs. Already a couple of manufacturers including Sony and Sharp have models with RGB LEDs.

So why get an LED TV then ?

An LED TV achieves deeper blacks as well as emitting brighter images, thereby producing better contrast ratios. They are slimmer (especially edge-LED lighting systems). They deliver better viewing angles than other LCD TVs. LEDs are long-lasting. LEDs are more energy efficient than their CCFL counterparts, and better than plasma Tvs and much better than CRTs. LEDs don’t use mercury like some other backlighting methods. So in effect they not only add to the viewing experience but also help save energy.

So whats next ?

The real LED TV. Manufacturers like Sony have been advertising and using OLED screens in various devices. Like the W series MP3 player from Sony that you charge for 2 mins and play for 10 hours. OLED is really the original LED TV that we should all be excited about. OLED displays make use of a thin organic film deposited on its surface with a simple printing process, and present several advantages compared to traditional LCD displays: most notably, they don’t require a backlight to function, which allows for much thinner and power-saving displays. So when this display comes out from LG and Sony as announced, expect to pay really a lot for this bleeding edge technology.

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For people who like thin displays, the OLED’s are going to be mind blasting. They nearly defy logic as you can have them roll around a can or a surface. Still you cannot make the displays ultra thin, why ? Because its not really the panel, the problem is trying to squeeze in the speakers / tuners / storage drives etc in less than 20mm space. Current OLEDs also suffer from a limited lifespan compared to other technologies – particularly the blue OLEDs, which have a typical working life of only roughly 5000 hours, while, in general, LCD and plasma technologies log in around 60,000 hours.

While I am finishing this post there are about 25 different models of 3D TV’s that are already out in the market and they seem to be wanting us to have more options and more confusing that choosing a good pair of jeans in a store. I will do a Introduction to 3D technology in a bit. But for now, the options in buying a TV are just growing.