Controlling Color Variation in White LEDs

The light emitted from LEDs can vary significantly across the white color spectrum. Colors ranging from “warm” white (yellowish hue) to “cool” white (bluish hue) occur with many variations in between. These ranges are each assigned Correlated Color Temperatures (CCT), measured in Degrees Kelvin. An LED array with different color temperatures mixed together may have profound ef­fects on the quality of the end product. Customers in the LED lighting industry are very critical of such color variations in their products, and this is where the challenge for attaining more uniform color output arises.

LED Manufacturers and Binning 

LED manufacturers control white color variations through the process of “binning”. Binning is the method of sorting and grouping LEDs according to specified parameters, satisfying applications that require tighter color tolerances and less variation between LEDs. For example, one kind of LED will have numerous bin codes that define a more precise color temperature within that LED “family”.

However, the precise outcome of color binning can be lost if companies purchasing from the LED manufacturers fail to keep track or handle the binned LEDs properly. Bin control remains crucial as the LEDs travel up the supply chain to LED solution providers or lighting manufacturers.

Norlux Solution 

At Norlux, the key to building LED arrays with similarly binned LEDs is lot binning control and traceability. Tracking the origin of raw material, especially LEDs, is important to a manufacturer like Norlux. Our team assigns internal part numbers along with a manufacturer’s LED part number in order to differenti­ate the number of LED variants we handle. Every time a new shipment of this particular LED arrives at Norlux, the receiving department will assign a specific internal lot number for that LED. All the LED information is stored under this specific internal lot number. By doing so, Norlux has the ability to trace back all the necessary information related to that LED lot.

Additionally, Norlux also has the capability to measure CCT and chromaticity values with integrating spheres and colorimeters. Data captured from measuring the LEDs’ output can be compared to the LED shipping data provided by the manufacturer and verified for synergy.

Benefits 

By assigning an internal part number and a specific batch number, Norlux is able to manage its white LEDs better when “kitting” the parts for assembly. The possible problem of having LEDs with different part numbers within one product is eliminated because only the specific part number shows in the bill of materials of the prod­uct. In addition, the possibility of releasing the LED with different bin codes is eliminated because each specific internal lot code assigned has the corresponding LED bin code information with the lot code.

If the customer requests a product to be built with a specific bin code, our production planners are able to trace back the bin codes through the internal lot code assigned. Norlux can even mix different internal lot codes as long as the bin codes assigned are the same (even with different manufacturer lot), thus maximizing optimal LED usage.

Conclusion 

By having appropriate control and traceability of white LED products, managing LED bin codes becomes second nature. Having this system in place eliminates the possibility of placing different shades of white LEDs in an array or assembly. This leads to reliable color consistency and ultimately great products that our customers appreciate and rely upon. For more information, please contact Norlux at 630-784-7500 or visit us at www.norluxcorp.com.

3D Renderings Make Product Design Complete

Successful engineering companies take advantage of two important assets: utilization of computer-aided de­sign (CAD) technology, and employment of skilled designers who know how to make the most of available CAD tools. CAD technology has become the cornerstone of today’s successful product development, as it elevates productivity and introduces innovation to the process. However, as with any tool, maximizing the potential benefits of the CAD system demands a combination of planning, organization, and expertise. Using the right tools can make the difference between success and failure.

Product development continually evolves, as do CAD tools. Competition demands improvements in productiv­ity and advances in innovation. With many variables and goals constantly changing, designers and engineers are required to be knowledgeable with CAD tools and be capable of using more than one CAD tool to design efficiently for the best result.

It is said that “a picture is worth a thousand words” and such is the case with design schematics. The capability to visualize the design during the engineering process produces fewer errors and quickens time-to-market. By incorporating a combination of CAD tools during engineering, the designer becomes familiar with the constraints involved and is capable of considering the overall picture and competent to design with fewer mistakes.

