| 1> | | | | displays are prone to burn-in, or image retention. |
| | | | Screen burn-in occurs when an image is left for too |
| A Plasma HDTV or a LCD Television — Is this | | | | long on the screen — resulting in a ghost of the |
| your dilemma? This is a rather difficult and complicated | | | | image burned on the screen. Surely, keeping the |
| comparison between two technologies that process | | | | brightness and contrast levels down will help reduce |
| the image in a totally different manner. | | | | the risk of burn-in. |
| This article highlights the pros and cons of plasma | | | | While some brands of plasma displays are more |
| versus LCD as applicable to a television display. It also | | | | prone than others to burn-in, yet in general, plasma |
| presents a set of guidelines to help you determine | | | | screens are more prone to suffer permanent burn-in |
| where either of these two flat panel display | | | | during their first 200 hours of use; the reason being |
| technologies fit best. | | | | that fresh phosphors burn more intensely as they are |
| Plasma or LCD — Which type of display is right | | | | ignited. |
| for you? | | | | Technically speaking, burn-in is the result of a damaged |
| Though both LCD and plasma displays come in the | | | | pixel, whose phosphors has been prematurely aged |
| form of slim flat panel displays, yet from a technology | | | | and therefore glows less intensely than those of |
| perspective, these two flat panel displays process the | | | | surrounding pixels. The presence of a static image for |
| image in a totally different manner. | | | | more than half-an-hour is enough to cause temporary |
| Plasma uses a matrix of tiny gas plasma cells that are | | | | burn-in; temporary burn-in or image ghosting, should not |
| charged by precise electrical voltages to emit light and | | | | be cause for alarm as normally this will wash out after |
| hence to create the picture image. Liquid Crystal | | | | several hours of use. |
| Displays (LCD) panels - work by trapping a liquid | | | | Worst still is the prolonged presentation of static |
| crystal solution between two sheets of polarized glass. | | | | displays, such as the use of black or gray bars to |
| When an electric current is passed through the liquid | | | | view a 4:3 picture in its original format on a wide |
| crystals, they change the polarization of the light | | | | screen display; this will result in a permanent burn-in. |
| passing through them in response to the electric | | | | Once permanent burn-in occurs, the damaged |
| voltage — as a result of which, more or less | | | | phosphors cannot produce the same levels of light |
| light is able to pass through the polarized glass on the | | | | output as the other phosphors around them do. |
| face of the display. | | | | In these circumstances, an LCD display may be a |
| It is not the scope of this article to go into the actual | | | | better choice. |
| details of how these different display technologies | | | | |
| process the image — after all, what really | | | | Viewing distance: It seems that the pixel size and |
| matters is not what is going behind the screen but | | | | shape of an LCD panel renders a smoother picture |
| rather how these different display technologies | | | | than an equivalently sized plasma panel for the same |
| perform as a television screen. At the same time, it is | | | | pixel count. |
| worth taking note that it is these same differences | | | | This means that even if your viewing distance falls |
| that gives each of these display technologies, its | | | | within the recommended distance of approximately |
| strengths and weaknesses, and that therefore renders | | | | twice the screen width, if this is less than at least nine |
| one more suitable than the other in certain | | | | feet, most probably you will be better off with an LCD |
| circumstances. | | | | TV. |
| The list below highlights the most important differences | | | | Life-time: The rare gases used in plasma display |
| between these two flat panel display technologies: | | | | panels have a life and will fade over use. Earlier |
| Size: For the time being, collision between plasma | | | | plasma TV sets had a quoted half-lifetime of between |
| television and LCD TV occur in the 40 to 50 inch | | | | 20,000hrs, following which the image brightness will fall |
| screen range. In reality, LCD TVs top out at around | | | | to half its original value. However, the latest plasma |
| 45 — meaning that for bigger screen sizes, a | | | | displays can boost anything between 30,000 and |
| plasma display is your only real option if what you are | | | | 60,000 hours. On the other hand, LCD displays have a |
| after is a direct-view TV system. On the other hand, | | | | guaranteed lifetime of between 50,000hrs and 60,000 |
| at the smaller end of spectrum, namely 15 to 36 | | | | hours. This degradation in image brightness takes place |
| TVs, LCD is the way to go if what you want is | | | | gradually over time. |
