Abstract: An image forming device includes: an image forming unit that forms an image on a transfer medium; and a controller that controls multiple image readers capable of performing image reading for the same surface of the transfer medium, and acquires reading results from the image readers. The controller is capable of performing failure/no-failure determination for the image on the transfer medium based on the reading results, of switching image reading by the multiple image readers between reading by a first number of image readers and reading by a second number of image readers, the second number being smaller than the first number, and of enabling, while the second number of image readers perform reading, at least one of the other image readers to execute a maintenance operation for the at least one of the other image readers.

Abstract: An image projector arranged to project an image onto a display plane. The image projector comprises a processing engine, a display device, an optical element and a light source. The processing engine outputs a computer-generated diffractive pattern comprising a hologram of an image for projection and a lens function corresponding to a lens having a first optical power. The display device is arranged to display the computer-generated diffractive pattern. The optical element is disposed between the display device to the display plane. The optical element has second optical power. The light source is arranged to provide off-axis illumination of the display device in order to spatially-modulated light in accordance with the hologram and lens function. The lens function of the computer-generated diffractive pattern and the optical element collectively perform a hologram transform of the hologram such that a reconstruction of the image is formed on the display plane.

Abstract: The invention relates to a light guiding device for guiding light. The light guiding device comprises at least one light guide, at least one beam splitter element, and at least one light decoupling device. The at least one light guide comprises at least two layers. The at least one beam splitter element is provided between the at least two layers of the at least one light guide, where the at least one beam splitter element is designed for partially transmitting and reflecting incident light propagating in the at least one light guide. The at least one light decoupling device is provided for coupling incident light out of the at least one light guide. Furthermore, the invention also relates to an illumination device and a display device for displaying two-dimensional and/or three-dimensional information comprising such a light guiding device.

Abstract: A method for controlling a projector having a projection lens and a camera includes an acquisition step of acquiring a focal distance of the projection lens, a determination step of determining a size and an interval of dots configuring a projection pattern based on the focal distance, a projection step of projecting the projection pattern by the projection lens, and capturing step of capturing the projection pattern by the camera to generate a captured image.

Abstract: A device includes a filter that enhances a beam profile of a received pulsed laser; a first optical element to direct the pulsed laser as a reference wave towards an optical sensor; an open cavity positioned between the first optical element and the optical sensor. The open cavity receives an aerosol particle, which enters the open cavity from any direction. The reference wave illuminates the aerosol particle. An illuminated particle generates and directs an object wave towards the optical sensor. A pixel array is connected to the optical sensor. The pixel array receives the reference wave and the object wave. The optical sensor creates a contrast hologram comprising an interference pattern of the illuminated particle. A processor creates an image of the illuminated particle based on the contrast hologram.

Abstract: A display apparatus configured to produce an interactive three-dimensional holographic image is disclosed. The display apparatus can include one or more coherent light sources configured to produce one or more beams, based on obtained image data of an object to display, and a lens assembly configured to direct the one or more beams to form a holographic image of the object. The lens assembly can include a collimating lens and a lens capable of beam steering one or more beams, including a micro-lens assembly with at least one micro-lens configured to generate a plurality of beams associated with a plurality of desired viewing angles. One or more optical sensors can be configured to obtain information regarding whether an interactive device interrupts the one or more beams, and a processor unit can determine a location of the interactive device with respect to the holographic image.

Abstract: An novel fiber pump signal combiner is disclosed in which a fiber bundle array is coupled to a double-clad fiber with a taper section that is formed by etching a tapered outer surface into the cladding of a fiber rod to produce a high quality tapered outer surface free of defects with an inner core that has a constant diameter.

Abstract: Various embodiments of the present invention are directed to negative refractive index-based holograms that can be electronically controlled and dynamically reconfigured to generate one or more color three-dimensional holographic images. In one aspect, a hologram comprises a phase-control layer having a plurality of phase modulation elements. The phase-modulation elements are configured with a negative effective refractive index and selectively transmit wavelengths associated with one of three primary color wavelength. The hologram also includes an intensity-control layer including a plurality of intensity-control elements. One or more color three-dimensional images can be produced by electronically addressing the phase-modulation elements and intensity-control elements in order to phase shift and control the intensity of light transmitted through the hologram. A method for generating a color holographic image using the hologram is also provided, as is a system for generating a color holographic image.

