My son got a bit sunburnt today while traveling in the car. Reason being, the sun shade over his window is a semi-transparent mesh which allows the driver to see out that window. There's probably a few good solutions to this problem (and I have the feeling you guys are going to tell me all about those).

Anyway, my solution is sunshade that is transparent from one viewing angle and opaque from all other angles.

Basically this is an array of tubes. The tubes would be in line with the vision of the driver (hence transparent) and at an angle wrt the window (hence opaque). The tubes would be extruded polygons (eg hexagonal). The sunshade would preferably be a flexible mesh. I'll put up an illustration shortly.
-- xaviergisz, Jan 23 2010

I've seen similar devices attached to traffic lights. Presumably they're intended to make sure that drivers aren't distracted by lights that aren't meant for them, at particurly complex junctions.

A driver's head doesn't stay in one place all the time, so the tubes would have to be wide and short enough to allow a reasonably wide range of viewing angles.

I wonder if photonic crystals might be able to provide an alternative hi-tech method of achieving the same thing one day.
-- Wrongfellow, Jan 23 2010


Fiber optics?
-- csea, Jan 23 2010


Fiber optics are pretty fine for transmitting light from certain angles only.
-- csea, Jan 23 2010


I don't know what process is used to produce privacy films used on computer screens, but if this could be modified to produce a film with an off-angle viewing zone, it would fill this need well.
-- Freefall, Jan 25 2010


I don't get this - if the window is closed, the glass ought to block pretty much all the UV. Your tubey array would work as a directional sunblock, but there shouldn't be a sunburn issue anyway.
-- MaxwellBuchanan, Jan 25 2010


OK, maybe he didn't get sunburnt; just a bit red from the heat (on the other hand, babies have particularly sensitive skin so it is still possible).
-- xaviergisz, Jan 25 2010


Genetically Engineered Sunflower?
-- Dub, Jan 26 2010



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