Patent ID: 9140834
Filing Date: 2015-09-22
Classification: B23K,B42D,B44B,B44F,G02B,G03H

Abstract:
1. A method for creating color patterns by diffraction gratings upon irradiation with light, comprising: directly producing diffraction grating arrays on a solid body surface in a laser microstructuring process by irradiation with at least one laser installation in the nanosecond range or in the pico or femtosecond range, a first laser installation in the nanosecond range for producing blazed gratings, groove and rib gratings or column grid gratings, the first laser installation comprising a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, a fluor laser having a wavelength of 157 nm, or a ZeC1 excimer laser having a wavelength of 308 nm, and a second laser installation in a pico- or femtosecond range for producing ripple structures, the second laser installation comprising a laser having a centre wavelength of 775 nm, its frequency-doubled wavelength, or its frequency-tripled wavelength, or a picosecond laser of a Nd:YAG type having a wavelength of 1064 nm, its frequency-doubled wavelength, or its frequency-tripled wavelength, wherein the solid body surface is a hard material coated surface of an embossing roller or of an embossing die for embossing packaging foils, wherein each of the diffraction grating arrays is composed of subareas whose longitudinal dimension has a value below a resolving ability of an eye, wherein each of the subareas contains at least one pixel, wherein the at least one pixel is a limited diffraction grating structure for producing a single spectral color, which is diffracted by chosen grating parameters and an angle of incidence in determined diffraction angles in at least one determined azimuthal viewing angle, further comprising: analyzing the solid body surface to obtain a grating geometry on the solid body surface, wherein before production of a diffraction grating surface, the solid body surface is adjusted based on obtained surface geometry requirements.