Abstract: Coherent light from a laser is magnified, made into a parallel light flux, and irradiated on a hologram recording medium in which a hologram image of a scatter plate is recorded. A hologram reproduction real image of the scatter plate is generated using the parallel light flux as illumination light for reproduction. The spatial light modulator consisting of a liquid crystal display, etc., is disposed so as to overlap on the position of the hologram reproduction real image, and a modulated image is obtained on the surface of the reproduction real image of the scatter plate. The modulated image is projected onto the screen by the projection optical system.

Abstract: A virtual image display device with an optical waveguide to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A virtual image display device with an optical waveguide to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A virtual image display device which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A virtual image display device is provided which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide (13) to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating (14) to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating (15) to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: An image projecting apparatus enables the formation of a projected image faithful to original image information by reducing degradation in the projected image due to decrease in imaging performance of a projection optical system. Image information is processed by an image processing device, which includes a first and a second image processor. A light modulating device modulates a flux of light emitted by an illumination optical system based on the processed image information. The modulated flux of light is projected on a screen by a projection optical system. If the image information processed by the first image processor in a pixel region is not within a representable modulation range of the light modulating device, the image information is processed by the second image processor.

Abstract: The invention concerns shutting down and restarting optical amplifiers, such as Raman amplifiers, in an optical link, depending whether the optical amplifier is a transmitting side amplifier or a receiving side amplifier. For controlling the amplifiers, at least one diagnostic signal is to be transmitted via an auxiliary optical channel in the optical link, and a number of physical events simultaneously taking place are to be taken into account to conclude whether to shut down or to restart one of the optical amplifiers.

Abstract: A method is provided for controlling an at least partly automatically implementable driving maneuver by which a motor vehicle can be moved from an actual position into a desired position. In the environment of the motor vehicle, a virtual target object is generated in a target position for the motor vehicle in the environment of the motor vehicle by projection using projection devices provided on the motor vehicle. As a function of operating actions of an operator of the motor vehicle, the target position is changed, whereby also the target object is displaced in the environment of the motor vehicle. And, by way of a selecting action of the operator, the changed target position is selected and utilized as the desired position of the driving maneuver.

Abstract: A security device including a surface relief microstructure which, in response to incident radiation, replays a hologram viewable within a viewing zone, the hologram including at least a first holographic image element in an image plane spaced from the surface of the microstructure. The device exhibits at least one further image in a plane spaced from the image plane of the first holographic element. On tilting the device, the first holographic image element exhibits apparent movement relative to the further image, which when expressed in radians, a rate of parallax movement per radian equals the spacing between phones and the product of the rate of movement and the included angle of the viewing zone defining a distance at least 20% of the dimension of the device in the direction of movement of the first holographic image element.

Abstract: An image elimination apparatus includes a first reader configured to read a status of a sheet, a first judgment portion configured to judge whether the read sheet is reusable or not, an image eliminator configured to eliminate an image formed on the sheet, a second reader configured to read the sheet passing through the image eliminator, a second judgment portion configured to judge whether the image formed on the sheet is eliminated or not, and a controller configured to control the first reader and the second reader so as to read with different reading precision.

Abstract: A reproducing device for performing reproduction regarding a hologram recording medium where a hologram page is recorded in accordance with signal light, by interference between the signal light where bit data is arrayed with the information of light intensity difference in pixel increments, and reference light, includes: a reference light generating unit to generate reference light irradiated when obtaining a reproduced image; a coherent light generating unit to generate coherent light of which the intensity is greater than the absolute value of the minimum amplitude of the reproduced image, with the same phase as the reference phase within the reproduced image; an image sensor to receive an input image in pixel increments; and an optical system to guide the reference light to the hologram recording medium, and also guide the obtained reproduced image according to the irradiation of the reference light, and the coherent light to the image sensor.

