See on Scoop.it – Cultibotics
“By mounting such a wafer in such a way that air passing out through the groves around the outer edge is forced to turn and flow in an inward spiral across the face of the glass, an air-flow, reminiscent of that in a hurricane, will be set up, with filtered air spiraling inward next to the lens cover, pushing out a bit, and then spiraling back outward a short distance in front of the lens cover, keeping the lens cover itself free of dust and small droplets in the ambient air.
If I may be forgiven for scooping myself, this is one of the better ideas I’ve ever had, and here I’ve laid it out in a recipe any engineering student could follow.
See on cultibotics.blogspot.com