Originally Posted by specuvestor
+1 what we are able to see is the color filter.
When we simplify LG/ Kodak OLED as WOLED it do become misleading
What I'm not so sure is if Sammy's implementation of individual emitter has no perceivable advantage when implemented properly.
It might have one. But I have two important observations:
1) Currently, it has no advantage I can detect.
2) Even if there is some small advantage, I doubt it's enough to matter in the marketplace. The Samsung might be slightly better -- emphasis on might -- but never enough to win on "better-ness".
Originally Posted by taichi4
A point I've reiterated on this and other threads. White is the output of the stacked RGB oleds.
Yes, and you are correct. I clarified the whole chain because the thread has a lot of misleading statements. Not all of the statements, however, were misleading.
Originally Posted by Raistlin_HT
Yeah, unless something has changed recently ... there really is no such thing as a white LED (at least commercially). For inorganic LED, it's usually a blue LED with a yellow phosphor for cost reasons. Higher end products use RGB (green is expensive IIRC). For organic LED, RGB is the typical method.
When you say "There are no pixels in the OLED layer at all" though, I'm not sure how that would work. The TFT needs to be able to address each white pixel with a luma value - otherwise how would this work? I assume the sub-pixel layers are in series so you don't need to individually control voltage. Of course that's assuming the sub-pixels' voltage vs luma ramps will allow that. Either way, they need to individually address the white (RGB) 'pixel' underneath each 4-color filter grouping.
Each visible pixel has four white sub pixels. You control voltage on the "red" sub pixel when you need to. The "red" sub pixel is the white sub pixel that is below the red section of the color filter. But when you control that, it turns on all the layers of OLED. That's why red is in quote marks. And, yes, I'm sure they are in series and it's designed that if you want say "red 162" (or the 162nd value of red on the way to 255), you apply enough voltage to the stack, the white lights up, it shines through a little tiny bit of red color filter and you go from there. Meantime, the blue 219 and the green 64 are also shining through. And the white 111 is joining them to provide extra illumination in that stop. Of course, this is just an example.
I suppose this may just be a semantics issue. Do you consider each individually addressable unit in the OLED layers a sub-pixel ... and the totality of the white light emitted through the top a pixel? Similarly, do you call each color filter element a sub-pixel ... and each group of 4 a pixel? I guess that's where I'm coming from.
So let me try again.
Sub pixel = stack of R + G + B OLED + a little tiny piece of color filter in only one color (or clear) [the stack is aligned precisely behind whichever piece of color filter the sub pixel is representing]
Pixel = 4 stacks of R + G +B OLED + a tiny piece of red color filter + a tiny piece of green color filter + a tiny piece of blue color filter + a tiny piece of clear front glass
I'm not sure either case is inherently true. In terms of performance, it's quite likely this will actually have less color shift over time. From what I understand the blue OLED layer is actually using FOLEDs instead of PHOLEDs. They age similar to green and red PHOLEDs ... and to my knowledge the Samsung panels will be a traditional PHOLED RGB design.
Yes, this needs to be specifically clarified. LG is using a fluorescent blue. It is designed to have good aging characteristics. My point is this, however: Nothing about stacking the colors changes the underlying issue. If any of those colors does
age differently, the display will color shift just like an RGB one. People are mistakenly assuming that the stacking of the colors is magically solving the differential aging problem and it isn't. Now, the fact that LG can use a different blue than Samsung might well help with aging, but let's just agree that's a second-order effect.
As for power consumption, the LG design has 3 things going against it. The layering of OLED's will lose some brightness ... FOLEDs use more power (blue layer) ... and color filters lose some brightness.
However they are using a RGBW arrangement for the color filter, which significantly increases output. Is it enough to match or beat the Samsungs? I don't know, but I'm not sure it will automatically be inferior. As you said though, either way it will be less than LCD which is good enough for most people.
If either the Samsung or LG reaches market with the brightness being used on the show floor, you will need sunglasses to watch them. I am not worried about brightness or power consumption.
The better 55" LCDs are already using about as much power as a light bulb. I am a legitimate environmentalist. We have to stop pretending getting TVs down from 1 light bulb to .7 light bulbs is actually an important change.
Incidentally, I'm confident later generations of OLED will use somewhat less power.
(Again, mobile phones are another matter. Ditto tablets and laptops. For those, Samsung's RGB design is superior and already approaching cost parity with LCD.)