Writing patterns, logos and lettering in light

Oct 01, 2008
This freeform lens projects the ITWM logo: The upper half contains a negative image of the logo, while in the lower half you can see the letters ITWM as reversed as in a mirror. © Fraunhofer ITWM

(PhysOrg.com) -- Logos and lettering can be written in light using freeform lenses. But how does the surface of the lens have to be structured in order to focus the light in the shape of a specific pattern? This used to be a task that took hours – now it can be done in a few seconds.

Over the main entrance to an industrial site, a lamp projects the lettering of the company’s logo onto a wall near the reception area. The sign is created by a freeform lens with a complex surface that directs the light in a defined pattern. Freeform lenses can be used in many other applications.

For instance, the outside walls of a house can be illuminated in such a way that no light penetrates through the windows that might dazzle occupants. The lenses can also be used in medicine, to direct light onto the specific site where a surgeon is operating. The special feature of these lenses is that they generate an image directly, without the need for a template or transparency. This saves energy, and produces more sharply defined images.

It is relatively easy to calculate the shape of an image to be created by a freeform lens. But it is far more difficult to define the surface structure of the lens required to project a specific image, such as a logo. Until now, it was more a case of trial and error. The developers would run a simulation of a lens shaped in approximately the desired pattern, study the image it produces, and gradually adjust the shape of the lens until it focuses the light in exactly the right pattern.

“The process could take several hours,” says Dr. Robert Feßler, a research scientist at the Fraunhofer Institute for Industrial Mathematics ITWM in Kaisers-lautern. Now the same task can be accomplished in a matter of seconds. ITWM researchers have developed a software program capable of calculating the lens geometry corresponding to the coordinates of a desired image in next to no time. It is the first software of this type to be offered on the commercial market. “Different values can be entered for a variety of parameters. These might relate to the specific operating characteristics of the milling machine, or the material used to produce the lens,” explains ITWM project manager Dr. Nobert Siedow.

Because the software solution is capable of calculating the surface geometry of the lens within seconds, it is easy to optimize the result. For instance, if the curvature of the lens required for a specific image is too great, this may cause technical problems when it is manufactured. A limit value for the curvature can be set in the software, and the lens geometry can be recalculated with a few mouse clicks.

A demonstration version of the software is already available, and will be presented live at the Vision trade fair in Stuttgart from November 4 to 6. Visitors can have their photo taken, and the software will calculate the geometry of the freeform lens required to create this image.

Provided by Fraunhofer-Gesellschaft

Explore further: Researchers develop a device for running shoes that prevents injuries

add to favorites email to friend print save as pdf

Related Stories

Review: Better cameras, less glare in iPad Air 2

Oct 22, 2014

If I've seen you taking photos with a tablet computer, I've probably made fun of you (though maybe not to your face, depending on how big you are). I'm old school: I much prefer looking through the viewfinder ...

Algolux tackles optics challenges in smartphones

Sep 05, 2014

Algolux is a company aiming to tackle blurring problems through computational optics. Algolux said its efforts are presently focused on smartphones and tablets. One can appreciate how this company sees their ...

IT student seeks to help mitigate risks of Google Glass

Sep 26, 2014

As online data breaches continue to challenge companies' and consumers' trust in cybersecurity, UC information-technology major Marina Grebenshchikova is exploring the risks associated with ever-evolving ...

Scientific instruments of Rosetta's Philae lander

Sep 23, 2014

When traveling to far off lands, one packs carefully. What you carry must be comprehensive but not so much that it is a burden. And once you arrive, you must be prepared to do something extraordinary to make ...

Recommended for you

Method to reconstruct overt and covert speech

17 hours ago

Can scientists read the mind, picking up inner thoughts? Interesting research has emerged in that direction. According to a report from New Scientist, researchers discuss their findings in converting brain ...

Study says upgrading infrastructure could reduce flood damage

Oct 29, 2014

The severe flooding that devastated a wide swath of Colorado last year might have been less destructive if the bridges, roads and other infrastructure had been upgraded or modernized, according to a new study from the University ...

Walk through buildings from your own device

Oct 29, 2014

Would you like to visit The Frick Collection art museum in New York City but can't find the time? No problem. You can take a 3-D virtual tour that will make you feel like you are there, thanks to Yasutaka ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.