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: MIT team's wireless Vital-Radio could follow breathing, heart rate at home

Related Stories

Nepal quake: Nearly 1,400 dead, Everest shaken (Update)

7 hours ago

Tens of thousands of people were spending the night in the open under a chilly and thunderous sky after a powerful earthquake devastated Nepal on Saturday, killing nearly 1,400, collapsing modern houses and ...

Russian hackers read Obama emails, report says

7 hours ago

Emails to and from President Barack Obama were read by Russian hackers last year in a breach of the White House's unclassified computer system, The New York Times said Saturday.

Supermarkets welcome cold-comfort edge of F1 aerofoils

12 hours ago

UK-based Williams Advanced Engineering, the technology and engineering services business of the Williams Group, has collaborated with UK-based Aerofoil Energy to develop an aerodynamic device that can reduce ...

Public boarding school—the way to solve educational ills?

16 hours ago

Buffalo's chronically struggling school system is considering an idea gaining momentum in other cities: public boarding schools that put round-the-clock attention on students and away from such daunting problems as poverty, ...

Recommended for you

Team develops faster, higher quality 3-D camera

Apr 24, 2015

When Microsoft released the Kinect for Xbox in November 2010, it transformed the video game industry. The most inexpensive 3-D camera to date, the Kinect bypassed the need for joysticks and controllers by ...

Researchers finding applications for tough spinel ceramic

Apr 24, 2015

Imagine a glass window that's tough like armor, a camera lens that doesn't get scratched in a sand storm, or a smart phone that doesn't break when dropped. Except it's not glass, it's a special ceramic called ...

Classroom acoustics for architects

Apr 23, 2015

The Acoustical Society of America (ASA) has published a free online booklet for architects to aid in the application of ANSI/ASA S12.60-2010/Part 1-American National Standard Acoustical Performance Criteria, Design Requirements, ...

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.