Abstract: A diffraction surface and a method of making the surface. The surface may be applied to labels and other items to identify the origin of the goods to which the label is attached. The surface can include a block grating including ridges and recesses in the enclosed squares or rectangles. The diffraction grating manufactured by processing a data stream indicative of the image including obtaining a Fourier Transform of the data stream and preferably clipping and quantising the data stream, and deforming a plate surface in accordance with the data stream. Also claimed is a diffraction grating having spaced first and second portions each producing an image on a receiving surface in response to illumination by a reading light beam, configured such that when the reading light beam moves from the first to the second portion, a change occurs in the first image to produce the second image.

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.

Abstract: A pixellated diffractive device includes a multiplicity of pixels (12,22) in turn divided into multiple sub-pixels (13,23). The device is related to one or more pixellated diffraction surface structures which when illuminated generate respective corresponding optically variable images. The sub-pixels (13,23) of each pixel of the diffractive device include diffractive elements (13a,23a) arranged in one or more groups, the diffractive elements of each group matching diffractive elements of a corresponding single pixel of the respective pixellated diffraction surface structures. In each pixel of the device the diffractive elements (13a,23a) of the or each said group are intermixed with other sub-pixels and cooperatively contribute a single element of the corresponding optically variable image which is generated on illumination of the diffractive device.

Abstract: A surface pattern (1) is composed of elements (2 to 5) which are arranged in a mosaic-like fashion and of which at least one pattern is formed from a background element (4) and a pixel (2) with microscopically fine relief structures diffracting visible light. The surface elements (3) and the element portions (5) either contain the microscopically fine relief structures diffracting visible light or they comprise reflecting or scattering surfaces. Arranged in the pixel (2) is a first diffraction grating B1 and arranged in the background element (4) is a second diffraction grating B2, wherein the first diffraction grating B1 and the second diffraction grating B2 are a superimposition of at least two different, microscopically fine relief structures F1 and F2 diffracting visible light. The first diffraction grating B1 and the second diffraction grating B2 differ only by virtue of a relative phase shift &Dgr;&phgr; between the relief structure F1 and the relief structure F2.

Abstract: A diffractive device has a surface relief structure which, when illuminated by a light source, generates one or more diffraction images which are observable from particular ranges of viewing angles around the device. The device includes background diffractive structural elements and interstitial diffractive structural elements. The interstitial elements are interspersed between the background elements such that the diffractive action of the background elements is modulated by the interstital elements, with differing interstitial element configuration in differing parts of the surface relief structure producing differing diffraction effects in corresponding parts of the diffraction images.

Abstract: Disclosed is a curved surface element (e.g., light bulb, ornament, light pipe, etc.) which has at least a portion thereof (inner or outer surface) covered with a holographic diffraction grating which was constructed to be essentially distortion free on said curved surface, whereby such diffraction grating diffracts light to emit color to the observer. The diffraction grating can take for form of a holographic optical element (HOE) attached to the curved surface or a diffractive holographic optical pattern (HOP) embossed into the curved surface.

Abstract: Disclosed is a curved surface element (e.g., light bulb, ornament, light pipe, etc.) which has at least a portion thereof (inner or outer surface) covered with a holographic diffraction grating which was constructed to be essentially distortion free on said curved surface, whereby such diffraction grating diffracts light to emit color to the observer. The diffraction grating can take for form of a holographic optical element (HOE) attached to the curved surface or a diffractive holographic optical pattern (HOP) embossed into the curved surface.

Abstract: The invention concerns a structure arrangement that includes surface regions having one or more structures having an optical-diffraction effect, in particular for visually identifiable, optical security elements for value-bearing documents, for example banknotes, credit cards, passes or check documents, or other items to be safeguarded; in order to make it more difficult to forge and in particular copy such a structure arrangement it is proposed in accordance with the invention that the structure arrangement is such that for the production of given items of optical information in given viewing directions in one or more of the surface regions (8, 30) of the structure arrangement there are provided sub-regions (10, 12, 14, 32, 34) with a structure (16, 18, 20; 36, 38) that is identical except for the structural parameter of optical depth and that the optical depth of the structure (16, 20; 36) is constant over the extent of a sub-region (10, 14; 32) but is different from the optical depth of the structure (18;

