Flat Panel Televisions

Flat panel televisions are produced by two different technologies, each with its advantages and disadvantages. Plasma technology is gas-based, somewhat like a fluorescent light bulb. The screen is made up of many, many tiny cells, each consisting of two glass panels. Neon-xenon gas is sealed inside the panels. When the gas is electrically charged, it strikes a red, green or blue phosphor. (Each group of red, green and blue phosphors is called a pixel, or picture element.) The phosphor burns, giving off colored light and thus generating the face of your favorite sitcom star.

Liquid Crystal Display or LCD screens are made up of two panels of polarized transparent materials which are bonded together. One layer holds the liquid crystals suspended in a polymer. When a current is passed through the individual crystals, they do not produce light themselves, but block or transmit light from an external source such as a fluorescent bulb. Since the crystals themselves don't produce light, this type of screen generates less heat and virtually no radiation.

Advantages and Disadvantages

Plasma screens, which are significantly more expensive than LCDs, come in larger sizes and have better definition and color accuracy. They are also better at tracking fast-moving images without lag or ghosts. One disadvantage is that the phosphors have a tendency to burn images onto the screen if they are too static. Plasma screens run hotter, necessitating a sometimes noisy cooling fan, and they do not work well at high altitudes.

LCD screens have no burn-in problem, no need for a cooling fan, and no altitude problems. They also last a lot longer, and in standard sizes are less expensive. However, those standard sizes don't run larger than about 37 inches. The display is less visible at side angles than a plasma screen, and they are not capable of the deep saturation plasma provides.