In the quest to improve the picture quality, LED TV manufacturers have introduced several new technologies to help achieve the sharpness and black levels we’re used to seeing with plasma-based flat-screen TVs. One such improvement comes in the way that LED TVs are illuminated. In this post we discuss the various benefits of the four different backlight methods incorporated in LED TVs. We also explain the differences between “full-array” and “edge-lit” backlighting and also discuss how local dimming can make a difference in picture quality.
So with that in mind let’s discuss the four popular types of LED backlighting techniques currently used today. Before we begin, however, it is important to note that all LED TVs are really LCD TVs with an LED backlight. LCD stands for “liquid crystal display” and LED stands for “light-emitting diode.” To illuminate the LCD screen, all LCD-based TVs require the use of some type of backlight. Before LED TVs became popular, LCD TVs used fluorescent backlights, commonly known as CCFL. In order to make LCD TVs thinner, lighter and more energy efficient, TV manufacturers started to use LED backlights instead, hence creating a new category of flat-screen TVs called the “LED TV.”
The type of LED backlight used and how the backlight is configured make a big difference between LED TVs. Four LED backlight configurations are currently used on the market today. Below we provide a brief description of each configuration. The four types of LED backlight configurations include:
Full-array Using Local Dimming: These are very similar to the way LCD TVs were configured but instead of using the CCFL backlight, they use LED backlights instead. The term‚ “full-array” simply means that the LEDs cover the entire backside of the LCD panel. As far as picture quality is concerned, you won’t notice much difference when compared to standard LCD TVs.
Full-array with Local Dimming: In addition to a full-array configuration, TVs with this configuration also have the ability to independently dim or brighten individual zones of LEDs, hence the term, “local dimming.” This results in an improved picture quality with much better black levels and a more uniform picture across the LCD panel. While the cost of the TV may increase when using this local dimming, the improved picture quality is very desirable.
Edge-lit without Local Dimming: When TV manufacturers decided to make LED TVs even thinner and lighter than they already were, they began using “edge-lit‚” configurations. In contrast to the full-array configuration, LEDs on edge-lit TVs sit along the edge of the LCD panel. When it comes to picture quality, you won‚’t see any major differences over standard LCD TVs. In fact, some lower quality models may not uniformly illuminate the LCD panel, thus leading to brighter edges.
Edge-lit with Local Dimming: TVs with this configuration give you the best of both worlds. They offer the advantages of an edge-lit configuration (namely being thinner and lighter) but are also equipped with some ability to dim the screen in independent areas. In other words, because of the edge-lit configuration, you get to achieve a thinner and lighter TV build but you also get the benefits that local dimming brings. This results in darker black levels when compared to edge-lit TVs that don’t use local dimming. However, TVs with this configuration still don’t match the picture quality achieved when using a full-array configuration with local dimming.
In summary, LED TVs are beginning to match the picture quality normally seen with plasma-based TVs. One way this is being achieved is through the way LED TVs are illuminated. We reviewed the pros and cons of four different LED backlight methods and their difference on picture quality. In your search for an LED TV, keep these tips in mind and don’t be afraid to compare how different manufacturers incorporate these technologies into their TVs. In the end you’ll find that with a little research, it is easy to find several affordable LED TVs that deliver amazing picture quality.
If you would like to do a little more research and compare models, visit our televisions page or contact us so we can help you search for that perfect TV.