LG 55EA8800 Gallery OLED TV at CES 2014 - AVS Forum
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post #1 of 89 Old 01-13-2014, 01:15 PM - Thread Starter
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I was very happy to see one flat OLED TV in the LG booth. The 55EA8800 measures 55" with a pixel resolution of 1920x1080. This model is surrounded by a fine-art frame, so when you're not watching TV, it becomes a digital painting. Very cool!

 

The 55EA8800's frame includes the speakers. I like that it's flat!

 

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post #2 of 89 Old 01-14-2014, 12:33 AM
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A bonus is that the Gallery frame can be removed and ones own speaker setup used. smile.gif
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post #3 of 89 Old 01-14-2014, 08:36 AM
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Originally Posted by mypretty1 
A bonus is that the Gallery frame can be removed and ones own speaker setup used. smile.gif
eek.gif Actually in my country the frame costs €1.000 extra.
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post #4 of 89 Old 01-14-2014, 08:41 AM
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Originally Posted by Scott Wilkinson View Post

I like that it's flat!

 

Do any of the top reviewers out there think that curved is anything other than bizarre nonsense?


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post #5 of 89 Old 01-14-2014, 04:19 PM
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Do any of the top reviewers out there think that curved is anything other than bizarre nonsense?

I doubt it.
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post #6 of 89 Old 01-15-2014, 10:19 PM
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It's interesting that the only flat OLED they plan to release in the U.S. requires wall mounting. Maybe attaching a stand to a huge 4mm thick surface wasn't a good idea after all.
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post #7 of 89 Old 01-16-2014, 07:20 AM
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It's interesting that the only flat OLED they plan to release in the U.S. requires wall mounting. Maybe attaching a stand to a huge 4mm thick surface wasn't a good idea after all.

 

That true?  Besides, there are plenty of stands that support the VESA mounting standard.  If it can go on a wall, it doesn't have to go on a wall.  Things like this:

 

images?q=tbn:ANd9GcQmywAHJ40_Dg_r2ZKTWpN8lsuNPrQGWgL45UB7X1BLjJgsMnljww

 

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post #8 of 89 Old 01-16-2014, 02:07 PM
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Playing Mario on a curved panel must be like living in a world created on the inside a cement truck.
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post #9 of 89 Old 01-16-2014, 08:55 PM
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Originally Posted by tgm1024 View Post

That true?  Besides, there are plenty of stands that support the VESA mounting standard.  If it can go on a wall, it doesn't have to go on a wall.  Things like this:

That's not really a stand. More like wall mounting without the wall. smile.gif

From what I understand, you have to use their custom swivel mount anyway.

My point was that I think they made these things too thin for their own good. Maybe the limited flat version with carbon-fiber frame was too complicated and expensive to ship in larger markets like the U.S. Curving (like wall mounting) was another solution to achieve the same goal while keeping it thin. Otherwise I don't understand why we never got the flat stand model like those in Europe and Korea considering the negative feedback on the curved shape.
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post #10 of 89 Old 01-17-2014, 12:44 PM
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I can't imagine wasting the finite lifespan on my OLED on displaying faux art. Burn-in is a lesser concern. The relatively short life of the blue emitters is a major one.

There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working.
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post #11 of 89 Old 01-17-2014, 04:24 PM
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Originally Posted by rogo View Post

I can't imagine wasting the finite lifespan on my OLED on displaying faux art. Burn-in is a lesser concern. The relatively short life of the blue emitters is a major one.
Do the LG sets have blue emitters?

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post #12 of 89 Old 01-17-2014, 07:38 PM
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Do the LG sets have blue emitters?

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Red, blue, green and white, as I recall.

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post #13 of 89 Old 01-18-2014, 05:58 AM
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Originally Posted by Trackman View Post

Red, blue, green and white, as I recall.
See, my understanding is that LG used a technique which just employed one, uniform white OLED pixel type across the whole screen, with conventional non-OLED red, green and blue filters placed on top in order to give the colours.

By employing this approach, it was my understanding that LG avoided the problem of non-uniform pixel fade, which might be a problem in the Samsungs.

Am I wrong on this?

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post #14 of 89 Old 01-18-2014, 07:01 AM
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Originally Posted by Desk. View Post
 
Quote:
Originally Posted by Trackman View Post

Red, blue, green and white, as I recall.
See, my understanding is that LG used a technique which just employed one, uniform white OLED pixel type across the whole screen, with conventional non-OLED red, green and blue filters placed on top in order to give the colours.

