Differences Between LED and LCD TVs

LED TVs Are Subsets of LCD TVs

Three Samsung Curved UHDTVs

Kārlis Dambrāns/Flickr/CC BY 2.0

There are several factors that make buying a new TV confusing, but few topics bewilder consumers as much as the use of LED terminology, especially when you introduce terms like OLED and S-AMOLED. LED TVs are simply a type of LCD TV.

LED vs LCD basic differences

The LED term used to describe a TV, in reality, refers to the TV's backlighting system, not the display technology that produces the image content. In truth, LED TVs are LCD TVs. However, LED TVs use LED backlights rather than the fluorescent-type backlights of what are generally referred to as LCD TVs.

Liquid crystal display (LCD) crystals in LCD TVs do not produce their own light. They require a source to illuminate its pixels for the image created by the LCD to become visible to the viewer, referred to as backlighting. LCD sets originally used a series of fluorescent tubes (termed CCFL-backlit technology) to illuminate the pixels that comprise the image you see on the screen.

In LED TVs the illumination source is a series of light emitting diodes, better known as LEDs. In most modern LCD sets, those fluorescent tubes have been replaced with full array LEDs, but both types of TVs use LCD technology.

Manufacturers make a big deal out of LED backlighting because sets that use the technology are usually more energy efficient than CCFL LCD TVs. There are other benefits as well, but to understand them you have to take a closer look at the implementation of LED backlighting.

LED-backlit LCD TVs currently use one of two systems:

  • Edge-lit: LEDs are placed along the edges of the LCD panel.
  • Full array: Rows of LEDs are placed behind the entirety of the LCD panel.

Backlighting: edge-lit vs. full array

Each backlighting system has advantages and disadvantages, and the one that’s right for you depends on your needs. Edge-lit sets are typically much thinner and lighter than those that use a full array because the lighting source takes up less space. Full-array sets are somewhat thicker and heavier, but they make up for that with local dimming, which means one section of the LED panel can be dimmed while other sections remain bright. That improves the appearance of black areas of the image and contrast in the resulting picture.

LED sets that use full-array backlighting tend to produce the best picture of all LCD TVs. Those that use edge lighting sacrifice picture quality but are the lightest and thinnest TVs on the market.

Price

Before you run out and buy an LCD TV with LED backlighting, you should consider one important factor: price. LED full-array backlit TVs are impressive, but they’re more expensive than their florescent-lit peers. If picture quality is extremely important to you, then spending a little more money to enjoy the benefits of full-array LED backlighting may make sense for you. If you’re looking to have the thinnest TV on the block, edge-lit LED is the way to go.

If you’re a bargain shopper, you will probably be able to satisfy yourself and your wallet with a well-made florescent-lit LCD TV—if you can find one, as they are not manufactured as often any longer.