E-ink readers (like a Kindle) has been out for years, but even now after several generations of the products, all of them still does a full-screen refresh to remove the ghosting.
I can't find the answer on the official e-ink website, however this question: Why does "flashing" prevent ghosting on E-Ink displays? does explained how E-ink works but still not anwsering my question:
Why is it necessary to refresh the whole screen?
Wouldn't it be enough to just refresh the part that wasn't empty (white) plus some "padding" (since a answer in the linked question mentioned that "However, each cell might be influenced by its neighbors as well as the applied charge.")
For example, when we read a book, it's very likely that some part of the screen will be always empty (like page margin, line margin, etc...) why can't those reigons be left out (like when you use the "Page Flip" function in Kindle PW2, only the small preview window gets refreshed and the rest part of the screen stays still)
@CL. reminds me in the comment section that no matter how much "padding" is added, the boundary between refreshed and unrefreshed parts is always there... So as long as a cell could be influenced by it's neighbors, this won't work - duh!
- But still, I think it would be nice to add a few padding to keep the ghosting away from interfering with new texts to keep readability without doing a full-screen refresh which I really, really hate.
So what's the technical difficulty to prevent this influencing between the cells? The latest generation of E-ink is "Carta" is introduced in CES 2013, no upgrade for two years already.