| Research News 10 - 2003 Special edition, Topic 3 |
Scratch-proof transparence for plastic | |
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Contact: Dr. Ulrike Schulz Fraunhofer Institute for Applied Optics and Precision Engineering IOF Further informations: |
The “one-times-one” chant of the witches “This must ye ken! From one take ten” guild in Goethe’s Faust could be re-written by this new process simplification - call it: “This must be done! From two makes one”. Until now, plastic lenses were first hardened and then treated with an antireflective coating in a separate step. Now it’s done simultaneously - without witchcraft. “We have achieved new levels of surface quality with our new coating process,” emphasizes Dr. Ulrike Schulz from the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena. “What really distinguishes this process are the outstanding antireflection properties.” Together with department head Dr. Norbert Kaiser and doctoral candidate Peter Munzert, Schulz was awarded the Joseph-von-Fraunhofer Prize.
“The idea was simple,” recalls Schulz. “Today, optics made from plastics are used in cameras or CD players. And most of us are familiar with plastic displays used in car radios, GPS receivers or telephones. To keep the surfaces from scratching, they must be hardened. Our thought was, why not add the antireflective property at the same time that the thick hardening layer is being applied?” To remove disturbing reflection, thin layers of high refractive metal oxides are integrated into a hard, glass-like silicon dioxide film. Owing to a high refraction index, the thin layers reflect the exact amount of incidental light needed to cancel out the light originally reflected from the plastic surface, making the surface nearly reflection-free. Such coating systems are patented under the name AR-hard®. The IOF spin-off, mso Jena Mikroschichtoptik GmbH, is already deploying this technology to harden and add antireflective coatings to optical instruments and sensor lenses. In addition, the IOF has been working with a consortium of companies over the past year to utilize the technology to coat displays. “The process can be adapted to the needs of the individual user, because it’s well suited for use even with more complicated surface forms,” adds Kaiser, head of the department. “We can also cover a wide spectral area - from 200-nanometer wavelength UV over visible light to near infrared.” |
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| © 2003 Fraunhofer-Gesellschaft |
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