The Lurks and Perks of LED TVs

There’s a reason that there is little difference in the name between LCD televisions and their LED counterparts – because the technology has the same basis, although the LED version is more refined. LED televisions are made in almost the same way as LCDs, just with a different lighting technique that produces energy savings, improved contrast ratio and an ultra-thin profile.

How do LED televisions work?

To understand LED technology, it is easiest to first understand how ordinary LCD televisions work. An LCD television is made of two sheets of polarising plastic filters, sandwiching a film of liquid crystals. When voltage is applied to a crystal, it turns on an angle; this effectively switches off the pixel, as light cannot pass through it. Red, blue and green filters and a light behind the panel create brightness and a range of colours.

Traditional LCD televisions use fluorescent lighting at the back of the screen. This can sometimes result in ‘leakage’ of light through switched-off pixels. LED televisions, on the other hand, use groups of individual light emitting diodes (LEDs) to light to pixels from behind. The lack of a large fluorescent tube makes the construction ultra-slim, and the more precise light control results in reduced light ‘leakage’ through switched off pixels. This improves the perceived contrast ratio.

The Perks of LED technology

Using LED backlights rather than traditional fluorescent tubes offers an enormous range of benefits for those buying televisions. For example:

• LED televisions are much thinner than traditional LCDs – they can be less than three inches from front to back, and are extremely lightweight.
• Power consumption is reduced over traditional fluorescent lit LCD televisions
• LED televisions have vastly improved contrast ratio. The LEDs in a dark area can be turned off automatically, so that no light leaks through pixels which are supposed to be turned off. This will net you  better picture quality in dark scenes, and deeper blacks overall.
• The leakage improvement also results in improved colour saturation, through reds, blues and greens.

It is impossible to fully appreciate the perks of buying an LED television without comparing them to plasma televisions. Picture quality is comparable, but LEDs hold advantages in several areas:

• Viewing quality remains much steadier than with plasmas, which start to reduce in brightness as soon as you start watching them and reduce to terrible quality after around 10,000 hours.
• LEDs use less than half the wattage that plasmas do
• LEDs are not subject to screen burn-in
• LEDs are much lighter, more streamlined, and more suitable for wall-mounting in a variety of positions.

The Lurks of LED Technology

The major turn-off for most people buying televisions is that LEDs are more expensive that ordinary LCD sets, and even more expensive than some plasmas. For example, a popular 32″ Samsung TV using traditional LCD technology costs around $830, while a 32″ Samsung TV using LED technology costs around $1600. However, reviewers often feel that the extra cost brings these LED sets up to roughly the same picture quality that you would find in a plasma television – but without all the enormous drawbacks of increased power consumption, fragility, screen burn-in from static items like channel logos, and a decrease in display brightness to pretty much non-viewability after around 10,000 hours.

LED televisions are the most durable, flexible and future ready sets on the market. For those buying televisions that they want to perform well for years into the future, LED is the way to go.

The Lurks and Perks of Plasma TVs

Plasma is a very well-known, although fortunately little-bought, television technology. There are some wonderful models out there, that have drool-worthy resolution, colour saturation and contrast ratio stats. If you also enjoy owning expensive items for the sake of it, plasma televisions have a much higher ‘friend-envy’ factor. However, unless you buy top-of-the-line models, there are quite a lot of technological issues to be found in plasma televisions. We look at when the model is preferable to LCD televisions, like favourite Samsung TVs and other big brands, and when LCD wins out.

How do plasma televisions work?

Plasma televisions have thousands of tiny cells in the screen – each pixel is divided into three cells, one coated with red phosphors, one with green and one with blue. These cells are filled with a plasma gas, and spanned by electrodes. When electricity is applied, the plasma gas gives off electrons that excite the phosphors, making them glow. The technology is inherently different to LCD televisions, and has vastly different benefits and drawbacks.

The Perks of Plasma Technology

If you are willing to spend the necessary dollars to make the potential of plasma a reality, the reward is amazing picture quality, in terms of colour saturation and contrast ratio. Unlike LCD televisions, light cannot ‘leak through switched-off pixels, so blacks are inherently ‘blacker’ than in LCD Samsung TVs, Sony TVs or Sharp TVs – the phenomenon of leakage in LCDs is model-independent. However, there are some big drawbacks to buying televisions that use plasma technology.