Abstract: A lighting apparatus is provided. The lighting apparatus includes a power supply housing section, a circuit board housing section, a light source housing section, a cutout portion, and a light source. An image recorded on a record medium is displayed in the state that an end portion of the power supply housing section and an end portion of the record medium secured to the cutout portion are placed on a surface where the lighting apparatus is placed.

Abstract: The combination of a truly realistic three dimensional real image in color and a second device to produce a repetitive passage of a solid object through the real image creates the illusion of one solid body passing through another. A simple method of accomplishing this is to mount a clockworks with a pendulum over or under the image and allow a pendulum end to pass periodically through the real image. Other means such as a device running on a circular track could accomplish the same illusory effect. The pendulum end or the device can take various forms as can the real image. In principle the designs are not limited in size. Further, an amusement ride is contemplated by directing a track with a vehicle and a rider in the vehicle at the proper angle toward the real image creating an exciting visual moment passing through the apparently solid object.

Abstract: A virtual image display device is provided which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide (13) to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating (14) to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating (15) to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: The invention relates to an information carrier (801) comprising: a data layer (802) intended to store a set of elementary data, a layer (803) comprising an array of apertures (804) placed parallel to said data layer (802) for generating an array of light spots intended to be applied to said data layer (802). The invention also relates to a system and apparatus for reading such an information carrier.

Abstract: An optically amplifying waveguide that can have a gain having a small wave-length dependency in a wavelength range shorter than the C-band, and the like. The optical amplifier module 1 optically amplifies a signal lightwave that has a wavelength lying in a wavelength range of 1,490 to 1,530 nm and that has entered an input connector 11 to output the optically amplified signal lightwave from an output connector 12. An optical isolator 21, a WDM coupler 31, an Er-doped optical fiber (EDF) 50, a WDM coupler 32, and an optical isolator 22 are provided in this order on a signal lightwave-transmitting path from the input connector 11 to the output connector 12. A pump source 41 connected to the WDM coupler 31 and a pump source 42 connected to the WDM coupler 32 are also provided. In the EDF 50, at least one of the stimulated-emission cross section and the absorption cross section assumes a maximum value at the shorter-wavelength side of a peak at a wavelength range of 1.53 ?m.

Abstract: In an image projection device, interferences between the light source and the light modulator leading to visible interferences in the projected image are suppressed by an interference cancellation circuit that pre-corrects the control signal that includes the image data that is to be projected.

Abstract: An optical device for security and anti-counterfeit applications comprises a diffractive structure comprising a discrete region that in response to white light illumination generates an image by a process of diffraction in close angular proximity to the specular reflection and which is thus substantially non-visible to an observer, and which under coherent illumination generates a laser projection covert image which forms an image in an image plane located away from the physical plane of the device and which is angularly co-located in close proximity to the direction and position of the specular reflection.

Abstract: In a hologram recording method for forming a plurality of areas of a refractive index light interference pattern of a coherent signal light beam in accordance with information data within a recording medium having a shape of parallel flat plates, the signal light beam and the recording reference light beam cross each other within the recording medium, and a gate light beam having a second wavelength for revealing recording sensitivity of the recording medium is simultaneously irradiated to the recording medium so as to pass through a portion of the recording reference light beam and demarcate a volume smaller than that of this crossing portion.

Abstract: An imaging system for motor vehicles has a holographic screen, which scatters incident narrow band light at a predetermined solid angle, and a modulator and a lens to project images on the holographic screen. A holographic, transparent ray uniter, which allows broad band ambient light to pass through essentially unimpeded, guides the narrow band light, coming from the holographic screen to the viewer, whereby a virtual image is produced at the viewing location by means of an imaging function. Images from the outside of the motor vehicle are shot by means of a camera system and are faded as virtual images into the windshield of the motor vehicle in order to enable there additionally a view to the rear or to the side.

