Saturday, January 12, 2008

LCD vs Plasma television

Anyone who is currently thinking about buying a flat panel television at the moment will probably be thinking about whether to buy an LCD television or a plasma television. The LCD vs Plasma debate shows no sign of going away any time soon. This article aims to explain the main differences between the two technologies and clear up any confusion.

Visually, LCD and Plasma televisions look very much alike. Both are variants of the flat panel genre, both are slim and both take up very little space compared with their traditional CRT relatives. But that's as far as the similarities go. Under the bonnet the technology driving LCD tvs is very different from that driving Plasma tvs.


A plasma display consists of two plates of glass, sandwiched between which are hundreds of thousands of tiny, gas filled cells. These cells are rather like tiny flourescent tubes as they are filled with neon gas and coated with phosphor.

Each plasma cell can be individually energised with an electric current. This causes the gas to release ultraviolet photons. These photons cause the phosphor coating of the cell to radiate visible light. If the cells are switched on and off in the correct sequence, the picture is formed. This switching happens 1000s of times a second.

These gas filled cells form the pixels of the display. In fact, each pixel consists of 3 cells, giving off red, green or blue light. By varying the relative intensities of red, green and blue, different colours are formed.


The pixels of an LCD TV dislay, unlike those of a Plasma display, do not give off any light themselves. A liquid crystal solution is trapped between two sheets of glass and the whole display is illuninated with a back light. The voltages applied to the various pixels is varied and this controls how much light from the back light reaches the screen. In turn, the pattern of light reaching the screen forms the picture.

Whis is better - LCD vs Plasma?

Traditionally, Plasma tvs have had the edge over LCD tvs, particularly at larger screen sizes. This difference is diminishing all the time, however, as LCD technology moves forwards. Prices are generally coming down and the price difference between the two is getting less. Performance-wise the difference is diminishing too. There is a slight issue regarding LCD tvs not displaying deep blacks as well as Plasma, but in general use this difference is becoming negligible.

Dave Cassidy is a staff writer at For more information on LCD and Plasma tvs, see LCD vs Plasma.

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