A couple of years ago, Henner Zeller developed a laser direct imager called ldgraphy.
In it he uses a circular mirror and a rotating polygon mirror;

Recently, I found out that Tecnica patented a very similar proces

They use this technology for selective laser sintering. It is very similar to Henner Zeller's idea but they did get patents (US10473915B2 and US9435998B1)
Both ideas have a curved mirror but Tecnica hits the first mirror along the rotional axis.
This is different from Zeller which hits orthogonal and as such "novel".

This is one of the drawings from the patent;

At first, i was a bit surprised Tecnica does not use pyramidal polygon scanning it would increase the duty cycle, see the figure below (source). I guess they face issues with the cross scan aberration.. Each facet is slightly different which produces error orthogonal to scanline (Zeller also noted this). By using one side this is fixed. It also reduces the tolerance of the curved mirror as it is hit a single spot and the deviations are constant. With a non uniform rotation speed, they might be able to increase the duty cycle. In selective laser sintering, the writing speed is typically lower.