The Design

Designing a high-density integrated electronics package for an aircraft application creates numerous challenges. The project had to fit a specific location with size constraints of 1 ½ inches square and with depth confine­ments of 2 ½ inches. The project housing was designed in 3D to define the interior space available for printed circuit boards (PCBs), wires, sensors and buttons. The design was exported from the 3D software and imported into the PCB design software. This provided a valid PCB outline to begin the electrical design work.

The unique aspects of this design were the use of multiple boards and mediums, two rigid boards and one flex board. Two boards in this appli­cation were a 3D puzzle that had to mesh together. Although irregularly shaped, the outlines provided a valuable design space for layout of the circuits. Additional keepouts were added for holes, stand-offs, and header placement. The net list was im­ported and a variety of components displayed for layout. The components each had custom attributes that defined the geometric height, which be­came imperative during the import back into the 3D tool.

The components were divided in power components and logic components. Power components were placed on one board, logic on the other. The power components were located per best layout practices to generate the optimum layout. This design was then exported, and then imported into the 3D tool to generate the area available for safe component placement on the logic board. Once defined, the design was exported and imported back into the PCB design tool.

Using this information, the logic board was generated to create the best possible outcome. Component layout was not as critical for logic components and longer circuits may have been generated since this was not high speed. Again, the design was exported and then imported into the 3D tool. The two designs were coupled and a verification of clear­ances was confirmed. If errors were located, the design was reverted back to the layout tool for correction. The process was continued until no errors were found, typically 2 – 3 iterations.

The Visibility

By maximizing the use of multiple CAD tools, the clearance issues are verified before a costly process of ordering, manufacturing and assembly is incurred. Costs are compounded as the engineering process progresses. By resolving any interference issues sooner, the overall expense is greatly reduced.

Using a 3D component library, realistic looking components are integrated into the PCBs and incorporated into the final 3D assembly. This creates a pleasing image the customer can appreciate. The customer now has the availability to see the final product long before any prototypes are run. The customer can then decide if any further changes are required before progressing to prototypes.

Not all companies make the most of 2D to 3D electrical design. Norlux utilizes multiple CAD tools to create valuable products for its customers. For more information or to inquire about Norlux’s engineering capabilities, please contact Norlux at 630-784-7500 or visit us at www.norluxcorp.com

Managing LED-Based Projects: Importance of Time to Market

The life cycle for LED products is relatively short due to the continued rapid advancement of LED technology. After a state-of-the-art product is launched, it may only have a couple years before it is overshadowed by new competitive developments. Time to market is important for most companies, but for those launching LED-based products, timing is absolutely critical.

When examining a typical LED project, measurements such as light output, effi­cacy, and size requirements are now seen as moving targets. This short product life cycle makes it that much more critical to get a product to market as quickly as possible. Clearly, the longer it takes to launch a new platform, the less time one will have to recoup development costs and turn profits. Time is money!

As project teams race through the Scope, Design, Prototype, Validation and Production stages, there are many opportunities for the baton to be dropped, that’s where pro-active project management comes in. A Project Manager can mitigate time delays especially as team members fail to realize the project was ready for them.  Each delay of this nature can be measured in hours and sometimes days; the end result can add up to weeks for any given project.

The Norlux Solution

At Norlux, the key to avoiding communication delays is to automate project management processes. One must create a project template (like Microsoft Project) preferably through an existing company database. This template would be linked to other aspects of the database to access information like part numbers and team members’ e-mail addresses. Using macros and auto-generated e-mails, individuals will automatically be sent an e-mail notification when they can begin their task. Of course, team members can always access the project within the database to view the status. Following is a step-by-step process highlighting the details:

1. Project Manager creates timeline, complete with itemized tasks and due dates. As typically done with Microsoft Project, the Project Manager would identify which tasks can be done in parallel and which are dependent on predecessors.
   
2. Project Manager enters each task into the project template within the database using pull-down menus for common tasks and team members’ names.
   
3. Project Manager enters predecessors for tasks (i.e. electrical schematic must be completed before PCB layout can begin).
   
4. Project Manager has standard kick-off meeting with all team members to walk through the project requirements, action items and timeline.
   
