I've worked close with e-ink before in a past life getting early access to prototypes and pre-release tech, and can confirm that yields ware a huge issue back t

I've worked close with e-ink before in a past life getting early access to prototypes and pre-release tech, and can confirm that yields ware a huge issue back then holding back progress (I remember they had some really cool shit in the lab that I still haven't seen come to market). It's why progress is so slow. Patents are a moat, like any other tech company does to protect it's IP, investments and hard work, but it's not the main moat. Making color/advanced e-paper displays for prototypes and concepts that only work in a trade show is not difficult, but making that at scale, with good yields to guarantee great image quality at low refresh power, low cost for your customers to stay interested and good margins for you to stay in business is the impossible part. Very similar to the challenges of scaling down silicon nodes except you're doing it at your own expense, without the dozens of billions that governments and major companies are pouring in it. Things will stay as is or will progress very slowly, not because e-ink is some evil corporation abusing the patent sistem to hold back progress, but because e-paper displays are used in this product niche of mostly e-readers and digital signage, which have long upgrade cycles and very low margins, meaning there's too little money to make huge leaps, while all the big money in display tech is going into OLED and micro-LED tech as that's what the consumer market wants and buys at large enough quantities and margins, so that's where the big players like Samsung, LG and BOE will be investing in, instead of in e-paper tech.