Omnidirectional pattern LED

[Ed Blackadder]

Hi, I'm looking for a white LED ideally around 1 watt with a near omnidirectional pattern ie throws light in all directions including backwards. The closest I can find on the net has a Lambertian pattern which is about 140 deg wide.
(I have also seen vehicle bulbs made of multiple LED's facing in all directions, but that's not what I'm looking for) I have seen some Xmas tree lights where each LED has a clear cylinder above it with a hollow cone moulded inside the top, which gives a reflecting surface and appears to distribute the light evenly in all directions.

Has anyone come across individual LED's made this way and is there a particular name for them.

Any help appreciated

Ed

 

[John_Galt]

I don't think you'll find such a product... LED dies are not spherical, they are flat, which allows heat the LED produces to be removed quickly and effectively.

 

[Benson]

There's some 5mm LEDs with a real wide beam angle (wider than lambertian, maybe 170 or so), but AFAIK no power LEDs.

 

[bobski]

superbrightleds.com sells some 5mm (20 mA) and 8mm (60 mA) 360° output LEDs in red, green, blue and white IIRC. The colored LEDs have a etched glass-like coating and reflectorless cathodes to throw light in all directions. The white versions similarly have reflectorless cathodes, but have their phosphors applied to the outer surface of the LED rather than the etched coating.

One of the 8mm white units compared to a 194 automotive bulb:

I don't think a power LED could be affordably constructed the same way due to heat sinking constraints, but it seems like a fairly novel design so I thought I would point it out.

 

[Neondiod]

I have seen some Xmas tree lights where each LED has a clear cylinder above it with a hollow cone moulded inside the top, which gives a reflecting surface and appears to distribute the light evenly in all directions.

Has anyone come across individual LED's made this way and is there a particular name for them.

Any help appreciated

Ed

Yes! The Lux I SIDE EMITTER is like this and have being around for a decade or so. There's also a lens that you can put on top of that to extract the light more backwards or to make an ordinary lambertian powerled to mimic the side emitting effect.