LED television technology
A LED television is not, as you might expect, a television that consists of an array of tiny LEDs. A LED television is in fact nothing but a special type of LCD television. To see why an LCD television would need LEDs, we'll take a very brief look at how an LCD television works.
An LCD screen consists of two parts: a light source and a thin layer of liquid crystals. The principle is simple. The light source produces a bright, white light. The LCD now acts as a filter. If the screen should be white, the crystals are transparent. If it should be dark, they are opaque. For the record, this is the opposite of how a plasma television works: a plasma television works by having tiny plasma lamps emitting light when parts should be bright and not emitting light when they should not.
As mentioned, an LCD television requires a light source. This is called a backlight. In a conventional LCD, this is formed by a folded fluorescent lamp. This works fine. In a LED television, a large number of white LEDs is used to replace this fluorescent lamp. this has some advantages, as we will see.
Advantages of a LED television
Apart from the fact that "LED" sounds more modern than LCD, what sort of advantages does an LED television have? I'll attempt to list them here.
- A LED backlight is more energy efficient. This means your room will be less hot and your electricity bill lower. A LED television saves about 30 to 50% of the electricity when compared to a "normal" LCD screen. Over the lifetime of the TV, this can add up to a few hundred euros. The savings over plasma are even larger.
- A LED television is thinner. A 52" television doesn't have to be much thicker than 1". That looks pretty sexy, if you care about that.
- Supposedly, a LED lasts longer than a fluorescent lamp, so the television should last longer as well. In fact, it could easily last a decade. Note that's a also a decade of energy savings.
- One of the major drawbacks of a LED television is the fact that the masking by the LCD is rarely perfect. As such, "black" is usually gray. This is perceived as a major advantage of a plasma television. However, with LEDs, it is possible to switch off the LEDs locally, at least in theory. This gives true black rather than gray, and as such, you get one of the best features of a plasma screen in your LCD.
- A fluorescent lamp backlight doesn't have uniform brightness, and as such, the screen won't, either. LEDs are much more uniform, giving a better image quality. Also, according to moosemanmoo, the LEDs are more color accurate, and this also helps the image quality.
Disadvantages of a LED television
So, we have seen there are advantages to using LEDs as a backlight. Are there any disadvantages, then? Well, there is one. Price. A LED television is a few hundred euros more expensive than a comparable non-LED television, and several hundred euros more expensive than a lower-end television with a slightly lower-quality display. As such, it is in the middle to top of the market. The point is, for this extra price tag, the advantages are not very compelling. Sure, the black looks better - but it's not like your DVDs or the stuff you downloaded from Bittorrent are substantially improved by that. The other advantages are slight. That said, the savings in energy compensate the higher price.
A LED television is not a television that works by changing the color of LEDs. Rather, it is an LCD television that uses LEDs as a backlight. This has several small advantages. These small advantages come at an increase in price. If you are in the market for a high-end television, it might be worth it, although the difference between it and a normal LCD are not earth-shattering. Think of it as an evolution, not a revolution.