927results about "Holographic optical components" patented technology

We describe a road vehicle contact-analogue head up display (HUD) comprising: a laser-based virtual image generation system to provide a 2D virtual image; exit pupil expander optics to enlarge an eye box of the HUD; a system for sensing a lateral road position relative to the road vehicle and a vehicle pitch or horizon position; a symbol image generation system to generate symbology for the HUD; and an imagery processor coupled to the symbol image generation system, to the sensor system and to said virtual image generation system, to receive and process symbology image data to convert this to data defining a 2D image for display dependent on the sensed road position such that when viewed the virtual image appears to be at a substantially fixed position relative to said road; and wherein the virtual image is at a distance of at least 5 m from said viewer.

The invention relates to holographic head-up displays, to holographic optical sights, and also to 3D holographic image displays. We describe a holographic head-up display and a holographic optical sight, for displaying, in an eye box of the display / sight, a virtual image comprising one or more substantially two-dimensional images, the head-up display comprising: a laser light source; a spatial light modulator (SLM) to display a hologram of the two-dimensional images; illumination optics in an optical path between said laser light source and said SLM to illuminate said SLM; and imaging optics to image a plane of said SLM comprising said hologram into an SLM image plane in said eye box such that the lens of the eye of an observer of said head-up display performs a space-frequency transform of said hologram on said SLM to generate an image within said observer's eye corresponding to the two-dimensional images.

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.

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.

Disclosed is a multiplexing method and apparatus that allows holograms to be spatially multiplexed with partial spatial overlap between neighboring stacks of holograms. Each individual stack can additionally take full advantage of an alternate multiplexing scheme such as angle, wavelength, phase code, peristrophic, or fractal multiplexing, for example. An amount equal to the beam waist of the signal beam writing a hologram separates individual stacks of holograms. Upon reconstruction, a hologram and its neighbors will all be readout simultaneously. An filter is placed at the beam waist of the reconstructed data such that the neighbors that are read out are not transmitted to the camera plane. Alternatively, these unwanted reconstructions can be filtered out with an angular filter at an intermediate plane in the optical system that has a limited angular passband.

A system for the production of a dynamic image for use in holography includes a light source (16) which travels via a liquid crystal modulator (18) placed in the path of the light source (16). The output of the LC modulator (18) passes modulated light through a lens array (22) which itself guides light to an optically addressed spatial light modulator (24). The resulting real image from the optically addressed spatial light modulator (24) may be used in holography. The addressing frame-rate of the liquid crystal modulator (18) is substantially greater than the frame-rate of the optically addressed spatial light modulator (24).

A display panel assembly comprises a transflective holographic screen, i.e., a transparent screen that reflects light from a projection system, comprising at least a volume hologram, a first protective element and a second protective element, each arranged in contact with the volume hologram such that the volume hologram is sandwiched between the first protective element and the second protective element. The display panel assembly further comprises a projection system focusing an image on the volume hologram comprising at least projection optics, mounting means arranged to fixedly mount the projection system relatively to the transflective holographic screen. The volume hologram comprises a plurality of diffractive patterns disposed in sequence across the volume hologram, each of the plurality of diffractive patterns being configured to diffuse the light rays from the projection system in a determined direction corresponding to the specific diffractive pattern and oriented towards a position of an intended eye of a user wearing the display panel assembly.

The invention belongs to an image display device and a method, relating to a holographical wave guide display taking a planar wave guide as a display screen and a generation method of a holographical image adaptive to the holographical wave guide display. The holographical wave guide display comprises a wave guide serving as the display screen and a holographcal projection system used for inputting the holographical image to the wave guide; the wave guide is provided with a light input panel and a light output panel; the incident light ray can be transmitted in the wave guide until leaving the wave guide from the light output panel; and the emergent position of the light ray on the light output panel is mutually determined by the position of point of incidence and the incidence angle of the light ray on the incidence panel. The holographical wave guide display of the invention can display the holographical image, can adopt the wave guide as a display carrier to manufacture the display which has jumbotron, low cost and environment protection and is energy-saving, sturdy and durable.

An apparatus and method to produce a hologram of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the object from the captured image.

The invention relates to techniques for speckle reduction in holographic optical systems, in particular holographic image display systems. We describe a holographic image display system for displaying an image holographically on a display surface, the system including: a spatial light modulator (SLM) to display a hologram; a light source to illuminate said displayed hologram; projection optics to project light from said illuminated displayed hologram onto said display surface to form a holographically generated two-dimensional image, said projection optics being configured to form, at an intermediate image surface, an intermediate two-dimensional image corresponding to said holographically generated image; a diffuser located at said intermediate image surface; and an actuator mechanically coupled to said diffuser to, in operation, move said diffuser to randomise phases over pixels of said intermediate image to reduce speckle in an image displayed by the system.

