Abstract: A light-diffractive binary grating structure has a microscopic mesa structure (2) whose plateaux (5) are separated by valleys (4) of substantially rectangular cross-section, wherein the arrangement of the valleys (4) is periodically repeated. Within a period (T) of the mesa structure (2) at least N valleys (4) separate the plateaux (5), N being an integer and greater than 2. The mesa structure (2) is an additive superimposition of N phase-shifted rectangular structures which have the same period (T) of the mesa structure (2). Each of the rectangular structures has a phase shift such that the plateaux (5) of the one rectangular structure fall into the valleys (4) of the N?1 other rectangular structures. In addition the resulting mesa structure (2) has only a single valley between two plateaux (5), which is of a width greater than a seventh of the period (T).

Abstract: A coin (1) with a metal surface (2, 3) has macroscopic reliefs (5) which serve for visually specifying the value of the coin and as an authenticity feature. Microscopically fine relief structures (8) with a diffraction effect are formed directly in at least one of the surfaces (2, 3). The relief structures (8) are preferably arranged in a recessed relationship and are covered with a lacquer (9). It is also advantageous if at least a part of the relief structures (8) entails an asymmetrical profile shape and/or the grating vectors in a radial orientation. The release structures (8) may also include a machine-readable coding which is recognized by inexpensive optical reading devices for installation in coin testers. The application of the microscopic relief structure (8) to a hard material surface (2, 3) can be effected by the removal of material by means of exposure of the material surface (2, 3) with a laser beam.

Abstract: A surface pattern (18) is in the form of a visually visible mosaic comprising a number of surface portions (8; 9; 15; 16; 17) and is embedded in a laminate (1) comprising at least a transparent cover layer (2) and a protective layer (5). The surface portions (8; 9; 15; 16; 17) are transparent, scatter or reflect incident light (10) or diffract the incident light (10) at microscopic relief structures (4). The surface portions (8; 9; 15; 16; 17) are at least partially covered with a reflection layer (3). At least one of the surface portions occupied by a microscopic relief structure (4), an area (16), is a ZOM-structure (4?) with a predeterminedly slowly varying profile height h and a spatial frequency f, wherein the product of a predetermined limit wavelength ?G of the visible spectrum and the spatial frequency f is greater than or equal to one.

Abstract: A label (1) comprising a layer composite (15) includes at least one machine-readable diffractive bar code (3) consisting of narrow rectangular fields (4) occupied by the optically active structures and intermediate surfaces (5). The optically active structures which are covered by a reflection layer are embedded between layers of the layer composite (15). The diffractive relief structure used in the diffractive bar code (3) for the fields (4) diffracts and polarizes incident light and scatters the diffracted light into a half-space above the diffractive relief structure. A second diffractive relief structure differs at least in respect of the polarization of the polarizedly backscattered light with respect to the first diffractive relief structure. The second diffractive relief structure can be used for example for field surfaces of a second bar code in the bar code field (9) on the label (1) or for the intermediate surfaces (5).

Abstract: A security element (2) in the form of a laminate can be used for the authentication of a document (1). The laminate has at least a transparent protective layer, a transparent lacquer layer and an adhesive layer, the lacquer layer being arranged between the protective layer and the adhesive layer. An interface in the form of a reflection layer separates the adhesive layer and the lacquer layer. The interface is divided into regions of a pattern (25) with flat surface portions and with relief structures which are formed in the lacquer layer. The flat surface portions form background surfaces (3) providing flat mirror surfaces for light which is incident into the laminate, while the regions with the relief structures of a predetermined, optically effective structure depth form pattern elements (4). The relief structures of the pattern elements (4) absorb the incident light.

Abstract: A reading arrangement includes at least one linear detector arrangement which is arranged in parallel relationship above a reading plane and behind an optical imaging element and is oriented on to a reading region of the reading plane, lighting devices and an evaluation unit and serves for machine reading of an information strip with optically encoded information. The light which is scattered or diffracted out of the reading region in which the information strip to be read off by machine is disposed into the optical imaging element is so projected on to the photosensitive faces of the detector arrangement that an image of the reading region is formed. The detector arrangement produces two detector signals and from a comparison of the detector signals, the read information is determined and its authenticity verified.

Abstract: A security element is embedded in a layer composite of plastic material and has reflecting, optically variable surface patterns which can be visually recognized from predetermined observation directions and which are formed from a mosaic of surface elements occupied by optically active structures. A part of the surface pattern is additionally covered by a regularly arranged matrix of unit cells. Each unit cell is occupied by a single elementary surface or a group of identical surface portions that contain optically active structures which are independent of the mosaic of the surface pattern. The arrangement of the elementary surfaces and the surface portions in the matrix form an item of concealed information which is not perceptible to the naked eye, in the form of graphic or alphanumeric characters which however are reproduced in a color photocopy with a color or gray value contrast which is perceptible to the naked eye.

