Gas Plasma Displays Buying Tips

If your looking for a flat screen picture that provides excellent picture quality with low picture distortion then a plasma TV monitor maybe the solution you have been seeking. There are currently a large number of plasma tvs available on the market which can be used for a number of different applications including presentations, home video and computer uses. Below are some features that can help you differentiate between the different plasma tv models.

Plasma TV Price Range
Plasma TVs currently start around $1500+ for a 42" screen and the price rises to over $7,000 for a 61" screen. Expect to pay about $1000-$2000 more for a plasma monitor of 50" over a plasma screen of 42". While expensive, plasma displays are quickly becoming the American viewers choice because of their stunning colors, excellent brilliance, and placement flexibility.

Screen Size
The majority of plasma TVs on the market have 42" and 50" screens, though there are a couple of monitors now with 61" sizes. LCD (liquid crystal diode) monitors/TV's are sized between 10" and 55" and are very similar to plasma monitors in terms of clarity, depth, color brilliance and their conveniently flat design. The best values in plasma displays and LCD monitors will be found where there is much competition between manufacturers in one size of monitor.

Distance - How far away from the plasma should I be?
Pixel distortion or motion artifacts can occur on early generation plasma monitors when displaying an incoming signal with poor resolution (some cable channels - a signal of around 250 interlaced is generally poor). However, this "pixelating" effect is lessened by increasing viewing distance from the plasma display. With early generation models I generally viewed the proper distances as 8 to 12ft. on a 42" plasma tv and 12 to 16ft. or more on a 50" plasma. Now, with the many improvements that have been made to the units, the latest 50" models can be viewed comfortably from 9ft. So it really becomes a matter of preference. I view a 42" plasma from 16ft. in my own home and it looks superb.

Aspect Ratio
Today's conventional NTSC TV signals are transmitted with an aspect ratio of 4:3 (the nearly square TV picture to which you are accustomed). All HDTV and some SDTV signals will be transmitted with an aspect ratio of 16:9 in the near future. HDTV broadcasts are delivered in the exciting, new 16:9 wide-screen format, the same aspect ratio in which movies are made. Most plasma TVs are manufactured in the widescreen 16:9 aspect ratio.This wide view lends itself to better DVD viewing because it displays the motion picture in its originally intended aspect ratio format.

Video Format Compatibility
The standard video formats are NTSC, PAL, and SECAM. Many plasma and flat screen tv models accept all three, but if you'll be playing video from Europe, pay special attention to whether the plasma TV you're considering can accept PAL and SECAM formats.

Video Signal Format
Most video devices accept composite and S-video as two types of signal transmission. Almost all plasma TVs will accept both inputs. However, there is a new standard known as component video. Some of the new DVD players offer a component video output signal in addition to composite and S-video. You will also be able to get component video signals from some satellite systems. Televisions and projectors that are equipped to handle the component video signal will produce a superior video image than those which cannot. If you are interested in optimizing video performance, and you have a video source that offers component video output, check to see which of the plasma tvs on your list are capable of accepting a component video signal. The spec sheet may say component video, or alternatively (Y, R-Y, B-Y) or YPbPr.

Audio Considerations
Several TV makers incorporate built in speakers into the plasma frame. Some offer speakers as additional options which can be attached to the side of the plasma TV. Amplification of these speakers comes through built in 7 or 8 watt amplifiers which are built in to the side of the plasma display (this is plenty of wattage for excellent audio output). Many users will want to attach speakers to the amplifiers for watching simple programming such as the news or displaying the unit in a board room or at a trade show. There are two options to consider here: 1) The user may purchase flat, slim speakers which attach to the sides of the plasma monitor, 2) The viewer may choose to use his or her own bookshelf, or satellite speakers. Small cube type speakers may also be attractively mounted on the wall beside the plasma display TV. In addition, home users will often use a sound system with surround sound or their external amplifier/receiver component. Some manufacturers of plasma TVs offer no built in amplifiers for sound. In this instance an outboard amplifier/receiver must be used.

Digital Television (SDTV & HDTV)
Digital television, or DTV, is the new industry standard for broadcasting picture and sound using digital signals, allowing for dramatic improvements in both picture and sound quality vs. conventional NTSC analog programming. DTV programming can be delivered in either of two basic formats: standard analog definition (SDTV) or high definition (HDTV).

DTV and HDTV Comparison Chart
Digital television, or DTV, is the new industry standard for broadcasting picture and sound using digital signals, allowing for dramatic improvements in both picture and sound quality vs. conventional NTSC analog programming. DTV programming can be delivered in either of two basic formats: standard analog definition (SDTV) or high definition (HDTV).


DTV Format Comparison
Transmission Type	Analog	Digital	Digital	Digital	Digital
	NTSC	Standard Definition	Standard Definition	High Definition	High Definition
Maximum Resolution	480i	480i	480p	720p	1080i
Aspect Ratio	4:3	4:3	4:3 or 16:9	16:9	16:9
Channel Capacity	1	5-6	5-6	1-2	1
Description	Standard TV as we know it today	Good Picture and Sound —DVD or DBS Quality	Better, depending on source; can be outstanding	Best Possible	Best Possible

HDTV is the highest form of digital television, delivering up to 1,080 interlaced scan lines. HDTV produces images that far surpass any you've ever seen in a home environment! SDTV, or Standard Definition, also represents a dramatic improvement over today's TV, with the added benefit of allowing stations to broadcast multiple programs within the same bandwidth as an HDTV signal.