5. Database shows each team member his/her personal list of open action items within a pop-up window each time they log into the database.
   
6. Team members simply click the “complete” box next to their action item when done. The database automatically fills in the completion date.
   
7. Database automatically sends an e-mail notification to the next team member(s) downstream showing they can now start on their action item.

When there are multiple predecessors, the auto-email notification is only sent out after ALL corresponding proceeding tasks are completed. Also, the auto-emails are sent only to those team members waiting on that specific task completion.  A critical component to the success of this automation scheme is to avoid sending unneeded notifications and reminders, otherwise team members may learn to ignore the messages. Keep all communication clear, timely and concise.

Smooth transitions are key to finishing projects quickly, and communication is key to smooth transitions. It takes a bit more time up front to set-up an automated project schedule. However, once it is put into motion, communication becomes effortless and instantaneous. By carving the dead time out of the project process, one can dramatically improve speed to market and enjoy all the corresponding financial benefits.

Contact Norlux today and take advantage of our accelerated product development process. We are the North American leader in the design and manufacture of custom LED lighting solutions.

Safety Is A Norlux Top Priority

Norlux utilizes several "best-practices" to ensure the safest possible working environment. These include the Gemba Walk, Residual Risk Reduction, and Behavioral Based Safety. These help the company to protect both employees and visitors.

A “Gemba Walk” on the factory floor has become daily practice for Norlux management. Gemba is the Japanese term for "the real place." Each morning, the Walk is focused on a different operating principle, such as standardized work, 5S, Green wastes, manufacturing wastes and safety.  If a hazardous situation is observed, action is immediately taken to fix it. Controls are put in place and additional operator training is conducted if necessary.  If the hazard requires more attention, an action is logged to ensure adequate follow up.

The Residual Risk Reduction (R3) proactive approach helps Norlux to eliminate unsafe conditions by constantly examining processes and executing ways to reduce risk before any accident occurs.

The Behavioral Based Safety (BBS) program helps ensure that each operator is performing his or her job in a safest manner possible. Monthly safety training sessions include both front-office and production employees. Case studies featuring hazardous situations are presented as a learning tool, complete with warning signs and appropriate immediate and future corrective actions. Education sessions cover issues from proper lifting technique for heavy items to proper handling of hazardous materials.

Norlux employees are empowered to speak up about safety issues and prevent accidents. The manufacturing floor is clean, with good visual safety indicators throughout the facility. Norlux is an ISO 9000-2008 certified LED systems integrator. 

3D Printer Brings Concepts to Life at Norlux

From the first minute our Stratays uPrint SE Plus 3D printer arrived in early June, the Norlux team of engineers immediately put it to good use. Having the ability to quickly fabricate and validate various product designs while trimming down prototype lead times from weeks to hours was critical for our business as well as our customers. The 3D printer works seamlessly with popular CAD software, translating complex designs into being before your very eyes. Adding this technology to our engineering capabilities was not only important to offer customers but it also has served internal customers as well. We’re very excited to have this new tool in our arsenal and below we'll illustrate some examples of how we’ve employed our 3D printing capabilities thus far.

Delighting the customer:
3D printing allows us to quickly produce product designs for validation or to identify potential design issues, otherwise known as “rapid prototyping”. By authenticating concepts early in the development process, customers can get product to market faster and at a lower cost. Below are two examples of 3D printed parts used by the engineering department to verify concepts and improvements for our customers.

Use in manufacturing:
Manufacturing has accounted for the largest use of our 3D printer to date. 3D printing technology has enabled Norlux engineers to model and print fixtures in the same day. The shortened conceptualization to actualization window allows for improved product quality and shorter lead times. Rapid fixture creation also improves employee morale by reducing fatigue and stress. Below is an example of fixture that went from concept to production in mere days.

