Application Note: Easy Solution to LED Wall Washing Color Problem

Remember our color temperature drifting in our LED wall washing application note? No? Click here to read all about it Well, as you may recall we had 6 high power LEDs on a linear board to be installed either in a ceiling or in a floor along a wall. The LEDs were fitted with large 3/4-inch diameter can-type prismatic, directional diffusers. The problem was that the LED manufacturer’s binning for accounts buying less than a zillion LEDs leaves something to be desired. Add to that the fact that the contract manufacturer didn’t assemble these first using LEDs from one lot and then progressing to the next but rather a mix and match approach as they went along. We were expecting the LEDs to be warm white but what we got was anything from deep amber to pink with several shades of yellow, orange, and green in between.  There were hundreds of these boards made and even with the solution of pulling the surface mount LEDs off the board and binning them by color on our end, we were faced with the prospect of 30 – 40% board loss. Ouch!

Well, using all of my artistic color theory I learned in college another engineer and I came up with a novel solution that is not only simple enough to be manufactured in-house but dirt cheap as well! I am hugely familiar with optical filter design in addition to light, light properties, and light measurement and knew that the way to cancel out a particular color was to use it’s complementary color in a gel filter (optical filter made of plastic, glass, or even gelatin which is where the name comes from – think Kodak Wratten filters) of some transparency level other then totally opaque. The other engineer assigned to the project came to the same conclusion at the same time separately from me – clever guy!  Now we could have gone out and bought expensive, ready-made optical gels but during the testing stage we would need to go through multiple shades of a particular complementary color to find just the right shade of complementary color to correct an LED. Not to mention that we would need several different complementary gel colors to correct for the various shades of LED colors PLUS the fact that we would probably need several levels of opacity since we had several strengths of each color from the LEDs output (i.e. amber, dark amber, and really dark amber).All this trial and error testing would leave us needing a huge library of color gels which would be a gigantic expense.  We both knew that the best way to do this would be to manufacture the gels in-house. I had done something similiar on a different project where I needed colored lenses to cover LEDs on an in-house manufactured vinyl instrument panel label – I had used ink-jet transparency film to print the LED lenses. BINGO! We could print various shades of the complementary colors we needed at various opacity levels on transparency film in my desktop ink-jet printer! We could print strips of 1 or 2 inch squares with each succesive color a darker or lighter shade of the color we thought was complementary to the LED colro we needed to correct. We could print all of these at whatever opacity we needed. In this way, we could hold the strip over the LED and cycle it through the squares on a strip and see it’s effect on the LED light ouput color in realtime. Testing with a light meter revealed that the gels reduced the light output by well less than 10%, which in this case was not a problem since the LEDs were to be operated at a power rating slightly ABOVE the design spec. The other engineer and I were able to come up with the 6 or so colors we needed and at what opacity levels we would need all for the cost of one box of ink jet transparency film ($15.00) and our time. As it turned out, this was a HUGE time saver as well. Taking the SMT LEDs off to correct the problem the board would require about 1 hour per board plus the time of resoldering a new LED on to a new board (the metal-core board would be destroyed taking the LEDs off). Anyrate, we settled on 5%, 10%, 15%, 20, and 25% opacity so we had 6 colors at 5 opacity levels for a total of 30 different types of gels. Once the testing was done and we had our selections, we set about manufacturing the actual gels to fit the LEDs. Here I took each color/opacity level and printed it out on an entire sheet of ink-jet transparency film (along with some text indicating what color and opacity level it was so we wouldn’t have any binning mistakes later). Once all 30 combinations had been printed in this manner, our production department set about punching out 3/4-inch circles using a hollow punch and a hammer. We got over 150 circles per page. We used plastic cups labeled with the color and opacity level and these were filled as the puncher went along. The entire punching process took about 4 hours – less than the time it would take to yank the LEDs off of 5 boards! Once all the punching and binning was done, then we went about correcting each LED on a board. The 3/4-inch round gels were designed to fit right in to the recess at the top of the LED’s can diffuser/lens. The fit was perfect! We would still need to do a little trial and error testing by occasionally swapping circle gels onto and off of an LED until it was corrected to the best of our ability. Once a gel was found that worked well, it could be glued into place with a few dabs of quick drying optical epoxy on the edges. Once a few had been done, the process got really easy and quick. We did find a few oddball LEDs with weird in-between colors in their output that required either printing and punching a new gel set or in a few cases, stacking gels to achieve the best possible correction level. For example we had an LED with orangish output that when we applied the bluish-purple complementary gel, shifted to a slightly green output which required the application of another gel of purplish-red to correct. There were a few LEDs that had colors that kept shifting around no matter what we did – these were chocked up to loss.

