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Why are you filtering out higher wavelengths?
Are they too ‘warm’ to be ‘useful’ to the phosphor layer?
Yeah, I’d doublecheck the wavelengths. 500nm and 550nm sounds “off” (500nm being around the cyan hole).
300nm and 350nm sounds right, in fact, spot-on. See
(dick on the pic for the link)
edit
Phosphor do reflect a lot of the light above 460nm
On any LED collar there is most of the lumen increase by recycled light that is not blue
i’m new to this and still learning too.
So some guy has an idea and gets a patent, but has this actually been proven to work? i’ve seen and reviewed lots of patents that were good in theory but poor in practice. How does the angle of reflection get changed such that the “recycled” light gets sent out? Has anyone done a ray trace to show that it works?
Yes, it does work.
Recycled light will not go out, it goes back at the led increasing its intensity by exciting the phosphor more.
This is intended for use with aspheric (zoomie) lens in fixed throw.
The idea is that light that doesn’t hit the lens due to emitting angle will be sent back to the led.
This is not meant to maximize lumens, rather maximize intensity, throw.
Collars work by reflecting more than just blue light back at the LED.
If you take a collar and shift it so that it is not focused on the LED, just a spot beside it, you will see a reflection of the LED die.
The light you see isn’t the phosphor being more excited, it’s simply light bouncing off of the surface.
The intensity increase that collars give is mostly from the waste light just being reflected back at the die and having it bounce off again.
Except instead of it just being a white surface, it’s the LED itself.
For this reason collars use a cold mirror coating.
This coating reflects everything BELOW ~700nm, so basically all visible light.
The stuff above 700nm is infrared, which just heats up the LED more (bad) and isn’t visible.
That’s why we don’t want to reflect that stuff back.
If you make a collar that only reflects blue light back at the LED, it will make very little difference to the intensity.
You need a cold mirror coating for best performance, or for a cheaper alternative, just a simple aluminum coating to reflect all light back, although this will also reflect infrared and heat up the LED a bit more.