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Technology ---> TV ---> LCD (Liquid Crystal Display)

 

Today, the Liquid Crystal Display, or LCD, is the most popular form of television display. Thin and lightweight, LCDs are great for those looking to wall-mount a television.

How it works:

On an LCD display, each pixel has a layer of liquid crystal molecules, sandwiched between two electrodes. On the other side of each electrode, a polarizing filter is placed, a vertical one on the front most side, and a horizontal one on the rear. A backlight is placed behind the horizontal filter to provide a light source. When the liquid molecules receive an electric charge, they become crystallized and twist. Depending on the voltage provided, the crystals will either allow a certain amount of light to pass through. In a color LCD like the ones we use on a television, each pixel is divided into three cells (one for each of the three primary colors) by another filter.   

 

Sony Bravia 46" KDL46XBR9

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Purchase at Best Buy

Advantages:

Brightness

One of the nicest things about LCDs is that they can definitely output a lot of light. For displaying brightly colored scenes, LCDs are significantly brighter than plasma displays, and LED-backlit have further improved this, as they output more more light.

 

No burn-in

One of the major downsides to plasma and CRT televisions is that, when left on a static image, ghost-like version of the image can get burned into the screen. With LCD screens, this does not happen at all, so you'll never have to worry about having your game score etched onto your screen. Due to their inability to receive burn-in, LCDs are the best choice for video gaming, or for those looking to to use their display as a computer monitor.

 

Great Viewing Angle

Unlike rear-projection TVs, which only be seen clearly if viewed straight ahead, LCDs maintain a great appearance at almost all angles. Although some of the early LCD TVs would get significantly dimmer as you moved to the side of the screen, almost all models made today have a horizontal viewing angle of 178 degrees, meaning a great picture, no matter where you are seated. This is due to improvements in the alignment of the liquid crystal material. 

 

Long Lasting:

LCDs are one of the most durable flat-screen technologies, and can last quite a while. Most models made today are rated for 50,000-60,000 hours. If you watch TV eight hours a day, that's over 27 years!

 

Wide range of sizes available:

Originally, LCD TVs were limited to smaller sizes such as 15", but due to higher demand and lower production costs, LCDs are now available in an incredibly large range of sizes, with models as large as 70" currently available to the public. 

Lightweight

Due to their thinness and small components, LCDs are incredibly lightweight. This makes them an excellent candidate for wall-mounted setups, or for those with limited space.

 

Energy efficient

Overall, LCD displays are more efficient compared to plasmas. Currently, the average LCD screen uses about 150 watts, compared to about 220 watts for a plasma screen. Also, LED-backlight models are significantly more efficient than traditional LCDs, due to their low power consumption.

Samsung 46" LCD LN55C650

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Purchase at Sears

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Disadvantages:

Poor Black Levels

While, LCDs are the king of brightness, they fall to plasma when it comes to black levels. Unlike a plasma, which can completely turn off it light in a pixel to create black, the light source on an LCD display is always on, so the black levels are determined by the display's ability to filter out light. Some companies, however, have been able to reach black levels that are as good as those on plasma displays. Samsung has done the best job at giving us the best of both worlds, just take a look at their LED displays, which use their "True Black" display. It's absolutely stunning.

 

Bad Pixels

On an LCD screen, it is not uncommon for pixels to fail. Sometimes pixels can go bad over time, but dead pixels usually occurs when the screen is damaged from impact or pressure.

 

Ghosting

Even though LCDs are not susceptible to burn-in, many older models suffer from ghosting, caused by the slower response time of an LCD compared to other displays. Unlike burn-in, ghosting is a temporary effect, and usually lasts less than a second. Today's models, however, have much faster response times, some as low as 2ms, meaning that ghosting is almost nonexistent. 

 

For LCDs, the pros certainly outweigh the cons, so make them your first choice when shopping for a new flat-screen.

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