Abstract: The present invention introduces a novel scatter plate into the optical path of source light used for illuminating a replicated object. The scatter plate has been designed to interrupt a focused, incoming light beam by introducing between about 8 to 24 diffraction zones blazed onto the surface of the scatter plate which intercept the light and redirect it to a like number of different positions in the condenser entrance pupil each of which is determined by the relative orientation and the spatial frequency of the diffraction grating in each of the several zones. Light falling onto the scatter plate, therefore, generates a plurality of unphased sources of illumination as seen by the back half of the optical system. The system comprises a high brightness source, such as a laser, creating light which is taken up by a beam forming optic which focuses the incoming light into a condenser which in turn, focuses light into a field lens creating Köhler illumination image of the source in a camera entrance pupil.

Abstract: A compact illumination device intended especially for illuminating an active matrix in a monochromatic or trichromatic display device. This device includes a source and collimating device in order to deliver a lighting direction from the source along a direction (Dy) and two optical components (M1) and (M2) which anamorphose the lighting in a direction parallel to the direction (Dy) and in a direction (Dz) perpendicular to the direction (Dy), respectively. These components may typically be of the holographic grating type operating in transmission or in reflection.

Abstract: A structural arrangement having optical diffraction qualities for use as a security element in a value bearing document, such structural arrangement having a plurality of surface regions having at least two subregions having identical relief structures which provide for an optical diffraction effect, the relief structures of adjacent subregions being displaced relative to each other by a fraction of the grating period.

Abstract: A display apparatus of the present invention includes: an illumination optical system for emitting illumination light; a reflective display panel divided into a plurality of pixels, illuminated by the illumination light from the illumination optical system, and selectively reflecting the incident illumination light pixel by pixel as projection light; a projection optical system for projecting image information the reflective display panel onto a projected surface by transmitting the projection light reflected at the reflective display panel; and a reflection angle converting optical system disposed ahead of the reflective display panel, changing the angle of incidence of the illumination light on the reflective display panel, and adjusting the sum of the angle of incidence of the illumination light on the reflective display panel and the angle of reflection of the projection light at the reflective display panel.

Abstract: An optically variable surface pattern includes at least one graphic representation producing an achromatic impression when viewed in visible light over a certain angular range without noticeable color fringes occurring in the adjoining angular ranges. A plane surface portion includes a grating structure which disperses incident light with comparable intensity into a cone within a predetermined angle range regardless of differing wavelength. An overlap of several successive high orders of diffraction results in a recombination of the dispersed light to white light at any diffraction angle within the cone. The surface portion viewed from a direction within the cone reflects white light, in contrast to a simple flat mirror which has a very narrow range of specular reflection. At viewing angles outside the cone, the surface portion is dim or dark grey. The shape of the surface portion is then recognized as an area white lit or dark depending upon a particular viewing angle relative to incident light.

Abstract: A static diffracting grating display system provides a fixed image representing high digital content information. A plurality of physical diffracting features are fixed into the surface of a substrate. The diffracting features are positioned and oriented to selectively diffract or reflect a first incident beam of light which is then collected by a first display optical system. For color, preferably three light sources, red, green and blue, are used to form three incident beams of light. The period between adjacent ones of the diffracting features can be adjusted to appropriately form full-color image from the collected light. Preferably the diffracting features are formed by embossing a deformable substrate. Where the material of the deformable substrate is not reflective, a reflective coating is then applied. In some circumstances a protective overcoat applied over the reflective surface to obviate scratches or other damage to the diffracting features of the embossed surface.

Abstract: A diffractive device has a surface relief structure which when illuminated by a light source, generates one or more diffraction effects which are observable from a range of viewing angles around the device. At least part of the surface relief structure is arranged in a series of tracks, each track being less than 0.25 mm in width. The device, which may be embossed onto a metallised foil, is suitable for use as an anti-forgery authentication element on valuable documents.

