Swiss scientists hope this technology will soon be widely used in security fields to enhance the protection of anti-counterfeiting identification features of passports and other documents.
We are all familiar with cards, rulers, or magnets that display three-dimensional images that change depending on the viewing angle. From this idea, researchers at the Swiss Federal Institute of Technology in Lausanne have developed a technology that allows for printing images that change content when viewed from different angles, with significantly higher quality.
How Did They Achieve This?
When the metal plates are rotated 90 degrees on the same plane, the ink dots that were previously perpendicular to the light become parallel to it, and vice versa.
The scientists use metal plates as a printing substrate, on which a printer applies tiny ink dots along lines to create two superimposed images that are perpendicular to each other. The final result depends on the ratio of colors such as gold, bright red, turquoise, black, and also on the viewing angle.
Light passing through the colorful ink lines creates different colored “shadows” on the metal surface. If the ink lines are perpendicular to the light, they create large bright shadows; conversely, if they are parallel, there are almost no shadows, and the colors appear unclear.
Light passing through colorful ink lines creates different colored “shadows” on the metal surface.
When the metal plates are rotated 90 degrees on the same plane, the ink dots that were previously perpendicular to the light become parallel to it, and vice versa. Consequently, the displayed images will also change.
The Swiss scientists noted that this technology can currently only be applied to metal substrates and inkjet printers. They hope it will soon be widely used in security fields to enhance the protection of anti-counterfeiting identification features of passports and other documents, as it would be extremely difficult to replicate or counterfeit this new printing technology.