Originally Posted by rogo
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 think the problem here is that this design is so unique, many want to talk about the underlying technology - and this design is essentially a two-step fractal. You have an underlying red element, green element, and blue element. These combine into white. You then take a group of those with red, green, and blue filtering (plus one unfiltered) and you have the top level structure.
What I've seen in many threads though is that when specifically discussing the tech behind the white OLED's ... many (including me) have called it a pixel and the elements making it from the red, green, and blue layers as being sub-pixels. While that's a bit of a broad usage, it certainly makes sense why people would call it that. So the question becomes ... just what should
we name everything in order to aid in discussion clarity? This two-step fractal makes discussions difficult unless someone is particularly verbose. And since this design is so new, I expect people will continue discussing both levels of the physical tech.
Any recommendations on some good naming conventions to proceed with? I would submit we should use the strict definition of pixel (picture element) and sub-pixel. In other words use it to describe what we can actually see on the screen. So with that in mind, a sub-pixel would be a white OLED and its color filter. A pixel would be a grouping of 4 of those (one with a red filter, one with green, one with blue, and one with none).
Now however, what is a good naming convention so people can discuss the tech used for the white OLED? I think for the sub components, maybe layer element instead of sub-pixel? So it would be red layer element, blue layer element, and red layer element? I can't really think of a cute name for the actual white OLED that's an aggregate of them though. I guess maybe just calling it a WOLED is easiest?
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.
While it may be a second order effect, one has to look at this in terms of actual deltas over the expected usage life time of an average TV - it's a question of magnitudes.
Obviously in a perfect world R, G, B would age at the same rate (or better yet, not at all) ... but that's not realistic at this time. There will be some drift, but we have to think about it in the aggregate. It's not just about comparing the actual half-life age values themselves ... but looking at how far those values push out serious error accumulation.
In modern PHOLEDs, both red and green have pretty long lives. Not the exact same, but it's far enough out there that the error accumulation over the average viewing life of a TV yields a relatively small drift. Regardless of how long the blue FOLED life is, as long as it's long enough ... the actual error accumulation won't be significant. And that's where the LG solution comes into play. Unless Samsung's partners have had some crazy new breakthrough for blue (which to my knowledge they haven't - and I follow Universal Display Corp quite regularly as I'm a stock owner) ... then the amount of drift their display will have will definitely be higher. While the half-life has been pushed out some ... it's still like an order of magnitude or more lower than red and green ... and the bigger problem, it's short enough that I'd expect some sizable error accumulation over the average viewing life of a TV. At least if it's used as your main set.
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.
Wasn't implying you necessarily should be - just discussing the tech differences. Though I'm sure some will use this for spec wars
That said, the answers to this may impact the above. All things being equal, the lower drive voltage being used ... the slower the aging.