Abstract: A decorative optical display (20) utilizing a reflective diffraction grating (94) or a transmissive diffraction grating (304) and a plurality of polychromatic light sources (60) disposed around perimeter (106) of the reflective diffraction grating or perimeter (314) of the transmissive diffraction grating. The light sources are disposed so as to the illuminate the reflective or transmissive diffraction grating at an oblique angle (204) or (328), respectively. The oblique illumination of the reflective or transmissive diffraction grating prevents a viewer (200) from seeing undiffracted light rays (212) or (336) emanating from the light sources, which can detract from the appeal of the optical display pattern (250). The reflective or transmissive diffraction grating may be flat or curved and may be supported by a support member (90). Further, the reflective or transmissive diffraction grating may have either a single or multiple axes.

Abstract: A display medium employing a diffraction grating to define and represent a display pattern by the contour thereof, which enables the display pattern to move smoothly as the visual point moves and which allows the display pattern to move in various ways and is easy to produce. A display pattern ("DNP"), e.g., a character, an image, etc., is defined and displayed by the outer or inner contour of a diffraction grating (A or B) composed of a group of smooth curves, or a diffraction grating composed of a group of partial straight-line diffraction gratings that form polygonal lines linearly approximating smooth curves. Accordingly, as the visual point is moved relative to the display medium, a position that looks bright by diffraction moves smoothly and variously. If the display medium is illuminated by white light, the region that looks bright becomes a rainbow-colored region. Accordingly, the display pattern becomes not only readily recognizable but also interesting to view.

Abstract: A surface pattern has two surface portions with microscopically fine, light-diffracting relief structures. The relief structures are in the form of grating structures GS1 and GS2, respectively, which are composed of at least two superimposed gratings G1 and G2, G3 and G4, respectively. The light-diffracting properties of the gratings G1 to G4 are so selected in accordance with various criteria that novel optical effects which cannot be holographically copied can be achieved with the grating structures GS1 and GS2. Such surface patterns are suitable as optical security elements for documents or articles of all kinds as well as packing foils.

Abstract: Graphic material includes at least one area bearing a hologram and at least one area bearing a diffraction grating. Preferably, the diffraction grating and the hologram are simultaneously viewable from at least one perspective. The graphic material is made using an embossing die grown from a precursor blank which has been embossed in discrete areas with a holographic microtexture and then partially overstamped with a diffraction grating microtexture. The stamping of the blank may be effected by pressing a suitably shaped die against a shim bearing a diffraction grating microtexture for forming the microtexture in the die shape on the blank.

Abstract: Diffractive indicia for a surface (1) comprising a plurality of small separate diffractive elements (2) and means for a adhering the diffractive elements to the surface. Each diffractive element has a diffractive surface relief structure and is not separately resolvable to the human eye. The appearance of the diffractive indicia, when applied to the surface, changes when the viewing angle and/or angle of illumination relative to the surface changes. In preferred arrangements, the diffractive indicia, are incorporated in an ink or a transfer medium. A palette of diffractive indicia with different characteristic colours and other optical properties may be provided.

Abstract: A pixellated diffractive device includes a multiplicity of pixels in turn divided into multiple sub-pixels. The device is related to one or more pixellated diffraction surface structures which when illuminated generate respective corresponding optically variable images. The sub-pixels of each pixel of the diffractive device include diffractive elements arranged in one or more groups, the diffractive elements of each group matching diffractive elements of a corresponding single pixel of the respective pixellated diffraction surface structures. In each pixel of the device the diffractive elements of the or each said group are intermixed with other subpixels and cooperatively contribute a single element of the corresponding optically variable image which is generated on illumination of the diffractive device.

Abstract: An information carrier has at least one diffraction pattern which is formed from microscopically fine relief structures and which, upon being illuminated with coherent light, produces in two spatially separate directions, a first and a second image of an object. The images can be rendered visible on a screen or analysed by means of photodetectors. The two images have strong-light and/or weak-light picture elements and includes a symmetry insofar as a weak-light picture element of the second image can be associated with a strong-light picture element of the first image and vice-versa. Such information carriers are suitable as security elements for documents of all kinds such as, for example, banknotes, passes, identity cards, credit cards, etc., wherein at least a part of the security information is not visible under incoherent illumination conditions.

Abstract: The invention is directed to an optical arrangement for coupling radiation into the viewing or recording beam path of a microscope and includes at least one light-diffracting element in this beam path. Preferably, the light-diffracting element is combined with at least one reflective element or a combination of at least two diffractive elements such as transmission or reflection gratings.

