Answering your basic questions about Plasma Television
Despite that plasma TVs have been around for a number of years now, most consumers still lack a basic knowledge of what plasma televisions are all about. Partly the reason behind this lack of consumer understanding is the result of misleading information often coming out from sales reps and TV manufactures.
To help you clear things out, we have prepared a comprehensive list of answers to Plasma TV FAQs, covering most of the common difficulties many may have, including use, technology and common myths.
It is a common experience for many new comers to flat-panel TVs that by the time they finish researching on Plasma TV sets, they end up with a couple of questions related to use, technology, and even fictions they might have heard or read about.
This happens to be one of the first questions that may arise in that these two terms are more often used in an interchangeable fashion. Yet there is a basic difference between the two.
A plasma display lacks an internal tuner and therefore, it is closer to a computer monitor than a television. The first plasmas that came out did not include a built-in tuner. Nowadays, the exception is the opposite in that the majority feature an internal tuner – hence the term plasma TV or plasma HDTV. Yet most people – including sales reps in electronic superstores – still call these devices plasma displays.
Flat panel plasma display is one of the latest display technologies; it is capable of excellent image quality, with large, flat screen displays that are easily viewable in almost any environment.
Plasma display panels consist of an array of cells, known as pixels, each of which is 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 are the same phosphors as used in cathode ray tube (CRT) devices. Compatible 720p HDTV plasma will have around 2.76 million sub-pixels while 1080p HDTVs have 6.22 million sub-pixels, each individually controlled by state-of-the-art electronics.
For more information, refer to our article How-It-Works: Plasma Display Technology.
Today, both plasma and LCD/LED TVs are capable of delivering a great image at screen sizes up to around 65-inches and more. Yet plasma TVs come with a price advantage especially at anything above 50-inch screen size.
There is also the issue that in general, plasma TVs are capable of a deeper shade of black than an LCD – though in this respect, the latest LED TVs are capable of similar deep black levels. A deep shade of black improves the realism of dark scenes while making colors look richer and more saturated. But a deep shade of black is not the only parameter that makes a great picture. Picture brightness uniformity in particular is often an issue with LED TVs – especially when viewing takes place at an angle to the screen. This renders plasma televisions as the best choice for those who want to enjoy the most in home theater image quality.
Please refer to our Plasma vs. LCD TV article for more information on the differences between these display technologies.
Probably, the greatest myth about plasma displays is that they only last two to three years. The truth is that present day plasma display panels have an expected half-lifetime of anything between 60,000hrs and 100,000hrs, which is substantially more than that of a traditional CRT TV. Well, even if expected plasma panel life were just 50,000hrs, at 7 hours a day, 365 days a year – this corresponds to almost 20 years of use! This means that most probable, the electronics inside the TV will fail before the display panel itself.
Note that by half-lifetime, we mean that the display brightness will gradually fall to half its original value at the end of the specified period of time. By this time, the image brightness would be too dim for normal viewing and the display panel will have to be replaced.
Technology changes fast, yet plasma TVs have reached a rather mature stage of development. Together with their LCD and LED TV counterparts, plasmas are the real BIG thing in today’s display technology. Though 2012 is bringing large 55-inch OLEDs to the consumer market, OLED display technology is not only very expensive, but still has to prove itself in the long term; in particular OLED TV makers have to prove that they have solved long term stability issues associated with the blue color.
We expect this new emerging display technology to take at least two to three more years before it is widely available at a price that is more within reach of most household budgets.
What are Dead Pixels? Do Plasma Display Panels suffer from dead pixels in a similar manner to LCD Displays?
Though very rare, plasma display panels do suffer from occasional dead pixels. Dead pixels are pixels that malfunction and that show up as either a colored speck of light in case of a damaged sub-pixel, a black spot i.e. a pixel that remains always off, or a permanent always on white spot of light. Dead pixels are most easily seen when an area of the screen is all one bright color, or white. A single dead pixel is not terribly noticeable; but as the set ages, more pixels may die.
Generally warranties on plasma display panels vary from one to five years (depending on brand and model); most exclude:
– Dead Pixels unless there’s more of them than the manufacturer deems acceptable
– Heat-related problems
When it comes to the dead pixels issue, return policies from manufacturers vary depending on the actual number of bad pixels and their placement. The presence of bad pixels does not automatically qualify a unit as defective, but the unit may always be returned to the manufacturer for evaluation. Every occurrence is most often treated on a case by case basis.