Abstract: An image display apparatus comprises a hologram screen 2 formed by bonding a hologram element 20 to light-transmissible films 21 and an illumination device 11 for irradiating image light 10 onto the hologram screen and reproducing an image on the hologram screen 2. The light-transmissible film 21 positioned on the irradiation side of the image light 10 relative to the hologram element 20 has an angle deviation of not greater than 45 degrees between a direction of the light-transmissible film 21 that gives the highest thermal shrinkage ratio and an axial direction in the hologram screen 2. Therefore, the image display apparatus can provide high-quality images without the superposition of an interference pattern on the images on the hologram screen.

Abstract: A hologram recording film has a hologram image of an object recorded in a volume hologram photosensitive material by holographic duplication and further has a hologram image of an additional information pattern, e.g. a character or an image, recorded superimposedly in the same volume hologram photosensitive material simultaneously with the holographic duplication so that the additional information pattern is reconstructable in a plane with a depth from the hologram plane. Reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with a reconstructed image from the volume hologram. In addition, transmission type additional information that is in mirror image relation to the reflection type additional information is recorded in the hologram recording film so as to be reconstructable simultaneously in superimposition with the reconstructed image from the volume hologram.

Abstract: An apparatus includes recording reference optics, recording signal optics, and reproducing reference optics. The recording reference optics supplies a recording reference light beam to a recording medium, and the recording signal optics supplies a signal light beam, which is modulated in accordance with image data, to the recording medium. The signal light beam and the recording reference light beam produce an interference pattern within the recording medium. The reproducing reference optics supplies a reproducing reference light beam, which propagates in an opposite direction of the recording reference light beam, to the recording medium. The reproducing reference light beam generates a phase conjugate wave from a refractive-index grating of the interference pattern, and the phase conjugate wave is split from an optical path of the signal light beam to image a dot pattern with the phase conjugate wave. Also, a photo-detector detects the dot pattern to reproduce image data.

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.

Abstract: Large format, highly selective display screens can be formed from a plurality of holographic optical elements. In accordance with the teachings of the present invention, systems and methods are described to provide a holographic screen for display of static and/or dynamic projected conventional two-dimensional images, two-dimensional stereograms, and holographic stereograms. One aspect of the present invention includes presenting live-image three-dimensional displays using an array of two-dimensional data projectors. Another aspect includes projecting and enlarging static or dynamic source three-dimensional images (real objects, holograms, or other autostereoscopic images).

Abstract: A method is provided for producing a holographic optical element that is comprised of at least one primary hologram (as defined herein) and at least one complementary hologram (as defined herein). The holographic optical element is useful as a security device, since it is relatively easily produced and yet is uncopyable in total. Also disclosed are methods for establishing the authenticity of the holographic optical element.

Abstract: An optically made, high-efficiency in-line holographic mask (ILHM) for in-line holographic patterning of a workpiece, and apparatus and methods for performing same. The ILHM combines the imaging function of a lens with the transmission properties of a standard amplitude mask, obviating the need for expensive projection optics. The ILHM is either a type I (non-opaque) or type II (opaque) specialized object mask having one or more substantially transparent elements which can be phase-altering, scattering, refracting and/or diffracting. A method of creating a pattern on a workpiece includes the steps of disposing an ILHM, disposing a workpiece adjacent the ILHM and illuminating the ILHM to impart a pattern to the workpiece. In another method, the ILHM is used in combination with a lens. The ILHM is disposed such that a holographic real image is formed at or near the lens object plane, and the workpiece is disposed at or near the lens image plane.

Abstract: A projection engine having a first kernel for modulating light of a first polarization, and a second kernel for modulating light of a second polarization, and a polarization combiner for merging light from the kernels into a dual polarization modulated output beam.

