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> Date: Sat, 08 Jan 2005 19:29:49 +0100
> From: "Stefan Trethan" <stefan_trethan@...>
> Subject: Re: Re: PCB drill viewing mechanism... reviewed
<snipped>
> project crosshairs... hmmm... how?
> ST
Stefan,
Just a thought: A small motor spinning a small mirror could be used to sweep the beam of a small laser through most of a plane. Using two of those setups, you could illuminate two planes that intersect along the axis of your drill bit.
Off-topic: They used to use rotating mirror systems to get satellite imagery: A rotating mirror system was used to scan perpendicular to the flight path, getting one line of the image at a time. The light was then sent through a prism. On the other side of the prism were sensors that measured the amount of energy at several spectral locations in the prism's output. Those numbers were digitized, many times along each scan line, and radioed down.
Tom Gootee
http://www.fullnet.com/u/tomg-----------------------------------
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