At the SID Display Week, June 2 – 4, 2015, in San José/USA (German Pavilion, booth no. 222) the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will present a coating which is required to expand the diameter of a laser beam by more than factor of one hundred. With this coating, backlighting for holographic displays can be realized in the future.
Wouldn‘t it be exciting to sit in the midst of a film without wearing annoying 3D glasses? Not only for television fans, holographic displays would be a giant step in this direction. Medical scientists could inspect spatial images of the inside of the body and observe detailed movements of organs.
The company SeeReal Technologies in Dresden works on such displays. Holographic displays use certain properties of laser light for the complete three-dimensional display of images. Therefore, an expansion of the laser beam to the display size is necessary. One can easily imagine that a laser beam with a diameter of a television display is difficult to realize. A conventional option would be large lens systems, but these are clunky and can only be manufactured complexly and at very high costs.
In a joint project with SeeReal Technologies the scientists of Fraunhofer FEP have now developed coatings that enable usage of low power lasers for illumination. The laser is directed in at a very flat angle into a glass plate (here 5°, respectively 85° against the vertical). Similarly to the shadow of a person which is extending in the setting sun and whose projected area on the earth also extends, the diameter of the laser beam increases. A small spot becomes an elongated ellipse.
In a second step the elongated ellipse impinges again on a second glass plate at 5°, whereby the second direction of the ellipse, the “short axis”, is elongated. Thus the laser spot is expanded to a circle, that is large enough in order to illuminate the entire display. However, if you shine with a laser on an uncoated glass plate at such a flat angle, approx. 73% of the beam is reflected. In case of two “expansion steps” more than 90% of the original intensity would be lost!
„We have developed an anti-reflective coating which increases the part of the transmitted light significantly”, says Dr. Daniel Glöß, head of the “Dynamic coatings” department of the “Precision Coatings” division at FEP. “By means of magnetron sputtering, thin layers are deposited on glass. These layers consist of two different materials with varying optical density. Even complicated optical functions can be achieved via multilayer systems, which, for instance, let only certain colors of the light pass through and reflect the others.”
With its new precision coating plant PreSensLine, Fraunhofer FEP is optimally equipped for the high-precision coating of larger substrates. Thus functional panes of size DIN A3 (approx. 300 × 400 mm² or 28” screen diagonal, respectively) have been coated with the special multilayer system. The specific challenge results from the combination of extreme requirements regarding the precision, reproducibility and homogeneity of the layers on this large area.
As in conventional color televisions, the color impression with holographic displays should result from a mixture of red, green and blue, whereby a white picture is created by overlapping. For this demonstrator 24 layers are required for the anti-reflective coating. The layer thickness of all 24 layers had to be hit correctly down to a few millionths of millimeters (nanometers) and must also remain constant over the whole area. That is equivalent to only a few hundred atomic layers or in other words: Would you enlarge the coated plate to the size of a football field, the allowed tolerances of the individual layer thicknesses would correspond approx. to one-hundredth of the thickness of a human hair. Even slightly larger deviations lead to loss of the desired anti-reflective properties. The picture quality would be strongly impaired or the color of the picture would appear distorted.
The anti-reflective coatings, which were manufactured at Fraunhofer FEP, were installed into the demonstrator of SeeReal Technologies. There, holography has already become reality. To produce significantly larger displays in the square meter range with the same precision is an ambitious goal. To achieve it, Fraunhofer FEP is also well equipped. It has the latest state-of-the-art pilot plant technology as well as the know-how for manufacturing demanding layer systems for the customer-specific development and production of the required coating components.
Find out more about our work:
Bidirectional Expansion of Collimated Laser Beam as Backlight for Holographic 3D Display
Speech at the Exhibitor Forum, Session 6: Innovative Display Technologies and Applications
Thursday, June 4, 2015 | 9.15 a.m. | Executive Ballroom 210
Roll-to-Roll Manufacturing of Functional Substrates and Encapsulation Films for Organic Electronics: Technologies and Challenges
Speech at the Symposium: 10.1 (Invited Paper),
Tuesday, June 2, 2015 | 2.00 – 2.20 p.m. | Ballroom 220C
SVGA Full-Color Bidirectional OLED Microdisplay
Speech at the Symposium: 15.5 (Late-News Paper)
Tuesday, June 2, 2015 | 5.00 – 5.10 p.m. | Ballroom 220B
Advanced Processing of ITO and IZO Thin Films on Flexible Glass
Poster on the Poster Session: Display Manufacturing, P.65
Thursday, June 4, 2015 | 4.00 – 7.00 p.m. | Ballroom 220A
Optimized anodes for flexible large area OLEDs
Poster on the Poster Session: OLEDs, P.133
Thursday, June 4, 2015 | 4.00 – 7.00 p.m | Ballroom 220A
Mrs. Annett Arnold
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP | Phone +49 351 2586 452 | firstname.lastname@example.org
Winterbergstraße 28 | 01277 Dresden | Germany | www.fep.fraunhofer.de
Annett Arnold | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Treated carbon pulls radioactive elements from water
20.01.2017 | Rice University
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences