Answer: Outward appearances are definitely deceiving when it comes to LCD and Plasma televisions. Although both types of televisions are flat and thin, they employ different technology in an attempt to deliver similar results.
Plasma TV Overview
Plasma television technology is based loosely on the fluorescent light bulb. The display itself consists of cells. Within each cell two glass panels are separated by a narrow gap in which neon-xenon gas is injected and sealed in plasma form during the manufacturing process. The gas is electrically charged at specific intervals when the Plasma set is in use. The charged gas then strikes red, green, and blue phosphors, thus creating a television image. Each group of red, green, and blue phosphors is called a pixel (picture element).
Although Plasma television technology eliminate the need for the bulky picture tube and electron beam scanning of traditional televisions, because it still employs the burning of phosphors to generate an image, Plasma televisions still suffer from some of the drawbacks of traditional televisions, such as heat generation and screen-burn of static images.
LCD TV Overview
LCD televisions, on the other hand, use a different technology (see also question #1 for this same explanation).
Basically, LCD panels are made of two layers of transparent material, which are polarized, and are "glued" together. One of the layers is coated with a special polymer that holds the individual liquid crystals. Current is then passed through individual crystals, which allow the crystals to pass or block light to create images. LCD crystals do not produce their own light, so an external light source, such as florescent bulb is needed for the image created by the LCD to become visible to the viewer.
Unlike standard CRT and Plasma televisions, since there are no phosphors that light up, less power is needed for operation and the light source in an LCD television generates less heat than a Plasma or traditional television. Also, because of the nature of LCD technology, there is no radiation emitted from the screen itself.
Plasma vs LCD
The ADVANTAGES of Plasma over LCD are:
1. Larger screen size availability.
2. Better contrast ratio and ability to render deeper blacks.
3. Better color accuracy and saturation.
4. Better motion tracking (little or no motion lag in fast moving images).
The DISADVANTAGES of Plasma vs LCD include:
1. Plasma TVs are more susceptible to burn-in of static images.
2. Plasma TVs generate more heat than LCDs, due to the need to light of phosphors to create the images.
3. Does not perform as well at higher altitudes.
4. Potentially shorter display life span - this used to be the case. Early Plasmas had 30,000 hours or 8 hrs of viewing a day for 9 years, which was less than LCD. However, screen life span has now improved and 60,000 hour life span rating are now common, with some sets rated as high as 100,000 hours, due to technology improvements.
LCD television ADVANTAGES over Plasma include:
1. No burn-in of static images.
2. Cooler running temperature.
3. No high altitude use issues.
4. Increased image brightness over Plasma.
5. Lighter weight (when comparing same screen sizes) than Plasma counterparts.
6. Longer display life used to be a factor, but now LCD and Plasma sets both have at least 60,000 hour or higher lifespans.
DISADVANTAGES of LCD vs Plasma televisions include:
1. Lower contrast ratio, not as good rendering deep blacks.
2. Not as good at tracking motion (fast moving objects may exhibit lag artifacts) - However, this is improving with the recent implementation of
120Hz screen refresh rates and 240Hz processing in higher-end LCD sets.
3. Not as common in large screen sizes above 42-inches as Plasma. However, the number is growing fast, with 46 and 47-inch screen sizes becoming more common, and some LCD sets having a screen size as large as 65-inches also available to the general public.
4. Although LCD televisions do not suffer from burn-in susceptibility, it is possible that individual pixels on an LCD televisions can burn out, causing small, visible, black or white dots to appear on the screen. Individual pixels cannot be repaired, the whole screen would need to be replaced at that point, if the individual pixel burnout becomes annoying to you.
5. LCD televisions are typically more expensive than equivalent-sized Plasma televisions (although this is changing), especially when comparing EDTV Plasmas to HDTV-LCD Televisions.
For a more detailed look at the LCD and Plasma comparison, check out:
Should I Buy an LCD or Plasma Television?
Same problem on my Samsung plasma. A blue haze of pixels keeps coming on the screen.. and then goes away as the picture changes.
i have exactly the same problem with my 42inch samsung and just like you said it appears after an hour of viewing which makes me think something being heated but then why does it go away only to reappear later. perhaps someone can help
Samsung HP-S4233 Blue dots appear lower left part of screen after an hour of viewing and now appearing to right of center in line with other dots. Error diffusion and call a technician to repair is what I have been told will fix it. Is error diffusion a sign that something needs adjustment or a component is failing? Sounds expensive either way!
I have a Samsung HP-S4322 purchased in Jan-07. Aug-07 - a thin blue line appear down the length of the left side of the screen. This lasts for about a month. Then, a blue "cloud" of sparkles appeared in the upper left-hand corner. It appeared periodically first but began to appear with increasing regularity. The blue cloud then began to appear all up and down the Left side of the screen, usually after the TV had been on for 20 - 30 minutes.
I called Samsung service. The were familiar with the problem and dispatched a service tech. The service tech adjusted the voltages of the transformers located on the back panel (I think - not positive). This worked for about 1/2 of a day and then the blue line and cloud reappeared. The cloud is smaller but still there. I called the service tech back and advised the problem had reappeared. He contacted Samsung who advised him to replace the "module". I'm not sure what the "module" is but will advise if it works.
Samsung is aware of the problem. Their website refers to it as "Error Diffusion" and advises one to contact service to request repair.
Other forums I've read on this subject trace the problem to panels manufactured in 2006. These panel have incorrect voltage settings which cause the voltage transformers to produce excess heat which in turns causes the plasmas to fire when they are not supposed to.
From what I've read, Samsung will first adjust voltages. If that doesn't work, they replace "panels" or "modules". If that doesn't work, they replace the panel. If you get to panel replacement, you will have to "burn-in" your set all over again.
Hope this helps,
Markal
I have the same problem with my Samsung HPS4253 42" Plasma. I've already had a part replaced, and continue to have the same issue -- any suggestions?
I had the same problem with blue patches of haze appearing after about 45mins of the tv being switched on. Took the tv to a local repairers who told me that there problems with certain screen panels made betweeen late 2005 and early 2006 had software upgrade problems. They said that to repair it would mean to force a software upgrade but there was a good chance that it would fail leaving the tv uneconomical to repair as the tv was only 22 months old but the panel and labour charges would cost nearly £500. Just my luck.... the software upgrade failed leaving the tv useless. I complained to the retailer stating that under the UK "Sales of Goods Act" the tv was "Not fit for purpose". A tv is expected to last a lot longer than 22 months. A got a letter back from the retailer within 10days apologising and attached was a cheque for £500 as compensation. It was all too easy which leads me to think that Samsung are well aware of this problem and are happy to pay up to draw the matter to a swift conclusion. So if you go the same problem, get onto your retailer and give them some grief !!
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