Abstract: A system for projecting images is provided having a group of diffractive phase plates each encoded with different image information which have phase shifts aligned to reconstruct visible images in a Fraunhofer diffraction region. The plates are arranged along a path, and may represent successive frames of animation. A light source illuminates the plates and provides, when multiple plates are illuminated, a composite image representing image information encoded in such multiple plates. This composite image is a coincident superposition of reconstructed images from the multiple plates. A mechanism is provided for moving the plates along their path such that images projected from the system in the Fraunhofer diffraction region represent the composite image from successively different illuminated multiple plates or the reconstructed image from a single plate. Both monochromatic and multi-color channel phase plates may be used in the system.

Abstract: An optical display apparatus is provided that can utilize a low intensity point light source and that requires a small physical profile. The optical display apparatus comprises an image display apparatus including at least one point light source to form an image to be displayed for viewing, a hologram screen that defracts and reflects light from the point light source, and an imaging optical system arranged to adjust a focus in one direction of the image so that the point light source of the optical display apparatus is focused to a line on the hologram screen. The optical display apparatus reconstructs and images the image displayed on the image display apparatus on a virtual display plane.

Abstract: Operator input into one or more devices to be controlled by the operator is provided through a holographic image of the keys or other input devices customarily actuated to provide input data to the system wherein actuation of the holographic image of the input devices is detected optically without tangible physical contact by the operator with a solid control object or control surface.

Abstract: The invention makes it possible to form a hologram for reproducing a three-dimensional image easily free of limitations placed by the size of the three-dimensional image to be reproduced, the size of the hologram and reference light for reproduction. A controller calculates a three-dimensional interference pattern for generating reproduction light associated with a desired three-dimensional image when a recording medium (1) is illuminated with reference light for reproduction, divides the three-dimensional interference pattern into partial interference patterns and calculates reference light and information light for recording for each of the partial interference patterns. A final hologram is formed by illuminating the recording medium (1) with reference light and information light for recording using a head (10) while changing the relative positional relationship between the recording medium (1) and the head (10) by moving the head (10) with a VCM (13) while transporting the recording medium (1).

Abstract: The gain control device in a semiconductor optical amplifier using an optical fiber grating includes an input unit for receiving an optical signal, an output unit for outputting an amplified optical signal, and input and output optical isolators connected to the input and output units to establish paths of the input and output optical signals. The gain control device further includes a tension-controllable optical fiber grating connected to the input optical isolator for fine adjustment of a reflection peak wavelength. A semiconductor optical amplifier connected to the tension-controllable optical fiber grating is also provided to amplify the optical signal. A power supply supplies power to the semiconductor optical amplifier to drive the optical amplifier. In addition, an optical fiber grating is connected to the semiconductor optical amplifier and has a predetermined reflection peak wavelength.

Abstract: An image processing system and method visually documents and displays the in-vivo location from which a biopsy specimen was extracted, by processing pre-biopsy and post-biopsy images. A composite image is created which visually emphasizes differences between the pre-biopsy and post-biopsy images. Preferably three-dimensional, digitized images, displayable in various projections, are stored for archival purposes on computer readable media. An image processor preferably exploits an optical correlator to register the pre-biopsy and post-biopsy images accurately. The images are then compared, voxel-by-voxel, to detect differences between pre-biopsy and post-biopsy images. The composite image is displayed with synthetic colors, synthetic icons, or other visual clues to emphasize probable in-vivo biopsy locations.

Abstract: A simulated weapon is disclosed which uses a hologram, an electric lamp and various other optical components to produce holographic images resembling the rays or beams of ray guns or space guns as portrayed in motion pictures, television programs, video games, and comic books in that the rays extend into and occupy space in front of the device itself but are not tangible. Sound effects accompany the projection of holographic images. The device also provides ancillary visual effects prior to the display of holographic images. Sound effects accompany the ancillary visual effects. The toy is intended for floor use and can be mounted on toy tank treads or other conveyance means. The rays are visible to those sitting, kneeling, or standing in front of the device. The preferred embodiment of the device is powered by an electric storage battery.