It wasn’t elegant but it was cheap and effective and will ultimately reduce the board loss to the barest minimum -  our test batch sent to the customer had LED with output colors well within their design specs so we are confident the solution will pass muster. I’ll let you know as soon as I hear back.

Technorati Tags: Innovative Lighting Design, Tools of the Trade. Tags: architectural lighting, architectural lighting design, architectural lighting design tools, color filters, colored filters, correcting led binning, correcting led color, designing with light, gelatin filter, gels, home made filters, homemade filters, homemade gels, led architectural lighting, led binning, led color, led color temp, led color temperature, led filters, led gels, led lighting, led wall washer, led wall washing, lighting design, lighting design tools, lighting designers

New Architectural Lighting Blog Image Gallery!

Just a quick note to let you know that I have posted a gallery page (click the “gallery” tab at the top of the blog just under the header or click here) . Currently it contains a small collection of some of my 3D renders and sketches of concept LED-based architectural lighting fixtures.  I will add to it as I can. Let me know what you think!

Sticky: Second Phase of HYVE/Osram “LED-Emotionalize your light” Design Contest Starts

I just received a follow up email from HYVE regarding the “LED-Emotionalize your light” design contest. Here it is for any of my readers that have participated:

The second phase of the LED-Emotionalize your light! Idea Contest has started!

At this very moment the jury is selecting the 3 best ideas and designs out
of more than 500 contributions and the winners will then be announced on
Wednesday. The first phase has been a huge success with 505 ideas, 764
members, 6599 community evaluations and 2897 comments within 7 weeks and
still new ideas are submitted. While the winning ideas are waiting for
their announcement the three most active community members have already
been chosen: Congratulations to howman, LED Head and Classic!

Contest Phase 2
The focus of the second contest phase will be on refinements and further
developments. The 10 most interesting ideas are selected by the jury and
the community is forced to advance these contributions by further designs,
applications or technical solutions. Phase 2 will be closed on July 20th,
2009 and two weeks later on August 4th, 2009 the 3 contributors of the
best improvements will be awarded. The best submission will receive
1.000€. The second prize will be 600€ and the third prize will be
400€. But keep in mind, the three most active community members will be
rewarded as well. You have the possibility to comment on ideas or
improvements, to evaluate them or to leave messages on
www.led-emotionalize.com.

Social Networks
Beside the contest platform all participants and everyone who is
interested can join the LED-Emotionalize your light – Design Contest
group or the contest community on facebook. You have the chance to receive
the latest contest news on twitter and in case of questions contact the
contest team by sending an email to info@led-emotionalize.com.

We really appreciate your participation in Phase II of the contest. Become
a part of continuous success of creativity and open innovation by
reporting on the contest or forwarding this information to your creative
network!

Thank you for your support

Technorati Tags: lighting design , lighting designers , lighting design software , lighting engineering , Office Lighting , office lighting design , designing with light , lighting contest , lighting design contest , osram , hyve , lighting innovations , led emotion , led emotionalize , competition , led competition , lighting design competition

Sticky: HYVE Innovation Community in collaboration with OSRAM, are hosting an online idea and design competition

First off, let me say that I am NOT posting this late. I did not get this until 25MAY09 but the contest runs until the end of July so you still have time. I am posting the email sent to me by HYVE regarding this really cool contest. I am considering entering and I hope all of you lighting designers out there do too. Come on! Strut your stuff – you might win something. If any of you do, please post back here or send me an email with images and an explanation (short) of your design – I would LOVE to post them here! Here is the email explaining the contest:

We, the HYVE Innovation Community in collaboration with OSRAM, are going
to host an online idea and design competition in the beginning of May
until the end of July. The contest “LED – Emotionalize your light”
(www.LED-emotionalize.com) asks international light and design lovers to
share their ideas in the field of light designs using LED technology and
to create innovative and emotional mood light concepts. Moreover the
contest aims to generate feasible ideas for light solutions, which are on
the one hand easy to use and implement and on the other hand affordable
for everyone.

