Home >> 8 ways to buy a plasma / LCD screen >> Step 1
Introduction to Plasma TV technology
This first step is a brief guide about plasma technology starting with the history and leading into the main benefits and advantages of plasma technology.
If you are already familiar with this information or would prefer to skip it for now, you can follow the link at the bottom of the page to the next section, which discusses which size screen you should consider for your application.
A Bit of plasma history
Plasma screens first entered the US market towards the end of 1999, but the concept has been around since July of 1964 at the University of Illinois. The first displays were nothing more than points of light created in laboratory experiments. The technology was developed and improved, and by the late 60's, it had become advanced enough to allow the scientists to construct geometric shapes.
Today the progression in high speed digital processing, materials, and advanced manufacturing technology has made full color, bright plasma displays possible.
Digital television is now a reality -- but you're not going to see it the way it was meant to be seen using yesterday's TV sets. Today, we're in the midst of a digital video revolution, thanks to HDTV, DTV, DVD-Video, digital satellite broadcasts and computer video. Plasma display technology is one way to fully enjoy the dramatically improved image quality of all these digital video sources.
Some of excellent advantages of plasma technology include:
Higher resolution
Plasma display devices have higher resolution than most conventional TV sets, and are capable of displaying full HDTV and DTV signals as well as XGA, SVGA and VGA signals from a computer. For example, a plasma display with a 1024 x 1024 pixel resolution can display images from 1080i and 720p HDTV resolution, as well as 480i and 480p HD signals.
No scan lines
Plasma screens have no scan lines due to the fact that each and every pixel cell has its own transistor electrode. This creates a smooth evenly lit image across the entire surface of the display. Most current plasma displays also include built-in line doubling to improve image quality from low resolution video signals. Conventional CRTs use an electron beam to scan the picture tube from top to bottom at regular intervals, lighting the phosphors to create the image. With standard (NTSC) TV, visible scan lines can be seen.
Exceptional color accuracy
High-end plasma displays are capable of displaying 16.77 million colors -- providing superb color realism with exceptionally subtle gradations between colors. Color saturation is one of the most poignant factors elevating plasma screens over other display technologies.
Widescreen aspect ratio
Plasma display devices have a widescreen 16:9 aspect ratio, which states the dimensional relationship between the screen's width and height. This is the proper aspect ratio for HDTV viewing, and is also the best aspect for DVD replay. What happens when viewing a regular TV or computer image? Does the image look stretched? There are several aspect ratios which plasma displays use to size the incoming video image. All plasma screens can show the image in its original 4:3 format with bars (either black or gray) on the sides of the image. There can be some variation among plasma screens in how well they convert a 4:3 image to the widescreen monitor. Manufacturing engineers accomplish a best of all worlds approach by limiting the stretching in the center of the screen and also by enlarging the entire image size to larger than the screen size. This scaling technique allows the most stretching to be located on the sides of the image thus reducing visible distortion.
So the answer to the question is that a viewer may watch the image on the plasma screen in a variety of ways when displaying an incoming "normal" or 4:3 picture image from satellite, VCR, or cable TV. It can be displayed as is with the bars on the sides. In Zoom mode the image will have very little distortion or stretching and will fill the entire screen area. However, this mode usually is not favorable because it cuts off too much of the picture image and also because it causes motion artifacts and pixelation, or grainy appearance. The 16:9 aspect option will not be the preferred method of converting a 4:3 image because it will be the most visibly stretched and distorted of all the options.
The best option for converting a 4:3 NTSC TV signal to the widescreen monitor is the "just" or "full" mode. Each manufacturer calls this mode something different. This aspect ratio option converts the 4:3 image with specially designed algorithms, which reduce the visible "stretching" as much as possible by using a combination of techniques. The end result is that the viewer will get passable performance and be able to enjoy the full screen dimension of the plasma display. This is accomplished by slightly enlarging the picture past the actual viewing area of the plasma panel while keeping the center of the picture more accurate. The sides of the image will appear slightly more distorted and stretched but the overall result is acceptable for long and short-term viewing. Much will depend upon what the viewer is watching. When I watch sports such as football or golf, I prefer to watch the original 4:3 format to see the most accurate production possible. When watching movies or sitcoms or the news, I watch the converted full screen mode. Of course, HDTV is shown in widescreen, which gives the widescreen format an advantage on future viewing.
Perfectly flat screen
Plasma display monitors have screens that are perfectly flat, with no curvature whatsoever. This eliminates the edge distortion that can occur in CRT displays and also assists in allowing the wide viewing angles. The plasma display element (glass) is most often protected by an antiglare Plexiglas layer.
Uniform screen brightness
Unlike some rear and front projection televisions that suffer from uneven screen brightness -- seen as "hot spots" in the middle of the screen or a darkening near the edges and especially corners -- plasma displays illuminate all pixels evenly across the screen. This gives plasma displays their "smooth" appearance.
Slim, space-saving design
Plasma display monitors are only a few inches in depth, providing installation options never before possible. Depth is usually measured at around 3.5 inches on 42" displays and 4" for 50" screens. In addition to stand mounting, they can be hung on a wall or from a ceiling, allowing you to enjoy big-screen impact from a component that doesn't dominate floor space. Conventional CRT's, DLP TVs, and rear projection TVs take up far more space and are much more limited in placement flexibility.
Plasma monitors are constructed with a chassis that's not much wider than the actual display screen, giving the monitors an elegant, understated "picture frame" appearance that blends inconspicuously with any décor.
Because they eliminate the need for a front projection unit and a projection screen, plasma display monitors are also ideal for use in a wide variety of business and commercial applications where the use of a front projector would not be feasible.
Wide viewing angle
Plasma displays offer a viewing angle of 160 degrees (top to bottom and left to right) -- much better than rear projection TVs and LCD displays. This allows a larger number of viewers to enjoy proper image reproduction from a wider variety of locations throughout the room.
Universal display capability
Most plasma monitors can accept any video format. Typically, they will include composite video, S-video and component video inputs, plus one or more RGB inputs to accept the video input from a computer. The composite video inputs are NTSC, PAL, and SECAM compatible, and are equipped with standard RCA or BNC jacks.
Immunity from magnetic fields
Components such as loudspeakers that contain strong magnets can distort the picture if placed too close a standard TV. However, because plasma displays do not use electron beams, as conventional CRT displays do, they are immune to the effects of magnetic fields. Plasma displays can be placed in close proximity to any type of loudspeaker and not experience image distortion. This is also the case when crossing into the Southern Hemisphere. Boats may use plasma displays as they are not sensitive the earth's magnetic fields.
