by Kenny Hemphill
LCD vs. plasma HDTV - which is best? If you're looking for a flat-screen, slim and sexy display, to watch HDTV, you have a choice of two technologies, LCD and gas plasma.
Each has benefits and disadvantages and so each is more appropriate in specific circumstances.
Historically, the LCD vs. plasma HDTV choice has been fairly simple. If you wanted a flat-screen that was about 40in or bigger, you had to choose plasma, otherwise you should choose LCD. However, as LCD technology improves, LCD
HDTV's are getting bigger and most of the major manufacturers expect the number of LCD's they produce to grow steadily over the next few years while the number of plasmas will decrease. However, if
you're looking for a flat screen TV today, plasma still has a lot to offer.
To understand the LCD vs. plasma HDTV question, we need to look at the way the two technologies work.
LCD
LCD HDTV's work by shining a light behind an LCD panel made up of a fixed number of pixels. Each pixel is either red, blue or green and is switched on or off when a voltage is applied to it. When voltage is applied to a pixel, it is switched off, meaning that light cant shine through it.
The main advantage of LCD vs. plasma HDTV is that LCD panels don't suffer from
what's called burn-in. This is a feature of plasma TVs where they are used to watch TV stations with logos permanently displayed on-screen or where they are used for video gaming with games that have static images such as a cockpit on flight simulators. The image literally burns-in the screen meaning that even when the image is not present you can still see a faint trace of it on screen. So for video gamers in particular, LCD is a better choice than plasma.
Plasma
Plasma HDTV's have over a million chambers which house one or a combination of gasses. When a voltage is applied to one of these chambers the gas ionizes and emits ultra-violet light. This light strikes red, green or
blue phosphors coated on the inside of the chamber and a pixel emits this color light.
Plasma HDTV's tend to have better contrast than LCD's because, even when a pixel on an LCD panel is switched off it
doesn't block all the light coming through and therefore the pixel isn't completely black. Plasma
HDTV's also tend to have a wider viewing angle than LCD's, as on LCD HDTV's the contrast and
color of the image can change when the screen is viewed from different angles.
LCD vs. Plasma HDTV conclusion
Technology is changing rapidly, but for now (July 2004) its still true to say that at sizes of 40in and above, plasma offers a less-expensive and generally better solution. For screen-sizes less than 40in LCD is better. However, as LCD technology improves and prices fall, this will change.
Kenny Hemphill is the editor and publisher of
The HDTV Tuner - a guide to the kit, the technology and the programming on HDTV.