DTV Format Detail
Scan Lines		Scan Rate	Pixelization	Frame Rate	Aspect Ratio	Formats
SDTV	525 total 480 active	15.75 kHz (60i)	480 x 640	24p, 30p, 60p or 60i fps	4:3	4
SDTV	525 total 480 active	31.5 kHz (60p)	480 x 704	24p, 30p, 60p or 60i fps	4:3 or 16:9	8 (4x2)
HDTV	750 total 720 active	45 kHz (60p)	720 x 1080	24p, 30p, 60p	16:9	3
HDTV	1125 total 1080 active	33.75 kHz (60i)	1080 x 1920	24p, 30p, 60i	16:9	3

TV Tuners
How do I input a television signal to a plasma screen display?

Plasma monitors do not come with built in tuners. Plasma TV's now do come with TV tunners. NTSC/ATSC television signal must be passed through a satellite box, cable box, HDTV receiver, VCR/VHS device, or an outboard tuning device. Most of these components offer an RF style cable input (what we think of as a cable connection). Signals are then passed to the plasma TV using the following connections:

1. From a satellite box an s-video cable is normally utilized.

2. From a cable box a composite RCA to RCA or RCA to BNC connection is used.

3. From an HDTV decoder box a 15 pin VGA to 15 pin VGA cable is normally used; though 3 cable component RCA to component RCA or BNC is also often an option.

4. From a VCR/VHS an RCA to RCA or BNC is normally used though S-video is better option if available on the VCR.

5. Optional decoders will have a mix of the above options.

How do Plasma TVs work?
Plasma technology is different from that used in other display systems in that red, green and blue lights are created in every pixel, reducing the need for space. Charged electrodes between glass panels cause tiny pockets of inert gas to change a state of plasma. This process causes UV light to be produced, which in turn reacts with the red, green, and blue phosphors in each pixel to produce visible light.

Unlike traditional displays, where the image is scanned across the screen, in plasma displays all pixels are "lit" at once. Having no electron beam, back lighting or light polarization, the image is inherently sharper and brighter. Perfect from edge to edge.

What is the plasma in plasma tvs?
An electrically neutral, highly ionized substance composed of ions, electrons, and neutral particles. Plasma contains almost equal numbers of free electrons and positive ions. In a plasma the electrons have been stripped away from the central nucleus. Therefore, a plasma consists of a sea of ions and electrons and is a very good conductor of electricity and is affected by magnetic fields. Electrons are separated from their respective nucleus when enough heat is applied

Will Plasma TVs become outdated soon?
Absolutely not. Plasma TVs are ready for the future. Whether it be DVD, HDTV, Digital TV, or a digital satellite receiver, the Plasma TV is the perfect display companion. The dramatic, high-impact picture makes it not only compatible but a very wise choice of television viewing.

What are phosphors?
Phosphors are the material on back glass that emit the visible light that makes up the picture we see. On a cathode-ray tube the phosphors are on the front glass and are excited by a beam of light from the cathode-ray. In all flat and plasma tvs the phosphors are excited by UV light produced by electromagnetically charged plasma.

Picture Resolution for Computer Applications

True Resolution/Native Resolution
The number rows of horizontal and vertical pixels that create the picture. The native resolution describes the actual resolution of the plasma display and not the resolution of the delivery signal. When the delivery format is higher or lower than the flat screen's native pixel resolution, the delivery signal will be converted to the plasma's native resolution through an internal converter. Generally, the closer the incoming picture signal is to the native pixel resolution on the plasma display monitor - the better the picture. For example, a VGA computer signal of 853X480 will match up perfectly with a plasma monitor with 853X480 native pixel resolution, while an XVGA signal of 1024X768 will match up better with a plasma monitor that has the higher resolution of 1024X1024. There are more considerations here that deal with the quality of the internal converter/scalar, and also whether or not the monitor is progressively scanning (853X480) or interlacing the signal (1024X1024). All 42" inch plasma display monitors are HDTV ready, while none will show the true HDTV signals of 1080i. However, they will benefit from the better signal and show something very close.

The options available for native resolution include: 1024x1024, 1024x768, 1280x768, 1365x768, 640x480, 825x480, 853x480.

Resolution options: Your basic choices for native, or true resolution are the following:

1. VGA, or "640 x 480" – This is the lowest data resolution currently on the market, and usually the least expensive.

2. SVGA, or "800 x 600" – This is a popular resolution today, because most notebook computers are SVGA. Matching the plasma resolution with the computer resolution will produce the best results.

3. XGA, or "1,024 x 768" - XGA plasma tvs are generally more expensive, and are the second most popular resolution format. Many of the newest products are coming out in XGA. They are getting more popular as prices drop and the use of XGA notebook computers increases.

