401 results about "Holographic optical element" patented technology

A method for displaying an image viewable by an eye, the image being projected from a portable head worn display, comprises steps of: emitting a plurality of light beams of wavelengths that differ amongst the light beams; directing the plurality of light beams to a scanning mirror; modulating in intensity each one of the plurality of light beams in accordance with intensity information provided from the image, whereby the intensity is representative of a pixel value within the image; scanning the plurality of light beams in two distinct axes with the scanning mirror to form the image; and redirecting the plurality of light beams to the eye using a holographic optical element acting as a reflector of the light beams, whereby the redirecting is dependent on the wavelength of the light beam, to create for each light beam an exit pupil at the eye that is spatially separated from the exit pupils of the other light beams.

A device, such as a heads up display, includes equipment for generating a virtual image in the field of view of an observer. The equipment includes at least one light source having a wavelength range less than 2 nm. The light source can be a low pressure gas discharge lamp. The device also includes a holographic optical element that provides a virtual image. The device also includes an image source, such as a mask or an LCD. In one embodiment the holographic optical element combines an image on a display with an ambient image. The holographic element provides multiple colors undistorted in a virtual image appearing to the observer as converging from the same distance.

One embodiment of the invention comprises a simplified light-weight head mounted displays comprising an off-axis combiner and a pair of plastic lenses. One of the lenses is a rotationally symmetric optical element and one of the lens is a non-rotationally symmetric optical element. This non-rotationally symmetric optical element comprises first and second lens surfaces that are tilted and decentered with respect to each other. One of these first and second lens surfaces may also include diffractive feature to provide a diffractive or holographic optical element for color correction.

The present invention provides a large format fingerprint capture apparatus, system and method that is low power, compact, and lightweight and has a platen area greater than 3.0 square inches. The present system is typically powered, controlled, and exchanges data over a single data / control / power connection to a host PC, e.g., a desk top computer, PDA, or laptop computer although the system can also be used in a wireless fashion with a power subsystem so no physical connections are required. In a preferred embodiment the large format fingerprint device is directly connected to a completely disconnected portable PC, such as a laptop having only a battery power source. The primary system components of the present invention combine to minimize power, size and weight and, thus, enhance portability and battery life. The system typically includes a light source, a prism, a camera (including the lens), and a case. Optional elements comprise holographic elements such as gratings and holographic optical elements (HOEs), a battery subsystem, magnetic stripe reader, barcode reader, platen heater, platen blower, and mirrors to divert the image beam.

Systems, devices, and methods that integrate eye tracking capability into scanning laser projector (“SLP”)-based wearable heads-up displays are described. An infrared laser diode is added to an RGB SLP and an infrared photodetector is aligned to detect reflections of the infrared light from features of the eye. A holographic optical element (“HOE”) may be used to combine visible light, infrared light, and environmental light into the user's “field of view.” The HOE may be heterogeneous and multiplexed to apply positive optical power to the visible light and zero or negative optical power to the infrared light.

Systems, devices, and methods that integrate eye tracking capability into scanning laser projector (“SLP”)-based wearable heads-up displays are described. An infrared laser diode is added to an RGB SLP and an infrared photodetector is aligned to detect reflections of the infrared light from features of the eye. A holographic optical element (“HOE”) may be used to combine visible light, infrared light, and environmental light into the user's “field of view.” The HOE may be heterogeneous and multiplexed to apply positive optical power to the visible light and zero or negative optical power to the infrared light.

Embodiments of illumination-based medical devices capable of projecting a holographic symbol are herein provided. In one embodiment, an illumination-based medical device incorporates at least a laser and a diffractive optical element within a housing. In one embodiment, the diffractive optical element may be a holographic optical element. In a particular embodiment, the holographic optical element may incorporate an interference pattern and / or a sacred symbol or pattern.

An optical switch formed of a holographic optical element (HOE) disposed above a top surface of a substrate and moveable relative thereto is shown. Light is traveling through the substrate under total internal reflection, which creates an evanescent field extending beyond the reflecting surfaces of the substrate. The HOE is characterized, in one embodiment, by being formed from a plurality of strips that are moveable between a first position in which the strips are above the evanescent field and a second position in which the strips are inside the evanescent field. In the first position, the light in the substrate propagates unaffected by the HOE in a primary direction of propagation. In the second position, the light in the substrate is altered by the HOE and made to propagate in a reflected direction oblique to that of the primary direction of propagation.