A method and system are disclosed for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process use thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence, while maximizing the contrast of the slanted fringe structures thereof. Different recording techniques are employed when the index of refraction of the substrate is greater than that of the recording medium, than when the index of refraction of the substrate is less than that of the recording medium. A recording and playback system of complementary design is provided for recording slanted-fringe volume holograms under relaxed conditions, without compromising the light diffraction efficiency of the holograms under different playback conditions.

A 3D display device with controllable device for tracking visibility regions is disclosed, and includes a controllable device for tracking a visibility region, generated by way of superposition of light source images, in a observer plane of the display device. In preferred embodiments, the cladding of a waveguide comprises at least one material with optical properties of an anisotropic liquid, or at least two materials with optical properties of an isotropic liquid; a matrix arrangement of control electrodes defines multiple positions to be generated for local exit points in the cladding of the waveguide at which the total reflection is locally cancelled; and a system controller modifies positions of the output coupling points for superposing the output-coupled light through the lens array to the visibility region by displacing an output coupling point, or by switching off one output coupling point and switching on another one.

The hologram recording sheet according to the invention is made up of a base film and hologram sensitive materials sensitive to different wavelength regions formed therein in a desired pattern, or a film and at least two hologram recording sensitive materials sensitive to different wavelength regions laminated on the film with a transparent plastic spacer layer located therebetween, thereby enabling the required diffraction light wavelengths to be recorded on the required sites without producing unnecessary interference fringes. At least two hologram recording sensitive materials sensitive to different wavelength regions are formed on different sites on a film in dotted or striped configuration, the size of which is up to 200 mm or at least twice as large as the thickness of the sensitive material layers, thereby enabling regions diffracting light of different wavelengths to be formed in the form of independent sets of interference fringes.

A near-eye display includes an image generator that generates angularly related beams over a range of angles for forming a virtual image and a waveguide that propagates the angularly related beams over a limited range of angles. An input aperture of the waveguide includes a plurality of controllable components that are selectively operable as diffractive optics for injecting subsets of the angularly related beams into the waveguide. An output aperture of the waveguide includes a plurality of controllable components that selectively operable as diffractive optics for ejecting corresponding subsets of the angularly related beams out of the waveguide toward an eyebox. A controller synchronizes operation of the controllable components of the output aperture with the propagation of different subsets of angularly related beams along the waveguide for ejecting the subsets of angularly related beams out of the waveguide for presenting the virtual image within the eyebox.

A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface perpendicular. In one embodiment, the planar waveguide includes a window pane which provides light transport from one location, where light is injected through the face of the pane, to another location where light is extracted. Additional embodiments of the face-lit waveguide illumination system are also disclosed.

A tamper indicating optical security device that operates to produce one or more synthetic images is provided. Any attempt to detach (e.g., forcibly remove) this device from an underlying base material will cause one or more layers of the security device to separate or delaminate, rending the device partially or totally inoperable. The inventive device is contemplated for use with, among other things, currency or banknotes, secure documents such as bonds, checks, travelers checks, identification cards, lottery tickets, passports, postage stamps, and stock certificates, as well as non-secure documents such as stationery items and labels. The inventive device is also contemplated for use with consumer goods as well as bags or packaging used with consumer goods.

Disclosed is a high resolution display on which decompressed high resolution image data is displayed, the display including pixels, the pixels being on a substrate, where circuitry is present on the same substrate as the pixels, where compressed high resolution image data which has been compressed using known data compression techniques is received by the circuitry, the circuitry being operable to perform decompression calculations which provide subsequent display of decompressed high resolution image data by the pixels of the display.

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.

A holographic display device comprising at least one magneto-optical spatial light modulator (MOSLM). The holographic display device may comprise a first MOSLM and a second MOSLM, the first and second MOSLMs encoding a hologram and a holographic reconstruction being generated by the device. An advantage of the device is fast encoding of holograms.

Disclosed is a holographic display including a spatial light modulator, and including a position detection and tracking system, such that a viewer's eye positions are tracked, with variable beam deflection to the viewer's eye positions being performed using a microprism array which enables controllable deflection of optical beams.

A holographic display comprising light sources (L51, L52, . . . ) in a 2D light source array, lenses (L1, L2, . . . ) in a 2D lens array, a spatial light modulator (SLM) and a beamsplitter, in which there are m light sources per lens, and the light sources are in m-to-one correspondence with the lenses. The beamsplitter splits the rays leaving the SLM into two bundles, one of which illuminates the virtual observer windows for m left eyes (VOWL) and the other illuminates the virtual observer windows for m right eyes (VOWR). In one example, m=1. An advantage is 2D-encoding with vertical and horizontal focusing and vertical and horizontal motion parallax.

A light modulating device comprises a spatial light modulator and a homogenizing element. A group of at least two adjacent pixels of the spatial light modulator form a macropixel: The spatial light modulator is of a type such that its pixels comprise a variable content. Each macropixel is used to represent a numerical value which is manifested physically by the states of the pixels of the spatial light modulator which form the macropixel. For each macropixel a homogenizing element is present in the optical path after the macropixel. The homogenizing element comprises an optical input and an optical output. The homogenizing element is adapted such that output light of the macropixel is entering the optical input of the homogenizing element and is mixed within the homogenizing element and is output at the optical output of the homogenizing element.