Abstract: A diffractive device having a surface relief structure which, when illuminated by a light source, generates one or more diffraction images which are observable from particular ranges of viewing angles around the device, wherein at least part of the surface relief structure (1) is arranged in a series of tracks (2), each track (4, 5) having a diffracting surface (3) which generates a component of a diffraction image, such that at least one of the diffraction images generated by the diffractive device is formed from image components generated by a plurality of the tracks.

Abstract: A security device includes two plastic layers and a metal layer. The plastic layers may be embossed or surface cast with contrasting surface relief diffraction patterns. A second metal layer may be provided including a pattern of voids through which the first metal layer may be seen by a human observer.

Abstract: A hologram seal for security is prepared in pseudo manner by using a diffraction grating pattern. A picture data of a plurality of motifs is inputted to a computer. Within the computer, there are prepared in advance plural kinds of pixel patterns in which grating lines are arranged within one pixel at a predetermined line width, a pitch and an arrangement angle. These pixel patterns are arranged in a matrix form like tiles by making reference to the inputted picture data to represent respective motifs. The picture data in which the motifs are represented is given to an electron beam picture drawing apparatus to prepare a diffraction grating original block. This original block is used to mass-produce pseudo hologram seals by press device. By varying an arrangement angle of grating lines, it is possible to carry out gradation representation, or to record a plurality of motifs in an overlapping manner.

Abstract: A holographic ornament comprises a hologram which has an operative surface. In one embodiment, the operative surface is masked by a masking member. The masking member is formed with at least one letter-shaped cut through which a part of the operative surface of the hologram is exposed. In order to protect the masking member and the exposed part of the operative surface, a transparent protection cover member covers them. In the other embodiment, the hologram per se is formed with at least one through cut which is shaped like a letter or the like. In order to protect the operative surface, a transparent protection cover member covers the same.

Abstract: A combiner for combining light traveling on two optical paths to permit coincident viewing of the light includes a light-transmissive substrate having first and second surfaces, the first surface having a first diffractive structure that is a computer-generated hologram formed thereon configured to correct aberrations in light travelling on the first optical path which may be incident on the first surface and a partially reflective coating on the first diffractive structure, the partially reflective coating being reflective in a narrow bandwidth only, the first diffractive structure and the partially reflective coating configured to provide corrected reflection to light travelling on the first optical path, the second surface having a second diffractive structure that is a computer-generated hologram formed thereon as a conjugate of the first diffractive structure, so that light travelling on a second optical path which may be incident on the second surface passes through the second and first diffractive stru

Abstract: An apparatus for reconstructing holographic images includes a white light source, diffraction grating (1112) for generating zero-order diffracted light (1416) and at least first-order diffracted light, and light control film (LCF 1810) which is configured to block the zero-order diffracted light and to facilitate passage of a desired bandwidth of first-order diffracted light therethrough. In one embodiment light control film (LCF 1810) comprises a front layer (1802), a core layer (1804), and a back layer (1806). The back layer (1806) may be thought of as a datum, whereby a lateral shift in front film (1802) results in wavelength selectively, and a corresponding shift in core layer (1804) results in good zero-order light blocking. The resulting light is a pseudo-monochromatic source having sufficient coherence for use as a hologram reconstruction beam.

Abstract: A display having a diffraction grating comprises a substrate, a plurality of diffraction grating cells formed over a surface of the substrate and comprising a diffraction grating having curve portions arranged in a parallel shift relation, and a light-shutting unit including light-shutting elements having an opening, wherein a length of the diffraction grating in a direction perpendicular to that shift direction of the curve portions is made substantially equal to a length of the opening of the light-shutting element in the light-shutting unit, a diffraction grating element in the diffraction grating is repeated at least once in a direction perpendicular to the shift direction of the curve portions to provide the above cell, a length of the cell in the direction perpendicular to the shift direction of the curve portions is made substantially equal to a pitch length of the light-shutting element in the light-shutting unit, and the light-shutting unit is arranged on an illumination light entry side of the diffr

Abstract: In a preferred embodiment, a method of producing embossed first and second elongate, edgewise side by side, repeating, optical patterns on a sheet for use in producing secure identification means, the method comprising: continuously embossing the first and second optical patterns on the sheet, such that the first and second patterns repeat at different rates, so that the first pattern will "walk" with respect to the second pattern.