The number of dead pixels that’ll be covered by the warranty isn’t always stated, and varies between manufactures. Some warranties are vague in this respect, using phrases like “within normal commercial tolerance” to describe pixel failure.
Luckily, some manufactures are realizing that what may be acceptable to their quality control standards, need not necessarily be so to the end customer; for this purpose, there is a shift among manufacturers towards a ‘zero bad pixel’ warranty – among these one finds Samsung and Viewsonic.
Keep in mind however that this is still not the norm with most manufacturers. Our suggestion is to get informed before you buy – it is important that you get an understanding of the manufacturer’s pixel policy before you buy a plasma screen to avoid disappointment later.
Another great fiction about plasma TVs is that they need to be re-charged or re-filled to extend their lifetime. No one can re-charge or re-fill the gas in a plasma TV, nor can anyone fix a dead pixel on your plasma screen.
In other words, you do not need a service contract to service your plasma TV annually; what most of the 3-year Television Service Plans advertised online do is to make the necessary arrangements for the repair of a faulty unit and pay the bill for you if the failure occurs within the 3-year period since your purchase subject to the terms of the extended warranty contract.
This means that in the case of a plasma TV, the repairs will only apply to the electronics inside but not the plasma display panel since plasma panels can neither be repaired, nor recharged or refilled with gas. In the unlikely event of a faulty display, the display panel will have to be replaced, not repaired.
A variety of resolutions exist for plasma display panels, including 1024×768, 1280×720, 1280×768, 1366×768, and 1920×1080 pixels.
The lowest resolution most common today is the 1024×768 – followed by 1366 x 768. Both classify as HDTV despite that the 1024 x 768 cannot handle the full pixel content of 720 HDTV.
The higher resolutions are ideal for situations where detail is important (small text, spreadsheets, CAD documents, etc), or when displaying full HDTV content. In particular, the 1280×720 and 1366×768 are ideal for displaying the full content in 720p HDTV on sets smaller and including 50-inch displays. A 1080p native screen resolution (1920×1080) is ideal if your screen size exceeds the 50-inch diagonal.
Some Plasma Displays are labeled for commercial use; are there any differences between commercial and home-use Plasma Display models?
The Federal Communications Commission (FCC) – as the responsible communications authority in the US established that:
For Commercial use: Digital device or peripheral that has been tested and complies with commercial environment limits should be labeled as Class A.
‘Class A’ equipment generates radio frequency energy that may cause harmful interference to radio communications if not properly installed. Such devices and peripherals are not intended for the home because of the likelihood of harmful interference of radio communication. Corrective measures would be required at the owner’s expense.
For Home use: Digital device or peripheral that has been tested and complies with residential environment limits should be labeled as Class B.
‘Class B’ equipment may still generate radio frequency energy that may cause harmful interference to radio communication if not properly installed. In other words, there is no guarantee that interference will not occur in a particular installation, yet all Class B devices and peripherals are safe for use in residential environments.
Plasma screens offer a number of options in this respect – from standard floor stands, to wall mounts and even ceiling mounts. We suggest that you take a look at our article on how to install a plasma TV for more details on this issue.
As the operating temperature of the display panel changes, the cabinet expands or shrinks slightly. There is no need for alarm here; this is not a problem.
Equally common with plasma displays is a soft buzzing noise; this is typical of all plasma displays and is mainly caused by the electrical charges used to create the images on the screen. Buzzing can also result from the high frequency power drive coils used in the so called switch-mode power supply (SMPS) board used to drive the panel. But the level of buzzing is generally quite low and inaudible from normal viewing distance especially during daytime.
One needs to be aware here that there are many factors that may influence this buzzing phenomenon. Changing the picture mode to one that produces a less bright an image will reduce the buzzing level – when present – since this affects how much power the panel is processing. Equally important is the panel installation; a hard wall surface directly behind a wall mounted plasma TV will reflect more of the buzzing noise than a wall covered with soft furnishing.
If the temperature of the plasma display unit becomes too hot, it may automatically switch itself off to prevent further damage. If power is suddenly turned off, it is probably because the air vents are blocked. Remove any objects blocking the vents and clean the vents from any accumulated dust before turning the unit on again.
We hope that the above answers most of the common
Plasma TV FAQs you may have about use, technology, and even fictions, you might have heard or read about.