4. SXGA, or "1,280 x 1,024" – SXGA products are high resolution, and notably more expensive than XGA. These products are targeted for high end personal computer users and low end workstation users. They are used primarily for command and control, engineering and CAD/CAM applications where acute resolution of small details is important.

5. UXGA, or "1,600 x 1,200" – UXGA is for very high resolution workstation applications that are detail or information intensive. These are expensive plasma tvs that support a broad range of computer equipment. Relatively few products on the market have this native resolution.

Plasma / Flat tv resolution and your application
One of the key factors in choosing the right resolution is your typical application. Do you have a need for very accurate display of small visual details, or not? If your primary use of the system is for "Powerpoint" style graphics, pie charts, graphs, and general business presentation, you don’t need to pay extra for high resolution equipment. SVGA resolution is very adequate for this kind of work, and the best solution for the money.

However, if you are often presenting materials like Excel spreadsheets that have a lot of numeric data on the screen, you will probably be happier with XGA resolution. This format is able to produce a clearer and more legible image of small numbers and other data.

Finally, if you are projecting engineering drawings or other images of a highly detailed and technical nature, you will probably need a very high resolution SXGA projector to produce an acceptable image for your purposes.

Plasma / Flat tv resolution and your application
As you consider the question of resolution, keep in mind that the best resolution for your plasma tv is the resolution of your intended computer application. If you typically use a notebook computer with SVGA resolution, you will want a plasma tv with the same native SVGA resolution in order to get the sharpest and cleanest image. Similarly, if you normally use a computer with XGA output, you will get the best picture from a plasma that has XGA as its native resolution.

Most of the plasma tvs on the market today are capable of projecting input signals other than their native resolutions. For example, you can usually hook up an XGA computer to an SVGA plasma. The plasma tv will automatically convert the incoming 1,024 x 768 signal to its native 800 x 600 output. However, there is always a loss of sharpness and detail in the process, so you will end up with a picture that is not quite as sharp as if the incoming signal had been the same format as the plasma tvs native resolution.

This loss of sharpness also happens if you plug an SVGA computer into a higher-resolution XGA plasma tv. You will usually get a decent image, but the conversion from the 800 x 600 input to a 1,024 x 768 output will produce some fuzziness that you may not appreciate after having spent the money for an XGA plasma tv.

The plasma tv’s process of converting a different input format to its native output format is called "scaling." Some plasma screen tvs are very good at scaling, so the resulting image fuzziness is relatively minor, and the image is very adequate no matter what the source. The quality of scaling varies widely among plasma tvs and like all technology, it is constantly being improved. If scaling is an important consideration, be sure you see it demonstrated as you would use it.

Which plasma / flat tv resolution is right for you?

In summary, the selection of the right resolution depends upon the computer sources you are using, your budget, and your application. Here are some general guidelines:

· Choose a resolution format for both your computer display and your plasma tv that is adequate for the type of materials you will be presenting. The smaller and more plentiful the details in your presentation material, the higher the resolution that is required to display them successfully.

· Use a plasma tv that matches the native resolution of your computer display, so that you can avoid the image fuzziness that often comes from scaling one input format to a different output format.

· If you are using a high resolution computer display, and find that a plasma with matching resolution is out of your budget range, select a plasma that is one step down in resolution. However, make sure that the scaled plasma tv image gives you results comparable to your computer display. By doing this, you can often save a lot of money and still end up with a very acceptable image on the screen.

· And finally, give some consideration to the useful life or your plasma tv. VGA resolution was popular for 8 years, SVGA resolution became the most popular resolution for projectors (similar use to plasma tvs) in 1997, and XGA is expected to replace SVGA in popularity by the end 1999. If you keep pace with the changes in the personal computer industry, you know that performance doubles about every 18 months. Keep this in mind as you make your plasma tv choice.

Why choose a plasma/flat tv over other presentation systems (i.e. front view projectors and TV screens)

Plasmas perform extraordinarily well under most ambient light conditions. Very bright light does not wash out the image on the screen. The beauty of these flat screens is that, unlike front view projection screens, you don't have to turn off the lights to see the image clearly and easily. Therefore, plasmas are excellent for video conferencing and other presentation needs, which require the lights to remain on.

Another characteristic of a plasma panel is the extreme viewing angles both vertically and horizontally. With 160 degrees viewing angle, people sitting off to the side of the plasma screen will still be able to see the image without losing any of it.

Plasmas tend to be very lightweight in comparison to similar sized standard display monitors and television screens.

No existing display system can compete with the low depths available in plasma panels. The thinness of theses systems allows for the monitors to be placed virtually anywhere. Some plasma panels are known to be as thin as 3.5 inches deep.

They can be hung on walls, mounted to ceilings, flush wall mounted or placed on a tabletop. Many mount manufacturers are designing more creative ways to mount plasma panels because of the ease of engineering involved.

Plasma panels are also not affected by magnetic fields.

Plasmas are easy to use. Almost as easy as plug and play. They tend to accept inputs for both data and video (industrial models). The main issue is resolution. Be sure to find a panel that works with your resolution needs. All will show standard VGA (640x480) and some will accept signals all the way up to UXGA.