One of the most frequent questions customers ask is ‘what’s the difference between plasma and LCD TV ? …which one is best?’
What’s the difference?
Plasma and LCD Television panels represent two different technologies for producing a picture.
A plasma screen is basically made up of two panels of glass with an inert gas sealed between them. Plasma refers to the ionised state of the gas when an electrical current is passed through it. The technology for producing an image is similar to conventional CRT televisions in that each of the plasma cells contain a layer of phosphors which glow a certain colour when a current is applied. Plasma screens are only manufactured at sizes of 37” or above (most common 42 or 50”). Contrary to many rumours, the gas in plasma panels does not have to be re-charged after a few years!
An LCD screen contains a thin liquid crystal layer in front of a single fluorescent backlight which ‘powers’ the whole picture. Each individual crystal is switched on or off electronically to control amount of light/colour passing through to outer surface.
LCD TV screens can be manufactured at much smaller sizes than plasma and generally range in size from 15” up to 60” (although not yet common above 40”)
The Pro’s and con’s of each technology
There are a number of factors to consider when comparing panels and judging picture quality.
Individual liquid crystal pixels are physically smaller than plasma cells – therefore more lines of pixel resolution can be manufactured into an LCD panel. To achieve a true high definition picture of 1080 lines of resolution, a plasma panel of at least 50” is currently required. For LCD this can be achieved in smaller sizes. herefore LCD panels typically have a higher resolution specification and images tend to look more detailed and crisp. LCD are also better at showing detailed pictures/text from computers.
Black level response:
For the full impact of films or programmes a TV should be able to differentiate between a wide range of shades of black. These are generally better for plasma than LCD due to the fact that an LCD has to block out all illumination from the backlight to achieve a black pixel. For a plasma display a pixel is made black simply by switching off current to individual pixel.
The contrast ratio reflects the brightness of the lightest and darkest colours a TV can produce simultaneously. LCD panels tend to provide a brighter image than plasma due to the presence of a strong backlight. This should be considered in bright rooms such as conservatories.
Plasma cells are able to produce a wider range of colours than LCD and colours on plasma screens appear more saturated and natural in tone especially with skin.
Fast moving images tend to look sharper on a plasma panel than LCD. This is due to the response time of LCD – the amount of time taken for a liquid crystal cell to adjust its light output in response to changes in the picture content. The corresponding refresh rate of a plasma panel is faster and therefore LCDs are more prone to picture smearing/blurring.
Phosphors in plasma panels can become ‘tired’ by extended exposure to a static bright image displayed on the screen (eg. channel logo/text). This may result in a shadow of image being ‘burned’ onto screen even after you change channel. LCDs are not affected by this problem.
Price, weight, power consumption and reliability:
Although some differences exist at certain sizes, these factors are now reasonably similar for both technologies