Quote:
Originally Posted by
Kenbar
The regular "shadow" (not CNN max) is the one of interest to me. A drop of just 3~5% becomes visible in content...if not sooner. I remember the fellow who's wife watched a lot of cooking shows and ended up with a blooby center area.
Yeah, that CNN shadow is reaching the point it probably will start becoing visible on actual content.
The CNN shadow has drropped ~2.5% in ~5 weeks, or 0.5% / week. That transates to 100 weeks or 14,000 hours to 50% degredation or 35.7% degredation after 10,000 hours, meaning ~65% brightness after 10,000 hours (again, using a simplified linearized model).
From the data in the aging curve I posted, 20mA/cm^2 results in ~70% brightness after 10,000 hours, so we know the average current density in the CNN shadow atea exceeds that. And 40mA/cm^2 results in 65% brightness after something like 2000 hours, so we know the current density is way below that. 20mA/cm^2 is the closest of those curves and 20-25mA/cm^2 is probably an accurate bracket.
Turning to the CNN Max logo area which is degrading at a rate of 3% per week (6 times faster), it degraded to 50% brightness over 19 weeks or 2660 hours. The 60mA/cm^2 curve degrades to 50% after ~2000 hours, so that's an upper limit on current density and 55-60mA/cm2 is probably an accurate bracket.
And if we look at the CNN logo area which is degradng at a rate of 1.36% per week, that translates to 37 weeks or just over 5000 hours to 50% brightness putting it somwhere near the midpoint of the 20mA/cm^2 and 40mA/cm^2 curves (so let's call it 30mA/cm^2 +/-).
So CNN Max Logo is being driven at an average current density of 55-60mA/cm^2 associated with OLED Light 100 for 380cd/m2 peak.
CNN logo is being driven at an aveage current density of ~30mA/cm^2 associated with OLED Light of ~60 for 200 cd/m^2 peak.
And the CNN Max Shadow area is being driven with an average current density of 20-25mA/cm^2 with the same Max OLED Light setting of 100.
Everything seems to tie up pretty consistently and if we ever see any degredation in the Live NBC test we should be able to estimate the underlying aging rate for truly random content at 200cdm2.
For what it is worth, my ultra-simplified model for random content has been ~10% the average current density of a static logo.
So if the CNN logo is being driven at ~30mA current density, that would correspond to a an average current density of ~3mA/cm^2 or an aging rate of 0.14% per week. If the headroom is as much as 40% as we now suspect, that would translate to 285 or more than 5 years before any degredation.
I love rtings.com but doubt that they are likely to keep their 2017 burn-in test running that long...