Abstract: A layer composite of plastic material forms a retroreflector and includes at least one transparent structure layer, a protective layer and a reflection layer enclosed at the common interface between the structure layer and the protection layer. A relief structure formed by substantially identically shaped three-dimensional structure elements is formed in the reflection layer. At their base surfaces the structure elements are of lateral dimensions in the range of between 1 &mgr;m and 100 &mgr;m. The structure elements have side faces which are covered by the reflection layer and which include an angle of inclination of 45°, with a free surface of the layer composite. The relief structure is additively superimposed with a microstructure in at least one surface element. The microstructure has a preferred direction and influences the quality of the reflection action of the layer composite. The retroreflector is suitable for the production of machine-readable optical markings.

Abstract: A security element which is stuck on to a substrate has a reflecting, optically variable surface pattern (11) which is embedded in a layer composite of plastic material and which is visually recognisable to the naked eye from predetermined observation directions. The surface pattern (11) is formed from a mosaic of surface elements (12; 13; 14) with optically active structures. At least in a part of the surface pattern (11) identical surface portions (15) with optically active relief structures are additionally arranged regularly in regions which are independent of the mosaic. The surface portions (15) involve a largest dimension of less than 0.2 mm and a length-to-width ratio of at least 3:1, wherein the center points (16) of the surface portions form a dot matrix with periods of more than 8 dots per mm and the longitudinal surface portions (15) in each region are oriented parallel to a preferred direction.

Abstract: A security element (2) comprising a reflective, optically variable surface pattern (3) which is embedded in a layer composite of plastic material and which can be visually recognized from predetermined observation directions is formed from a mosaic of optically active surface elements (13). In the mosaic of the surface pattern (3) at least two of the mosaic surfaces (11; 12) of the surface pattern (3) are arranged substantially adjacent and have microscopically fine light-diffractive relief structures (4). The spatial frequencies of the relief structures in the mosaic surfaces (11; 12) are of values from predetermined spatial frequency ranges in such a way that, in the case of illumination beams which are incident obliquely relative to a normal onto the plane of the layer composite, the relief structures of the mosaic surfaces (11; 12) deflect visible monochromatic light parallel to the normal (32).

Abstract: A security element (1) is embedded in a layer composite of plastic material and has reflecting, optically variable surface patterns (11) which can be visually recognised from predetermined observation directions and which are formed from a mosaic of surface elements (12; 13; 14) occupied by optically active structures. A part of the surface pattern (11) is additionally covered by a regularly arranged matrix (18) of unit cells (15). Each unit cell (15) is occupied by a single elementary surface (16) or a group of identical surface portions (17), wherein the elementary surfaces (16) and the surface portions (17) contain optically active structures (4) which are independent of the mosaic of the surface pattern (11).

Abstract: A decorative foil is in the form of a layer composite structure (1) and comprises at least a transparent base foil (2), a transparent cover layer (4) and a transparent dielectric layer (3) arranged between the base foil (2) and the cover layer (4). When the decorative foil serves as a lamination foil for a substrate (5) the material of the cover layer (4) is an adhesive. A reflective metallic layer (6) is arranged at least in surface portions between the dielectric layer (3) and the cover layer (4) and optionally a metal film (11) is also arranged on the side of the dielectric layer (3) facing the base foil (2). General items of information shown by the decorative foil are produced by means of modulation of the thickness (s) of the dielectric layer (3). Transparent locations (7) form individual items of information, wherein the transparent locations (7) are produced with a laser beam (19) by perforating the metal layer (6; 11).

Abstract: The invention relates to a pattern (18) which is designed as a visually perceptive mosaic consisting of a plurality of surface elements (8; 9; 15; 16; 17) and which is embedded in a laminate (1) consisting of at least one transparent outer layer (2) and one protective layer (5). The surface elements (8; 9; 15; 16; 17) are transparent, scatter or reflect incident light (10) or diffract the incident light (10) to microscopic relief structures covered with a reflecting layer (3). An area (16) corresponding to at least one of the surface elements provided with a microscopic relief structure (4) has a ZOM structure (4′) with a profile height h which can be slowly modified in a pre-determined manner and a spatial frequency f. The product of a predetermined critical wavelength &lgr;G of the visible spectrum and the spatial frequency f is greater than or equal to 1.

