Abstract:
We describe a window assembly comprising: a window pane comprising a glass or plastic sheet; and a layer of holographic recording medium attached to said glass or plastic sheet; wherein said layer of holographic recording medium has recorded within the medium a volume hologram configured to direct light incident onto said glass or plastic sheet to propagate within a thickness of said glass or plastic sheet. In embodiments the volume hologram is fabricated by recording a transmission hologram and shrinking the recorded hologram to convert the transmission hologram to an edge-directing hologram configured to direct light in a direction to be totally internally reflected within the window pane, for example at greater than 40°, 50°, 60°, 70°, 75° or 80° to a normal to the surface of the hologram.
Abstract:
We describe techniques for recording a holographic image onto holographic recording film, in particular for security holograms. We thus describe a structure having a stack comprising the holographic recording film and a multichannel image generation device under the film. A three-dimensional object (or hologram of a 3D object) is provided, located under the multichannel image generation device. At least a portion of the multichannel image generation device is substantially transparent or absent in a region above the object. A holographic image is recorded in the film by illuminating the stack with laser light. The multichannel image generation device under the film may comprise a volume reflection hologram of a lenticularly generated image. The structure records a hologram of the 3D object in conjunction with a multi-channel holographic image.
Abstract:
A security element, preferably for documents of value, which at least has one area with a diffraction structure, which under specific viewing conditions reconstructs a diffractive image. This area has subareas, which do not take part in the reconstruction of the diffractive image, and which represent a recognizable information. Essential is that the information represented by the subareas is recognizable mainly only under the viewing conditions, under which the diffractive image can be perceived.
Abstract:
A single method and apparatus for producing many of the most common types of hologram from digital data is disclosed. The data are generated entirely by a computer as a 3-D (animated) model or from multiple 2-D camera images taken of a real 3-D (moving) object or scene from a plurality of different camera positions. The data are digitally processed and displayed on a small high resolution spatial light modulator (SLM). A compact low energy pulsed laser, is used to record composite holograms. The present invention permits the creation of restricted or full parallax master transmission or reflection type composite holograms, known as H1 holograms, that can be copied using traditional methods. Alternatively the same invention and apparatus permits the direct writing of hologram without the need to pass through the intermediate stage of the H1 transmission hologram.
Abstract:
Two original images to be recorded are prepared as data (S10). A plurality of unit regions, each having an adequate area to record interference fringes of visible light, are defined and positioned on a hologram recording surface (S20). A gradation pattern, with which appearance probabilities of two record attributes gradually change in space, is overlapped onto the recording surface, and to each unit region, one of either record attributes is assigned according to the appearance probabilities of the respective record attributes at each individual position (S30). In each unit region, to which the first record attribute is assigned, the first original image is recorded as an interference fringe pattern, a diffraction grating pattern, or a scattering structure pattern, and in each unit region, to which the second record attribute is assigned, the second original image is recorded as an interference fringe pattern, a diffraction grating pattern, or a scattering structure pattern (S40), and a record pattern is formed on a physical medium (S50).
Abstract:
A single method and apparatus for producing many of the most common types of hologram from digital data is disclosed. In one embodiment the data are generated entirely by a computer as a 3-D (animated) model. In another embodiment the data are generated from multiple 2-D camera images taken of a real 3-D (moving) object or scene from a plurality of different camera positions. The data are digitally processed and displayed on a small high resolution spatial light modulator (SLM). A compact low energy pulsed laser, which avoids the usual vibration problems encountered at high rates of production and the installation in normal working environments, is used to record composite holograms on an holographic emulsion using a special optical design. The present invention permits the creation of restricted or full parallax master transmission or reflection type composite holograms, known as H1 holograms, that can be copied using traditional methods to produce full or single color rainbow white-light transmission holograms, achromatic white-light transmission holograms or single or full-color white-light reflection holograms. Alternatively the same invention and apparatus permits the direct writing of full or single color rainbow white-light transmission composite holograms, achromatic white-light transmission composite holograms or single or full-color white-light reflection composite holograms without the need to pass through the intermediate stage of the H1 transmission hologram. The present invention allows the creation of a compact rugged machine that is capable of producing holograms covering a large size range. In addition the invention produces holograms that can be tiled together to form composite holograms much larger than the component panels.
Abstract:
A single method and apparatus for producing many of the most common types of hologram from digital data is disclosed. In one embodiment the data are generated entirely by a computer as a 3-D (animated) model. In another embodiment the data are generated from multiple 2-D camera images taken of a real 3-D (moving) object or scene from a plurality of different camera positions. The data are digitally processed and displayed on a small high resolution spatial light modulator (SLM). A compact low energy pulsed laser, which avoids the usual vibration problems encountered at high rates of production and the installation in normal working environments, is used to record composite holograms on an holographic emulsion using a special optical design. The present invention permits the creation of restricted or full parallax master transmission or reflection type composite holograms, known as H1 holograms, that can be copied using traditional methods to produce full or single colour rainbow white-light transmission holograms, achromatic white-light transmission holograms or single or full-colour white-light reflection holograms. Alternatively the same invention and apparatus permits the direct writing of full or single colour rainbow white-light transmission composite holograms, achromatic white-light transmission composite holograms or single or full-colour white-light reflection composite holograms without the need to pass through the intermediate stage of the H1 transmission hologram. The present invention allows the creation of a compact rugged machine that is capable of producing holograms covering a large size range. In addition the invention produces holograms that can be tiled together to form composite holograms much larger than the component panels.
Abstract:
The invention relates to a security element, preferably for documents of value, which at least has one area with a diffraction structure, which under specific viewing conditions reconstructs a diffractive image. This area has subareas, which do not take part in the reconstruction of the diffractive image, and which represent a recognizable information. Essential is that the information represented by the subareas is recognizable mainly only under the viewing conditions, under which the diffractive image can be perceived.
Abstract:
A holographic effect generating structure (HEGS), either stand alone or integrated with a security diffractive image, generates a holographic optically varying image by a process of diffraction of light, this image under white light illumination generates a smoothly and continuously variable structureless optically variable apparent motion effect which moves along a pre-determined track within pre-determined limits, the device characterised that it generates 3 planes of images under white light illumination an image plane image located at or near the image plane corresponding to the real plane of the device which defines the predetermined movement track of the apparent motion effect and its bounds, a second virtual image plane situated away from the image plane of the device forming a virtual viewing zone corresponding at which an observer would be positioned to observe the visual effect and a third image plane, which defines a region where all the light rays from the image plane artwork to the viewing zone pass through or appear to originate from which defines the defines the viewing track of the apparent motion effect.
Abstract:
In an image reconstructing apparatus 10 for reconstructing a hologram, when a lid 11 is nearly upright in relation to an apparatus body 12, a light emitted from an illumination light source 15 is projected at a predetermined angle of incidence to a hologram 17a placed on a mount surface 16a of a holder 16 of the apparatus body 12 while the light source 15 is being moved.