With the help of an easy to use submission procedure ideas can be
contributed, described with simple application scenarios and extended by
designs or technical solutions. Participants will not only have the
possibility to create their own Light design, but also to have it
discussed within the community. The community members can comment the
ideas of other participants as well as to evaluate or refine them.

The competition has already started and will run until the end of July
2009. Within the first phase new ideas and designs are collected and
discussed by the community. In the following second phase the best designs
and ideas are presented and jointly advanced by the community.

All participants of the competition have the chance to win valuable prizes
amounting to 7000€. The designs will be judged by a professional jury,
consisting of senior staff of OSRAM and selected professional
representatives. The selection considers community and expert evaluations
and will be based on creativity, innovation and emotionality of the
submitted ideas. Furthermore the most active community members in each
phase can receive valuable non-cash prizes.

The “LED – Emotionalize your light” Idea contest is supported by the
light producer OSRAM and the Siemens AG

The following link will guide you directly to the competition:
www.LED-emotionalize.com

Really cool designs have been submitted up to now. For example Luminous
speaker, which can change their colour according to the music or luminous
chairs which might change their colour if it’s happy hour.

So check out the competition and if you find this competition exciting and
interesting, we would appreciate it if you could report on our contest in
your blog.

Thank you for your support.
So there you have it – get going already – I want to see what you guys and gals come up with. I’ll try to enter and post what I come up with too. 

Technorati Tags: lighting design , lighting designers , lighting design software , lighting engineering , Office Lighting , office lighting design , designing with light , lighting contest , lighting design contest , osram , hyve , lighting innovations , led emotion , led emotionalize , competition , led competition , lighting design competition

Smart LED Parking Lot Lights

UC Davis parking garage. Photo courtesy of Cree.

Ruud Lighting/BetaLED along with the University of California at Davis have developed “smart” LED parking lot lights that reduce the energy consumption by 80% over the more traditional metal-halide lamps they replaced. The 50 LED light fixtures implement a two-level activity sensing system that dims the lights to half power when no motion is detected and then bring them back up to full power when motion is sensed. Along with conserving energy, drivers, pedestrians, lot attendents, and security personnel will now have visual ques to the presence of other drivers/pedestrians in the area. After two years of development and testing, the fixtures were installed in the UC Davis South Entry Parking Structure. The smart lighting system technology is being destributed via Cree’s LED University program. Very cool indeed!

Click here to read the full article from LED News

Technorati Tags: architectural lighting, parking lot lighting, parking lights, led parking lot lights, UC Davis, University of California, California Lighting Technology Center, Smart LED lighting, Smart lights

Company combines fiber optics and LED technology to create fiber optic fabric and luminious clothing

Let’s chock this next one up to architectural “accessories” lighting, perhaps? Whatever you want to call it, these were neat enough to mention here so make sure you go take a look at these, OK?

LumiGram SARL a French high tech fashion and design company started by the famous fashion designer Jacqueline has come up with a line of table clothes, sculpture, throw pillows, and among other things fashion tops that are all made out of or incorporate arrays of LED illuminated fiber optics creating a shimmery, colorful glow of light. Some are AC powered and others are battery operated (AC powered fashion tops are available as window displays). The table cloths, pillows, and sculptures could be of interest to an architectural lighting designer (perhaps even the clothing if they’re a particularly fashionable lighting designer ) working on finishing upscale commercial venues or perhaps a private residence that wants that pulse-pounding dance floor look at night. Swaths of illuminated fiber optic fabric can be used as swags or tapestries.

Anyrate, these are all handmade items that are fun and highly unique and they incorporate two of my favorite things, fiber optics and LEDs. Definitely different. If any of my readers tries any of these, I’d be really interested in a picture or two. Kewl

Click here to checkout their website

Technorati Tags: LEDs, fiber optics, architectural lighting, architectural lighting design, solid-state architectural lighting, led architectural lighting, architectural led lighting, lighting design, solid-state lighting design, lighting designers, lighting artist, artistic lighting, lighting engineering, architectural lighting industry, designing with light, lighting fashion, fashionable lighting, illuminated clothing, illuminated cloth, luminous clothing, luminous fabric, fiber optic clothing, fiber optic fabric, fiber optic table clothes, fiber optic pillows, fiber optic sculpture, fiber optic fashion, led fabric, led clothing, French fashion design, Jacqueline, LumiGram

Story on LED Replacement Lamps Highlights Need for Standardized Testing Methods

I recently read a story on LEDs magazine about Toronto’s Palace Pier condominium tower becoming the largest residential LED conversion in North America. The Palace Pier is an upscale, 44 floor condo building with spectacular views that the designers wanted to carry over into the interior of the building. They replaced the existing 1300 MR16 halogens with direct MR16 replacement LED modules. The halogens consumed 35 watts of electricity versus 4 watts for the LED replacements. Kudos on being green!

