One of the most exciting aspects of the advent of LED lighting has been the chance for companies to take unique approaches to how they want to solve the challenges presented by the shift in technology. Switch Lighting, for example, has pioneered a liquid-cooled design while GE has decided to utilize a form of active cooling that uses an oscillating diaphragm to move air inside the bulb. 3M, a company not generally associated with light bulbs, has entered the LED market with its own novel design.
3M isn't a top name in household lighting but the company knows quite a bit about LEDs. Its specific expertise is in backlighting for televisions and other displays, through the company's Optical Systems Division. With this expertise already cultivated, 3M developed an LED bulb that was able to take advantage of its experience. Rather than using a more conventional design, the Advanced Light — the company's first home bulb — uses lightguides in order to distribute the light generated inside. This comes with some interesting advantages, most importantly a design that looks a lot like a conventional incandescent bulb and one that casts a similar light pattern.
The use of lightguides — which is similar to the technology used in edge-lit televisions — allows for 75% of the bulb to emanate light. That number is much greater than standard LED designs that use a large heatsink at the base. This amount of lit surface area is what allows 3M to use a conventional A-bulb shape and to have very even light distribution without significant glare or hotspots.
3M doesn't say much about the rest of the secret sauce — eventually I'm going to have to take the bulb apart — but in addition to the lightguides, its release mentions the use of "multilayered optical film" and "optical adhesives." The company doesn't produce its own LEDs or semiconductors but it did remark on the quality of its electronics, saying that their performance is second to none (specifically in terms of EMC and power factor).
The most important part of the design are the lightguides which direct light from the emitter to the diffuser, where it can then go on to create a regular pattern. 3M's diagram of the bulb does not mention the use of heatsinks but a quick look at the bulb makes it immediately clear that there are cooling slits in the exterior which will allow heat to escape from the internal components. This design allows for proper cooling without a hunk of metal taking up a significant part of the bulb's exterior. 3M noted that the bulb can be used in any orientation though is not designed for use in an enclosure.
The 3M Advanced LED light is available in 3000K and 4000K models, both of which produce 800 lumens (making it 60W-equivalent) and are rated for 25,000 hours. The bulbs are dimmable and instant-on.
The Advanced LED lights consume 13.5 watts. That means about 60 lumens per watt, which is acceptable but far from cutting edge at this point. For comparison, Philips' L Prize bulb is rated at 94 lumens per watt, while its standard 12.5W LED bulb is 64 lpw.
While the price and efficiency numbers won't be winning any records, 3M hopes to compete with light quality and a handsome bulb. The bulb doesn't excel, at least on paper, in any specific arenas but 3M wanted a competitive total package and that's what it ended up with. The product is on the path towards Energy Star approval and is just the first step in a larger LED lighting push for the company. 3M doesn't speak much about their future plans, but it does note that 75W- and 100W-equivalent models are on the way.
The 3M LED Advanced Light (that's actually the name) is available now from Walmart for $24.88 (though it's currently out of stock.