The Lurks of Plasma Technology

If picture quality is high on your list of must-haves for buying televisions, plasma will be a major contender in the race for your TV dollar. There are plenty of other considerations to be made before buying, though:

• The technology is not inherently perfect. Lower-priced sets are almost invariably much lower quality.
• Plasmas are subject to screen burn-in, so if you watch one channel consistently you might get a ghosted version of their watermark while watching other channels.
• The brightness starts to diminish from the moment you turn the screen on. The half-life of the screen is around 10,000 hours, so after three years of average viewing the plasma screen will be down to half its original brightness.
• Early models of cheap plasmas have a screen resolution around 30% lower than cathode ray tube sets
• If you consistently watch television in a brightly lit room, the display resolution drops enormously – to a level where an old cathode ray tube set would be classed as irreparably faulty.
• The power consumption compared to a similarly sized LCD screen is huge – around double the figures for LCD in most cases. This quirk of plasma technology has led the EU to consider banning the technology, and Australia is said to be considering it also. While early indications are that the market will be left to its own devices to sort out what consumers want, the fact that legislative action is being considered should act as, at least, a warning to potential purchasers!

LCD televisions are cheaper, more reliable and durable, more future-ready, and take less energy both to run and to manufacture than plasmas do – although contrast ratio and colour saturation shows definite improvements in plasma televisions. If you are buying a television and looking for a good all-rounder, go for an LCD; if you are willing to sacrifice long-term quality and quite a few dollars for better colour and contrast, plasma should be your choice.

The Lurks and Perks of LCD TVs

LCD televisions, despite having a display type with inherent scientific difficulties, have risen to become the market leader in the multimedia world. Buying televisions always engenders a debate about whether ‘to LCD, or not to LCD … that is the question’! Today we are exploring exactly what makes LCD televisions ‘tick’, and whether the display technology will be the right one for your viewing preferences.

How do LCD televisions work?

LCD stands for Liquid Crystal Display; the display panel on an LCD TV uses a film of crystals in a viscous liquid, with light either travelling through them or being blocked, to display an image. It is the same technology (although at a completely different level) as is used in your alarm clock.

An LCD TV panel uses two sheets of polarising plastic filters, with a layer of electrically sensitive liquid crystal in between. When voltage is applied to a pixel, the crystals turn on an angle. The polarised light travelling from the backlight cannot pass through pixels that are polarised at right angles to the light, so a ‘switched-off’ pixel is effectively created. Red, blue and green filters are included, to show the full range of light colours.

The Perks of LCD technology

LCD technology has one big inherent advantage – that is its cost effectiveness in manufacturing. Every LCD television screen is cut from a single large sheet of liquid crystal display that has been pre-engineered. With every manufacturing generation, processes are improved to make larger and larger single sheets, improving cost effectiveness. Other factors that make LCD technology preferable to either plasma, DLP rear projection televisions or cathode ray sets include:

• The screen is made from plastic rather than glass, so is lighter and less fragile
• Screen burn-in is not an issue
• Edge definition for pixels is much better that in the glowing phosphor dots used by plasma technology – so pictures are much sharper.

Green credentials are a big part of the reason that many consumers buy LCD televisions. While the energy consumption differences between brands are relatively small, the difference between technologies is significant. Both plasma and cathode ray sets use around twice as much power as an LCD screen of similar size. It seems that with the cost efficiencies of LCD TVs, researchers will be spending much more time improving the technology – so LCD is the way of the future. It is inherently HD ready, cheap, light, durable, offers great definition and uses less power than other types.

The Lurks of LCD Technology

LCD televisions do have their drawbacks, which is the reason that plasma, rear projection and cathode ray televisions continue to be sold. A flaw inherent in the technology is that sometimes the backlight can bleed through switched off pixels, and contrast ratio suffers. The good news is that the way you use your television makes much more of a difference to the perceived contrast ratio than the manufacturer’s specifications do. Sitting at an optimal viewing angle and removing external light sources when you watch your television will a big difference to your viewing experience.

Colour saturation is less potent in LCD televisions than in plasmas, however depending on your preference, the improved picture ‘sharpness’ that LCD Samsung TVs, Sharp TVs and Sony TVs have may make up for this in your perception of picture quality. Most of the drawbacks of LCD televisions are easy to compensate for – it is only picture quality enthusiasts that usually consider more expensive, fragile, power hungry plasma or rear projection sets.