The thing that I found most interesting here is that the contracted company providing the replacement LED fixtures does not put up complete specifications for either of their replacement LED products:  no datasheets, nothing specific. Just a general 300+ lumens for their MR126 replacement product. I question the comparison in brightness between MR16 halogens and the LED replacements. The story just says comparable brightness but when you go to the CRS website, all you see is the 300+ lumens. Ignoring the fact that lumens is not brightness but total light output in all directions as measured in an integrating sphere, 300 lumens isn’t even close to the 1000+ lumens light output you get from a typical 35 watt, 12 VDC MR16 halogen lamp. What I am sure they are referring to is center beam candela, which is a brightness measurement but their website doesn’t have that specification. Perhaps the MR16 halogens they are replacing weren’t particularly bright, a very real possibility but who knows? I’m sure the fixtures were tested, at least by their own eyes, to make sure they were as bright or brighter but the published specs alone don’t bare that out. I am also sure that in this case it is just an oversight but it does lead me to ramble on about something that is all too common in the industry these days: confusing. missing, or misleading specifications.

Unfortunately, beam candela measurements have to take into account the measurement distance and the angle at which the beam is sampled, neither of which needs to be defined in the results. So a manufacturer that took a measurement at 4 feet away from the lamp over a 26 degree sampling angle and only came up with 480 Candela could retake the measurement at 3 feet from the lamp for a 10 degree sampling angle and get a more favorable 950 Candela and publish that as their spec without saying it was measured at 4 feet at a sample angle of 10 degrees. If these were separate manufacturers and separate lamps, how could you make a direct comparison based on 480 candela versus 950 candela without knowing the missing information? You couldn’t, really. Beam candela refers to how bright a narrow beam of light will look to an average human observer at some specific distance away. A lamp such as the replacement lamps used at the Palace, may only output 300 lumens but at a very narrow 15 degree beam angle so the brightness at, lets say 4 feet away may be quite high compared to an MR16 halogen at the same 4 feet with a more impressive 1000 lumen output but with a broader beam angle of 30 degrees. Kind of confusing isn’t it?  One lamp manufacturer may publish their 1000+ lumens as a measure oft their lamps brightness while another may publish 850 Candela as theirs. So which one is brighter? You’d have no clue without actually buying each and testing them both. Errr!

As an LED manufacturer and distributer, I have a real problem with LED lamp manufacturers that do not put up their specifications and when they do, they only put up generalities or use the more confusing numbers such as lumens as an indicator of brightness. This leads to confusion and hurts the industry as a whole. I know of several large companies/institutions that would switch over to LED lighting if the market weren’t full of confusing and misleading numbers. They just won’t take the chance. The DOE, working on standardized testing methods for LED based architectural lighting, has run into this big time with submissions that had stated outputs no where near what the DOE’s testing bore out. Click here to read more about the DOE’s efforts on standardized testing methods for solid-state lighting.

Well I’m not going to go on much further. I said what I wanted to say. I’m not impugning the company in the story. In fact, congratulations to them on their success on this project. I’m merely citing the story as an example of an industry-wide practice that needs to improve if solid-state lighting hopes to make it into every home.:(

Click here to read the full story at LEDs Magazine

Technorati Tags: leds, solid-state lighting, lighting industry news, lighting industry market, lighting market, solid-state lighting, led news, led technology, leds in the news, energy star, energy-star, energy savings, saving energy, energystar, energy efficient, residential lighting, residential lighting projects, led city, led cities, led-based residential lighting, led residential light, residential leds, residential light design, residential street light, architectural lighting, architectural lighting design, solid-state architectural lighting, led architectural lighting, architectural led lighting, lighting design, solid-state lighting, department of energy, us department of energy, us doe, doe, commercial product testing, product testing, standards and procedures, ssl product testing, solid-state lighting product testing, led specifications

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LEDs Modernize Time’s Square New Years Eve Ball

Thanks to reader Kc for giving us the link to a great article about the new LED version of the venerable Times Square New Years Eve ball.

