E Ink owns the majority of the patents, so direct clones of E Ink are being made under license. I do not think that the patents are the limiting factor - the specific applications are somewhat limited compared to widespread use of OLED.

For the applications that have mass apeal we saw that the price goes down to a comparable level of an LCD (eg in ebook readers and shelf labels).

There is also a bunch of innovation happening in the market - competitors like ClearInk are trying to build a better version of E paper, but it's always hard to scale some new technology and it will take some time before anything substantial comes along. E Ink was lucky that they found the killer app in ebook readers and that really helped them get to volumes that allow them to build these screens in commercial volumes.