An optical head-mounted display includes an eyeglass frame, a holographic optical element supported by the eyeglass frame to be confronted by an eye of a wearer, and a projector mounted on the eyeglass frame to project image information on the holographic optical element. The projector includes a LED light source, a beam-splitting polarizer, a spatial light modulator, a lens set and a mechanical one-dimensional scanner. The mechanical one-dimensional scanner reflects the transformed light beam from the lens set onto the holographic optical element in one dimension at a time. When the reflective sheet is rotated at a range of angle in a brief moment of time, the holographic optical element receives from the rotating reflective sheet an array of one-dimensional modulated light beams and reflects the latter to form a two-dimensional image in the eye because of persistence of vision.

An apparatus for image acquisition of topological features of the surface of skin. The apparatus comprises a waveguide, having an entrance edge and top and bottom surfaces; a light source, configured to direct a light beam at the entrance edge of the waveguide; a skin contact layer, disposed at or near the top surface of the waveguides; a holographic optical element (HOE), disposed at the top or at the bottom surfaces of the waveguide, configured to diffract the light beam incident from the light source to the skin contact layer; a sensor array, configured to detect light reflected from the surface of skin in contact with skin contact layer; and means for compensating for changes in the Bragg matching condition of the HOE due to temperature.

Systems, articles, and methods that integrate photopolymer film with eyeglass lenses are described. One or more hologram(s) may be recorded into / onto the photopolymer film to enable the lens to be used as a transparent holographic combiner in a wearable heads-up display employing an image source, such as a microdisplay or a scanning laser projector. The methods of integrating photopolymer film with eyeglass lenses include: positioning photopolymer film in a lens mold and casting the lens around the photopolymer film; sandwiching photopolymer film in between two portions of a lens; applying photopolymer film to a concave surface of a lens; and / or affixing a planar carrier (with photopolymer film thereon) to two points across a length of a concave surface of a lens. Respective lenses manufactured / adapted by each of these processes are also described.

A volume-phase reflection hologram optical element is fabricated by exposing a hologram photosensitive material to two coherent light beams. One exposure light beam has an axis-asymmetric wavefront, and the other exposure light beam has focus points different in the optical axis direction (Z-direction) between on a plane (ZX-plane) including one of two directions (X- and Y-directions) mutually perpendicular on a sectional plane perpendicular to that light beam and on a plane (YZ-plane) including the other of those two directions. Thus, an image display apparatus is realized in which at the time of reproduction, the component of a predetermined wavelength of the image light diffraction-reflected by the hologram optical element is focused at positions different in the optical axis direction between on the ZX-plane and on the YZ-plane, offering different image viewing characteristics between in the X- and Y-directions.

Disclosed is an apparatus and method of illuminating an image display via an electrically switchable holographic optical element. The method includes a first electrically switchable holographic optical element (ESHOE) receiving illumination light. The first ESHOE comprises oppositely facing front and back surfaces. The first ESHOE diffracts a first component (e.g., p-polarized blue light) of the illumination light while transmitting the remaining components of the illumination light without substantial alteration. An image display is provided and receives the diffracted first component. In response to receiving the diffracted first component, the image display emits image light. The first ESHOE receives and transmits this image light without substantial alteration. In one embodiment, the diffracted first component emerges from the first ESHOE at the back surface thereof, and the first ESHOE receives the image light at the back surface thereof so that the image light is received by the first ESHOE in a direction substantially parallel to a direction at which the diffracted first component emerges from the back surface of the first ESHOE.

The present invention is directed to a transmission type laminated hologram optical element constituting an image display apparatus, wherein plural transmission type hologram optical elements (13), (14), (15) where diffraction acceptance incident angles are different from each other are laminated. The respective transmission type hologram optical elements are adapted so that outgoing angles with respect to center incident angles of respective diffraction acceptance incident angles at an arbitrary wavelength of the visible region are different from each other, whereby a diffraction acceptance angle of incident light can be broadened, light utilization efficiency is permitted to be high, and distance with respect to color pixels of the spatial light modulation element can be optimally set from viewpoints of light utilization efficiency.

