This invention relates to the field of anti-counterfeiting film technology, specifically to an optical anti-counterfeiting film device and its preparation method, comprising a
polymer-dispersed
liquid crystal, a carrier layer, a pattern layer, a protective layer, and a substrate layer; wherein the
polymer-dispersed
liquid crystal, also known as PDLC, typically contains
liquid crystal,
polymer, and spacers. The spacers are usually micron-sized microspheres randomly distributed in the PDLC
system, and the liquid
crystal is usually randomly dispersed in micron-sized droplets in the cured polymer. The beneficial effects of this invention are: by setting the liquid
crystal to be an optically and dielectrically anisotropic material, the liquid
crystal molecules can change their orientation under the action of an
electric field, thereby changing the
refractive index and realizing the change of the
transmittance or color of the PDLC; and through the combination of the substrate layer, carrier layer, pattern layer, polymer-dispersed liquid crystal, protective layer,
adhesive, and functional additives, the device can generate structural colors, and the difference in the
electric field response speed of the liquid crystal at different positions is small.