Electronic Devices: How Plasma Displays Work

Explanation of new developing technology for televisions and moniters that use plasma to enhance color, reduce size and improve the viewing experience.

Through the years, the simple television set has evolved into what many call "˜home theater systems'. Large and bulky, the majority of these new systems are cumbersome to move and take up a sizeable portion of room, discouraging small home owners from making such a purchase. In recent years, however, the plasma display has arrived on the market and has revolutionized the way we view our television sets. A far cry from the boxy, cumbersome screens that we are used to, the plasma display actually conserves space, as well as providing a more modern, hi-tech appearance that looks elegant in any room. How does such a thin plasma display work, and how does it add up to the conventional screens that we"˜re used to? Read on, to learn more about the wonderful workings of plasma displays!

For about 75 years now, television sets have operated on the same basic system, using a cathode ray tube or CRT. While these CRT sets give off vibrant, clear pictures, they have always had the downfall of being bulky. In order to increase the size of the viewing screen, manufacturers were forced to increase the length of the tube, only serving to make the televisions sets larger and more awkward. Plasma displays allow for wide screens that are comparable to the largest CRT sets, but are only about 6 inches thick. Unfortunately, plasma displays are merely monitors, lacking the television tuners; one must always keep in mind that some form of tuner, be it a VCR or a cable box, will have to be used in addition to the plasma display.

CRT sets receive information from television signals, a high-energy beam of electrons then used to light up thousands of pixels to produce your picture. Plasma monitors work on the concept that each individual pixel contains three florescent sub-cells; one blue, one green and one red. By illuminating these three cells with lights of varying intensities, plasma displays are able to produce more than 16 million different colors, allowing for a full color spectrum and graduating shades that rival that of the CRT sets! Also, due to the fact that plasma displays operate without the use of the high-energy electron beams, they suffer fewer problems, from magnetic fields, than their larger counterparts.

Plasma, the principal component in florescent lighting, is a gas made from an equal number of free-flowing ions and electrons. When electrical current is introduced to this plasma, the particles within the gas begin to move rapidly, bumping into one another. These produce ultraviolet photons, which are invisible to the human eye, but assist in creating visible light photons.

Within a plasma display, electrodes are placed in a horizontal and vertical pattern, forming a grid which sandwiches hundreds of thousands of tiny cells between two plates of glass. This grid allows the display's computer to then send currents through the grid rapidly, charging each individual cell thousands of times in less than a second. These cells, filled with xenon and neon gas, then produce ultraviolet photons which react with a phosphor material that coats each cell; the phosphor material reacting and producing light when another form of light hits it.

Varying the pulses of electrical current through each of these cells, and thereby illuminating the colored sub-cells within, the plasma display is able to create a variety of green, blue and red shades. These varied shades, when combined, produce the vast array of colors that plasma displays are capable of. Another perk is that, due to the fact that each cell is charged individually, there are no scan lines, as commonly seen on television sets.

Designed with a 16:9 aspect ratio (width, in relation to height), plasma displays are ideal for viewing HDTV programming as well as being the optimal dimensions for ideal DVD playback (wide screen or commonly known as letterbox). While standard television 4:3 programming can also be viewed on plasma displays, they can be viewed in their intended format with black bars on either side of the picture, or viewed to fit the screen. Fortunately, plasma displays are formatted so that the majority of image stretching, in such cases, occurs at the sides. This means there is minimal picture distortion in the main section of screen and, due to the Plexiglas protective covering that is usually present on the fronts, they are designed to cut glare substantially. Additionally, plasma display units are manufactured with flat screens, as opposed to the curved screens of CRT sets, enabling a far better viewing area!

In the past, keeping speakers or other objects that contained strong magnets near television sets would cause disruption or distortion of the picture. Plasma display units are immune to the effects of magnetic fields, since they do not use high energy beams to illuminate the pixels, and can now be used with loud speakers. Also convenient for boating, plasma displays are unaffected by the magnetic field of the earth and can, therefore, be viewed even when crossing into different hemispheres.

Naturally, the cost of plasma displays are more than CRT sets, but as technology continues to advance, they become more and more affordable. Offering superior viewing capabilities, with the ability to save space, the plasma display unit is quickly becoming the upscale television for tomorrow.

© High Speed Ventures 2011