Luminus's new emitter with circular die

But if you make the sides of the square equal the diameter of the circle you get more surface area with the square chip and thus more lumens.

According to several sources the top 10 LED companies in 2011 were:

1. Nichia
2. Samsung LED
3. Osram Opto Semiconductors
4. LG Innotek
5. Seoul Semiconductor
6. Cree*
6. Philips Lumileds*
7. Sharp
8. TG
9. Everlight

*Companies have the same ranking when the difference in revenue is within the margin of error. Revenue includes packaged LED sales only.


Altogether holding a market share of 68% while the first 3 had a revenue >1 billion $.

But I these numbers seem weird. Because whenever you read about a big breakthrough or the most efficient LED, its a Cree.

And if you want to maximise throw instead of basic luminous efficiency then a smaller die with the same current (assuming similar efficiency per unit of area) will give much higher surface brightness..

That list is odd, because guess who Seoul Semi gets their chips from, Cree. All Seoul does is package them.

This is true, but to be honest, the flashlight market isn’t even a blip on Cree’s radar, general lighting is. The goal is to replace the incandescent bulb and fluorescent lighting.

In the case of flashlights 99% of the time the leds sit at the bottom of the circular hole in the reflector, to fill that hole would make more light rather than just make it bigger to fit a bigger square led, then you could still fill in around it (round led) and produce more again.

Either way, 2 types, 10 types, 573 types.. I don't really care, the more choice the better.

The more competition the more they will work harder to make better leds.

Yes, true again. I don’t think there are any LED manufactures that are really focusing on the flashlight though. In comparison to the lighting market it is a small segment. I mean, all these LEDs are targeted towards things other than flashlights, they just happen to work in that role as well.

Yeah, I wasn't suggesting that that would be a factor in Cree's design specifications (although with the auto-headlamp market growing you could see the demand for more easily focusable LEDs growing in the future).

I was just trying to point out that the fact that a circular die can supposedly maximise the ratio of space taken up by the die itself in relation to the footprint of the LED package, and therefore alloow for a larger surface area, isn't necessarily a good thing in all respects for flashlights. We can choose XM-Ls over XP-G and XR-E for higher surface area already and this allows slightly better efficiency and higher max drive currents. However, for surface brightness, and therefore for 'throw', a smaller die will still be better. The 'higher surface area in the same footprint' isn't really one of the main benefits of circular dies.

Having said this, I don't actually know what collimation benefits a circular die would actually give? Other than a circular beam in an aspheric lense or other form of direct projection of the die area..

I am more interested by Luminus' new version of the SST-90 without a dome but with a flat layer of optical silicone instead (at least I think it's optical silicone used, I know it's expensive). This will be used in the upcoming Nitecore TM20 I think and as the traditional dome effectively gives the die an apparent increase in surface area/size (and so concurrent apparent surface intensity decrease) this new optical design should allow for much better collimation from the same base die.

Maybe dumb question, but increasing the die size (round or square) will need bigger reflectors to throw well, right?

How's then they stated in the article that it throws well with narrow beam and long distance?

If this is real and not just advertisment, it makes me think the new die is round but somewhat small in diameter, so to make it easier to focus with a reflector.

Or not?

Edit, just read on the flashlight maker page that head diameter is 70mm. Any led throws well with a 70mm reflector...

Will need to wait for more info to seep through...

Take a close look at that picture. The die itself is still rectangular. The active area is a round area in the middle. I don't see any real advantage to that design... it wastes all that material in the corners, which could be put to use making light.

I think diameter shouldn't really be the point of consideration, as a round or circular die can be made at different sizes anyway.

I thought much the same as you though and they are good questions. Increased die size does need a bigger reflector to collimate properly. I could imagine that a round die would allow for a more efficient collimation than a square one in a round reflector, but the differences I am imagining would not be that great, and I could be plain wrong.

I would like to know exactly what the benefits of a circular die of the same emissive area as a square one with the same optics and package etc would be for a conventional reflector.

I would also hazard a guess that these benefits would be much more apparent in dies without the conventional dome over them, which seems to spread the light more evenly anyway..

TSB-70? compare with my TMA-66 TM....

Waiting for real spec.

No dome = wide angle = less throw for aspherics lights.

