Friday, September 12, 2008

What is Flat Screen Plasma Technology?

Flat panel plasma display is the latest display technology and the best way to achieve displays with excellent image quality and large, flat screen sizes that are easily viewable in any environment. Plasma panels are an array of cells, known as pixels, which are composed of three sub pixels, corresponding to the colors red, green, and blue. Gas in the plasma state is used to react with phosphors in each sub pixel to produce colored light (red, green, or blue). These phosphors are the same types used in cathode ray tube (CRT) devices such as televisions and standard computer monitors. You get the rich dynamic colors that you expect. Each sub pixel is individually controlled by advanced electronics to produce over 16 million different colors. All of this means that you get perfect images that are easily viewable in a display that is less than six inches thick.

Superior Performance

With flat panel plasma screens, in addition to bright, crisp images, there are other advantages. Unlike projection screens, which are designed to concentrate reflection to a narrow viewing area for brightness, plasma screens permit an exceptionally broad viewing angle -- over 160 degrees. This means that no matter where audience members are in the room, the brightness and clarity come through. And unlike conventional television screens, plasma panels are absolutely flat. This reduces glare and permits viewers to see the entirety of the screen from a broader perspective. Since panels are backlit rather than reflective (as in projection), they perform exceptionally well in bright environments.

Versatile and Ready

Plasma panels are available in a variety of configurations. Along with varying resolutions, panels come in two aspect ratios: 4:3 and 16:9. 4:3 ratio is the same as conventional televisions and computer monitors. Where, as is the case with current broadcast standards, the media has been formatted for these devices, 4:3 ratio delivers a quality picture that fills the entire screen. Presentations that have been prepared on conventional monitors will appear as they did on the original authoring platform, completely filling the screen. There is an exception in SXGA (1280 x 1024) resolutions, where the actual aspect ratio is 5:4, due to legacy issues of that pixel count.

In the 16:9 ratio, plasma panels are capable of delivering wide-screen media without "letterboxing" or blanking of parts of the screen. Wide screen panels are typically capable of higher resolution in data modes and capable of displaying wide screen video formats such as HDTV. What's more, 16:9 panels are also capable of displaying media prepared for traditional 4:3 screens via letterboxing. With video cards available from Plasma-USA, users can take advantage of the larger perspective by preparing presentations and other media for wide-screen showing.

A Note About DTV and HDTV

On April 4, 1997, the FCC ushered in digital television (DTV) by giving 6MHz of spectrum to approximately 1,500 stations for DTV broadcasting. The decree required the three commercial networks in the top ten markets to broadcast digitally by May 1, 1999, with markets 11 through 30 online by November 1, 1999. All stations must broadcast digitally by 2006, when their current analog spectrum is scheduled to revert back to the Fed.

While there is only one standard, there are 18 different video formats. The first split is between high definition and standard definition TV. Six of the video formats in the ATSC DTV standard are high definition TV: these are the 1080-line by 1920-pixel formats at 24 and 30 frames per second (1080i) , and at 60 fields per second for interlaced HDTV, and the 720-line by 1280-pixel formats at 24, 30 and 60 fps (720p). The HDTV formats have a 16:9 aspect ratio.

The 12 video formats which compose the remainder are standard definition television -- not high definition. These consist of the 480-line by 704-pixel formats in 16:9 wide screen and 4:3 aspect ratios (at the 24, 30 and 60 pictures per second rates); and the 480-line by 640-pixel format at a 4:3 aspect ratio at the same picture rates.

The formats which represent HDTV are 1020i and 720p. The "i" and the "p" in the format names refer to interlaced and progressive scanning. In interlaced scanning, half of the lines in a full frame are scanned onto the screen in a sixtieth of a second, followed by the remaining half of the scan lines in the next sixtieth. The odd lines are scanned first, then filled in by the even lines.

In an attempt to meet expectations, many plasma manufacturers are building both standards into their units. For a quick comparison of the HDTV readiness, refer to our buyer's guide.

Aspect ratios explained
Plasma screens are mainly available in one of the two aspect ratios below:

  • 4:3 aspect ratio - This is the same shape screen as a computer monitor or non-wide screen television. The width of the screen being 4 parts long and 3 parts high.
  • 16:9 aspect ratio - This is the 'wide screen' television screen shape. The width of the screen being 16 parts long and 9 parts high.