This year is the 100th anniversary of the New Years Eve ball and the ball has been completely redone by Waterford Crystal and has been updated with a brand new, sophisticated LED lighting system by Philips Lighting. Philips has replaced the 600 incandescent light bulbs and halogen bulbs with 9,576 Luxeon LEDs to give us all a New Years Eve ball that is brighter and way more energy efficient. Another benefit, provided by Focus Lighting, is that the LEDs are now under better computer control and can produce millions of colors and changing patterns of light never before possible with traditional lighting.

Anyrate, click here to check out the article, it’s well worth it. There is a brief history of the Times Square New Years Eve Ball and also a video of the New Ball.

Technorati Tags: leds, led modules, accent lighting, architectural lighting, engineering lighting, light engineering, color changing light, color cycling light, rgb leds, color leds, light design, designing with light, lighting design, architectural light industry, leds for fun, fun with leds, led projects, projects with leds, solid-state architectural lighting, office lighting, lighting in architecture, architectural design, innovative architectural lighting, Philips Lighting, Philips LED Technology, Waterford Crystal, New Years Eve, Times Square, Times Square New Years Eve Ball, New Years Eve Ball, Time Balls, Focus Lighting

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Gigantic Animated LED Rugby Ball

There’s a phrase I never thought I’d be saying in my lifetime.

Thanks to reader Walt Jacquemin for pointing out yet another fun and interesting use of LED technology as accent lighting or in this case as sculpture. In the past, a 13.5 by 9 foot rugby ball might have been made of stone or concrete or wire and flowers (think Rose Bowl float) or whatever. Now, thanks to LEDs we have a gigantic, fully animated rugby ball. How cool is that?!? This thing is covered with 2000 Barco LED light tiles that together along with sophisticated controllers and software combine to make what amounts to a Jumbotron rolled into a football shape (American football that is).

Fun stuff! Thanks Walt!

Click here to read the full story at LEDs Magazine

Technorati Tags: leds, led modules, accent lighting, architectural lighting, engineering lighting, light engineering, color changing light, color cycling light, rgb leds, color leds, light design, designing with light, lighting design, architectural light industry, leds for fun, fun with leds, led projects, projects with leds, solid-state architectural lighting, office lighting, lighting in architecture, architectural design, innovative architectural lighting, Barco, rugby world cup, rugby world’s cup, led sculpture, creative technology, dimension audio, led rugby ball, led rugby sculpture, Colour Coordinate, Pinpoint, animated lighting array, animated led array, animated office lighting, animated architectural lighting

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“Pixel Cloud” LED Array Just Might Be The Coolest Architectural Accent Light Ever!

Finally! A really, really cool application of LEDs in architecture! Lately, everything has been “like wow, we replaced a bunch of light bulbs with LEDs…hooray!” or innovative LED illuminated windows on a very non-innovative cube building, or “look more facade uplighting”. I’ve been waiting for a really “WOW” architectural lighting project to come along and this is it.

Seriously, you have to go read the full article, these “Pixel Cloud” LED arrays are way cool for large atriums, lobbies, concert halls, my cubicle….just kidding on that last one. These “Pixel Clouds” are made of pendant-like LED globes suspended at various heights from the ceiling forming a 3-dimensional array. Each LED globe is cleverly constructed of 24 LEDs in a dodecahedron (I’ve been waiting years to write about a dodecahedron for something) , with each LED individually controllable and each globe individually addressable via some seriously sophisticated software. The software and dedicated server can perpetually change the appearance of the cloud array even projecting images from passing clouds from a skyward pointed video camera mounted on the roof of the building. How kewl is that! I’m going to hit my boss up for one of these things.

Check out the full story at LEDs Magazine

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Technorati Tags: leds, led modules, accent lighting, architectural lighting, engineering lighting, light engineering, color changing light, color cycling light, rgb leds, color leds, light design, designing with light, lighting design, architectural light industry, leds for fun, fun with leds, led projects, projects with leds, solid-state architectural lighting, office lighting, lighting in architecture, architectural design, innovative architectural lighting, pixel cloud, Ledon, Jason Bruges Studio, atrium lighting, atrium accent lighting, animated lighting array, animated led array, animated office lighting, animated architectural lighting