Comment by daemonologist

Yes, although the original patent expired in 2017 so it's a little less clear-cut nowadays. They do have hundreds of patents and bought up basically all non-Chinese competitors though.

Regular old trade secrecy is also a big factor I think. I look for interesting new EPD papers on scholar.google from time to time, and they tend to be about stuff an undergrad would think of in the first twenty minutes, which suggests to me that everyone is trying to keep their tech very much under wraps.