 

 

 

Use internally:
When Norlux acquired our 3D printer, engineers immediately began thinking of ways to fully utilize the technology. In only a month we’ve collectively imagined many creative ways of using 3D printed parts here internally. One example involved fabricating a replacement part for one of our solder screen printers. These parts routinely fail and cost Norlux $50 to replace. Now, rather than purchasing a replacement when a failure occurred, we found that 3D printing the part at a fraction of the cost worked just as well.

Another example of internal usage involved the initial setup of Norlux’s new 2 meter integrating sphere. We needed a way to route wires and sensors into the sphere. Openings were available, but there was no elegant way to house the necessary wires and sensors. We decided to 3D print the adapters that were needed to house the sensors and route the wires into the sphere.

 

 

With our new 3D printing capabilities, the sky is the limit. This is just another tool we offer our customers to help create the finest LED based products in the market today. Please contact us today to learn how our 3D printing capabilities can help with your product's design.

LEDs Helping to Advance Medical Research

When it comes to surgical, examination and dental lighting, most manufacturers turn to LED technology as a means to reduce heat and eye strain while producing accurate color rendering of live tissue. Couple that with the environmentally friendly and energy efficient aspects of LED technology and it becomes clear why LEDs are king in to medical illumination applications. But where do LEDs fit of in terms of the advancement of medical science? Can LED technology actually help address and alleviate common mental conditions?

An article in Science Daily's April 2013 edition titled “Tiny Wireless Device Shines Light On Mouse Brain, Generating Reward” describes how implanting a miniature electronic device in the brain, scientists can manipulate the internal reward system of mice by illuminating specific areas and “prodding neurons to release dopamine, a chemical associated with pleasure” (Science Daily, 4/13). The lighting technology described in the article that was small but effective enough to elicit promising results were in fact LEDs. "This strategy should allow us to identify and map brain circuits involved in complex behaviors related to sleep, depression, addiction and anxiety," says co-principal investigator Michael R. Bruchas, PhD, assistant professor of anesthesiology at Washington University (Science Daily, 4/13).

To work in such a sensitive and fragile location such as the brain, engineers needed to devise a way to affect precise areas safely and accurately. “Washington University neuroscientists teamed with engineers at the University of Illinois to design microscale (LED) devices thinner than a human hair. This was the first application such devices in optogenetics, an area of neuroscience that uses light to stimulate targeted pathways in the brain” (Science Daily, 4/13). Now engineers invented a less invasive way to conduct very sensitive experiments where fiber optics and lasers were used in the past. “With the new devices, the mice freely moved about and were able to explore a maze or scamper on a wheel. The electronic LEDs are housed in a tiny fiber implanted deep in the brain. That's important to the device's ability to activate the proper neurons”, according to John A. Rogers, PhD, professor of materials science and engineering at the University of Illinois. "You want to be able to deliver the light down into the depth of the brain," Rogers says. "We think we've come up with some powerful strategies that involve ultra-miniaturized devices that can deliver light signals deep into the brain and into other organs in the future” (Science Daily, 4/13).

You might be asking yourself how exactly did LED light affect the mice’s decision making process. The article describes how “using light from the cellular-scale LEDs to stimulate dopamine-producing cells in the brain, the investigators taught the mice to poke their noses through a specific hole in a maze. Each time a mouse would poke its nose through the hole, that would trigger the system to wirelessly activate the LEDs in the implanted device, which then would emit light, causing neurons to release dopamine, a chemical related to the brain's natural reward system. When the brain cells were activated to release dopamine, the mice quickly learned to poke their noses through the hole even though they didn't receive any food as a reward. They also developed an associated preference for the area near the hole, and they tended to hang around that part of the maze" (Science Daily, 4/13).

So where will this research lead us into the future? “Researchers believe the LED implants may be useful in other types of neuroscience studies or may even be applied to different organs. Related devices already are being used to stimulate peripheral nerves for pain management” (Science Daily, 4/13). Testing of this nature could “help scientists better understand what goes on in the brain in disorders such as depression and anxiety. We believe these devices will allow us to study complex stress and social interaction behaviors," Bruchas explains. "This technology enables us to map neural circuits with respect to things like stress and pain much more effectively” (Science Daily, 4/13).