By employing this approach, it was my understanding that LG avoided the problem of non-uniform pixel fade, which might be a problem in the Samsungs.

Am I wrong on this?

Desk

 

If that were true, there wouldn't be a way to have a single subpixel be less intense than another.

 

We had considerable discussion about this quite some time ago.  Most of us believe that it's a blue OLED with a yellow phosphor (a dichromatic white) for each subpixel.  They are then put through individual filters.

 

But each subpixel still needs to be addressed and emitting independently.


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post #15 of 89 Old 01-18-2014, 07:29 AM
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Quote:
Originally Posted by Desk. View Post

See, my understanding is that LG used a technique which just employed one, uniform white OLED pixel type across the whole screen, with conventional non-OLED red, green and blue filters placed on top in order to give the colours.

By employing this approach, it was my understanding that LG avoided the problem of non-uniform pixel fade, which might be a problem in the Samsungs.

Am I wrong on this?

Desk

Per HDTV Test, "WOLED-CF, i.e. White OLED backlight with 4-colour (RGBW) filter on top." BTW - they preferred Sammy's RGB approach. Also note the screen uniformity issues they observed. http://www.hdtvtest.co.uk/news/55ea980w-201312083487.htm

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post #16 of 89 Old 01-18-2014, 07:42 AM
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Quote:
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Quote:
Originally Posted by Desk. View Post

See, my understanding is that LG used a technique which just employed one, uniform white OLED pixel type across the whole screen, with conventional non-OLED red, green and blue filters placed on top in order to give the colours.

By employing this approach, it was my understanding that LG avoided the problem of non-uniform pixel fade, which might be a problem in the Samsungs.

Am I wrong on this?

Desk

Per HDTV Test, "WOLED-CF, i.e. White OLED backlight with 4-colour (RGBW) filter on top." BTW - they preferred Sammy's RGB approach. Also note the screen uniformity issues they observed. http://www.hdtvtest.co.uk/news/55ea980w-201312083487.htm

 

Yes, but it cannot be a single white backlight because it needs to output varying amounts of red, green, and blue (and white).  This is accomplished in an LCD by having an LCD array act as the gate through which the backlight (which is always on full blast unless using local/frame dimming technology) goes through.  But this is an OLED (an emissive device) so there is no LCD to mitigate the light.

 

In LG's case, instead of Samsung's approach of having an R, G, and B, OLED, they are using a separate white OLEDS (which are blue + yellow phosphor, or blue + red & green phophors, or in some documents a stacked red, green and blue OLED---which I don't believe for a second), which are then filtered.  I think this filtering business is nonsense IMO, except that it allows for 1: a potential even wear (because everything starts as blue), and 2: a potentially cheaper production process because there's only one type of OLED they have to create.  I have no idea at what stage they add the filters.

 

Note: at one point there was some information from LG that implied that there were no subpixels at all.  Strictly speaking this is impossible, because to get a varying red/green/blue, you have to supply separate regions with differing amounts of electricity.  This means subpixels.  So I have no idea where that business came from, and I haven't seen any documentation that explains it.


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post #17 of 89 Old 01-18-2014, 10:48 AM
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Originally Posted by tgm1024 View Post

If that were true, there wouldn't be a way to have a single subpixel be less intense than another.
I think you may have misunderstood me. I referred to one uniform, white OLED pixel type, as in lots of little white OLED pixels, all constructed the same and decaying at the same rate, operating independently underneath colour filters.
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Originally Posted by tgm1024 View Post

In LG's case, instead of Samsung's approach of having an R, G, and B, OLED, they are using a separate white OLEDS (which are blue + yellow phosphor, or blue + red & green phophors, or in some documents a stacked red, green and blue OLED---which I don't believe for a second), which are then filtered.  I think this filtering business is nonsense IMO, except that it allows for 1: a potential even wear (because everything starts as blue)
Yup - that was my understanding of LG's approach.

Thanks,

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post #18 of 89 Old 01-18-2014, 10:58 AM
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Quote:
Originally Posted by Desk. View Post
 
Quote:
Originally Posted by tgm1024 View Post

If that were true, there wouldn't be a way to have a single subpixel be less intense than another.
I think you may have misunderstood me. I referred to one white, uniform OLED pixel type, as in lots of little white OLED pixels, all constructed the same and decaying at the same rate, operating independently underneath colour filters.

