Abstract:
The invention optical device comprising a self-processing photopolymer material configured to produce a variable two- or three- dimensional diffraction pattern when said material is illuminated by a light source. The invention provides a new material science and process technology which produces a serialisable anti-counterfeit optical device, based on a self-processing photopolymer.
Abstract:
Methods and apparatus for making, encoding, and encrypting binary patterns for storing recorded information. One of the methods includes the steps of providing an original image, framenting the original image into at least two parts including a first part and a second part, forming a mirror image of one of the at least two parts, inverting the first and second parts, forming a binary pattern of the first part and the second part, and forming a mirror image of the binary pattern of the one of the at least two parts. In this method the binary pattern in each of the parts includes information representing a respective portion of the original image.
Abstract:
A method and apparatus for producing durable embossing tools is disclosed. An anisotropic etching process, such as ion etching, is used to etch a relief pattern into a hard substrate. A transfer layer is formed overlaying a generally smooth, seamless surface region of a substrate. A desired relief pattern is formed in the transfer layer, by exposing a photoresist, embossing, or the like. The substrate having the photoresist thereon is subjected to an anisotropic etch. The anisotropic etch continues until the transfer layer is completely removed and the relief pattern is formed in the upper surface of the embossing tool. The relative etch rates between the transfer layer and the surface region of the embossing tool are selected to provide the desired depth modulation in the surface of the embossing tool. An embossing tool produced according to the invention has a relatively hard surface and may thus be used for the mass production of holographic images without significant degradation of the pattern. Because the embossing tool can be made from an extremely hard material such as chromium or hardened steel, materials which previously could not be economically embossed with holograms, such as aluminum or steel, may now be embossed by an embossing tool made according to this invention.
Abstract:
Поверхность метки полируют и наносят на нее технологический слой, через который на поверхности создают оптически визуализируемое в отраженном свете под углом дифракции изображение метки в виде дифракционной структуры. Структуру организуют по типу отражательной фазовой дифракционной решетки и формируют посредством ионного травления поверхности совместно со структурой технологического слоя. Перед образованием на поверхности метки в технологическом слое формируют дифракционную структуру в виде регулярного микрорельефа синусоидального профиля, путем обеспечения абляции материала слоя посредством импульса интерферируемых пучков когерентного лазерного излучения. В результате в технологическом слое образуют дифракционную структуру с голографической точностью. Структуру формируют путем частичного удаления толщины материала технологического слоя. Изображения метки в виде дифракционной структуры на маркируемой поверхности также образуют с голографической точностью посредством интерферируемых когерентных лазерных пучков. Осуществляют экспонирование ионным пучком сформированной в технологическом слое дифракционной структуры.
Abstract:
A method of producing a security document or article including a substrate (100), which is transparent at least to visible light, and a diffractive optical microstructure (112). The method includes applying an opacifying layer (102) to at least one surface of the transparent substrate (100). An area of the opacifying layer (102) is exposed to laser radiation (108) to a~ ate apertures (110) in selected portions of the opacifying layer (102), thereby forming a diffractive optical microstructure (112) on the surface of the substrate (100). The laser radiation may be patterned prior to exposing the opacifying layer (102), for example by passing the radiation through a mask (104). Alternatively, a focussed or collimated laser beam (206) may be directed onto the selected portions of the opacifying layer (102). Laser radiation may be directed onto the opacifying layer (102) either directly, or through the transparent substrate (100). Security documents or articles made in accordance with the method are also provided.
Abstract:
Methods for incorporating information, within the same or in distinct physical locations, in the form of patterns represented by visual, audio or electronic formats, that originate from a single source but that carry encrypted, complementary 5 information, and such patterns upon appropriate interrogation, regenerate the original. Covert images are created using inverse functions like Fourier transformations of one or more sets of complementary patterns from the original. Covert or hidden images are prepared by methods including converting the spatial domains to the frequency domain of at least a portion of the original image that has been sampled or generated by the computer. Techniques based on phase contrast modulation are also provided. Binary patterns transform the amplitude/phase values of a signal into encoded messages. These are invisible to the naked eye unless viewed using limited-extent sources of light. Methods and apparatus for making, encoding, and encrypting binary patterns for storing recorded information are also provided. One method includes the steps of providing an original image, fragmenting the original image into at least first and second parts, forming a mirror image of one of the a least two parts, inverting the first and second parts, forming a binary pattern of the first part and the second part, and forming a mirror image of the binary pattern of the one of the a least two parts. In this method the binary pattern in each of the parts includes information representing a respective portion of the original image.
Abstract:
Method of patterning a surface of an object or a tool with nano and/or micro structure elements having dimensions in a range of 1 nanometer to 1 millimeter, comprising the steps of producing a flexible mask with said nano or micro structure pattern formed on a surface of said flexible mask, chemically activating said surface of the flexible mask and/or said surface to be patterned of the tool, placing said patterned surface of the flexible mask in contact with said surface to be patterned of the object or tool, promoting a covalent bonding reaction between said patterned surface of the flexible mask in contact with said surface to be patterned, removing the flexible mask from the tool whereby a layer of said flexible mask remains bonded to said surface to be patterned of the tool, etching said surface to be patterned of the tool whereby the bonded layer of flexible mask material resists etching. An anti-activation mask defining a periphery of the surface area to be patterned, or peripheries of the surface area to be patterned if there are a plurality of separate portions of surface area to be patterned, is deposited on the flexible mask prior to placing the patterned surface of the flexible mask on the surface to be patterned. The anti-activation mask prevents bonding of the flexible mask to the surface of the object or tool in areas where the anti-activation mask is present.
Abstract:
A method of producing a security document or device comprising a substrate and an optically diffractive device, the method comprising the step of: irradiating an area of the substrate (2) on one surface with patterned laser radiation to ablate selected portions of the surface and thereby form an optically diffractive structure in said one surface. A method of producing a security document or device comprising a substrate and an optically variable device, such as a means for creating polarisation patterns, the method comprising the step of: exposing an area of the substrate on one surface to a light source which causes photo-polymerisation of the substrate which in turn produces a polarisation state or pattern.
Abstract:
A method and apparatus for producing durable embossing tools is disclosed. An anisotropic etching process, such as ion etching, is used to etch a relief pattern into a hard substrate. A transfer layer is formed overlaying a generally smooth, seamless surface region of a substrate. A desired relief pattern is formed in the transfer layer, by exposing a photoresist, embossing, or the like. The substrate having the photoresist thereon is subjected to an anisotropic etch. The anisotropic etch continues until the transfer layer is completely removed and the relief pattern is formed in the upper surface of the embossing tool. The relative etch rates between the transfer layer and the surface region of the embossing tool are selected to provide the desired depth modulation in the surface of the embossing tool. An embossing tool produced according to the invention has a relatively hard surface and may thus be used for the mass production of holographic images without significant degradation of the pattern. Because the embossing tool can be made from an extremely hard material such as chromium or hardened steel, materials which previously could not be economically embossed with holograms, such as aluminum or steel, may now be embossed by an embossing tool made according to this invention.