100K to 150K mcd LED's -- Time to Reconsider?

[Ben_Tech]

I know we have looked at LED's for our light engines in the past, but those were only 16k to 20k mcd LED's. It seems that there are now some (multi-chip) 10mm LED's that feature mcd ratings in the 100K-150K range (max).

See:

Here

and

Here
(They don't seem to have the 150's on their official site yet, just the 120's)

.....For example.

Has anyone here tried similar LED's? All I've seen discussion of folks having actually tried are lower-rated LED's as mentioned. Several Asians and Europeans may have tried these higher-rated high intensity LED's in their designs already, but it's not like I can ask them.

Thermal issues aside for a moment, I would be interested in some informed opinions regarding the viability of these. For example, placing, say, 400 of them behind the typical 15.4" LCD panel.

I am assuming (correctly?) that this approach would be less viable the smaller the display panel size becomes, due to having less area for a straight-through 'beam' from an LED array. One could only put so many LED's directly behind a 1.8" LCD for example! Unless a larger array of LED's is condensed and collimated optically before hitting the display panel.

Access to refractive (LCoS, DLP) rather than transmissive display technology might make this more viable as well due to the efficiency gains. Hmm.

[superdaveumo]

Yes, but I don't think with those LEDs. Although they are inexpensive... The Luxeon line puts out many more MCD (closer to 1,000,000 mcd if I read correctly). LEDs are coming. I don't think they're there quite yet... But I do believe they will be the optimal option once they do arrive.

[Just In KY 2002]

Originally posted by Ben_Tech
I know we have looked at LED's for our light engines in the past, but those were only 16k to 20k mcd LED's. It seems that there are now some (multi-chip) 10mm LED's that feature mcd ratings in the 100K-150K range (max).

See:

Here

and

Here
(They don't seem to have the 150's on their official site yet, just the 120's)

.....For example.

Has anyone here tried similar LED's? All I've seen discussion of folks having actually tried are lower-rated LED's as mentioned. Several Asians and Europeans may have tried these higher-rated high intensity LED's in their designs already, but it's not like I can ask them.

Thermal issues aside for a moment, I would be interested in some informed opinions regarding the viability of these. For example, placing, say, 400 of them behind the typical 15.4" LCD panel.

I am assuming (correctly?) that this approach would be less viable the smaller the display panel size becomes, due to having less area for a straight-through 'beam' from an LED array. One could only put so many LED's directly behind a 1.8" LCD for example! Unless a larger array of LED's is condensed and collimated optically before hitting the display panel.

Access to refractive (LCoS, DLP) rather than transmissive display technology might make this more viable as well due to the efficiency gains. Hmm.

Yes it is possible and I have done it, but it is still in progress. I used 100 130,000mcd LEDs (4 filament 10mm) from www.lck-led.com .

They are currently spaced too much apart, and are a bit spotted when the screen is bright white or off. Right now I am waiting to order some more to fill in the gaps (another hundred). Otherwise I have had a 10ft usable screen in total darkeness. When it is done I will post pics, however you will have to wait for now!

P.s. It currently draws 6 amps for those of you wondering about power consumption.