What Is Plasma And Lcd Technology?

By Author: Thomas Lindblom
Total Articles: 200
Comment this article

What is Plasma and LCD Technology?

At first glance LCD panels and plasma screens look very much the same, however both use totally different technologies to display your favorite movie, Xbox game or sporting event.

A plasma display panel consists of thousands of pixel cells, each containing a mixture of rare gases (usually neon and xenon). Electrodes charge the cells with precise electrical voltages to excite these gases causing them to glow and produce a certain colour.

LCD (Liquid Crystal Display) screens make use of millions of crystals suspended in a liquid that is sandwiched between two glass panels. When these liquid crystal cells are charged the crystals untwist to let a certain amount of light, generated by a fluorescent lamp behind the panels, through. The amount of voltage applied to the liquid crystal determines how much light is filtered and the resulting colour you see on the screen.

What do you normally use your television for?

Before you ask which technology is superior ask yourself what you use your television for? Do you use your flat screen television to watch sports? Play ...
... video games? Display computer data? Watch DVD's? Or maybe just general use? Determining how you use your flat screen TV plays a big role in deciding whether to buy a plasma display or LCD screen.

You should also think about where you will be using your television. Are you buying a flat screen television to complete the ultimate home entertainment centre or do you need something much smaller for the bedroom? Do you need a television for a well-lit area, for example in a room with lots of natural light or outdoors? Or will it be placed in a reasonably dark room? Remember also, when you are looking at televisions in a store they are displayed in a room that is usually well lit by fluorescent lighting - does your living room have similar lighting?

The Differences between Plasma and LCD

Before we look into which is better, Plasma vs LCD, remember that over the past year both technologies have seen some huge improvements with many features that were considered short-comings 12 months ago now being considered equal to the other. The phrase you get what you pay for comes to mind when buying a television today - the more expensive models offer much better quality than the cheaper models and are less susceptible to some of the problems we discuss below.

Picture

On the whole both LCD displays and plasma screens deliver great picture quality however there a few things to be aware of when purchasing a flat screen TV.

Brightness - When viewing televisions in a store most would agree LCD televisions appear brighter - the reason for this is that in well lit environments the matte screen of a LCD reflects little light and so retains much of its brightness and colour.
A plasma screen, on the other hand, often has a mirror like finish that can reflect more light than an LCD making it appear dull. It is for this reason that many prefer buying an LCD television if they intend to place it outdoors or in a room with lots of natural light.

In darker areas plasmas generally perform slightly better in terms of brightness and would be a good choice for a home entertainment setup.

Colour - LCD's are generally known for their sharp picture and vibrant colour that produces images that seem to be alive. Plasma's, on the other hand, generally have a wider range of colours and have a warmer, more realistic feel to them.At end of the day, it does come down to personal preference - you may prefer the bright and vibrant look of a LCD or the warm, true-colour feel of a plasma.

Contrast

- Plasma displays have been renowned for having better contrast than LCD's. This is mostly due to how each technology functions. Plasma TV's can display true blacks as a result of being able to switch off pixels by blocking voltage to the gas filled cells. LCD's have until recently lacked the ability to show true blacks because they operate by filtering out light coming from behind the screen. Often due to pixel leakage small amounts of light still shine through causing blacks to look a dark grey. This means that plasmas have a slight advantage when viewing dark movies because the higher contrast gives more detail in the shadows of the dark scenes. LCD's are becoming increasingly more advanced in this department and recent improvements have seen the gap between the two close significantly with many LCD's now matching plasmas when it comes to contrast.

Resolution

Generally, LCD displays offer higher resolution than plasmas of the same size. High Definition TV is also something to take into consideration. To comfortably view HDTV a resolution of 1280 x 720 is needed. Almost all LCD's above 30 inches and most plasma's above 50 inches accommodate this.

Viewing Angles

This refers to how far off axis you can view the picture clearly. Between the two technologies there is not much difference with most LCD's claiming they have a slightly higher viewing angle. However, viewing a plasma or LCD from 155-175 degrees will never be as good as watching from directly in front - colour, contrast and brightness quality all decrease the further off axis you sit.

Computer Use

LCD's were originally designed for computer use and still have the advantage when displaying static images, data, etc. LCD's generally have a higher number of pixels per square inch meaning that they display large amounts of data more clearly. Issues relating to burn-in also mean that LCD flat screens are a better choice if you are mostly using it for computing applications. If you were to buy a plasma and required computer use it would be wise to go for a more expensive model where the above issues aren't a problem.

