Abstract: A video holographic display device operates so that the size of a reconstructed three dimensional scene is a function of the size of the hologram-bearing medium; the reconstructed three dimensional scene can then be anywhere within a volume defined by the hologram-bearing medium and a virtual observer window through which the reconstructed three dimensional scene must be viewed. This contrasts with conventional holograms, in which the size of the reconstructed scene is localised to a far smaller volume and is not a function of the size of the hologram-bearing medium at all.

Abstract: In a video hologram that enables a three dimensional scene to be reconstructed, a specific region in the hologram encodes information for a particular, single point in the reconstructed scene. This region is the only region in the hologram encoded with information for that point, and is restricted in size to form a portion of the entire hologram, the size being such that multiple reconstructions of that point caused by higher diffraction orders are not visible at the defined viewing position. This contrasts with conventional holograms, in which the information needed to reconstruct a given point is distributed across the entire hologram.

Abstract: A display device generates a holographic reconstruction of a three dimensional scene from a hologram; the device is operable such that the holographic reconstruction is the Fresnel transform of the hologram and not the Fourier transform of the hologram. With a conventional holographic display, at least some of the holographic reconstruction can always be described as the Fourier transform of the hologram.

Abstract: A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transform these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

Abstract: A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

Abstract: The data defining an object to be holographically reconstructed is first arranged into a number of virtual section layers, each layer defining a two-dimensional object data sets, such that a video hologram data set can be calculated from some or all of these two-dimensional object data sets. The first step is to transform each two-dimensional object data set to a two-dimensional wave field distribution. This wave field distribution is calculated for a virtual observer window in a reference layer at a finite distance from the video hologram layer. Next, the calculated two-dimensional wave field distributions for the virtual observer window, for all two-dimensional object data sets of section layers, are added to define an aggregated observer window data set. Then, the aggregated observer window data set is transformed from the reference layer to the video hologram layer, to generate the video hologram data set for the computer-generated video hologram.

Abstract: An autostereoscopic display has a flat display for representing a left stereo image and a right stereo image. It also has an image separating mask having vertical periodic structures for channeling the left and right stereo images onto a left eye and a right eye of a viewer. A device for horizontally moving the image separating mask in accordance with a position of a viewer is provided. A periodicity interval of the vertical periodic structures of the image separating mask is smaller or identical to two pixels. The device for horizontally moving the image separating mask is carries out a horizontal movement that is smaller or identical to the periodicity interval, wherein upon reaching a limit of the periodicity interval the image separating mask is returned by a length of the periodicity interval.

Abstract: The invention relates to video holograms and devices for reconstructing video holograms, comprising an optical system that consists of a light source, lens and the video hologram that is composed of cells arranged in a matrix or a regular pattern with at least one opening per cell, the phase or amplitude of said opening being controllable. The video holograms and devices for reconstructing the same are characterised in that holographic video representations of expanded spatial objects can be achieved in a wide viewing area in real time using controllable displays, whereby the objects are either computer-generated or created by different means. The space-bandwidth product (SBP) of the hologram is thus reduced to a minimum and the periodicity interval of the Fourier spectrum is used as a viewing window on the inverse transformation plane, through which the object is visible in the preceding space. The mobility of the viewer(s) is achieved by tracking the viewing window.

Abstract: A method and a device for encoding and reconstructing computer-generated video holograms using a conventional LC display: it provides holographic reconstruction of three-dimensional scenes using electronically controllable pixel in a holographic array (3) with a conventional resolution, and is reasonably free from flickering and cross-talk. Reconstruction is in real time, and for both eyes at the same time, over a large viewing zone. The method takes advantage of an optical focusing means (2) in order to image vertically coherent light emitted by a line light source (1) into viewing windows (8R, 8L) after modulation by the pixel array (3). The holographic reconstruction (11) of the scene is rendered visible from viewing windows (8R, 8L) for both eyes of an observer by way of diffraction at the pixels.

Abstract: An autostereoscopic display has a flat display for representing a left stereo image and a right stereo image. It also has an image separating mask having vertical periodic structures for channeling the left and right stereo images onto a left eye and a right eye of a viewer. A device for horizontally moving the image separating mask in accordance with a position of a viewer is provided. A periodicity interval of the vertical periodic structures of the image separating mask is smaller or identical to two pixels. The device for horizontally moving the image separating mask is carries out a horizontal movement that is smaller or identical to the periodicity interval, wherein upon reaching a limit of the periodicity interval the image separating mask is returned by a length of the periodicity interval.

Abstract: An arrangement for spatial stereoscopic and/or holographic representation of information has a flat display having a rough surface and a frontal mask connected to the flat display. The rough surface has an immersing layer or a transparent layer or both provided thereon. As an alternative, between the rough surface of the flat display and the mask a space is provided and a closed body made of transparent material and containing immersing material is positioned in the space between the rough surface of the flat display and the mask.

Abstract: The invention relates to an autostereoscopic method and a device for the three-dimensional representation of information according to a barrier-, lenticular-, prismatic mask-, or similar method using flat-panel displays (liquid crystal-, plasma-, electroluminescent- or other displays) for use in the computer and video technology, games and advertising, medical engineering, virtual reality applications, and other fields. According to the invention, the image points are proportionally tracked to lateral movement of the observer by shifting, for each colored subpixel, of the intensities of the colored subpixels to horizontally adjacent colored subpixels. The method can be used with known devices. It becomes especially useful when, for each image point, n+1 adjacent colored subpixels are addressed. Observers moving sideways continue to see the image in practically consistently high quality.

Abstract: An optical system for the two- and three-dimensional representation of information by the use of transmission displays for the computer and video technology, for head-up displays for aviation and space flight, in advertising and presentation, in medical engineering, in the field of virtual reality and in other fields comprises: a light-source arrangement with at least one point or line source of light, a collimating optics for rendering the light parallel, a transmission display, a prism mask with prisms in a matrix arrangement, the prisms having two different prism angles, a field lens as a focussing optics as well as a phase mask. The image can be well seen by several viewers without any aid, the viewers being able to move laterally and vertically as they like. It is possible to offer two different TV programs to two or more persons at the same time. If all the viewers watch the same program, no sequential switching-over is necessary.