 

Subpixel, yes.


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we have had it since November last year.
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post #20 of 89 Old 01-19-2014, 01:54 PM
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Quote:
Originally Posted by tgm1024 View Post

1: a potential even wear (because everything starts as blue)

Actually, it has no potential for even wear.
Quote:
, and 2: a potentially cheaper production process because there's only one type of OLED they have to create.  I have no idea at what stage they add the filters.

A dramatically cheaper process because they vapor deposit the entire layer of OLED without any pixels whatsoever. Samsung has to push the OLED material through a screen which has to be scanned across a large substrate to avoid sagging (from a large screen). LG has no screen, they just deposit a layer over the whole substrate.
Quote:
Note: at one point there was some information from LG that implied that there were no subpixels at all.  Strictly speaking this is impossible, because to get a varying red/green/blue, you have to supply separate regions with differing amounts of electricity.  This means subpixels.  So I have no idea where that business came from, and I haven't seen any documentation that explains it.

So, you're still confused then.

There are no OLED subpixels made on the display in any conventional sense. The TFT backplane is made with subpixels... The transistors they excite a bit of OLED material that is a "subpixel's worth". That material is always "white", but represents a subpixel that will ultimately be red, green, blue or white depending on the color filter in front of it. The color filters sit above the OLED layer in much the same way they sit between you and the light in an LCD (which is also white, of course).

In some very loose sense, LG's OLED resembles LCOS in that the pixels are not directly patterned in the active layer.

Strictly speaking, what you consider "impossible" is what's going on. The transistors feed the OLED layers exactly the same for each subpixel, with the only difference between a current modulation to determine intensity (let's say it's 0-255, though I'm not strictly sure what shenanigans are going on that may make them a bit different). Colors are made by mixing sub pixels like in all flat panels but within a subpixel there is no internal modulation.

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post #21 of 89 Old 01-19-2014, 04:21 PM
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Reading this discussion it seems to me that all of you are understanding the design concept but are explaining it in different ways.

The way I understand it from the literature is that LG does not pattern the OLED emissive material (or the injection and transport materials IIRC). They are just large monolayer sheets covering the entire display area (similar to the picture below). The TFTs/andode/cathose/filters are patterned to form pixels.

3112_zps7201dfe3.jpg~original

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post #22 of 89 Old 01-19-2014, 08:22 PM
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Originally Posted by rogo View Post

Actually, it has no potential for even wear.

It absolutely does. I have posted the paper here before but here it is again. Figure 5 on page 11 shows the color stability of the system. The half life of the red and green materials are an order of magnitude larger than for the blue material and yet there is little color shift in the system. A quick glance at the relative peaks tells you that.

http://www42.tok2.com/home/ksatsch/pdf/60_WhiteOLEDs(OLEDs).pdf
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post #23 of 89 Old 01-20-2014, 12:43 AM
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Quote:
Originally Posted by xrox View Post

Reading this discussion it seems to me that all of you are understanding the design concept but are explaining it in different ways.

The way I understand it from the literature is that LG does not pattern the OLED emissive material (or the injection and transport materials IIRC). They are just large monolayer sheets covering the entire display area (similar to the picture below). The TFTs/andode/cathose/filters are patterned to form pixels.

That's pretty much exactly what I said.
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It absolutely does. I have posted the paper here before but here it is again. Figure 5 on page 11 shows the color stability of the system. The half life of the red and green materials are an order of magnitude larger than for the blue material and yet there is little color shift in the system. A quick glance at the relative peaks tells you that.

I am not talking about color stability. I am talking about the potential for burn-in/image intensity degradation of any subpixel that is overutilized. It doesn't matter if they can mystically solve the "blue problem" of a given subpixel. If that subpixel is used extensively, it will wear out faster than a neighbor. And because the blue (in particular) doesn't last especially long, subpixels don't last especially long.

There is a ton of confusion here about what's going on, but at the end of the day there are 4 x 2 million subpixels on the existing display. And even though the OLED layer itself is comprised of what looks like one giant layer of material that emits white, those 8 million subpixels do not have any chance of even wear (other than the chance generated by 100% random content).

I stand by my statement and nothing in the linked paper disputes it.