Switchable holographic optical elements (HOEs) can used in systems and methods for projecting three-dimensional images, or for projecting two-dimensional tiled images with increased size and / or resolution. One of the methods may include sequentially displaying first, second, and third color components of a first two-dimensional image at an object plane. The first two dimensional image represents a first slice of a three-dimensional image. As the first, second, and third color components are displayed, first, second and third HOEs may be activated so that the activated first switchable HOE focuses the first color component of the first two-dimensional image onto a first image plane, the activated second switchable HOE focuses the second color component of the first two-dimensional image onto the first image plane, and the wherein the activated third switchable HOE focuses the third color component of the first two-dimensional image onto the first image plane. It is noted that the first, second, and third HOEs may be activated concurrently or sequentially with the display of the first, second, or third color components of the first two-dimensional image. After the first, second, and third color components are displayed, the first, second and third switchable HOEs are deactivated. Then, first, second, and third color components of a second two-dimensional image are sequentially displayed. The second two-dimensional image represents a second slice of the three-dimensional image. A fourth switchable HOE may be activated to focus the first color component of the second two-dimensional image onto a second image plane. The second image plane is adjacent to the first image plane.

Systems, devices, and methods for combined angle- and wavelength multiplexing in holographic optical elements (“HOE”) are described. An angle- and wavelength-multiplexed HOE includes multiple angle-multiplexed sets of wavelength-multiplexed holograms. Each set of wavelength-multiplexed holograms includes at least two holograms that are each responsive to a different wavelength of light. Each angle-multiplexed set of wavelength-multiplexed holograms includes a respective set of wavelength-multiplexed holograms that are all responsive to light that is incident thereon with and angle of incidence that is within a particular range. An example application is described in which an angle- and wavelength-multiplexed HOE is used as a holographic combiner in a wearable heads-up display, where angle-multiplexing provides multiple spatially-separated exit pupils in the eyebox of the display and wavelength-multiplexing provides multiple colors to each respective exit pupil.

Systems, devices, and methods that integrate eye tracking capability into scanning laser projector (“SLP”)-based wearable heads-up displays are described. At least one narrow waveband laser diode is used in an SLP to define one or more portion(s) of a visible image. At least one corresponding narrow waveband photodetector is aligned to detect reflections of the portion(s) of the image from features of the eye. A holographic optical element (“HOE”) may be used to combine the image and environmental light into the user's “field of view.” Three narrow waveband photodetectors each responsive to a respective one of three narrow wavebands output by the RGB laser diodes of an RGB SLP are aligned to detect reflections of a projected RGB image from features of the eye.

Apparati and methods for generating a three-dimensionally perceived image from a stereo endoscope by at least one viewer include an autostereoscopic display having a left projector and a right projector that project corresponding left and right images received from corresponding left and right cameras of a stereo endoscope through a transmissive holographic optical element functioning as a Bragg diffraction grating to redirect light from the left projector to a left eye-box and to redirect light from the right projector to a right eye-box for viewing by left and right eyes of a viewer to create a three-dimensionally perceived image without glasses or optical headgear.

Systems, devices, and methods for spatial multiplexing in holographic optical elements (“HOEs”) are described. A spatially-multiplexed HOE includes multiple spatially-separated holographic regions and each spatially-separated region applies a respective optical function to light that is incident thereon. An exemplary application as a spatially-multiplexed holographic combiner (“SMHC”) in a scanning laser-based wearable heads-up display (“WHUD”) is described. In this exemplary application, a scanning laser projector directs multiple light signals over the area of the SMHC and the SMHC converges the light signals towards multiple spatially-separated exit pupils at or proximate the eye of the user. The particular exit pupil at the eye of the user towards which any particular light signal is converged by the SMHC depends on the particular region of the SMHC upon which the light signal is incident. Such may be useful in engineering particular eyebox and / or user interface display configurations in the operation of the WHUD.

A microscopy method and apparatus includes placing a specimen to be observed adjacent to a reflective holographic optical element (RDOE). A beam of light that is at least partially coherent is focused on a region of the specimen. The beam forward propagates through the specimen and is at least partially reflected backward through the specimen. The backward reflected light interferes with the forward propagating light to provide a three dimensional interference pattern that is at least partially within the specimen. A specimen region illuminated by the interference pattern is imaged at an image detector. Computational reconstruction is used to generate a microscopic image in all three spatial dimensions (X,Y,Z), simultaneously with resolution greater than conventional microscopy.

