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fc417fc802today at 5:37 PM2 repliesview on HN

As I understand it going faster typically skips steps that are necessary for maintenance of the panel. Fine for a while but if you don't periodically run a "proper" cycle the panel could eventually be permanently damaged.


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birdsongstoday at 6:10 PM

That's exactly it. I was a firmware engineer at reMarkable making the latest tablets.

We had some secret eink sauce (propriety waveforms) to get the high refresh rates and colour contrast without a full flashing screen reset, but even then you need to run longer maintenance refreshes occasionally.

Pixels are just vertical columns of viscous fluid with charged ink particles. A waveform is just voltage changes over time to these columns to shift the particles up and down. More black to the top = darker shade of grey. Colour (in the gallery display, at least) is the same, just with each CMY particle group having different charges and responses to different waveforms.

Every once in awhile this vertical column gets messy with loose particles distributed through it (ghosting, muddy contrast) so performing a hard rail-to-rail voltage reset forces all the particles up and then down, and gives you a clean slate.

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gamblor956today at 8:17 PM

It's not that those steps are necessary to prevent damage, it's that those steps were traditionally necessary to maintain calibration of the individual cell states. Also...the first several generations used really slow graphics processors based on the premise that use cases didn't require fast refreshing.

eInk mostly fixed the calibration issue years ago before the first eink monitors came out, and most eink products these days use beefier graphics processors.

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