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post #24 of 89 Old 01-20-2014, 05:16 AM
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Originally Posted by rogo View Post

That's pretty much exactly what I said.
I am not talking about color stability. I am talking about the potential for burn-in/image intensity degradation of any subpixel that is overutilized. It doesn't matter if they can mystically solve the "blue problem" of a given subpixel. If that subpixel is used extensively, it will wear out faster than a neighbor. And because the blue (in particular) doesn't last especially long, subpixels don't last especially long.

There is a ton of confusion here about what's going on, but at the end of the day there are 4 x 2 million subpixels on the existing display. And even though the OLED layer itself is comprised of what looks like one giant layer of material that emits white, those 8 million subpixels do not have any chance of even wear (other than the chance generated by 100% random content).

I stand by my statement and nothing in the linked paper disputes it.

I think the original comment was talking about wear within a pixel, but in any case, we agree. Wear across pixels is a definite worry, but within a single pixel, color stability should be very good. LG does use a pixel compensation circuit in their TFT but I am not sure if this is to compensate for the degraded luminance of the OLED materials or to account for variations with the IGZO substrate itself.

FWIW, a Korean research house believes that LG is going to go with a two blue architecture in their 2014 OLED models. I assume that is to increase the half-life of the white subpixels.
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post #25 of 89 Old 01-20-2014, 06:54 AM
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Quote:
Originally Posted by rogo View Post

That's pretty much exactly what I said.
I am not talking about color stability. I am talking about the potential for burn-in/image intensity degradation of any subpixel that is overutilized. It doesn't matter if they can mystically solve the "blue problem" of a given subpixel. If that subpixel is used extensively, it will wear out faster than a neighbor. And because the blue (in particular) doesn't last especially long, subpixels don't last especially long.

There is a ton of confusion here about what's going on, but at the end of the day there are 4 x 2 million subpixels on the existing display. And even though the OLED layer itself is comprised of what looks like one giant layer of material that emits white, those 8 million subpixels do not have any chance of even wear (other than the chance generated by 100% random content).

I stand by my statement and nothing in the linked paper disputes it.

I think the original comment was talking about wear within a pixel, but in any case, we agree. Wear across pixels is a definite worry, but within a single pixel, color stability should be very good. LG does use a pixel compensation circuit in their TFT but I am not sure if this is to compensate for the degraded luminance of the OLED materials or to account for variations with the IGZO substrate itself.

FWIW, a Korean research house believes that LG is going to go with a two blue architecture in their 2014 OLED models. I assume that is to increase the half-life of the white subpixels.

 

 

1. Yes, I was talking about wear within a pixel, and it's absolutely has to do with the way LG is forming the white.  We never did end up with a clear consensus as to whether or not they were following the original Kodak patent or not, but as I recall most of us read this as a blue LED exciting a yellow phosphor.  When THAT blue fades, the yellow fades with it.  This causes the white to lessen, but remain white.  Since this is under each of the color filters, each red, green, blue, (and white) subpixel end up with the same tendency to fade.

 

2. Rogo, this business of there not being pixels or subpixels is still just not true.  The resulting out is and always has been discrete regions of light emission.  It doesn't matter in the least how the material was placed down.  The anode/cathode MUST control a tightly defined region.  It doesn't matter at all that there is OLED un-excited material to the sides unused.  This is no semantic argument Rogo, they are pixels.

 

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Originally Posted by xrox View Post

Reading this discussion it seems to me that all of you are understanding the design concept but are explaining it in different ways.

The way I understand it from the literature is that LG does not pattern the OLED emissive material (or the injection and transport materials IIRC). They are just large monolayer sheets covering the entire display area (similar to the picture below). The TFTs/andode/cathose/filters are patterned to form pixels.

3112_zps7201dfe3.jpg~original

 

Correct.  However Rogo's statement needs clarification still.
 

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Strictly speaking, what you consider "impossible" is what's going on. The transistors feed the OLED layers exactly the same for each subpixel, with the only difference between a current modulation to determine intensity (let's say it's 0-255, though I'm not strictly sure what shenanigans are going on that may make them a bit different). Colors are made by mixing sub pixels like in all flat panels but within a subpixel there is no internal modulation.

 

Transistors aren't magic.  If you're using "modulation" as a term describing the changing of levels (not limited to pulse-width, etc.), then if there is a current (or voltage) level change, it needs to change the subpixel "internally".  There's no other way for the region of OLED material underneath a filter to excite at varying amounts, and this is required for any emissive display.


