Blue LED inventor - Wins prize.

Lunal_Tic

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Calif. Prof Awarded Millennium Tech Prize


ESPOO, Finland (AP) - An engineer whose high-profile patent dispute challenged the Japanese tradition of selfless devotion to employers has been awarded the $1.2 million Millennium Technology Prize for his inventions in light and laser technology.

Shuji Nakamura, now a professor at the University of California, Santa Barbara, created "new and elementary lights sources," the Millennium Prize Foundation Chairman Jaakko Ihamuotila said at a ceremony announcing the award Thursday in Espoo.

Nakamura, 52, developed the blue light-emitting diode, or LED, widely used in traffic signals, illumination and for storing information onto optical disks.


Good to see this guy finally started winning. I think originally he got something like $200 as a bonus from Nichia.

-LT
 

Planterz

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Very cool. The advent of the blue LED is easily the biggest innovation in lighting technology for quite a long time. Possibly the biggest since the electric incandescent light bulb replaced fire.
 

Lunal_Tic

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greenlight said:
haven't seen any blue traffic signals...

turquoise=blue in this case. Also in Japan they call the "green" on a traffic signal blue, of course they also call grass blue and have little blue onions. :shrug:

-LT
 

The_LED_Museum

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In Japan, they use what is commonly referred as "Tokyo blue" blue-green LEDs in the "green" part of traffic signals; with a dominant wavelength (where you would point to on a color chart) of 490nm.
This is still green enough that drivers would recognise it as a green light, but blue enough to be seen by those with red/green color blindness.
 

goldenlight

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Right here....
The_LED_Museum said:
In Japan, they use what is commonly referred as "Tokyo blue" blue-green LEDs in the "green" part of traffic signals; with a dominant wavelength (where you would point to on a color chart) of 490nm.
This is still green enough that drivers would recognise it as a green light, but blue enough to be seen by those with red/green color blindness.

I used to have real problems picking out a green traffic light at night fro a distance if there were steetlights behind it; often streetlights from several blocks away. The green wasn't saturated enough for my color blindness. The strange thing is, on a color blindness quantitative test, I score pretty badly, but I seem to see most colors the same as other people. I imagine that I'm seeing much less color intensity. So the older green incandescent traffic lights, when I see them from several blocks away, simply aren't 'green' enough for me to pick them out, especially when there are other lights at about the same height and intensity. When I would get about a city block or so away from the traffic light, it would start to look green to me.

Many years ago, green traffic lights with the then new Fresnel(sp?) lenses made a HUGE difference for me: the 'green' was a 'deeper', more 'grass greeni' color that I could much more easily see.

I can almost always see the green LED traffic lights, mainly because they are much so much brighter than the old type of traffic lights.

The thing that seems strange to me is that most 'green' traffic lights are really not very green looking to me, except for the lights using the Fresnel lenses. They are very much of a 'turquoise green' color, especially the LED ones.

I seem to be able to see the losers in the Luxeon lottery, but I usually have to compare it to a 'known' light to see the tint if it's subtle.

I have several 3 watt Luxeons that have a fair amount of a 'sea green' tint to them......but I can't see it unless I compare them to another, whiter light. My Fenix L1P is like that.

I wonder if I'd see the 'Tokyo blue' traffic lights better than the ones here in America? I don't have a frame of reference for what 490 nm is.


Hmm.... Color blindness could make for an interesting thread. I didn't even know I had it until I got to college basic chemistry. I couldn't read titration endpoints, where you add a chemical drop by drop to another chemical, and look for a subtle color change, or a change from clear to a faint color. My error was as much as 60%, when only a few percent, or less, was acceptable.
 
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