Fast Moving Scenes

If sport or fast-action scenes are a major part of you television viewing then it may be worth while looking at a plasma screen to satisfy your needs. Plasmas generally offer better performance with fast moving images being displayed crisply and clearly. Until recently LCD's performed poorly with fast moving action but have made huge improvements over the past twelve months so that fast scenes no longer appear blurred. The best indication of how well a model performs is to look at the refresh rate - the lower the number the better. Anything below 15ms is good, 5ms is excellent.

High Altitude

Although not really an issue in Australia it is worth noting that plasmas can be affected by pressure differences at high altitude. If using your plasma screen TV at altitudes greater than 2000 metres you might notice a buzzing due to the effect of the low pressure on the rare gases. Many plasma brands do make models specifically for high altitudes but are more expensive.

Longevity

Many people say that LCD's last longer than plasmas because image colour can fade over time. Others say that LCD's aren't a good choice because the backlight can wear out (even though these can be replaced on some models). To be honest I wouldn't really concentrate on this issue too much - most models (plasma and LCD) claim to have a lifespan around 40,000 - 60,000 hours. If you watched TV for 6 hours a day, everyday, it would last well over 20 years. By that time LCD's and plasma will probably be obsolete with some new technology offering much better performance. If you are planning to hold on to your flat screen TV for more than 20 years it would be wise to buy a well-known brand that offers good quality.

Screen Burn In

One of the major drawbacks of plasma technology has been the burn-in issue, where an image that is displayed for long periods of time is burned into the screen. Static images like channel logos, video game displays, and images left paused on screen for long periods of time can be etched into the screen leaving a ghosted image. Newer models don't suffer from this problem so much due to new pixel orbiter technology. These days you would need to leave an image on screen for more than an hour before burn-in occurs and even then this will disappear in a short time unless the image has been displayed for many, many hours where permanent burn-in may occur.

LCD displays do not suffer from burn in however stuck or dead pixels can be an issue. It is worth buying from well-known manufacturers who have better quality to reduce the chance of this happening - if this does occur they are often easier to get fixed.

Size and Cost

When deciding the size your flat screen you should first think about where you're going to use it. If you have a large space and would like a larger screen you will find that there are many more plasma's to choose from. You will also find that plasma's are cheaper than an LCD of the same size. For very large screens - over 127cm (50 inches) - plasmas are usually the way to go because there is more choice and they are generally cheaper however recent LCD advancements have seen a handful of LCD screens at this size introduced to the market. If you are looking for something smaller, for the bedroom or kitchen, LCD's offer a wider variety of choice.

In general, if you are looking for a TV that is smaller than 94cm (37 inches) go with an LCD display. Over 106cm (42 inches) go plasma. Between 94-106cm (37-42 inches) you can choose either way with many options in both technologies. Your choice might be influenced by cost where plasma's have a slight advantage, offering cheaper prices than an LCD of the same size, but expect this to level out as the competition between the two technologies heats up.

Power Consumption

If power consumption is a concern, especially now that climate change is a major issue, go with an LCD display. They use approximately 40% less power due to the fact that they use fluorescent backlighting to produce an image.

Size, Weight, Durability

LCD's weigh less than a similar sized plasma screen and they are also more durable. Due to the fragility and weight of a plasma screen it may be worth getting your plasma TV professionally mounted, especially the larger models. The cost of shipping and installation might be something to factor into your purchase of a plasma TV.

In terms of width there isn't much difference between the two technologies with LCD's being slightly thinner.

Plasma or LCD - What is best for me?

There is no right or wrong when choosing between a plasma television set and an LCD flat screen display. It's like choosing a car - you determine what you use it for, what features you require, what colour you like, and how much you can afford to spend.

Deciding what TV you should buy is the same. First you decide what you mostly use your television for, be it gaming, computing, watching sport, movies or general viewing?

Next you look at the where your TV will be displayed - is it a small room like the kitchen? Or a large living area? Is the room well lit? Or is it a dark area with little natural light?

What features do you require - Are you interested in HDTV? Do you want something that uses less power? Does size and weight make a difference?

Personal preferences should also be factored in to the decision process - do you prefer the vibrant colour of an LCD screen or the warm, natural look of a plasma? Looking around the stores and even viewing your friends flat screens can help form an opinion on what you prefer.

Finally, you should consider cost and what would best suit your budget. Comparing products and prices from different stores can not only mean you buy at the cheapest price but you might be able to get a better quality television that is still within your budget. A quick look around the Internet will provide you many shopping comparison sites that show customers the store with the lowest price.
This article has a look at both Plasma and LCD TV's technologies and offers you an explanation and comparison of the two, laying out the advantages and disadvantages of each so that you can make an informed choice.