Toshiba Introduces White LED Close to Natural Sun

NewBie

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March 7, 2005...Toshiba of Tokyo, Japan has introduced a florescent substance for white LEDs that can be used in conjunction with blue LEDs to create a white light close to natural sunlight, according to report from Asia Pulse. The new material boasts 1.7 times the brightness of conventional white LEDs. Asia Pulse reports that products containing this fluorescent substance could be available in two or three years.
http://www.sslighting.net/lightimes/?date=2005-03-08&id=5221#top


Nice, first we get a 2X improvement in the blue LED which bumps up output by 2X shipping from CREE back in Sept., then from LumiLeds hopefully this summer, and now Toshiba introduces a much higher efficiency phosphor (1.7X).

Not bad at all. Looks like it won't be too long before the standard output is raised by 3.4X of the current Luxeons.

Times are good...
 

PeLu

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Hard to believe as Nichia's phosphors already were pretty close to 100% efficiency (somewhere in tha 90ies AFAIK).

Developing phosphors for fluerescent lamps has a relatively long tradition (even when there are differences).

A gain of 70% could only be possible with shifting the spectrum to the more sensitive wavelengths.

That means even more bluish.
I have the impression that more bluish in marketing speech is called 'Close to Natural Sun' .-)

BTW, is there also an unnatural sun?
 

The_LED_Museum

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[ QUOTE ]
PeLu said:
BTW, is there also an unnatural sun?

[/ QUOTE ]
Well, if our planet orbited a type O star, and the planet was still class M (nitrogen/oxygen atmosphere, temperate surface conditions), the sun would appear very, very, VERY blue - and very unnatural. /ubbthreads/images/graemlins/wink.gif
 

HarryN

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The phos for LEDs is not nearly as good as for fluorescent lamps. One reason, is that the long tradition of phos. for fluor types, are based on using very short wavelengths in the tube, typically well into the UV range, and the light color is tuned be mixing phos.

The traditional white LEDs start with blue, which greatly restricts which phos will actually work for the yellow downconversion. Some of the firms (mostly in Japan) use near UV LEDs for the white, which have the potential for greater color range, but also will suffer more from Stokes conversion losses since the efficiency is at least partially dependent on the difference between lamda in vs lamda out.
 

idleprocess

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Re: Toshiba Introduces White LED Close to Natural

I thought that white LEDs using UV LED + UV-reactive phosphor were still experimental but close to production. I know that some UV LED dice have lifespan problems and that traditional LED packaging degrades under UV.

Floresent lighting is more efficient than blue LED + yellow phosphor, so it seems safe to assume that UV LED + UV-reactive phosphor could be nearly as efficient as conventional floresent.
 

LowBat

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[/ QUOTE ]Well, if our planet orbited a type O star, and the planet was still class M (nitrogen/oxygen atmosphere, temperate surface conditions), the sun would appear very, very, VERY blue - and very unnatural. /ubbthreads/images/graemlins/wink.gif

[/ QUOTE ]

Type O stars are the hottest known and would fry out little planet, and mentioning the fictional "class M planet" means you watch a lot of Star Trek. /ubbthreads/images/graemlins/buttrock.gif


s772.jpg
 

NewBie

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Re: Toshiba Introduces White LED Close to Natural

[ QUOTE ]
idleprocess said:
I thought that white LEDs using UV LED + UV-reactive phosphor were still experimental but close to production. I know that some UV LED dice have lifespan problems and that traditional LED packaging degrades under UV.

Floresent lighting is more efficient than blue LED + yellow phosphor, so it seems safe to assume that UV LED + UV-reactive phosphor could be nearly as efficient as conventional floresent.

[/ QUOTE ]


Actually, Toyoda-Gosei has been shipping UV die with phosphor for two years now, and I haven't seen any life issues. The LED color is extremely uniform (even across a batch of 300 I wired up at the same time), and doesn't shift with various currents, nor shift with temperature.

The B.S. that folks have been saying here on cpf about the UV die eating itself is exactly that, B.S. As these UV die white LEDs are built with proper materials (special silicones and such), these Toyoda-Gosei LEDs easily outlast the 5mm blue+phosphor such as Nichia and others sell.

Look at the past part on this page:
http://www.microlamps-tg.com/html/Prod_white_compare.htm

MicroLamps has been distibuting them since 2002.

I'm surprised you haven't seen my posts on this before...
 

idleprocess

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Re: Toshiba Introduces White LED Close to Natural

Note the "traditional" disclaimer...

Toss a UV die in a typical 3/5/10mm epoxy package and the epoxy will gradually fail because of UV exposure. I've heard speculation that the trace amounts of UV put out by blue LEDs can shorten their (packaging) lifespan.

I don't know if this is related to claims that UV LED die kills itself premeaturely.
 

The_LED_Museum

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[ QUOTE ]
LowBat said:
Type O stars are the hottest known and would fry out little planet, and mentioning the fictional "class M planet" means you watch a lot of Star Trek. /ubbthreads/images/graemlins/buttrock.gif

[/ QUOTE ]
Correct, and correct. /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/buttrock.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/smile.gif
 

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Re: Toshiba Introduces White LED Close to Natural

[ QUOTE ]
idleprocess said:
Note the "traditional" disclaimer...

Toss a UV die in a typical 3/5/10mm epoxy package and the epoxy will gradually fail because of UV exposure. I've heard speculation that the trace amounts of UV put out by blue LEDs can shorten their (packaging) lifespan.

I don't know if this is related to claims that UV LED die kills itself premeaturely.

[/ QUOTE ]


Thats exactly why, a few years ago, Toyoda-Gosei started utilizing silicone in their packaging. You will notice, CREE, OSRAM, Nichia, and even LumiLEDs did the same, even with their regular visible output parts.
 

idleprocess

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Re: Toshiba Introduces White LED Close to Natural

I think I was "educated" on this matter several months ago.

I look forward to the UV+RGB phosphor LEDs being more widely available. I guess I could be brave and order some from Future or some other large distributor...
 

kitelights

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Re: Toshiba Introduces White LED Close to Natural

I'm not sure if this is relevent, but traditional UV fluorescent tubes do degrade in their UV output. I use UV lights in my business daily. I don't notice a drop in light output, but I'm told that the UV output itself does drop. My industry recommends yearly replacement of lamps. I've been told by a manufacturer that the on/off cycles are the culprit for the degradation. It's my understanding that it's the nature of UV light sources to degrade. I would assume that the same is true for LEDs.
 
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