Lynx photo finish cameras. Same idea:
The downside is that they are highly specialized (in other words: expensive) and require knowledge of the belt speed to reconstruct a proper image. I would not be too surprised if modern high-framerate video cameras took over a decent chunk of that niche.
I've used modern high-speed cameras (>10k FPS in real-time streaming) and they just don't come close currently. Mainly an interface issue. There are some DMA/frame card alternatives but they haven't overtaken the market yet.