The different types of displays and how they work

[Tony V.]

Over the last few years there has been a lot of advancements in display technology but there still seems to be a lot of misinformation and confusion about how these different types work.
I want to take this time to help elaborate on how each of these main types work in a clear and informative way.
With the older format the old CRT television being all but phased out below is the list of the 5 main types of displays: , LCD, LED, OLED, DLP and Plasma
You can still find some people hanging on to CRTs for use with old retro computers or some elderly who simply don't care about the new HD formats. We wont discuss them 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 back-lit 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



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 but is growing in popularity as the months go on. Many of the big display manufacturers are already releasing these to the market.
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
Can be made almost any size
Lightweight
Very very low power consumption
Stunning color reproduction and amazing black levels
Small footprint
Cons:
Large displays bigger than 70" are very costly and thus not ready for the average consumer market but prices are coming down fast.

See how it works here




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 was by far the best display available up until OLED was released.
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

NOTE: this display format has been discontinued and no longer in production.
See how it works here



DLP or Digital Light Processing is not very common and was mostly used in rear projection or projectors but is still common enough that its worth mentioning.
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

NOTE: this display format has been discontinued and no longer in production.
See how it works here


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

 

[Todd Anderson]

Great summary!

 

[Sonnie Parker]

Yep... very informative... and did not realize LCD had that many cons.

 

[Asere]

Great info. I'm leaning towards the TCL Series 6 line. Per consumer reviews and https://www.rtings.com/tv/reviews/tcl/6-series-2018-r617
they have very good HDR and is DV capable.

 

[tripplej]

Nice write up. Good info. Thanks for making it.

 

[Asere]

Which brand is more reliable as far as PQ Vizio or TCL? I know they both have come along way especially the newer TCL's.

 

[Tony V.]

I would have to say that Vizio has had a good run as of late. Dont hear much about TCL

 

[Todd Anderson]

TCL’s top end has garnered a ton of attention over the last year... it seems they’ve become the new “budget pick.” The upper end Vizio’s are super solid performers!

 

[Matthew J Poes]

@Todd Anderson has mentioned this in the past, but micro-LED seems to be the wave of the future. I was surprised that we weren't seeing more development with OLED but it seems like micro-LED is a better technology for the future. The pitch spacing on these micro-LED is allowing displays with no discernable screen door effect even in small displays. They have all the benefits of OLED but with cheaper and more reliable production, much brighter, no burn-in. After Todd mentioned this to me, I started reading up and I'm excited for this future.

I think we will see this in theaters first, as they replace projection screens. Imagine 300" cinema displays (or more) with 2000 nits of peak brightness or more allowing true HDR images with true Rec.2020 color reproduction. Black levels that are as black as possible, only limited by the physical environment. Resolution exceeding 8K!

What if 100" or 150" versions of this could be created for the home and sold for under $5000? Wouldn't that be truly competitive with projection, while offering really compelling advantages? I'd give up my AT screen for that! Especially if the price came down to $3000.

 

[Todd Anderson]

Samsung’s “The Wall” will be available to consumers this year, albeit exhorbitantly expensive. But microLED is definitely on its way to the home environment. The prototype at CES had excellent off-axsis performance and was producing beautiful images.

I do believe that OLED will eventually go the way of plasma... not because of energy considerations, but not ebecause of its apparent limited peak brightness capabilities.

 

[Matthew J Poes]

Samsung’s “The Wall” will be available to consumers this year, albeit exhorbitantly expensive. But microLED is definitely on its way to the home environment. The prototype at CES had excellent off-axsis performance and was producing beautiful images.

I do believe that OLED will eventually go the way of plasma... not because of energy considerations, but not ebecause of its apparent limited peak brightness capabilities.

My understanding is that they have a functioning Cinema Display too, with available sound system. Someone who has heard the sound described it as needing help. I was trying to talk Don Keele into working with them. More than likely the future of cinema surround will involve beam steering and minitiature drivers rather than the current and common large woofers and waveguides. Think giant HomePod more than simply giant speaker.

A major limitation is the exact same problem facing good sound in domestic displays. Good sounding minitiature drivers with high output and appropriate dispersion. The best 2” or 3” drivers simply handle too little power, are too in-sensitive, and sound too poor for use in cinemas.

Still, I see the problem easily overcome and I think the breakthrough this will offer in picture quality is enough to bring about at least a small resurragnce in cinemas. Further, good use of multi-driver arrays can improve sound evenness and reduce loss over distance such that high volume in certain sections won’t be needed. Everyone will hear and see the same thing.

 

[andremcc]

Hello, I wish I had came across this thread a few months ago, This was very informative and it really explained the difference between each display in detail.