| something stylish and slim (at under 4-inches in depth). | | | | Now, the average household in the US replaces their |
| Picture Quality, Contrast and Color Saturation: Both | | | | TV set every 7 years. Taking a conservative figure of |
| plasma and the latest TFT-LCD flat panel displays are | | | | 30,000 hours for either technology, this corresponds to |
| capable of producing excellent picture quality — | | | | well over 6hrs usage a day - every day - for over a |
| with bright, crisp clear images. | | | | period of 14 years! In other words, both plasma and |
| However, plasma flat panel displays are more suitable | | | | LCD displays are extremely stable and reliable devices. |
| for basic home theater usage than LCD. The gas cell | | | | This means that life-time should not be an issue with |
| structure within a plasma display is such that there is | | | | either display technology. |
| no light leaking between adjacent cells (or pixels). This | | | | At the same time, keep in mind that there is no way to |
| renders plasma displays capable of displaying deeper | | | | re-generate the gases in a plasma display or to repair |
| blacks — hence better contrast and detail in | | | | any dead’ pixels in an LCD display — |
| television and movie scenes where lots of dark and | | | | the only option in such circumstances will be to replace |
| light content is shown simultaneously. | | | | the display. |
| In comparison, the nature of LCD technology — | | | | Response: Some LCD panels — especially on |
| where a backlight shines through the LCD layer | | | | older generation models - had a tendency to blur |
| — means that it is hard for it to achieve true | | | | images particularly during fast moving scenes in |
| blacks (i.e. true absence of light) as there is always | | | | movies and sports. However, recent advancement in |
| some light leakage from adjacent pixels. | | | | LCD technology means that response times are such |
| This does not mean that LCD panel s are not suitable | | | | that there is no noticeable difference in performance |
| as TV screens; today’s LCD TV sets make | | | | between LCD and plasma TV sets in this regard. |
| use of extreme high contrast panels that are capable | | | | Power requirements: The advantage here goes to |
| of displaying deeper blacks, yet the latest plasma TV | | | | LCD panels as these consume less electricity. |
| sets still have a slight edge over LCD when it comes | | | | Estimates show that the use of LCD panels can result |
| to contrast levels. | | | | in some 30% power savings for the same screen size |
| The situation is somewhat similar when it comes to | | | | than plasma display. |
| color saturation. Again, it is the different display | | | | Price: Price is always a big issue when it comes to |
| structure between LCD and plasma that is the reason | | | | choosing your TV display. Although prices online vary |
| behind the difference between the two technologies in | | | | considerably, yet LCD TV sets tend to be more |
| this respect, and though both are capable of handling | | | | expensive than Plasma Televisions. The main reason |
| color in an exceptional manner, yet plasma displays still | | | | behind this price gap is that the production process for |
| lead in this respect - producing more accurate and | | | | plasma technology still supports a better yield and thus |
| vibrant colors. | | | | carries a pricing advantage — especially at the |
| | | | large screen end of the market. |
| Viewing-angle:Plasma Television sets — like their | | | | This contrasts heavily with LCD display technology |
| CRT TV counterpart - typically have better viewing | | | | where an estimate 30 to 40 per cent of all |
| angles than LCD. The viewing angle represents how | | | | manufactured panels will have to be discarded as a |
| far one can sit on either side of the screen away from | | | | result of defects leading to what are known as |
| the center, without experiencing significant deterioration | | | | 'bad-pixels'. |
| in picture quality — mainly as a result of color | | | | Making the Choice: |
| shifts and reduced contrast. | | | | There is a market for both plasma and LCD displays - |
| Though recent developments in LCD technology | | | | Plasma gives you a bigger screen for your dollar, |
| means that this is less of an issue with some of the | | | | deeper blacks, but then LCD do not suffer from burn-in |
| latest LCD TV sets boosting a viewing angle of 160 to | | | | and at the smaller end of the market (less than 40-inch |
| 170 degrees vertically and horizontally, yet it is always | | | | screen size), LCD is your only way forward if you |
| best to check. The tendency — especially with | | | | want something slim and stylish. |
| cheaper sets — is that the deterioration in | | | | It is all a question of knowing what are the advantages |
| picture quality is more accentuated with LCD than with | | | | and limitations of each with respect to your specific |
| plasma displays. | | | | needs. |
| Burn-In: As with all phosphor-based displays, plasma | | | | |