Artifacts in Lux III's ??!?!

Artifacts in Lux III\'s ??!?!

Hi guys,

I am curious if others have noticed a few of the new Lux III's with artifacts? I have had a few of these LED's, from different bins that have shown some yellow and or blue in the corona around the spot beam in a PR application. I recently received some TW0J Lux III's which are very bright and efficient but the first three that I have built out all have evidence of colored artifacts in the corona around the hot spot. I don't use optics in my builds these days since I am concentrating on the PR but for the heck of it, I dropped a NX05 down on one of these LED's and the focused optic certainly shows some blue satellite artifacts. I wonder if the EOS coating isn't thin in some places, especially with the T rank?!?! None of the S rank III's so far have shown such artifacts in my limited experience. Has anyone else noticed this? I am now suspicious that some of these Lux III's are going to turn out to be characters as well.

For data points, I recall noticing this in TX1K, TWAK, TV0K and now TW0J.

They say the truth will set you free. Hah! For me as a modder, this possible truth is a PITA!! /ubbthreads/images/graemlins/frown.gif Although these artifacts don't bother me, I feel the standard here at CPF is such that anything short of full disclosure on any possible color discrepancy could result in disappointment if not hard feelings. There have been times in the Luxeon evolution when I personally felt that our expectations, as a group, was above and beyond the capabilities of the current technology and manufacturing standards. It seemed that Lumileds had closed the gap with the Lux III's but now I wonder once again................

Re: Artifacts in Lux III\'s ??!?!

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Re: Artifacts in Lux III\'s ??!?!

That's a bummer Don. And just when we all thought that Lumileds was starting to show some good consistency...

I haven't seen any anomalies with the Lux III's personally, but we're talking about a *much* smaller sample size yours.


Peter

Re: Artifacts in Lux III\'s ??!?!

DrJ,

Yes, I believe these are similar artifacts. I had presumed that these were done away with when Lumileds went to the EOS process. Perhaps they are pushing for a thinner film of phosphor in attempts to gain more flux? More likely, I don't know what I'm talking about....

Re: Artifacts in Lux III\'s ??!?!

Don,

I noticed a very slight blue fringe on one of the 917's that I bought from you several weeks ago. In my opinion this is just barely noticable and not worthy of complaining about [and I'm pretty anal about those type things]. I'm guessing what you are refering to is something much more obvious.

Re: Artifacts in Lux III\'s ??!?!

FlashlightOCD,

I think these artifacts vary in degree and of course the host will dictate how they are seen. I prefered the early Pelican reflectors which had a more agressive orange peel as they did a nicer job of blending the LED's as well as rubbing out the black hole of the 5W. When the light image is not consistant in intensity and color, any reflector or optic that provides a sharp image of the source will suffer the blemishes. Frankly, a perfect projection of the light image will show the individual dies anyway so I guess it's a question of blurring to suit the quality of the LED as well as blurring to suit?!?! The bleeding edge takes a few more nicks I guess.

Re: Artifacts in Lux III\'s ??!?!

I believe it is a thinning of the phosphor around the edges of the die. I have macros of 8 of my 1W Q2s running at low power - most of these exhibit some blue fringing around the edge of the die. I will try to compile and post pictures of these when I get home from work.

One of these with a Mag reflector shows blue arcs around the outer edge of the hotspot.

I'll bet it's the same thing happening with the LIII.

Re: Artifacts in Lux III\'s ??!?!

I just put a SW0K on a module for someone and I saw a small crescent moon shape of yellow in the center portion of the beam. The rest of beam was nice and white including the fringe.

Bummer. and not a Bummer. This is still a vast improvement over the previous bin coding and sorting process that Lumileds had in place. At least all the Lux3s are now white with maybe a tinge of hue to them.

Re: Artifacts in Lux III\'s ??!?!

Don, I hope the emitters we sent to ____ for our ____ are ok!

That's a bummer...

Re: Artifacts in Lux III\'s ??!?!

Don,
I have seen this defect in person also. Back around thanksgiving, I built a Lux III into a 3D cell Mag lite under DD for my father-in-law when he was here. The bin was SV1J if I remember correctly. Upon turning the light on, the main beam was pretty nice, maybe just a bit on the yellow side of white (I checked the emitter color before putting it into the light).

However, there was a very noticable (to me at least) purplish-blue spot in the beam! /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/mad.gif I couldn't figure it out, the emitter looked fine before... /ubbthreads/images/graemlins/thinking.gif

I pulled out a 20x jeweler's loupe, and inspected the LUX III with it (the LED was turned off, or I'd be blind /ubbthreads/images/graemlins/wink.gif). Sure enough, on one corner of the die, the phosphor was missing altogether. Now we're not talking about a large piece missing, no! It was only a very small speck missing, but it was indeed the culprit! (I rolled the light body on the table without the head while turned on, and it was quite apparent when the purple spot was turned toward the table) I offered to replace the LED, but it didn't really bother my F-I-L because he didn't notice nearly as much as I did.

The size of the artifact in the beam was a decent bit larger in proportion to the size of the missing piece of phosphor, (I assume because more purple photons are making it out without having to go through the phosphor) but the color difference was pretty noticable (again, to my eyes). Also, placement of the purple spot in the beam depended on how the beam was focused in the mag reflector (spot or flood). In spot mode, the artifact was shaped like a piece of pie, wider at the outside, and narrower toward the middle, but was more out toward the outside edge of the beam (I assume since the other light in the center began to overpower the purple color).

It looked to me that when the machine that adds the phosphor to the LUX III during manufacturing pulled back, the small piece of phosphor stuck to the machine, and not the die, since the edges were torn looking.

So there you have it! There are still Luxeon production problems... /ubbthreads/images/graemlins/crazy.gif /ubbthreads/images/graemlins/icon6.gif Go figure... /ubbthreads/images/graemlins/icon3.gif

However, that all being said, I do think that the Lux III's have much better color consistency than the 1 Watt parts do, and the new binning structure seems to hold more true also. They're making some progress at least! /ubbthreads/images/graemlins/icon23.gif

Re: Artifacts in Lux III\'s ??!?!

Here's the pic:

http://myweb.cableone.net/evan9162/dies.jpg

These are 8 1W Q2 luxeons, all driven at 100mA. Fixed exposure and white balance on the camera. You can see blue fringes along the edges, and corners of the die for most of these. I would imagine that the process for depositing the phospohor is still not perfected. The phosphors probably can't be deposited in a manner that would provide a repeatable and even coating, such as vapor deposition, etc. It looks like a drop of phosphor is placed on the tip of a device, and it's stamped down onto the die (the square outline and spooched out appearance of the phosphor hints at this.)

Re: Artifacts in Lux III\'s ??!?!

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Re: Artifacts in Lux III\'s ??!?!

Hey Don,

I noticed the same thing with some TV0K emitters I had. Very white all the way out into the hotspot except for one corner of the square Fraen beam. That one corner had just a slight blue tint.