Abstract: A real-time, dynamic, free space-virtual reality, 3-D image display system which is enabled by using a unique form of Aerogel as the primary display media. A preferred embodiment of this system comprises a 3-D mosaic topographic map which is displayed by fusing four projected hologram images. In this embodiment, 4 holographic images are projected from 4 separate holograms. Each holographic image subtends a quadrant of the 4&pgr; solid angle. By fusing these four holographic images, a static 3-D image such as a featured terrain map would be visible for 360 degrees in the horizontal plane and 180 degrees in the vertical plane. An input, either acquired by 3-D image sensor or generated by computer animation, is first converted into a 2-D computer generated hologram (CGH). This CGH is then downloaded into large liquid crystal (LC) panel. A laser projector illuminates the CGH-filled LC panel and generates and displays a real 3-D image in the Aerogel matrix.

Abstract: A projection system and a method of displaying a projected input image on a projection screen of the system utilize one or more reconfigurable holographic optical elements (HOEs) to optically manipulate propagating light in the system. The reconfigurable HOEs may be configured to perform simple optical functions that are commonly associated with traditional optical devices, such as lenses, prisms and mirrors. However, the reconfigurable HOEs may also be configured to perform sophisticated optical manipulations, such as varying the light intensity toward a specific direction and generating virtual (holographic) images. Each reconfigurable HOE includes a hologram that is sandwiched between two electrode layers. The hologram is a holographic photopolymeric film that has been combined with liquid crystal. The hologram has an optical property that changes in response to an applied electrical field.

Abstract: A holographic optical device includes a light transmissive substrate carrying first and second laternally separated holographic optical elements. The first holographic optical element diffracts incident light into the substrate where it is trapped by internal reflection so that light impinges more than once at different angles at different locations on at least one of the first and second holographic optical elements with a significantly higher efficiency for one angle of incidence. The second holographic optical element diffracts light out of the substrate. The second holographic optical element may be a display hologram for displaying a three-dimensional image.

Abstract: The invention relates to a space-saving yet high-quality real image type finder indicator wherein an optical member such as a hologram is used for a device for indicating various information in a finder. In a finder optical system has an objective system, an image erection system and an eyepiece system; A hologram H is provided on a reflecting surface of the image erection system, so that an image at an indication portion is indicated by hologram H in visual field of the finder.

Abstract: An autostereoscopic display system and a method of displaying a scene in a stereoscopic form on a screen of the system include two or more reconfigurable holographic optical element (HOE) stacks in the screen. The reconfigurable HOEs may be configured to perform simple optical functions that are commonly associated with traditional optical devices, such as lenses, prisms and mirrors. However, the reconfigurable HOEs may also be configured to perform sophisticated optical manipulations, such as optimally diffusing light with respect to light intensity toward a predefined viewing region. Each reconfigurable HOE includes a hologram that is sandwiched between two electrode layers. The hologram is a holographic photopolymeric film that has been combined with liquid crystal. The hologram has an optical property that changes in response to an applied electrical field.

Abstract: A projection system incorporating a screen (2, 14) with a substantially achromatic response in a direction substantially perpendicular to the plane of the screen. The screen (2, 14) comprises a diffraction grating (4), means (5) for attenuating zero order and a diffuse holographic optical element (6). The system further comprises a focusing element with positive optical power. The aggregate optical power of the grating and the holographic optical element is substantially less than that of the focusing element.

Abstract: A diffractive display system and a method of collecting first order light beams from a diffractive display of the system utilize holographic optical elements (HOEs) to deflect one of two first order diffracted light beams that emerge from each diffracting pixel of the diffractive display, so that the first order diffracted light beams can be separated from the zeroth order light beams. The utilization of the HOEs allows the system to be implemented in a compact optical configuration, without sacrificing any portion of the first order diffracted light. In a first embodiment, the system includes three HOEs that have static diffracting properties that are optimized for red, green and blue lights. For each set of light beams from a diffracting pixel of the diffractive display, the HOEs are holographically configured to deflect only one of the two first order diffracted light beams, such that the deflected first order light beam propagates in the same direction as the other non-deflected first order light beam.