Multilayer Element Comprising Microlenses

A multilayer body comprising a transparent first layer in which a plurality of microlenses are shaped and a second layer which is arranged beneath the first layer and which has a plurality of microimages, wherein the microlenses are arranged in accordance with a microlens raster and the microimages are arranged in accordance with a microimage raster, wherein

• the second layer has a plurality of microimage regions, with each of which there are respectively associated two or more of the microimages and which are arranged in accordance with a microimage region raster, the raster width of which is <300 μm, wherein within each one of the microimage regions respectively two or more of the microimages differ from each other, the microimages have first regions with a color value of zero and second regions with one of G different colors and a respective unitary color value>zero, with respect to a standardized color value scale of between 0 and 1 embracing FG color values, two or more of the microimages of each microimage region differ in their color and the microimages are so selected from a set of microimages that upon superpositioning of the optical action of the microimages arranged in a microimage region the result is a graduated image impression with color values from a color space embracing G*FG color values, and the raster spacings of the microlens raster and the microimage raster in each microimage region differ from each other by less than 10%.

A process for the production of a multilayer body comprising an optical security feature, wherein the process includes the following steps:

• splitting up a representation into M image regions, wherein M is greater than 1;
• determining the color values of the M image regions;
• calculating a set of >=N different microimages, wherein N is greater than 1, each of the microimages comprises M image regions and each of the M image regions has a color value determined in dependence on the color value respectively of the respective image region of the representation;
• providing a multilayer body comprising a transparent first layer in which a plurality of microlenses are shaped, which are arranged in a microlens raster;
• and
• providing a second layer in the multilayer body, which has a plurality of microimage regions arranged in accordance with a microimage region raster, wherein each of the microimage regions has N microimages which are so selected from the calculated set of microimages that the microimages have first regions with a color value of zero and second regions with one of G different colors and a respective unitary color value>zero, with respect to a standardized color value scale of between 0 and 1 embracing FG color values, two or more of the microimages of each microimage region differ in their color and upon superpositioning of the optical action of the microimages arranged in a microimage region the result is a graduated image impression with color values from a color space embracing G*FG color values, the raster spacings of the microlens raster and the microimage raster in each of the microimage regions differ from each other by less than 10%, the microimage region raster has a raster width of less than 300 μm and two or more of the microimages respectively differ from each other within each microimage region.