[quote name=\'rollercoaster87\' post=\'195144\' date=\'Aug 25 2008, 01:15 PM\']
I've always been curious how it works, because I've seen them on shows like Nick Double Dare, Jeopardy, and Pyramid. I assumed for the longest time that they were lights, like most other game show displays were, but after a closer look, I don't think they are. I was watching a TOC final episode from Jeopardy's last set, and when Alex cleared the scores, I heard a distinct click as each contestant's score was reset to zero. If somebody could correct me (I'm not even 100% sure that they're called vane displays), I would appreciate it.
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Those are plastic reflective segments on hinges, yes. The "home" position is rotated 90 degrees so you only see the black edge of a segment, and to activate a number, the relays for the seven segments fire to cause the necessary segments to flip out such that the reflective side now faces forward, and the unnecessary ones (if needed) to flip in so that you can only see the edge again and it's effectively invisible. This, of course, is MUCH less energy-hungry than a traditional display, as it only uses electricity for the actual numbers during state changes, where an eggcrate or an LED display or has a constant drain of power to keep the necessary lights lit. (In fact, aside from during a state change, at least in some vane displays, you can flip the segments by hand...when we did the Children's Miracle Network telethon, we would always set the tote board by hand so that it read "HELLO" for the opening segment.)
So there you go.
