Hi Does japanese driver maker Tonogen still exist? operating under a different name?

A couple pair of older speakers I own(ed) have Tonogen tweeters,  Linn Index Plus, and Linn Tukan.
Can’t find anything on Tonogen when I google, anyone know if still in business, bought out by anyone, and I am also curious where Tonogen ’ranked’ in the opinion of some DIY’ers. Still have the Linns.