Unsurprisingly, 240Hz is not actually recommended (at least that’s what I get from the abstract, and I’m not about to pay to read the rest of it).
And, in an IMO pathetic example of how the US patent world works, there are apparently patents on obvious architectures like using a fast PWM clock and then discretizing the VRR frame interval to multiples of the PWM time. I thought of this myself about 15 seconds after contemplating that VRR was a complication and then I searched for it and immediately found two patents. WTF!
alt Hacker News
I did some digging, and apparently there are serious designs using this sort of hybrid dimming:
https://www.imec-int.com/en/articles/displays-health-patches...
Apparently brightness consistency between pixels is poor at low drive current, so designers often use a separate PWM envelope to compensate.
And there are even papers studying the choice of frequency, e.g.:
https://pubmed.ncbi.nlm.nih.gov/41411543/
Unsurprisingly, 240Hz is not actually recommended (at least that’s what I get from the abstract, and I’m not about to pay to read the rest of it).
And, in an IMO pathetic example of how the US patent world works, there are apparently patents on obvious architectures like using a fast PWM clock and then discretizing the VRR frame interval to multiples of the PWM time. I thought of this myself about 15 seconds after contemplating that VRR was a complication and then I searched for it and immediately found two patents. WTF!