Abstract: A light-diffractive binary grating structure has a microscopic mesa structure (2) whose plateaux (5) are separated by valleys (4) of substantially rectangular cross-section, wherein the arrangement of the valleys (4) is periodically repeated. Within a period (T) of the mesa structure (2) at least N valleys (4) separate the plateaux (5), N being an integer and greater than 2. The mesa structure (2) is an additive superimposition of N phase-shifted rectangular structures which have the same period (T) of the mesa structure (2). Each of the rectangular structures has a phase shift such that the plateaux (5) of the one rectangular structure fall into the valleys (4) of the N−1 other rectangular structures. In addition the resulting mesa structure (2) has only a single valley between two plateaux (5), which is of a width greater than a seventh of the period (T).

Abstract: A decorative foil (1) has a laminate structure comprising at least two layers (2; 3). The layers (2; 3) include a for example transparent base foil (2) which is coated on side with a reflection layer (3). A protective layer (4) can protect the reflection layer (3) from external influences. The shaping surface (7) of the base foil (2), which is towards the reflection layer (3), has a structure, obtained by shaping, of groups of geometrical shapes. An area occupied by the group is of width of between 30 &mgr;m and 300 &mgr;m. Elements (14) of the group, which are shaped in the base foil (2), are of a substantially rectangular cross-section, wherein the surface occupied by the group is composed of element surfaces (9 through 11) which are in a parallel plane (8) with respect to the shaping surface (7) and residual surfaces (13) which have remained in the plane of the shaping surface (7). The surfaces occupied by the groups are separated by regions of a background area in the plane of the shaping surface (7).

Abstract: A coin (1) with a metal surface (2, 3) has macroscopic reliefs (5) which serve for visually specifying the value of the coin and as an authenticity feature. Microscopically fine relief structures (8) with a diffraction effect are formed directly in at least one of the surfaces (2, 3). The relief structures (8) are preferably arranged in a recessed relationship and are covered with a lacquer (9). It is also advantageous if at least a part of the relief structures (8) entails an asymmetrical profile shape and/or the grating vectors in a radial orientation. The release structures (8) may also include a machine-readable coding which is recognized by inexpensive optical reading devices for installation in coin testers.

Abstract: A surface pattern is made up of surface elements (1 to 7) which are arranged in a mosaic-like fashion and which have microscopic relief structures. The surface elements (2 to 6) which are divided at least into first and second surface portions (8; 9) have in the first and second surface portions (8; 9) asymmetrical diffraction gratings (12; 13) with an optical diffraction effect, wherein in each divided surface element (2 to 6) adjacent first surface portions (8) are separated by at least one second surface portion (9). The grating vectors of the asymmetrical diffraction gratings (12) of the first surface portions (8) of all divided surface elements (2 to 6) have the same first value in respect of azimuth and the asymmetrical diffraction gratings (13) of the second surface portions (9) of all divided surface elements (2 to 6) have the same second value in respect of azimuth.

Abstract: A surface pattern comprises microscopically fine relief structures that diffract visible light. When the surface pattern is illuminated perpendicularly with white light, the surface pattern appears with bright and dark regions from a first viewing direction. The length and/or position and/or number of bright and dark regions changes as the viewing angle changes. Preferably, the contour of the surface pattern is selected so that the length or position of the bright regions changes markedly when the viewing angle changes.

Abstract: The invention relates to a device for the simultaneous machine recognition of Q diffraction optical markings (11) of a security element (4), which devices comprises a light source (1) for projecting parallel light (10) onto a document (3) provided with said security element (4), an optical collector element (2), photodetectors (5; 6) for converting the light (15; 16) diffracted on the markings (11) or the rays reflected on the substrate (3) into electrical signals, as well as an evaluation unit for evaluating said signals. The photodetectors (5; 6) are positioned in the focal plane (8′) of the optical collector element (2). In each case two photodetectors (5; 6) form a photodetector pair. The electrical signals of each pair are analysed and the results of all photodetector pairs are compared with corresponding reference values in the evaluation unit. All the optical markings (11) are read simultaneously and form a code for identifying the security element (4).

Abstract: A surface pattern (1) has N visually recognizable patterns which are composed of optically diffractive, microscopically fine relief structures, plane mirror faces or absorbing or scattering structures. The N patterns share at least one independent common surface element (11). The surface element (11) is subdivided into surface parts and has an arrangement of the surface parts which is independent of the N patterns, which has a predetermined structure, and which is not recognizable to the naked eye. A single microscopically fine diffraction structure or a structure which has an absorbing or scattering property or is a plane mirror is applied to each surface part. The relief structures, diffraction structures and other structures are embedded in a plastic laminate (20) and can have their optical performance enhanced by a reflection layer (21). The surface pattern (1) is applied as a security element to a document (2) and allows the document (2) to be identified by machine in a reading machine.