Absolutely fascinating stuff right here.
In my latest video I talked about early single pass color scanners from Epson which used three different fluorescent tubes to illuminate the document. The only further info I had on how this was done was a passage in a magazine that said each tube used a different gas to achieve red, green and blue output, and I doubted that because pure gas discharge is just such an uncommon way to produce bright illumination, phosphors make it much easier and more efficient.
Fortunately a viewer had one that still worked, and sent me pictures! And very clearly those are pure gas discharge; fluorescent is even the wrong term, I think that implies phosphor, but we can obviously see from the shape of the glow that they're clear tubes and we're seeing the gas directly. That red one looks like it literally contains neon.
Good luck replacing these if they break!!!!