Hmm.. are you sure, maybe I've got it wrong? If you de-dome an XM-L or XP-E etc though you get a more focused beam, I was under the impression this was due to the dome apparently making the die appear (through optical effects) as a larger surface area. I certainly remember being surprised at how small an XM-L die actually was having accidentally de-domed one.

Umm…personal attacks? Bose made none. You, however, have done nothing but make personal attacks against his intelligence, his job, his knowledge as well as resorted to name calling. What does that make you?

Well, use the wasted material as it's own star-shaped led

For some reason, feminine hygiene comes to mind...

Darn, saw that "how does it made" vid and... wow, didn't thought that you need to make all those dozen of steps :o

As for the new emitter - too many wires inside :| And the color of that emitter is... definitely not the same phosphor material CREE is made :|

Interesting, wanna see it in action :P

PD: why the base is so big?? They definitely must make it smaller. How you will fit it in P60 host, for example?

Just re-read my posts and nope, I don't see where I called anybody names. Darn it, I don't see where I called anybody dumb either. I did however suggest bose301s is smug. That's not exactly name calling. If my pointing out that the world doesn't revolve around Cree (great company, by the way) and that others do it differently and equally well blows air up your skirt, well................... If ever I intend to insult someone on purpose, you will know I am insulting you before you even finish reading it.

In bose301s own words - "I don't need to watch your link as I work in the industry". That tells me he thinks that there is nothing else to learn because he already knows it all. Or maybe he's afraid to watch the video because it will prove my point. There is something new going on every week and if you fail to look around at what others are doing you will be left in the dark (pun intended) and in the dust.

All that said, working as an engineer for Cree sounds like a great job, bose301s. But a Process Sustaining Engineer? What the heck is that? I'm not trying to be a smart a$$. I've just not heard of that one before. Is it your job to see how long you can sustain using a saw before you have to start using a laser? Yep, that last sentence was intended to be a joke!

My background is in computers. I have a double Masters in Computer Engineering and 35 years on the job. I'm semi-retired and do private contracting now to pay for my toys and other crap I don't really need. OK, OK, I do need them! "Lord grant me the strength to accept the blah blah blah". It's a sickness for sure. My last place of employment was a State College as Director of IT for 12 years. Many years with the Federal Government before that. I know my stuff. I'm also smart enough to know that I don't know everything and as soon as I stop learning new stuff - I'm toast. Learn like you were going to live forever. Live like it was your last day. The biggest reason I read things on this forum is that I do learn new stuff here. Lots of good contributors.

Hey, ChicagoX - not man enough to actually use the word douche? Feel the need to hint at things you are to embarrassed say? Maybe you thought your comment was 'witty'. Grow a pair already! Others made comments about what I have said and that's OK with me but, only you chose to call me a name. Interesting. Besides, nobody was talking to you, mr. butinski. I can already see that bose301s is smart enough to hold his own, doesn't need your help and has garnered a little respect from me. You however, not so much. I've read plenty of good posts made by you and you undo them all by pulling the rug out from under yourself with one snide comment. Obviously, my respect doesn't count for much in the greater scheme of things but not many people ever get it at all. Nice talking to ya.

To the OP - Sorry to hijack your thread. I'll do better next time. Round LEDs make perfect sense. No need for pattern conversion (most folks want a circular beam) is, in and of itself, more efficient. I expect to see more about them in the future.

To bose301s - Sorry you took my comments as a slam. That was not my intention. Hope you see that. Sometimes my being frank, comes across as insulting. This (the internet) is a lousy way to communicate. It always has been.

Process engineer, same difference really, just what Cree calls it. I work in Nitride Epi, which is where the magic happens, it's where we grow the LED structure on the wafers. MOCVD, it's cool, lol. Anyway, a process engineer's job is to analyze data as it comes back to make sure it is staying within our process parameters and to adjust the process as necessary to do that. I don't deal with it after it's a wafer with the LED structure on it, however I do know our back end processes pretty well because it all is very interesting to me and I have sought out the info. Very cool stuff.

Not really insulting, I can see how you could take it personally. But to be honest he was just stating a fact, if you work in something you can be pretty sure you know more about it than someone else who almost certainly doesn't.

Come on, if you want to interpret Bose's comments as insulting then there is no way you can say yours weren't.