Connection to equipment

  • 42" and 50" plasma screens from any manufacturer can be connected to a computer and a video source such as a video recorder, TV, DVD player or satellite system. If, for example, you connect the plasma screen to a video recorder and a computer, you can then use the remote control to switch between the two as required. This can be very useful for presentations/training/induction's where you need to use presentation software such as PowerPoint but also show a video in the middle.

LCD monitors versus plasma screens

  • LCD monitors are very thin flat screen computer monitors. They range from around 12 to 20 inches in size and come in two sorts: computer LCD monitors and video LCD monitors. LCD technology limits the maximum size of the display. Plasma screens use a different technology and can therefore have sizes over 60 inches.
  • Plasma screens have a viewing angle of 160 degrees, which in plain English means that if you look at it from the side, you see a good clear image. LCD screens vary in quality but most do not give a good image unless you look straight at them. They is very noticeable on notebook computer screens.
  • Plasma technology is also unaffected by magnetic fields unlike CRT technology used in normal computer monitors.

What sizes do plasma screens come in?
Currently, these are:

  • 21" 4:3 aspect ratio
  • 25" 4:3 aspect ratio
  • 33" 4:3 aspect ratio
  • 37" 4:3 aspect ratio
  • 40" 4:3 aspect ratio
  • 42" 16:9 aspect ratio (wide screen) - Most Popular size
  • 50" 16:9 aspect ratio (wide screen) - Widely Accepted size
  • 60"/61" plasma screens now on the market.


  • Some Plasma screens have built-in speakers for a limited volume output from either your computer or video. Most also have speakers that can be attached to the plasma screen to increase this volume and give better quality sound. These are optional extras at additional cost.

Apple Macintosh computers and UNIX workstations

  • Plasma screens will work with PC's, Apple Macintosh computers and UNIX workstations. With some Apple computers, you will need a small device called a MAC adapter costing around £10 to connect to the plasma screen. These are supplied as standard on some screens but not all.

Lifespan of plasma screens

  • This varies considerably between manufacturers but usually from 20,000 to 30,000 hours. After this time the plasma screen will only be at around half the original brightness. 20,000 hours is 833 days or 2.3 years of continuous 24-hour use. At the end of the plasma screen's life, the screen will be very dull and you will need to replace the plasma screen with a new one. This is one advantage plasma screens have over LCD projectors which have a bulb life of usually 2,000 hours before replacement.

The distance that plasma screens can be from the computer

  • All plasma screens come supplied with a cable that connects into the monitor port (or external monitor port on notebooks) to display the computer's image. These are normally around two meters in length. You can purchase longer cables up to ten meters in length so that you can position the computer further away.
  • 30'-35' is the maximum distance that the computer's signal will travel without the picture being degraded with loss of image quality. There are devices on the market that can be used to extend this distance:
  • Booster boxes and extra cabling to extend the distance between the computer and plasma screen

Scan converters

  • Some plasma screens are only made to display a low resolution, for example 640 x 480 pixels. A scan converter will take a larger resolution, for example 800 x 600 pixels, from a computer and then output to the plasma screen at the lower resolution (640 x 480). It does this using a technique called 'compression' which will miss-out some of the lines from the original image in order to display a picture.
  • Scan converters to turn the computer signal into an RGB signal that will travel long distances on RGB cabling. This is turning the digital computer output into a video signal so that it will travel further distances to the plasma screen.
  • Many 42" and 50" plasma screens have a built-in scan converter. This is how a 852 x 480 pixel 42" screen can display an XGA image, i.e. one made up of 1024 x 768 pixels. Some quality and detail is lost by using scan converters.

Brightness and contrast ratio

  • Plasma screen brightness is measured in candelas. Plasma screens generally range from 50 to 550 candelas. 250 candelas is television level brightness.
  • The contrast ratio is the difference in definition between the colors black and white when displayed on screen. The higher the number the better the definition.

Using plasma screens with more than one computer

  • In a conference/board room setting, users with notebooks can simply take it in turns to connect the plasma screen cable into the external monitor ports on their notebook computers. You can also purchase switch boxes that allow several computers to connect to a plasma screen at once. On the switch box is a button for each input computer, which when pressed, will show that computer's picture on the plasma screen.

