Elongating light spot
Elongating light spot
(OP)
I am trying to illuminate a surface with light from a light guide. At the distance I am using, the spot is 7mm dia, but the surface is 7x28. Can I use a plano-concave cylindrical lens to stretch the spot 4:1 in one direction? If so, how can I calculate the object distance given the focal length and elongation? If not, is there a better alternative? Space is very limited. I can handle the 4:1 reduction in intensity, but not the 16:1 reduction from expanding the beam in both directions.
Thanks,
Steve
Thanks,
Steve





RE: Elongating light spot
reflect it to a sensor ?
You can find equations in any physics book.
<nbucska@pcperipherals.com>
RE: Elongating light spot
TTFN
RE: Elongating light spot
POC (http://www.poc.com/) sells light-shaping diffusers with elongation primarily along one axis. These spread angles are most likely suited to your needs:
40ºx0.2º
30ºx5º
CEV
RE: Elongating light spot
I will try illuminating it from the side.
Thanks,
Steve
RE: Elongating light spot
first ignore the azimuth which is correct as your lens will have no optical power in that direction. second work out your magification (or reduction) . This is the ratio of guide dimension to 16mm , image dimension. From basic optics image to object distance ration is the same. so using the lens formaula 1/v+1/u = 1/f (You know u/v ) you can work out your focal length in the power azimuth.
opticsman.