"High Lights from the Heartland" 2-7-10

Welcome to "High Lights from the Heartland". A little humor plus news and observations on the LED / Solid State Lighting markets for your enjoyment. Feel free to share this with your friends!

A little humor: A lawyer phoned the governor’s mansion shortly after midnight. “I need to talk to the governor, it’s an emergency!” exclaimed the lawyer. After some cajoling, the governor’s assistant agreed to wake him up. “So, what is it that’s so important that it can’t wait until morning?” grumbled the governor. “Judge Pierson just died, and I want to take his place,” begged the attorney. “Well, it’s OK with me if it’s OK with the mortuary,” replied the governor.

News & observations on the LED / Solid State Lighting markets:

Opinion: The Super Bowl is being played today and the game of football has been called a “game of inches”. The lighting industry can be called a “game of lumens” and every lumen is precious. Humans have been producing lumens for hundreds of thousands of years every time they set something on fire. Burning something to create lumens has been mankind’s primary lighting process until we got around to phosphor conversion, first in fluorescent lamps and now with LEDs. Fluorescent lamps are currently in the 90 to 120 lumen per watt range and as you will see in the news item below from Cree, white LEDs are now pushing 208 lumens per watt in the lab (however still averaging 80 to 130 lumens per watt in production). Every time we see a boost in LED lumen output, more lighting applications for this light source become possible. Getting white LED output up to and beyond the levels of existing glass lamp technologies has been the big challenge for the last 10 years.

The other big challenge is consistent white CCT output at acceptable CRI. LED die and phosphor packaging can have a big impact on how well this gets done. The problem here is the variance that exists in each blue LED die’s output wave length (~455 nm +/- 5 nm). Since the wave length varies slightly from wafer to wafer and across each wafer, these small changes will alter the output from the yellow phosphor used. To add to the manufacturing surprise value, phosphors are chemical mixtures that can vary from lot to lot. So with small changes at the blue die level and small changes in the phosphor mix can produce wide changes in the resulting CCT values. One way to get around this problem is to mix multiple small LEDs into an array and then apply the phosphor mix over the array. BridgeLux and now Cree have developed products that use the multiple die approach (see news stores below). While they are not the first to embrace this solution, they do bring their own special edge to it as die manufacturers. This also solves manufacturing and supply chain issues that LED fixture and retrofit lamp companies have be struggling with as well: binning consistent CCT from discrete white LED components. If you have enough of an air gap in your fixtures or lamps, you can achieve white LED color mixing but many of these end products do not afford this option. Using white LED arrays also better utilizes blue die production, which will be in short supply this year and next. So this approach is better for the LED companies and the end users, solving multiple problems on both ends of the supply and production chains.

Finally, one of my readers reminded me, in the spirit of full disclosure, that in the last issue of High Lights I mentioned Sharp Electronics’ CES announcements on LED Lighting for the USA market. If you did not already know, I work for Sharp as their Business Development Mgr for LED Lighting (LED Retrofit Lamps, LED Fixtures and Solar Off-Grid LED Fixtures). This newsletter is strictly a personal endeavor, analyzing the LED components and LED Lighting markets and the rapid changes occurring there.

News:

Cree Breaks 200 Lumen Per Watt Barrier - LIGHTimes News Staff, February 4, 2010. The company announced that its white, power LED achieved a record of 208 lumens per Watt at a drive current of 350mA under standard LED test conditions. The LED had a correlated color temperature of 4579 K. Cree noted in a news release that this R&D result passes a significant milestone within the solid-state lighting industry. Cree says that while this level of performance is not yet available in Cree’s production LEDs, it continues to lead the industry with the broadest family of high-performance LEDs. “We have now broken the elusive 200-lumen-per-watt efficacy barrier for a single white power LED.” “This is a result of improvements in blue optical output power, lower operating voltage and higher conversion efficiency. We continue to push the envelope in white LED technology to enable the highest efficiency white lighting products in the marketplace.
http://www.solidstatelighting.net/news/?date=2010-02-04&id=118808

LED maker Bridgelux targets general lighting - At the current rate of technology development, it's possible that LED replacements for 60-watt incandescent bulbs could drop below $10 by the end of this year, said Mark Swoboda, the president of LED maker Bridgelux. Although technically feasible, that six- or eight-fold price drop is not likely to happen. Swoboda figures that price could only be reached in the case of a lighting company selling directly to a customer. Bridgelux is set to introduce a line of LED arrays which can be used in different applications, such as household light bulbs, down lights, and street and commercial lighting. With the new line of LEDs, the amount of light per watt has improved by over 30 percent in the past year and the costs have fallen between 10 percent and 30 percent, Swoboda said. "Our core technology has improved to the point where it can deliver a light source that makes it very easy for a lamp or luminaire company to meet or exceed requirements to meet EnergyStar or California's Title 24," Swoboda said. Its arrays range in output from 240 lumens to over 4,500 lumens, making them suitable for both general consumer lighting and commercial applications, such as retail stores.
http://news.cnet.com/8301-11128_3-10446253-54.html

Cree’s MPL EasyWhite LED obsoletes binning - With Cree’s announcement today of its XLamp MPL EasyWhite LED the company moves another step forward on its quest to eliminate “binning” from the vocabulary of LED lighting application designers.
The XLamp MPL Easy White can provide as much as 1500 lm at 250mA. This is a best-case number with a pulsed, rather than a constantly-on drive current, but with proper drive electronics and heat sinking, the LED can deliver the light output for a 3000 K, 75-Watt equivalent BR-30 light bulb, while consuming 78% less power than a traditional halogen bulb. (This performance meets the efficacy/lumen requirements for integral LED lamps as defined by the Energy Star program.) Which is impressive, but just as important is how the EasyWhite series frees light application designers from having to worry about matching the color output of multiple LEDs in each light bulb fixture. LED manufacturers have historically had difficulty in holding the LED chips to a uniform color output, and have sorted the chips into different color bins. Light manufacturers would mix-and match from different bins to get a uniform color, but this approach requires a large inventory of LEDs to meet the production lines need for a variety of bins. Plus, the whole idea of binning is confusing: Traditional light sources require only two specifications: color temperature and light output. This simplicity of specification and inventory is what Cree is driving at by eliminating or at least reducing the need for binning. 24 die are packed into a 12x13mm footprint that Cree believes is 72% smaller than the next-smallest alternative. In volume quantities, expect the pricing to be under $20. http://www.edn.com/blog/1470000147/post/170052417.html