Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Illumination made to measure

14.05.2008
Light-emitting diodes save energy. In terms of their light output, however, they have so far been unable to compete with light bulbs. A new, low-priced optical component is set to change that situation: It concentrates the light and directs it precisely to where it is needed.

Light-emitting diodes are unbeatable in terms of energy efficiency. A one-watt LED delivers roughly the same optical output as a hundred-watt light bulb. If a high light output is required, however, the tiny light sources are not the preferred means of illumination. A novel optical component is set to change that situation.

It directs the light to the exact spot where it is needed. In the case of a desk lamp, for instance, the light can be concentrated in such a way that only a DIN-A4-sized surface in the middle of the table is brightly lit. The LED evenly illuminates the required area, while everything else stays in the dark.

“A light-emitting diode is a single-point light source that emits light in a large, uncontrolled area,” says Dr. Christian Wenzel, head of department at the Fraunhofer Institute for Production Technology IPT in Aachen. “We use special lenses to direct all of the light to the place where it is needed, thus increasing the efficiency of the LEDs. The spot of light created by the light source does not therefore fade out at the edges, but has a sharply defined edge.”

This channeling of light is based on a free-form system of optics – a plastic lens whose geometry can be shaped in any way desired. “The lenses are cast using an injection-molding technique. The two halves of the tool that serve as a mold have to be aligned with extreme precision just once – they have an accuracy of a few microns, or less than a tenth of the diameter of a hair. Once the tools have been tared, the lens can be manufactured in large batches at low cost,” says Dr. Wenzel. The researchers at the IPT have optimized the entire process chain: from planning and manufacturing the lens systems to checking their accuracy. “There’s nothing like it anywhere else in Europe,” the expert claims. There is just one challenge that had to be mastered: The plastic, which is inserted into the mold when hot, shrinks as it cools – the finished lenses are therefore slightly smaller than dictated by the mold. The researchers take this effect into account by repeated, gradual improvement – to an accuracy of a few microns.

When the lenses are finished, the scientists check them. To do this, they project a pattern of stripes onto the lens. The distortion of the stripes reveals the curvature, inclination and shape of the lens.

The researchers will demonstrate the entire process chain along with optical systems for practical application at the Optatec trade fair in Frankfurt from June 17 to 20 (Hall 3, Stand D53).

Dr.-Ing. Christian Wenzel | Fraunhofer-Gesellschaft
Further information:
http://www.ipt.fraunhofer.de

More articles from Power and Electrical Engineering:

nachricht Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts
08.12.2016 | Institut für Solarenergieforschung GmbH

nachricht Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>