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Does anyone out there know anything about "burn-in" ? I know that it is a phenomenon that can occur if an OLED TV has a static image displayed on it for an excessively long time; whereby a ghost of that static image can be seen on the TV screen even after that image is no longer sent to the TV. If that ghost image is temporary, then that phenomenon is known as "image retention". If the ghost image is permanent, then that phenomenon is known as "burn-in".
But what specifically happens with "burn-in" ? Is the ghost image burnt into the glass panel that covers the TV screen ? (I doubt it.). But if not the glass panel, then which layer of the stack experiences the burn-in ? Is it one of the host material layers ? Or is it one of the emissive materials that experiences the burn-in ? If it is one of the emissive materials, is "burn-in" the right term, or would "burn-out" be closer to what actually happens ? Or is it the emissive material drivers that burn out ?
It seems like the solutions for "burn-in" offered so far have been topical in nature. Is a solution possible at a more specific level ?
Samsung & Friends have been shouting about the risks of burn-in at the top of their lungs. Now it appears that they will be making an OLED TV variant. Do they know something ?
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I'll take a stab: burn-in happens when there is a static portion on the display, like in a CNN or Fox broadcast. A set of pixels are on continuously for many hours - rather than turning on and off, like the rest of the display - to the point that those pixels degrade and visibly produce less light than the rest of the display. Burn-in becomes apparent when the display subsequently is set to one color that is supposed to be a uniform brightness. I don't see how burn-in would be due to the backplane, or to one of the charge transport layers. It seems to me that it has to be due to the emitter/host layers.
I've been trying to figure out why Samsung believes its blue QD OLED display will be less prone to burn-in. Here's a theory: LG's white OLED consists of multiple hosts and emitters, with red, green and blue layers. When a white OLED ages, there must be differential aging of each layer: I assume the red and green layers are more durable than the blue. That would create a color shift, so a flat white image could have not only a darker segment but also a segment that's not quite white anymore.
With a Samsung blue QD OLED display, there shouldn't be much, if any color shift with aging. So, a white pixel with burn-in would still be white. My guess is that the absence of color-shift would make burn-in less apparent.
Regarding its decision to make OLED TV's, after shouting about the risks for a few years, does Samsung know something? Yes, I think so. First, a lot of the burn-in brouhaha is bogus. It happens, but not with reasonable use. Second, enthusiasts consistently rate the OLED TV's as superior to current competitors. Third, micro-LED's will probably (almost certainly?) never be cost competitive with OLEDs, consigning micro-LED's to very large and outdoor displays, or to very small (watch?) displays that may benefit from more brightness. |
