SOLIDFELIX: A transportable 3D static volume display

摘要

Flat 2D screens cannot display complex 3D structures without the usage of different slices of the 3D model. Volumetricdisplays like the "FELIX 3D-Displays" can solve the problem. They provide space-filling images and are characterizedby "multi-viewer" and "all-round view" capabilities without requiring cumbersome goggles. In the past many scientiststried to develop similar 3D displays. Our paper includes an overview from 1912 up to today. During several years of investigations on swept volume displays within the "FELIX 3D-Projekt" we learned about somesignificant disadvantages of rotating screens, for example hidden zones. For this reason the FELIX-Team startedinvestigations also in the area of static volume displays. Within three years of research on our 3D static volume displayat a normal high school in Germany we were able to achieve considerable results despite minor funding resources withinthis non-commercial group. Core element of our setup is the display volume which consists of a cubic transparent material (crystal, glass, orpolymers doped with special ions, mainly from the rare earth group or other fluorescent materials). We focused ourinvestigations on one frequency, two step upconversion (OFTS-UC) and two frequency, two step upconversion (TFTS-UC) with IR-Lasers as excitation source. Our main interest was both to find an appropriate material and an appropriatedoping for the display volume. Early experiments were carried out with CaF_2and YLiF_4crystals doped with 0.5 mol%Ee~(3+)-ions which were excited in order to create a volumetric pixel (voxel). In addition to that the crystals are limited to avery small size which is the reason why we later investigated on heavy metal fluoride glasses which are easier to producein large sizes. Currently we are using a ZBLAN glass belonging to the mentioned group and making it possible toincrease both the display volume and the brightness of the images significantly. Although, our display is currentlymonochrome, it is possible to create an RGB-display. For the same reasons we started tests with polymers. We were ableto achieve meaningful results which point out a new direction in the investigation on polymers. For the reasons described above, our new solid state device is one of modular design. The simplicity to change allcomponents makes it possible to do experiments with different display volumes and lasers for every specific purpose ofthe display in a very effective way. The images can be drawn inside the display volume by acousto-optic, galvanometricor polygon mirror deflection units. We control our galvanometric deflection unit with a personal computer and a self-written software which makes it easier to handle the setup and makes interactivity possible. This setup makes it apowerful and flexible tool to keep track with the rapid technological progress of today and helped us to experience thedisadvantages and the advantages of most of the possible deflection units in practice. These experiences are a mainelement in our paper and lead to some conclusions which will be of big importance in future display developments. Potential applications include imaging and computer aided design as well as scientific data visualization.