A device for combining tomographic images with human vision using a half-silvered mirror to merge the visual outer surface of an object (or a robotic mock effector) with a simultaneous reflection of a tomographic image from the interior of the object. The device maybe used with various types of image modalities including ultrasound, CT, and MRI. The image capture device and the display may or may not be fixed to the semi-transparent mirror. If not fixed, the imaging device may provide a compensation device that adjusts the reflection of the displayed ultrasound on the half-silvered mirror to account for any change in the image capture device orientation or location.

Variation of the wavelength of the light emitted from a light source is reduced by a wavelength variation reduction mechanism. Hence, wavelength deviation of the intensity peak of the light emitted from the light source from the diffraction-efficiency peak of a hologram optical element is reduced. Thus, even when a high-brightness light source is used, the light emitted therefrom can be diffracted with the hologram optical element efficiently. Moreover, the heat generated by the light source is efficiently rejected through the surface of a land portion of a flexible printed circuit, is then, via an insulating layer of the flexible printed circuit, efficiently absorbed through the surface of a heat absorbing member, and is then, via a shield conductor, led out of a casing, so as to be thereby expelled.

A holographic see-through optical device, a stereoscopic imaging system including the same, and a multimedia head mounted system are provided. The holographic see-through optical device includes a micro display; a relay optical system, which relays an image generated by the micro display; at least one waveguide comprising at least two portions having different thicknesses or different refractive indexes; at least one first holographic optical element, which is arranged at one of the two portions; and at least one second holographic optical element, which is arranged at the other one of the two portions.

A solar concentrator receives sunlight for generating solar power with the concentrator including holographic optical element (HOE) separators for separating sunlight into separated bands, including HOE concentrators for concentrating the separated bands into concentrated bands, including HOE reflectors for reflecting the concentrated bands as reflected bands onto a multiple junction photovoltaic solar cell for generating the solar power with reduced aberrations of the bands for improved conversion of the solar light into the generator solar power, all of which can be constructed in an integrated structure using spacers, waveguides, and a substrate, where the HOEs use chirp Bragg gratings for reducing optical aberrations of the separated, concentrated, and reflected optical bands, with the option of multiple HOE separators for receiving sunlight from various angles of incidence.

A projection display system includes (1) a polarizer, (2) a holographic screen with holographic optical elements having the properties of a display portion and a polarizing portion, and (3) a projector for projecting an image through the polarizer and onto the holographic screen. The polarizing portion of the holographic screen has a different polarization direction from the polarizer such that the image is visible from a first side of the holographic screen and invisible from a second side of the holographic screen.

A beam control system and method. The system includes an illuminator for providing a first beam of electromagnetic energy at a first wavelength; a source for providing a second beam of electromagnetic energy at a second wavelength; and an arrangement for compensating wavefront errors in the second beam using a bias representative of a comparison between the first wavelength and the second wavelength. In the illustrative embodiment, the arrangement includes a processor which corrects wavefront errors using a bias representative of a difference between said first wavelength and said second wavelength. In the disclosed application, a target wavefront sensor is included and the laser is a high-energy laser beam. The wavefront errors include a chromatic aberration and the errors are compensated using a deformable mirror and a correction algorithm executed by an adaptive optics processor. In one alternative embodiment, the errors are compensated using an optical aberration corrector. The aberration corrector may be a holographic optical element or other suitable device. In another alternative embodiment, the errors are corrected with the above embodiment in combination with the use of “woofer” and “tweeter” correcting elements with the woofer being a long stroke low frequency element and the tweeter being a short stroke high frequency element.

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. In a second embodiment, the system includes three HOEs that have reconfigurable diffracting properties that are also optimized for red, green and blue lights. In a third embodiment, the system further includes a holographic color filter that is comprised of three reconfigurable HOEs to sequentially illuminate the diffractive display with each of the tristimulus color lights.

Photo-thermo-refractive (PTR) glass is a multi-component silicate glass having photosensitivity in rear UV region. A novel process is disclosed for PTR glass sensitization to visible region by means of two-step illumination followed by thermal development. This disclosed process utilizes a first illumination at approximately 325 nm followed by a second illumination with radiation in the visible spectral region out of the region of original photosensitivity of the PTR glass which enables fabrication of complex holographic optical elements for visible region such as plane elements, lenses, curved mirrors, combinations of complex elements and optical correlators. The same process provides a positive increment of refractive index in the bulk of the PTR glass and, therefore, can be used for refractive optical elements recording, such as lenses and waveguides.