A high-resolution PμSL system and method incorporating one or more of the following features with a standard PμSL system using a SLM projected digital image to form components in a stereolithographic bath: a far-field superlens for producing sub-diffraction-limited features, multiple spatial light modulators (SLM) to generate spatially-controlled three-dimensional interference holograms with nanoscale features, and the integration of microfluidic components into the resin bath of a PμSL system to fabricate microstructures of different materials.

A laser beam is reflected by a light beam scanning device and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a linear scatter body is recorded as a hologram by using reference light that converges on a scanning origin. The light beam scanning device bends the laser beam at the scanning origin and irradiates the laser beam onto the hologram recording medium. At this time, by changing a bending mode of the laser beam with time, an irradiation position of the bent laser beam on the hologram recording medium is changed with time. Diffracted light from the hologram recording medium produces a reproduction image of the linear scatter body on a light receiving surface of the stage. When an object is placed on the light receiving surface, a line pattern is projected by hologram reproduction light, so that the projected image is captured and a three-dimensional shape of the object is measured.

We describe a method of determining an aberration correction for a holographic image display system using a spatial light modulator (SLM) to display a hologram. Embodiments of the invention measure the corrections needed for a particular projection system, using the same system SLM as used to generate the images to provide wavefront-sensing holograms. The projector's projection optics are used to provide the wavefront sensor and there is no need for lenslets. Embodiments of the invention use a plurality of successive holograms directing light from differently-located patches on the hologram into the image.

The invention discloses a three-dimensional imaging method and a device utilizing a planar lightwave circuit. The three-dimensional imaging method includes that coherent light emitted from coherent light source is converted into a two dimensional point light source array; the position of every point light source in the two dimensional point light source array is randomly distributed; three-dimensional images are discretized into a large amount of vexel; the vexel is divided into a plurality of groups from high to low according to the brightness; a phase regulating amplitude of the point light source is calculated according to the distance between every point light source and every vexel of every group to enable the lightwave from every point light source to be in the same phase when reaches the vexel; every point light source is accumulated as a complex amplitude regulation amplitude for generating every vexel; and an amplitude regulator and a phase regulator of every point light source are driven to generate every group of vexel based on constructive interference. The imaging device is formed by coherent light source, the planar lightwave circuit, a conductive glass front panel and a back driving circuit. The three-dimensional imaging method and the device utilizing the planar lightwave circuit are capable of being widely applied to the fields of three-dimensional display of a computer and a television, three-dimensional human-machine exchange, robot vision and the like.

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. According to the invention, the controllable pixels are disposed in vertical pixel columns (15, 16), which encode separate holograms of the same scene for each of the viewer's eyes (R, L), where said holograms are one-dimensional in the vertical direction and horizontally interleaved. An image separation means (7) with separating elements arranged parallel to the pixel columns reveals the respective pixel columns (15, 15′ or 16, 16′) for one eye and covers them for the other eye.

A method and system for encrypting multi-dimensional information utilizing digital holography is presented. A phase-shifting interferometer records the phase and amplitude information generated by a three-dimensional object at a plane located in the Fresnel diffraction region with an intensity-recording device. Encryption is performed by utilizing the Fresnel diffraction pattern of a random phase mask. Images of different perspectives of the three-dimensional object focused at different planes can be generated digital or optically with the proper key after decryption. After decryption, images of the object, focused at different planes, can be generated digitally or optically. The method allows for the reconstruction of the object with different perspectives from a single encrypted image. The method does not require sending the key exclusively through a digital communication channel. Instead, a copy of the random phase key itself can be sent to the authorized user. A method of forming an image of an object is disclosed. The method comprises forming an original hologram of the object; compressing the original hologram of the object to form a compressed hologram; decompressing the compressed hologram of the object to form a decompressed hologram; and reconstructing the object from the decompressed hologram to form a multi-dimensional image of the object.

A backlight unit (BLU), for a binocular holographic display apparatus, and the binocular holographic display apparatus including the BLU are provided. The BLU includes: a light source unit that emits coherent illumination light; and a light guide plate that is transparent and includes a light incidence surface onto which the coherent illumination light emitted by the light source unit is incident and a light emission surface through which the illumination light is output. The light source unit includes a beam deflector that adjusts an incidence angle of the illumination light incident onto the light guide plate.

According to one aspect and example, a method for recording holographic media and / or holographic master data masks includes recording at least a first hologram or information layer with a first holographic medium (e.g., a “submaster”) and recording at least a second information layer with a second holographic medium (e.g., a second “submaster”). The first information layer and the second information layer from the first and second holographic media are then sequentially reconstructed and stored with a single holographic master medium (e.g., a “master”). The holographic master may then be used to record the stored first and second information layers into additional holographic media, for example, into HROM devices or the like.