Abstract: A signaling mirror assembly for mounting to an exterior of a motor vehicle comprises a mirror shell mounted to a side of the vehicle body and a mirror mounted within the shell having reflectivity of at most 70% and transmissivity of at least 40%. The signaling mirror also has a light source disposed between the mirror and the shell which is operably illuminated in response to operating signals. Also included is diffractive means disposed between the light source and the mirror for diverting light from the vehicle operator to a viewing pattern which generally fans out from the side of the vehicle body.

Abstract: A diffraction grating providing an optically variable image includes a pixellated diffraction grating in which each pixel is an individual optical diffraction grating so that the pixellated diffraction grating when illuminated generates an optically variable image. In another aspect the grating in some or all of the pixels of a diffracting grating formed by a regular matrix of pixels is arranged such that a reproduction of the grating by reflection contact printing generates a zero-order pattern which is grossly flawed by Moire or Talbot fringe effects. A method of forming the diffraction grating includes producing a counterpart pixellated diffraction grating of a substantially optically invariable image wherein each pixel of the optically invariable image is maped to a respective pixel of the pixellated diffraction grating.

Abstract: A display having a diffraction grating pattern includes:(a) a flat substrate; and(b) at least one dot formed on a surface of the flat substrate, the dot being formed by a diffraction grating pattern as an aggregate of a plurality of curves obtained by translating a curve.

Abstract: An optical device for receiving incident light having a minimum wavelength, and for producing a resultant light containing an optical image. The device includes a first material having a first index of refraction and a surface embossed with an optical interference pattern, and a second material having a second index of refraction deposited onto the embossed surface of the first material. The depth of deposition is at least equal to three quarters of the minimum wavelength component of the incident light within the second material.

Abstract: Methods for creating a plurality of holographic diffraction grating patterns in a raster scan fashion. In accordance with the method, the desired pattern is made up of a large plurality of individual spots, each spot comprising a holographic diffraction grating of a predetermined grating spacing and angular orientation for that spot. Variation of the angular orientation and/or grating spacing between spots and/or groups of spots provide the desired holographic effect. The spot locations may vary as desired, including locations drawing out a desired pattern, and two-dimensional orthogonal matrices in which a pattern is drawn by variations between spots or group of spots as in a raster scan type image. Various embodiments and methods for creating the same are disclosed.

Abstract: A decorative multi-colored material and method of making same using rainbow gratings simultaneously evidence different color patterns which change through the color spectrum. The patterns are formed from separate impressions from different portions of a common rainbow grating to provide color differentiation. The multi-colored material may be used for a variety of applications, for example, decorative package wrappings, stickers, product enhancement and the like.

Abstract: A decorative substrate consisting of a paper base sheet coated with a thermoplastic material, involving a novel technique for coating and embossing the substrate. The paper sheeting is supplied with a thermoplastic material, as by coating or extrusion. The coated sheet is heated to adequately soften the coating, such as by use of a heated cylinder, and remote heat sources such as infrared heaters. The softened sheet surface is then decorated using an embossing member, to provide a diffraction pattern or hologram. Use of an embossment pattern of lesser depth than the surface roughness of the sheet before embossing provides attractive decorative patterns.

Abstract: A method for producing a display with a diffraction grating pattern comprising the steps of reading image data, assigning color for light exposure and moving a slit of an optical system to a position corresponding to the assigned color, moving an origin of an X-Y stage and setting initial data of the assigned color, reading data of an assigned address of the image data and opening a shutter of the optical system for light exposure when data of the assigned color exists, moving the X-Y stage to increase the address by one and repeating the data-reading and shutter-opening step until no further data exists, and changing the assigned color and repeating the above sequence of steps until no further color exists.

Abstract: A decorative multi-colored material and method of making same using rainbow gratings simultaneously evidence different color patterns which change through the color spectrum. The patterns are formed from separate impressions from different portions of a common rainbow grating to provide color differentiation. The multi-colored material may be used for a variety of applications, for example, decorative package wrappings, stickers, product enhancement and the like.