Abstract: The invention relates to a method and an apparatus for replicating planar, thin-layered, and microstructured flat lens system and optical mask (LM) that are provided with such microstructured lens system which are hardened from a highly viscous transparent fluid on a supporting substrate plate (TP). The fluid is introduced between a plate-shaped master plate (M) and a movable supporting substrate plate and remains joined to said substrate plate after hardening. The inventive method is carried out in a non-rotational manner while the molding space is not delimited by sidewalls or similar in the direction of expansion of the fluid. The inventive flat lens systems or optical masks are embodied as lenticular arrays, field lenses, or Fresnel lenses. The final shape of the mask is homogeneous, has a geometrically accurate layer thickness, and is free from air pockets. The inventive method and apparatus allow for controlled replication at great geometrical accuracy and extremely good optical quality.

Abstract: The invention relates to a sweet spot unit for multiple user display with an enlarged observation area, preferably for an electronic display for reproducing stereoscopic and/or monoscopic representation which are automatically oriented towards the eyes of different observers by means of a position finder and a tracking and image control system. A said sweet spot unit contains deviation means (5), between the imaging means (3) and the image matrix, provided with deviation elements (511, 512, . . . 51n) which have a width (WL) and are periodically arranged in groups (L, N, R) in a matrix, vertically in accordance with the vertical screening (HV) of the illumination matrix (1). Each group deviates the bundle of rays (91, 92, 93, . . . ) respectively at another pre-determined angle, in order to reproduce the same in one of a plurality of horizontally arranged sweet spots areas.

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 (SR1/SR2) visible to various eye positions (EL1/ER1, 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: 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: The invention relates to a method and device for tracking the sweet spots of a sweets spot unit for a transmissive electronic display. The aim of the invention is to improve the reproduction quality and the uniformity of illumination in displays of this type. The display contains a sweet spot unit consisting of an illumination matrix (1) and reproduction elements, in addition to an image matrix (4). Once the position of at least one observer's eye (6) has been determined by a control unit using inverse ray tracing, address data for activating illumination elements (LE) of the illumination matrix (1) is provided from the position data in order to prepare the defined sweet spots (5) for said observer's eye (6). To improve the reproduction quality, an additional optical component is used in ray path for the inverse ray tracing process.

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: The invention relates to a controllable illumination device for an autostereoscopic or holographic display, which illumination device contains an illumination matrix of primary light sources having at least one luminous element per light source and a controllable light modulator (SLM) and a reproduction matrix. A computer-generated hologram (CGH) illuminated by the primary light sources (11, . . . , 1n) is coded on the controllable light modulator (SLM) and generates, in at least one plane downstream of the SLM, a matrix—reconstructed from the computer-generated hologram (CGH)—of secondary light sources (2) having a secondary light distribution for the purpose of illuminating the reproduction matrix (4) and for the purpose of focussing in light bundles onto each eye of the viewer via an imaging matrix. The CGH is calculated and reconstructed on the basis of the number of and the positions of the viewers and the system parameters.

Abstract: The invention relates to a projection device and a method for holographic reconstruction of scenes comprising a light modulator (8), an imaging system (3) with at least two imaging means (4, 5, 9) and an illumination device (1) with sufficient coherent light for illumination of hologram (2) coded in the light modulator (8). The at least two imaging means (4, 5) are arranged such that a first imaging means (4) is provided for the magnified imaging of the light modulator (8) on a second imaging means (5). The second imaging means (5) is provided for imaging of a plane (10) of a spatial frequency spectrum of the light modulator (8) in a viewing plane (6) at least one viewing window (15). The viewing window (15) corresponds to a diffraction order of the spatial frequency spectrum.

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 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 device for holographic reconstruction of three-dimensional scenes includes optical focusing means which directs sufficiently coherent light from light means to the eyes of at least one observer via a spatial light modulator that is encoded with holographic information. The device has a plurality of illumination units for illuminating the surface of the spatial light modulator (SLM); each unit comprises a focusing element (21/22/23 or 24), and a light means (LS1/LS2/LS3 or LS4) that emits sufficiently coherent light such that each of these illumination units illuminates one separate illuminated region (R1/R2/R3 or R4) of the surface, whereby the focusing element and the light means are arranged such that the light emitted by the light means (LS1-LS4) coincides close to or at the observer eyes.

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: 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.