small (!) lenses for LUXEON 1W emitters

Hi LED-freaks,
i'm using the luxeon emitters without the PCB and i need lenses making a ~20degree beam. They must have a diameter of 12mm max. Are there any such lenses anywhere in the world?
Let's light the world with LEDs,
Joachim

This is a good question. So, how far can you turn down an NX05 or Fraen LP and still get a decent beam?

I would imagine that such a small optic would make for a really cool 1W AAA stick light or even a really slim AA light.

I have used small acryllic half balls to achieve a focused beam in my Arc AAA LS mod and Luxeon Bullet. They worked well. As far as chopping down NX-05's, when you go to 12mm, there isn't much light being collected by the cone, and the inverted lens is the major thing doing the job. The result is much lower efficiency in focusing the light.

Hi guys,

I am in the middle of that exact connundrum right now! I bought the shortest focal length, 12mm plano-convex from here . (Grab your wallet! /ubbthreads/images/graemlins/grin.gif ) Interestingly, it gave the best beam with the convex side towards the emitter. As to turning down NX-05s, I turned down a doz to .435"/~11mm today, and will eventually shorten them to .25/.26". They seem to result in an actual beam - hot spot/corona/side spill, and I like it better than what I get with the lens. I wish you luck in your T&E efforts!

Larry

Hi,
you're right, that _is_ hard for the wallet...
I also have turned down some NX05 but i found the side loss too much. there is too much space between the total reflection area and the lense area causing side loss.
i wonder how many people also would like to have small lenses. It should be possible to compute a profile and have this things injection-moulded. But for a single user a minimum amount of 1000 or so lenses is pretty much. and there are also the costs for the injection tool.
let's light the world with LEDs
Joachim

RGBrainbow,

I am not an optical engineer, but as I understand it, the principal challenge results from the size of the LS die. If it were a point source..... I wonder if an aspherical lense could help? Probably not or the experts at Lumileds and Fraen would be doing so rather than compound reflect/refract optics? BTW, welcome to the forum!

Larry