TV tuners

  • Very few screens have a built-in TV tuner which allows the plasma screen to act as a normal television by picking up terrestrial TV channels and also Teletext. The Universal 42" plasma screen and the Philips Flat Screen television both have this feature as standard. Optional television tuners are available from other manufacturers.

Split screen plasma screens

  • Some plasma screens have split-screen and picture-in-picture functions. This can be very useful in public areas as you can display information on one side and display adverts on the other side. This can be even used to generate a revenue from advertising. Universal 42" and 50" screens are the only ones currently available with the split screen feature and picture in picture. Eizo produce a 50" plasma screen with picture in picture but this is limited to 3 set sizes. You can use these features with 1 computer and 1 video input or 2 video inputs at the same time without additional hardware.

Can I use a plasma screen without a computer or video recorder?

  • You can think about a plasma screen as the same an a computer monitor. If the computer is not attached then nothing is displayed.
  • However, some older discontinued plasma screens, for example the Fujitsu PDS-4204, had a built-in PCMCIA card slot feature. This allowed you to download still images from a PC to an PCMCIA card (a credit card sized memory card) and insert this card into the plasma screen. The screen would then display still images (without sound).


  • If you are planning to mount the plasma screen on a wall and you do not want cables going to a desktop computer, you can purchases mini-computers that will sit in the very small gap between the wall mount bracket and the plasma screen.

Connecting to plasma screens by telephone and modem

  • You may need to update the images displayed on a plasma screen remotely. For example, if the plasma screen is used as an advertising board in a shopping center. You will need:
  • A computer attached to the plasma screen
  • A modem attached to the computer
  • A dedicated telephone line that you can dial into
  • 2 copies of remote control software such as PC-Duo. PC-Duo is loaded on the plasma screen computer and sit waiting for you to dial into it by modem (can be password protected). You then take control of the plasma screen PC so that you see what's on the plasma screen and can change what is displayed or fix any problems.

Video walls

  • Plasma screens can be connected together to display a single image as a video wall. You then have the option of:
  • Displaying a huge single image between all the screens on the wall
  • Displaying the same image on all the component screens
  • Displaying a different image on each screen
  • You will need a control box to connect all the screens together. Some plasma screens also come with the hardware to do this built-in so that you can connect several of them together as an instant video wall. The NEC 50PD1 and 42PD2 screens have this feature. You can buy 2 or 4 screen mounting brackets to connect the screens together into the video wall. The Eizo 50" screen also has this feature.

Class A and Class B plasma screens

  • Electromagnetic wave standard Class B is required for the home market all over the world. Class A is for standard commercial use.

Home cinema

  • Plasma screens are very impressive mounted on a wall for use as a television screen or for watching movies. Most plasma screens do not have built-in tuners to pick up television signals so you need to connect them to your video recorder or satellite system. You need to purchase a plasma screen that is class B (see above).

Plasma screen inputs

  • You will need to see the specification sheet of each plasma screen for its inputs. See the manufacturers section. They usually have several different types of video input and a cable to plug directly into a computer.


  • Most plasma screens are supplied without any type of stand. The stands are available at extra cost, but you will need to purchase one of them.
  • Ceiling-mount Bracket
    Normally fully adjustable so that you can possible a plasma screen with ease. Double sided ones are available to mount 2 screens.
  • Desk Top Stand
    These are ideal for exhibitions or on top of boardroom tables.


  • Most plasma screens have built-in speakers. The optional speakers attach to the side of the screen to increase maximum volume.

Speaker Stands

  • For use with optional speakers (see above) for table top use.

Wall-mounting Bracket

  • These allow the screen a small amount of tilt up and down. Some can even be adjusted left or right.

Flight Case

  • This is an expensive extra which is designed to fully protect plasma's during shipping. Most screens arrive in cardboard boxes. Flight cases are ideal for hire companies.

Wide screen 16:9 aspect ratio

  • Normal computer graphics cards output in a 4:3 aspect ratio, e.g. 800 x 600. These cards can be used to output in a 16:9 aspect ratio, for example 852 x 480. This is only necessary for exact pixel by pixel control of the screen. Screens will automatically display normal computer images without problem.