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With all of the various TV display technologies on the market today (Plasma, DLP, LCD, etc.), it is important to understand the basic pro’s and con’s of the display technologies used in manufacturing High Definition TVs. First, here are the dominant types of displays available today:
- Direct view tube CRT
- Flat panel LCD
- Plasma
- Rear projection LCD
- Rear projection DLP
- Rear projection CRT
- Rear projection LCoS
What makes a plasma TV better than a direct tube CRT? Why would I choose a rear-projection TV over an LCD? Each type of display has inherent advantages and disadvantages associated with the technology used in manufacturing the display. The following guide provides a synopsis which should help you understand relevant points to consider when deciding which HDTV display type is right for you.
Direct-view CRT HDTV Displays
CRT stands for “cathode ray tube" and is the type of TV we are all most familiar with. Chances are, if you have a TV that is 5 or more years old, you have a CRT TV. Despite their age, CRT displays still offer a lot of bang for your buck.
The main advantages of CRT’s include:
- Flat screen – which provides wide viewing angles (most new CRT’s built today have flat screens, but you will still find a few that have are manufactured with curved screens)
- Outstanding picture quality
- Relatively inexpensive in all sizes
- No danger of burn-in
- Capable of producing true blacks
Sounds great, so why are CRT displays losing market share new display technology like plasmas and LCD’s?
- Bulky size and very heavy weight
- Maximum screen size is limited to approximately 36"
To give you an idea of what is meant by “bulky" and “very heavy", a typical 27" flat screen CRT will weigh around 100-120 lbs, a typical 30" flat screen CRT will weigh about 150 lbs and a typical 36" flat screen CRT will tip the scales at about 200-225 lbs. At over 200 lbs., that kind of weight is going to require at least 2 strong people to lift it up onto the TV stand.
CRT’s are also much larger in terms of depth. A typical 27" CRT measures 20" deep, a typical 34" CRT measures 24" deep, and a typical 36" CRT measures 26" deep.
Why should I choose a flat screen CRT over a curved screen CRT?
The answer is two-fold:
1) Having a flat-screen will allow for wider viewing angles, so that you can those people sitting on the left and right sides of the TV also have a good view of the images being displayed.
2) Having a flat screen will allow you to view the picture as it was meant to be seen, without any of the stretching in images that is associated with a curved tube. A curved tube has inherent flaws that cause the image to be “stretched" as it reaches the edges of the screen. While this may not be an important feature for you, I would encourage you to look at a flat screen and a curved screen side-by-side. The difference in image quality will be much more apparent.
Flat panel LCD HDTV Displays
LCD stands for Liquid Crystal Display and is the type of TV you will be familiar with if you have seen the flat-panel LCD monitors used with many newer computers. The same technology is also used in LCD TV’s.
The main advantages of LCD’s include:
- Flat screen – but see below for note on the viewing angles- Thin, lightweight and stylish looking
- High resolution and excellent picture quality
- No danger of burn-in
Flat panel LCD’s main disadvantages: - Relatively narrow viewing angles- Expensive in sizes over 30" - Incapable of producing true blacks
To give you an idea of what “thin" and “lightweight" means, a typical 27" to 30" LCD will weigh about 40-50 lbs, a 32" LCD will weigh about 50-55 lbs, a 37" LCD will weigh about 60-65 lbs. These types of TV’s are thin and light enough to be hung on a wall.
Plasma HDTV Displays
While plasma displays used to be much too expensive for the average Sunday football fan, they have come down in price enough to become a very attractive choice for many HDTV shoppers. Having said that, you will more than likely still pay more for a big-screen plasma TV than a similarly sized rear-projection display. What makes plasma TV’s so attractive?
- Flat screen with very wide viewing angles
- Very thin and lightweight
- High resolution with deep, saturated colors
- Excellent picture quality (especially for home theater)
Plasma’s main disadvantages:
- Fairly expensive compared to other HDTV display types
- Slight potential for burn-in
- Limited lifespan
To clarify “thin" and “lightweight", a typical 42" plasma will weigh between 50-90 lbs, a 50" plasma will weigh about 80-110 lbs. These types of TV’s are thin and light enough to be hung on a wall.
Rear projection HDTV Displays
Rear projection TV’s are an economical choice for a large sized TV and they still offer excellent picture quality. They are, however, too large to be hung on a wall and work best when placed on a TV stand (or on the floor in the case of rear projection CRT’s). The most economical type of rear projection display is the rear projection CRT.
Rear projection CRT HDTV's offer:
- Flat screen
- Relatively low cost
- Excellent picture quality (especially for home theater)
Rear projection CRT’s main disadvantages:
- Very heavy and very bulky
- Narrow viewing angles
- Image visibility suffers in brightly lit rooms
Very heavy and bulky is a nice way of saying that rear projection CRT’s are HUGE. A typical 48" rear projection CRT weighs 150 lbs. and is a little less than 24" deep, a typical 56" rear projection CRT weighs almost 200 lbs. and is over 2 feet deep, a typical 65" rear projection CRT weighs 300 lbs. and is over 2 feet deep, and a typical 73" rear projection CRT weighs over 400 lbs. – now THAT is a huge TV!
Rear projection LCD, DLP and LCoS HDTV Displays
These types of rear projection HDTV displays are also referred to as microdisplays. They work by using a lamp that bounces light off of or through a tiny pixel-filled microchip and onto the screen.
Rear projection LCD’s offer these advantages:
- Flat screen with good viewing angles
- Thin and lightweight compared to CRT
- Not susceptible to image burn-in
- No “rainbow effect" artifacts that are sometimes found in rear-projection DLP TV’s
- Excellent picture quality (especially for home theater)
Rear projection LCD’s main disadvantages:
- Fairly expensive
- Slight delay when powering up
- Lamp replacement required periodically
- Possibility for “screen door effect" artifacts
Rear projection DLP’s offer these advantages:
- Flat screen with good viewing angles
- Thin and lightweight compared to rear projection CRT
- Not susceptible to image burn-in
- No “screen door effect" artifacts that are sometimes found in rear-projection LCD TV’s
- Excellent picture quality (especially for home theater)
Rear projection DLP’s main disadvantages:
- Fairly expensive
- Slight delay when powering up
- Lamp replacement required periodically
- Possibility for “rainbow effect" artifacts
LCoS, D-ILA and SXRD
These technologies are all variations on the same manufacturing process that utilizes liquid crystal on silicon (hence the acronym LCoS). However, implementation of this display technology differs significantly from one manufacturer to the next, so it is impossible to lay out common pro’s and con’s of the technology itself. Each TV with this type of technology will have different characteristics for image quality, viewing angle and cost. I recommend researching each manufacturer and their specific models featuring LCoS in order to compare their benefits and drawbacks to other display types.
Conclusion There are lots and lots of choices online and in stores today for new TV’s. Enter into the television section of any Best Buy or Circuit City and you’ll get bombarded with a myriad of options for plasma, LCD, direct-view tube and rear-projection TV’s. What you choose for your new TV will either brings you hundreds of hours of enjoyment watching movies, sports and news or will bring you many hours of frustration by not choosing the best type of TV for your needs. My hope is that this information will give you the knowledge, and the confidence, to make the right decision for your next TV purchase. |
