"Holy Grail" of LEDs: Pure White Light Achieved

[Michael Haney]

Scientist have finally developed an LED that produces Pure White
Light. This is a major step, since LEDs use much less power than
regular light bulbs and last longer. There are a lot of applications
for these such as indoor lighting for homes that last longer and cost
less on your electric bill, emergency flashlights that could last for
days rather than hours, better backlighting for laptops that use less
battery life, and possibly they could be used for rear projection DLP
televisions.

http://www.ecogeek.org/content/view/1000/

--
Michael "TheZorch" Haney
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http://thezorch.googlepages.com/home
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[ThreadWeaver]

While a pure white LED is a great advance, I think it will be a while before it's accepted in everyday home use.  The best they've been able to achieve in day to day use so far has been on overloaded blue LED where the light is a harsh white with blue overtones.

Since electronics is the field I have my degree in, I think they will have two problems:
1) A LED is an inherently unidirectional light emitting device.  In other words, LEDs only put light out in a very narrow angle from straight on.  Any diffusion from that is caused by the lens surrounding the diode and then at BEST (but I haven't seen one that's efficient that is) is a 180 degree emitting angle.  To light a room evenly and effectively you would have to produce a spheroid shaped 'bulb' made out of many individual LEDs to maximize the light dispersion.  This will be quite expensive for quite a while.

2) Color.  'Pure' white is not a color people appreciate in their homes.   This is a fact that the Compact Fluorescent industry has learned over the last 5 years.  People like softer light with a tinge of yellow.  Must be that ancient fire attraction we have.   They will probably tinge the plastic used to make the lens a slight yellow to overcome this, or place a diffusing shield over the 'bulb' itself.

I do however see this taking off right away in commercial and office environments and in other situations where fluorescent lighting is common.

Ultrabright LEDs, the ones used in these cases, in and of themselves have been a major boon to us.  Before a single LED couldn't put out enough light to make an effective lighting tool other than as a electronics device indicator.  The first commercial inroads of these ultrabright LEDs were in stoplights, where their long life and low power consumption have helped municipalities save buckets of money in electricity.  That was in '98.  Now we see them in car taillights and loads of other applications.

This should be interesting as the technology develops.