Featured Research

from universities, journals, and other organizations

Light Emitting Diodes Save Energy And Can Now Concentrate Light Precisely Where Needed

Date:
May 14, 2008
Source:
Fraunhofer-Gesellschaft
Summary:
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.

A novel optical component (bottom left) channels the light from light-emitting diodes (right) to the exact place where it is needed.
Credit: Copyright Fraunhofer-Gesellschaft, IPT.

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.

Related Articles


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, Germany from June 17 to 20.


Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.


Cite This Page:

Fraunhofer-Gesellschaft. "Light Emitting Diodes Save Energy And Can Now Concentrate Light Precisely Where Needed." ScienceDaily. ScienceDaily, 14 May 2008. <www.sciencedaily.com/releases/2008/05/080513101620.htm>.
Fraunhofer-Gesellschaft. (2008, May 14). Light Emitting Diodes Save Energy And Can Now Concentrate Light Precisely Where Needed. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2008/05/080513101620.htm
Fraunhofer-Gesellschaft. "Light Emitting Diodes Save Energy And Can Now Concentrate Light Precisely Where Needed." ScienceDaily. www.sciencedaily.com/releases/2008/05/080513101620.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
In Japan, Robot Dogs Are for Life -- And Death

In Japan, Robot Dogs Are for Life -- And Death

AFP (Feb. 25, 2015) Robot dogs are the perfect pet for some in Japan who go to repairmen-turned-vets when their pooch breaks down - while a full Buddhist funeral ceremony awaits those who don&apos;t make it. Duration: 02:40 Video provided by AFP
Powered by NewsLook.com
London Show Dissects History of Forensic Science

London Show Dissects History of Forensic Science

AFP (Feb. 25, 2015) Forensic science, which has fascinated generations with its unravelling of gruesome crime mysteries, is being put under the microscope in an exhibition of real criminal investigations in London. Duration: 00:53 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins