They’re both wrong

Sony OLED TV longevity claim challenged | Register Hardware

Like all colour TVs, the XEL-1 colours its pixels by mixing different intensities of red, green and blue light. DisplaySearch found that, during the 1000-hour test period, the ability of the two screens to display blue had degraded by 12 per cent. A seven per cent drop was recorded for red and an eight per cent decline for green.

This discussion of OLED lifetime seems really stupid for a bunch of reasons.

First, who in their right mind these days wouldn’t make a self-calibrating set that adjusts its voltage curves to get the out put right regardless of what the emitters are doing?

Second, the conversion of lifetime in viewing hours to lifetime in years depends so very crucially on what people use the thing for — my monitor is on for probably close to 12 hours a day (which means 17000 hours in about 4 years), but if we watch more than 15-20 hours of TV a week that’s a lot (which means more like 20 years)

But third, if the degradation of OLEDs really is about oxygen and water diffusing into the screen, it’s not clear that the screen being turned on has anything to do with how fast the OLEDs go bad, because that diffusion is happening regardless of whether the screen is on. (Insofar as the the OLEDs generate heat, that might slow down the diffusion — things tend to diffuse away from hot areas. Or it might speed it up, because hot plastics are more permeable.) Or you might need an electrical potential in addition to the diffused-in oxygen and H2O, in which case there will be two separate degradation curves superimposed, with weird things happening when one gets ahead of the other, for example the first few days you turn the TV on after coming back from vacation.

But since the current target market for these widgets will be replacing them in 6 months for the next shiny thing, who cares?


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