Is this a silly idea or is it possible.

Having seen LED torches utilising internal reflection I had an idea. A "what if" moment.

What if you combined 4 LED's, be they normal or luxeon into 1 light. Where all 4 were reflected into 1 beam.

But, here is the difference, 3 of those 4 LED's (if they exist) would match the wavelengths of the primary colours of light.

The thought was by mixing the colours, possibly with a 4th white LED would give better spectral enhancement.

I got this thought when I used my red, blue and white "photon's" together.

Is this possible, would it have the desired effect?

Your thoughts please?

Though not using 3 leds using TIR, RGB led's are out there. I in fact got one at a dollar store, one that looked like it had a white led but when you move it, you see bands of red, green, and blue, as it strobes through each in succession very quickly.

I don't see anything inherently impossible w/ using 3 different leds, but I also don't see the need to use it to attain good whiteness. Almost all my leds, even semi-cheap ones, seem to approximate white light very well enough.

Using RGB to create a single beam would be efficient and give you a good range of color. The problem comes in trying to get a good even mix of the light. Normally, because each light source is in a different location, you get overlapping fringes of different colored light.

I think CaptCarrot might have been suggesting that the combination of different wavelengths may attain a white light that has better illuminating qualities due to comprising a fuller spectrum as opposed to just one wavelength with a phosphor coating on it.

Those who still prefer incandescents often cite the "washed-out ghostly" light
that leds produce as a disincentive for conversion. Maybe using different
colours to achieve a fuller white light would prevent this.

I don't know enough to say whether this is the case or not, but I do know it is not a new idea and has been thought of before.

I was once thinking of building a RGB A2, which would feature red, green and blue LEDs in place of the white Nichias. Unfortunately the Vf of the different color LEDs, not to mention intensity, makes such a project seem difficult or even impossible?

I like the idea, even better would probably be a LuxeonV-like LED with red, green and blue die in place of the four white die!

I've mentioned a few times that an Internal Reflection Optical Device might be designed with multiple inputs.

In the hole of a common IROD is a refraction lens that directs the rays to the correct angles to reflect off of the side walls of the main optic forward. Of course, this is taking advantage of indices.

I think the challenge in designing a multiple input optic would be to alter the multiple refraction optical lenses to correctly direct the rays. If this were successfully designed I believe the rays from each of the emmiters would be adequately mixed and result in a beam void of fringe colors.

Take it a step further. Have all the emitters seperately driven so their output can be adjusted to get the color mix you want.

Take it a step further. Design the optic so that the output side was not flat but coned with a tiny dome shape or side emitter shape on top. A de-collimating design element if you will. Insert the tip of this whole rig into a parabolic reflector for a single, almost point source.

Now you have the light from 3 or 4 LEDs being emitted from one source directed forward by the reflector.

I think it's a viable idea. It needs a needs a couple of PHDs in optics and a couple of optical prototypers along with a large bag of money to come to fruition.

It most likely depends on the quality of the phosphorous being used on the white LED. In theory you should be able to get perfect white light with RGB but this will greatly depend on whether the red, green, and blue wavelengths are exactly what they need to be and their intesity is exact to produce perfect white light.

Individual colored LED's are required to fall with in some exceptable tolerance for their wavelength specification so again it will depend on how close to the perfect red, green, and blue you get from each LED to produce perfect white light. Then the next hurdle is to mix the colors without reminents of each being appearant.

Another thought is, would there be any benifits mixing different tint Luxeons in a Tri or Quad configuration such as a xV1x, xWOx, and xYAx together.

The biggest problem is the driver you would need for that. Different colored LEDs have different forward voltages (unavoidable) and different driving currents.

You need a driving electronics with three individually adjustable power supplies for the red, green, blue LED. And you need to adjust all of them (at least the forward currents), either with a controller (probably digital), or the final user has to, which means a quite complex user interface.

MillerMods said:

Another thought is, would there be any benifits mixing different tint Luxeons in a Tri or Quad configuration such as a xV1x, xWOx, and xYAx together.

Click to expand...

That's an intriguing idea.