Looks like some of the patents have expired, but the e-ink company keeps adding more. At least to my layman's eye the new patents don't seem to be particularly revolutionary :/
It's the same trick that pharmaceutical companies use to extend their patents. Find a slightly new use or way that also covers the old use, and bam, exclusivity for another 20 years.
This effect in the case of eInk is clearly described by others in this thread.
The real problem is that E-Ink is a niche product that lacks economy of scale, because LCDs do everything an EPD can do and more.
I don't know if it's been patented, but E-Ink's recent Gallery 3 screen is pretty amazing, they got multi-dye color screens to refresh fast enough to use in an e-note. That's insane, that's an order of magnitude reduction! It might actually make color e-notes a viable product category.