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: 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: This invention relates to a lenticule-prism-unit and to an illumination device for an autostereoscopic display. The display comprises (seen in the direction of light propagation) an illumination matrix (7), a projection matrix (8) and a transmissive image matrix (5). The illumination matrix consists of a multitude of controllable illumination elements (21). The projection matrix (8) focuses the light of these illumination elements (21) such that the image matrix (5) and a preferred visibility region (6) are illuminated in a directed manner. According to this invention, the projection matrix (8) comprises a lenticular array (LM) and a prism mask (PM) with wedge elements (K1, K2, . . . ) and coplanar elements (P1, P2, . . . ). The elements (K1, K2, . . . , P1, P2, . . . ) are arranged such that a multiple number of projections of the light of an illumination element (21) are projected into the visibility region (6), thus generating a broadened resultant luminance distribution (V) stretching from (A) to (C?).

Abstract: The invention relates to autostereoscopic multi-user displays with a sequential representation consisting of a sweet-spot unit and an image matrix. The sweet-spot unit, configured from an illumination and focusing matrix and positioned in front of the image matrix, focuses approximately parallel light bundles in sweet spots onto the eyes of observers. The aim of the invention is to achieve, by optical means, a tracking with a clear image allocation for observers located at a lateral distance from one another that is less than the distance between the eyes. The freedom of movement in terms of the display should be maintained and the information that is assigned to each observer should remain private with regard to other users. To achieve this, the sweet spots are limited horizontally and vertically with the aid of a focusing matrix, which consists of two crossed lens arrays L1 and L2, or a two-dimensional lens array comprising lenses that are arranged in a matrix, or a double lens array.

Abstract: An autostereoscopic multi-user display comprising a sweet-spot unit which is directionally controlled by a tracking and image control device (160), wherein an illumination matrix (120) is provided with separately activatable illuminating elements (11 . . . 56), in addition to an imaging device used to alternatingly image active illuminating elements, for making expanded sweet spots (SRI/SR2) visible to various eye positions (EL1/ERI, EL2/ER2) of viewers observing alternating images or a stereoscopic image sequence on a transmissive image matrix (140) with the aid of directed beams (B1R . . . B5L).

Abstract: The invention relates to a multi-lens lenticular system and a lighting device for an autostereoscopic display. Said display comprises, in the direction of light, an illuminating matrix (7), a focusing matrix (8), and a transmissive data panel (5). The illuminating matrix is provided with a plurality of light-penetrated controllable openings (21). The focusing matrix (8) focuses the light of said openings (21) in such a way that the data panel (5) and a preferred visible zone (6) are illuminated in a directed manner while being composed of a multi-lens lenticular system (LM) whose lenticles (L) are structured into several subordinate lenticles (S1, S2, . . . ).

Abstract: The invention relates to an autostereoscopic multi-user display comprising a focussing element and a selectable display for the time-sequential representation of 2D and/or 3D images. When viewed in the direction of the observer, said display contains a sweet-spot unit and an image matrix, which function separately from one another. The sweet-spot unit focuses a light distribution with a large surface area onto the eyes of the observer by means of a lateral sweet-spot extension, which is greater than or equal to the distance between the eyes of the observer. The sweet-spot bundle traverses the imaging matrix completely in a uniform manner on its way to the observer(s) and is thus modulated by the image content of the image matrix. The size of the sweet spot reduces the need for tracking precision. The sweet-spot unit consists of an illumination and imaging matrix.

Abstract: A display device for computer generated holography can time sequentially re-encode a hologram on the hologram-bearing medium for the left and then the right eye of an observer. Conventional holograms do not have to time multiplex for the left and then the right eye because, at any one time, the view seen by the left eye differs from the right eye anyway.

Abstract: A video holographic display device includes a light source used to illuminate a hologram-bearing medium encoded with a hologram. The device operates so that only when an observer's eyes are positioned approximately at the image plane of the light source can the holographic reconstruction be seen properly. This contrasts with conventional holographic displays, in which the observer's eyes do not have to be at the image plane in order for a holographic reconstruction to be seen.

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 geometrical method for working out how to encode a hologram onto a hologram bearing medium is disclosed. The method involves (a) selecting a point on the three dimensional scene to be reconstructed; then (b) defining a virtual observer window through which the reconstructed three dimensional scene will be seen; then (c) tracing a pyramid from the edges of the observer window through the point and onto a region that forms only a portion of a hologram bearing medium; and finally (d) generating, solely in that region of the hologram-bearing medium, holographic information needed to generate a holographic reconstruction of the point.

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: 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: 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.