METHOD FOR PRODUCING A COLORED SECURITY IMAGE WITHIN A SHEET MATERIAL

摘要

The invention relates to special types of printing and makes it possible to produce a colored public security image which is unique in terms of ease of perception and is visible in transmitted light within a sheet material. This image is produced within the sheet material by means of a monolayer of microlenses which are partially submerged in a layer of light-reflecting dyed material, which monolayer is arranged between layers of film and plastic, being exposed to pulses of laser radiation. When set points on the surface of the film are exposed to the pulses of laser radiation, each pulse produces a point of an image within the sheet material. This point comprises a cluster of microlenses with plastic crystals formed thereon with impregnations of dyed particles of the light-reflecting material and interfused microlenses. From a combination of such points within the sheet material, a colored three-dimensional image is formed which is visible in transmitted light. Each point of such an image corresponds to a pair of coaxial openings in the surfaces of the layers of film and plastic. From the combination of such openings on these surfaces, planar images are formed which reproduce the image within the sheet material. Since the image within the sheet material is visible at the same angle at which the pulses of laser radiation were directed onto the sheet material, the possibility is provided of producing, for example, two images which are visible at different angles on one and the same area within the sheet material.