[David] has always wanted use UV LEDs to write on a phosphorescent surface ever since saw an article about it on Make. He accidentally purchased UV LEDs when he meant to buy purple ones, so he figured that his mistake was all the reason he needed to give UV light writing a try.
He built a PIC16F628 UV POV board using the LEDs, and while manually swiping the writer across various glow in the dark surfaces was cool, he wanted to keep the POV board stationary, moving the writing medium instead. He bought some phosphorescent vinyl, but found that it wasn’t too flexible, meaning he could not use a conveyor belt approach for his display. One day it dawned on him that a vinyl ring might work pretty well, and using a motor from an old cassette player, he constructed the UV writer you see above.
It seems to work pretty well despite a small flaw in the UV ring, and while [David] is happy with the results, he already has plenty of ideas in mind for the second revision.
Check out the video of his UV light ring in action after the jump.