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post #26 of 89 Old 01-20-2014, 06:57 AM
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FWIW, a Korean research house believes that LG is going to go with a two blue architecture in their 2014 OLED models. I assume that is to increase the half-life of the white subpixels.

 

I speculated about this a long time ago.  Even in the case of the LG dichromatic white (blue exciting yellow) it makes perfect sense if they can pull it off underneath everything.


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post #27 of 89 Old 01-20-2014, 07:06 AM
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Originally Posted by tgm1024 View Post


1. Yes, I was talking about wear within a pixel, and it's absolutely has to do with the way LG is forming the white.  We never did end up with a clear consensus as to whether or not they were following the original Kodak patent or not, but as I recall most of us read this as a blue LED exciting a yellow phosphor.  When THAT blue fades, the yellow fades with it.  This causes the white to lessen, but remain white.  Since this is under each of the color filters, each red, green, blue, (and white) subpixel end up with the same tendency to fade.

FWIW, I have seen a SID presentation from LG which confirms that they are using a hybrid tandem stack for their OLED . That matches the paper that I linked.

There is an interaction between the emitting regions but I am not sure that I agree with your description that the blue OLED "excites" the yellow phosphor. That sounds like the blue light itself is causing the yellow emission. I dont believe that is the case. Both the blue and yellow emitter layers are current driven emitters that are capable of emitting light on their own.
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post #28 of 89 Old 01-20-2014, 07:21 AM
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1. Yes, I was talking about wear within a pixel, and it's absolutely has to do with the way LG is forming the white.  We never did end up with a clear consensus as to whether or not they were following the original Kodak patent or not, but as I recall most of us read this as a blue LED exciting a yellow phosphor.  When THAT blue fades, the yellow fades with it.  This causes the white to lessen, but remain white.  Since this is under each of the color filters, each red, green, blue, (and white) subpixel end up with the same tendency to fade.

FWIW, I have seen a SID presentation from LG which confirms that they are using a hybrid tandem stack for their OLED . That matches the paper that I linked.

There is an interaction between the emitting regions but I am not sure that I agree with your description that the blue OLED "excites" the yellow phosphor. That sounds like the blue light itself is causing the yellow emission. I dont believe that is the case. Both the blue and yellow emitter layers are current driven emitters that are capable of emitting light on their own.

 

I'd like to see the presentation if you could PM it to me.  I'm totally up for that part of this to be true either way: I have no skin in the game, and would love to learn.  BTW, I'm frustrated with LG.  It seems that every time someone over there tries to explain something they contradict it later.  It's almost as if their marketing team just cant shut up long enough for the engineers to talk properly.

 

I want to know more about the stacking interactions as well.

 

The dichromatic blue + yellow phosphor in the documents is a confusing one.  Because they both are emission entities, they get labled blue + yellow, and sometimes blue + red/green carelessly.  I went with the information and explanation from ynotgoal a long time ago because it followed the kodak patent that presumably everything was based upon.

 

That, and I believe that dichromatic white from a blue LED and yellow phosphor was the first way a white LED was created a long time ago.


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post #29 of 89 Old 01-20-2014, 07:58 AM
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I'd like to see the presentation if you could PM it to me.  I'm totally up for that part of this to be true either way: I have no skin in the game, and would love to learn.  BTW, I'm frustrated with LG.  It seems that every time someone over there tries to explain something they contradict it later.  It's almost as if their marketing team just cant shut up long enough for the engineers to talk properly.

I want to know more about the stacking interactions as well.

The dichromatic blue + yellow phosphor in the documents is a confusing one.  Because they both are emission entities, they get labled blue + yellow, and sometimes blue + red/green carelessly.  I went with the information and explanation from ynotgoal a long time ago because it followed the kodak patent that presumably everything was based upon.

That, and I believe that dichromatic white from a blue LED and yellow phosphor was the first way a white LED was created a long time ago.

In the LG case the yellow (or red/green) emitter is NOT a photo excited phosphor like you see in LEDs/Plasma/Fluourescent light bulbs. They are seperate red and green phosphorescent EL materials (ie - singlet+triplet).

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Transistors aren't magic.  If you're using "modulation" as a term describing the changing of levels (not limited to pulse-width, etc.), then if there is a current (or voltage) level change, it needs to change the subpixel "internally".  There's no other way for the region of OLED material underneath a filter to excite at varying amounts, and this is required for any emissive display.
Yes, I did not catch that. Subpixels of course have to be modulated (current, voltage, or PWM).

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