What Exactly is an LED Television?

by B Totanes

Lately, there have been a lot of advertisements hyping about LED televisions. What exactly is an LED television and how can it benefit you, the consumer?

First of all, let me get a few terms defined, so you can understand the big picture:

Different layers of an LCD panel display.

LCD – this stands for “Liquid Crystal Display”. This simply means what it says. It is a display that uses liquid crystals sandwiched in between two glass panels and electrodes. The electrodes within these panels activate the liquid crystals and make the crystals dark, light or produce colors from the RGB spectrum, thus creating images depending on how the electricity is passed through them.

An LED lamp and its basic components (Image Credit: Howstuffworks.com)



LED – “Light Emitting Diode” is an electronic component that produces light. This device, a Diode, is a semiconductor device that allows electricity only to pass on one direction. LEDs have been around since 1962, and were very commonly used as indicatorlamps on switches. Today, LEDs can be much brighter and some of its applications are as light sources for flashlights, traffic lights, automobile tail lights and others. They normally last many times longer than regular incandescent bulbs. Often, the device it is installed on becomes obsolete and discarded way ahead of the LED lamp’s useful life. In ultra-large displays, thousands of Red, Green and Blue (RGB) LED lamps are placed on arrays in a huge panel and are controlled by a computer to produce TV-like images. These panels are what you see in big stadiums and ultra-large displays in Las Vegas, for example.

A vintage Altair PC using LED lamps

So, what is an “LED Television”?

Basically, the name “LED television” is a misnomer. It is really a combination of LCD and LED technology. In a traditional LCD television, the LCD panel that produce the images is back-lit by cold-cathode flourescent lamp (CCFL), similar to those white flourescent lamps in our homes. LCD panels by themselves will produce images, but you will barely see the picture as it requires some form of backlight. The floursecent lamp is placed on the back of the LCD panel to reveal the picture.

In an LED Television, the same LCD panel is used, but the cold cathode fourescent lamp (CCFL) is replaced by bright LED lamps. LED lamps are either placed directly behind the LCD panel or lined just behind the outer edge of the display (Edge-LED). So basically, the correct term should be “LED-backlit LCD Television”. However, Samsung, who invented LED-backlit LCD TVs, conveniently dropped “LCD” and started calling their LED-backlit LCD Televisions,simply “LED Televisions”. And so, the confusion started.

Some more expensive implementation of LED-backlighting involves putting Red, Green, and Blue (RGB-LED) LEDs directly behind the LCD panel and then dynamically controlled depending on what is being viewed on the screen. This makes for even brighter colors and deeper contrasts.

RGB LED Array (Image Credit: cNet Australia)

What are the benefits of LED-backlit LCD versus LCD Televisions? LED-backit LCD TVs differ from conventional CCFL-backlit LCD TVs in the following:

* LED-backlit LCD TVs produce images with greater dynamic contrast.
* With Edge-LED lighting they can be extremely slim. Models on the market can be approximately one inch thick.
* Offer a wider color gamut, especially when RGB-LED backlighting is used.
* Less environmental pollution on disposal.
* Generally 20-30% lower power consumption.


The Samsung Series 5000 LED TV

In a nutshell, LED-backlit LCD Televisions are fast becoming the preferred choice in televisions now-a-days. However, it is NOT the must-get feature if your budget does not allow the higher price. Do not disqualify traditional LCD televisions from your list. Chances are, you might just find a great deal out there.

Next: HDTV: 480p, 720p, 1080i, 1080p, what are the differences?

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