Most shops have now stopped selling tube based TV’s and as such when your current TV breaks and you want to replace it you are going to be left with the choice of two different types of technology that are on sale in mainstream retailers.  Then to add further confusion there are some “other” technologies that are just emerging onto the market to enhance your viewing pleasure.

LCD (Liquid Crystal Display).  In a LCD TV, liquid crystals are sandwiched between two transparent electrodes and two polarizing filters. Two grids of electrodes (one is horizontally aligned and another is vertically aligned) contact either side of the crystals. The job of this network of electrodes is to access each pixel of the crystal layer and control the electric flow.

A backlight device made of fluorescent lamps diffused by a white panel, passes through the liquid crystals. This white panel ensures that the entire surface of the screen gets uniform brightness. The front panel of LCD is made up of a grid of wires which are in contact with each pixel of the screen and activate it separately.  Some manufacturers have now opted to use LED instead of fluorescent lamps.  This has resulted in thinner, lighter more energy efficient TV’s.

With in network of crystals, each molecule functions like a gate to open or close the passage of light through them depending on the voltage of the current. To produce bright display, the voltage is kept low while for dark details the voltage is increased. By nature, liquid crystals always allow a smaller amount of light to pass through them making the pure black levels somewhat impossible.

Pros

• Slim profile
• Lighter and less bulky than rear-projection televisions
• Can be viewed from almost any angle, upto 170 degrees
• Less expensive than Plasma
• LED Backlit versions are very energy efficient, Light and slim

Cons

• Some models do not perform well with fast moving footage due to slow response times.
• Colours sometimes appear washed out.
• Generally do not come in sizes larger than 46 inches

Some top rated LCD TV’s from Sony, Samsung (LED Backlit) and Panasonic

Plasma.  Plasma screens are made up of tiny red, green and blue pixels which sit in front of Xenon & Neon gas filled chambers.  At the front of each chamber are phosphors, and at the rear an electrical source.  The electrical source ionises the gases which excite the phosphors which generate the light through the pixels giving you a picture made up from all the pixels.

Pros

• Slim profile
• Lighter and less bulky than rear-projection televisions
• Achieves better colour reproduction than LCDs, Upto 68 billion Colours
• Produces deep, true blacks allowing for superior contrast ratios
• Faster response times make Plasmas ideal for fast motion video
• Can be viewed from almost any angle, upto 170 degrees

Cons

• Susceptible to Screen burn-in and image retention (however newer models have built-in technologies to prevent this such as pixel shifting)
• Susceptible to “large area flicker”
• Generally do not come in sizes smaller than 32 inches
• Susceptible to reflection glare in bright rooms
• Heavier than LCD due to the requirement of a glass screen to hold the gases
• Damage to the glass screen can be permanent and far more difficult to repair than an LCD

Some top rated Plasma TV’s from Panasonic, Pioneer and Samsung.

Others…

OLED (Organic Light Emitting Diode).  Put simply is a LED covered by an emissive electroluminescent layer composed of a film of organic compounds.  The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple “printing” process. The resulting matrix of pixels can emit light of different colours.

OLED TV’s do not require a backlight and as such require less energy and can also be made thinner & lighter than ever before.  The technology is still very new and currently there are only a handful of screens on the market.  An example is the SonyXEL1.