By mapping brain circuits involved in specific behaviors, we may be on the road to finding ways to alleviate and prevent common ailments in humans. "Understanding which populations of neurons are involved in these complex behaviors may allow us to target specific brain cells that malfunction in depression, pain, addiction and other disorders" (Science Daily, 4/13). LEDs and their specific form and function proved ideal for these experiments which are going a long way to advancing medicine and the understanding of our own brain functionality.

Reference:
Washington University in St. Louis (2013, April 11). Tiny wireless device shines light on mouse brain, generating reward. ScienceDaily. Retrieved June 25, 2013, from http://www.sciencedaily.com/releases/2013/04/130411142708.htm

LEDs Illuminate Famous Austrian Museum

After a decade of closure to the general public, the Kunstkammer Wien Museum (Vienna, Austria) reopened for legions of admirers of fine art. As described in a March, 2013 LED Professional article titled “Contemporary Lighting Art by Zumtobel at the New Re-Opened Kunstkammer Wien”, the museum embarked anew with the “highest conservation requirements, content-related didactic criteria, but also emotional factors played an equally essential role for the new presentation of the Kunstkammer” (staff author). A modern solution for lighting diverse art pieces within the museum was provided by well-respected Austrian lighting company, Zumtobel. Now, contemporary LED lighting solutions bring energy efficiency as well as elegance to the historical pieces from days long past.

The article describes beautifully how Zumtobel “developed a customized LED lighting solution in order to obtain a highly differentiated, gentle and effective illumination of the various objects on display. ‘The point was literally to present the objects in the best possible light. All exhibits are originals, and each of them has its very special aura that we want visitors to be able to feel and experience,’ says Sabine Haag, General Director of the Kunsthistorisches Museum. At the heart of the lighting solution is the Starbrick, a Zumtobel Masterpiece developed in collaboration with Danish-Icelandic artist Olafur Eliasson. Boasting unpretentious elegance and multi-functionality, the Starbrick is the only representative of contemporary art and cutting-edge technology in these rooms of the museum that were opened for the first time in 1891. The installation includes a total of 51 Starbrick assemblies consisting of four modules each, especially designed for illuminating the unique and sensitive works of art. Additional direct light is ensured by integrated Supersystem spotlights and indirect light is provided by a Panos Infinity module, while one of the Starbrick's surfaces that is directed downwards doubles as emergency lighting. ‘Due to the height of the ceiling, we had to increase the levels of light intensity, but the original shape of the Starbrick remained unchanged. Taking the historical rooms into particular consideration, a highly specific Starbrick assembly was created, so that the modules work like a picture, like stars in the sky,’ explains Olafur Eliasson” (Contemporary Lighting, 2013).

Zumtobel’s masterful use of LEDs with the museum walls goes beyond the Starbrick. “In addition to LED Supersystem spotlights mounted on the walls, single Supersystem spotlights were also installed in the showcases. Especially in the showcases, each of them a highly sensitive closed system, the benefits of LED technology can be fully exploited. Thus, light-emitting diodes not only boast a long service life and high energy efficiency, combined with reduced maintenance cost, but also ensure an effective and at the same time gentle presentation of the exhibits. More-over, the light colors can be individually matched to the colors and materials of the exhibits, so that they can unfurl their full charm and allow visitors to experience them authentically” (Contemporary Lighting, 2013).

At Norlux, we're developing cutting edge LED lighting solutions for OEMs, lighting designers and manufacturers. Contact us today and let's work together to design and manufacture a custom LED solution for your company.

References:
LED Professional.com, “Contemporary Lighting Art by Zumtobel at the New Re-Opened Kunstkammer Wien”. 3/1/13, Author Unknown.http://www.led-professional.com/project_news/art-museum-lighting/contemporary-lighting-art-by-zumtobel-at-the-new-re-opened-kunstkammer-wien

Visit the Kunstkammer Wien web site:
http://www.khm.at/en/?cHash=dfb045333efd096a1ea1afd262c4a608