# Sticky  Understanding The Different Types Of HDTV Displays



## tonyvdb

There has been much discussion about HDTV displays and the types however not in detail and in one place. There still seems to be a lot of misinformation about how these different types work. Hopefully this will clear up some of the confusion.

There are 5 main types. Plasma, LCD, DLP, LED and OLED


*Plasma Displays* PDPs consist of millions of small cells containing electrically charged ionized gases. These displays are made up of Glass rather than plastic like most LCD displays and are more commonly found in larger sizes above 32" due to cost of manufacturing. Over the last year or so some manufacturers have decided to stop making them however some think this is by far the best display available.
*Pros*: 
Plasma displays have excellent contrast and color as well as black levels. 
Can be made into very large sizes 40"-150"
Very good viewing angles
Cost per size is low
Very fast response time withe very good clear motion
*Cons*:
Gives off a lot of heat
Uses a fair bit of power comparable to older CRT displays
Burn in is still a possibility so is not good for gaming or PC use

See how it works here



*LCD* or Liquid Crystal Display is the most common type and is found in computer monitors, watches, instrument panels, digital picture frames and tvs.
This display type is made up of 6 very thin layers including liquid crystals pixels that when given an electrical current and lit from behind can display a monochrome or color image.
The light most commonly used in these monitors is a florescent tube no different than the one you have in your light fixtures.
Recently the florescent tube has been replaced with an array of LEDs either just around the perimeter of the screen or directly behind the entire display. The displays with full LED back lighting behind the LCD panel use whats called "local dimming" giving much better black levels and over all contrast.
*Pros*:
Good color reproduction and reasonable contrast ratio
Low power draw
Lightweight
Can be made any size and even shape
low heat
no burn in issues
*Cons*:
Poor viewing angle
Poor black levels although getting much better if fully LED backlit black levels have been compared to Plasma displays
Only one native resolution
Slower response time than Plasma
Do not work well in high heat or very cold temperatures.

See how it works here


*DLP* or Digital Light Processing is not very common and is mostly used in rear projection or projectors but is still common enough that its worth mentioning. DLP is now used in some digital video cameras for projecting images onto a wall or screen.
DLP displays are made up of microscopically small mirrors laid out in a matrix on a semiconductor chip that when a light is reflected off the mirrors that are Rapidly toggled back and forth then passed through a rapidly spinning color wheel then through a lens will display an image. 
*Pros*:
Very smooth motion of images
Excellent black levels
Low cost
Low power consumption if the lamp is LED or laser based
No screen burn in possible
*Cons*:
Rear projection displays are large
Some people are bothered by the rainbow effect caused by the rapidly rotating color wheel but not common
Can be a little noisy
poor viewing angle

See how it works here


*LED* or Light Emitting Diodes is commonly used in very large displays seen in stadiums, advertising billboards and Concert venues.
*This is one display that causes a lot of misinformation as LED displays you see at your big box store or you have in your home are not true LED displays. These displays only use the LEDs to backlight the LCD displays rather then a florescent tube explained above.*
LEDs are diodes that when given a very small amount of voltage will glow red, green or blue (or many other colors) and when alot of these are mounted to a panel will make an image. The largest LED display panels are known to be over 1500ft in diameter and can be used to broadcast just about anything.
*Pros*: 
No real size limitation other than cost
Relatively low power consumption
Low heat output
Very very long lifespan
no image burn in possible
*Cons*:
You wont find these in small displays due to the limitations on the spacing of the LEDs (only good for long distance viewing) causing "Screen door effect".
Cost is still high



*OLED* Organic Light Emitting Diode is the newest and by far the most exciting display format.
You will already find this display in most smartphones and some small laptops. Being that this is still a new technology it is also the least known. 
Organic light-emitting diodes work somewhat the same as a normal LED however are much smaller and uses organic compounds which emit light in response to an electric current. The biggest advantage to OLED is that is can be literally printed onto a thin clear surface like a flat piece of glass or even a sheet of plastic that can be rolled up when not in use. The possibilities are endless.
*Pros*:
Ultra thin
Lightweight
Very very low power consumption
Stunning color reproduction and amazing black levels
Small footprint
*Cons*:
Large displays bigger than 12" are very costly and thus not ready for the average consumer market

See how it works here

Hope this helps to clear up some of the confusion that is out there.


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## Sonnie

Nice work Tony... we'll make it a sticky. :T


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## Alan Brown

Here's a link to a series of very in-depth technical articles by Dr. Raymond Soneira, at his DisplayMate Technologies web site. Some of the articles are older, but still fundamentally sound when it comes to how various types of video displays are built and perform: http://www.displaymate.com/shootout.html .

Best regards and beautiful pictures,
Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants affiliate

"Advancing the art and science of electronic imaging"


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## tonyvdb

Looks Good :T Thanks Alan


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## mechman

PCWorld has a fairly decent write up on the various display types here.


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## spurdarren

Nice write up. I do have to disagree with you saying that plasmas are not good for gaming. I have had 2 plasmas and have had 0 issues with them. I play a fair amount of games and havent had any burn in at all. I have had a small amount of image retention that goes away after a few minutes of watching tv. I have had a lot of Call of Duty gaming marathons on both tvs. I am talking about 8-12 hour sessions.


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## GortWillSaveUs

It seems that the prices on LED HDTVs have come down drastically.
If all things being considered, including pricing,..then LED seems to be the way to go.

Plasma (way too hot)
LCD (glare, and weird viewing angles)


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## tonyvdb

LCD and LED are the same display. LED displays are just LCD using LEDs to backlight the LCD panel rather than a florescent tube in the older displays. This has little to no effect on the viewing angle or glare.


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