Abstract: A head mounted display system includes focusing optics to focus light from an image source, retro-reflector and beamsplitter, the image source and beamsplitter directing light toward the retro-reflector being directed via the beamsplitter for viewing, thereby to use conjugate optics effectively to place the viewing eye or detector in relation to the image source the same as the relation of the focusing optics or it may be remotely located. A method for forming an image using conjugate optics which light from a source is focused to form a real image at a retro-reflector and is reflected for viewing.

Abstract: The present invention eliminates the relay lens systems found in conventional helmet mounted displays (HMDs) by removing field distortions and aberrations with a contoured fiber optic faceplate placed in close proximity to a liquid crystal display (LCD) or cathode ray tube. The optical system typically consists of a spherical dielectric or holographically made collimator-combiner, a dielectric or holographically made fold mirror, and a contoured fiber optic faceplate. The fold mirror is flat, and the collimator-combiner is made by coating a spherical eye glass blank. The system is configured as a folded and tilted catadioptric projector with the novel feature being the contoured faceplate. There are no dispersive elements in the imaging assembly which means it can be completely polychromatic (full color) without the need for additional color correction optics as found in all refractive color systems.

Abstract: A compact image display system in which the optical pathway is folded and thereby extended between the image source and the imaging optics of the system. The image display system may be used in place of computer or television screens, and may further be affixed to a frame so that it is wearable by a human user as either a monocular or binocular device.

Abstract: A device to improve the field of vision in aircraft that lack sufficient transparent surface area. The device includes at least one collimator connected to an imaging sensor of the space outside the aircraft. The collimator projects an image in the pilot's field of vision. The image covers both the transparent window surface and the instrument panel of the cockpit. The image coincides with the real image in the field of direct vision produced by the transparent surface. A further image may also be viewed by the pilot through a periscope arrangement.

Abstract: A head mounted display system includes focusing optics to focus light from an image source, retro-reflector and beamsplitter, the image source and beamsplitter directing light toward the retro-reflector to focus a real image, and the light reflected from the retro-reflector being directed via the beamsplitter for viewing, thereby to use conjugate optics effectively to place the viewing eye or detector in relation to the image source the same as the relation of the focusing optics to the image source. The retro-reflector may be mounted on a common housing or support with the beamsplitter and focusing optics or it may be remotely located. A method for forming an image using conjugate optics in which light from a source is focused to form a real image at a retro-reflector and is reflected for viewing.

Abstract: An assembly for producing a visual display includes a light-reflecting type spatial light modulator and an illumination arrangement for providing a particular source of light. The spatial light modulator has a light reflecting surface cooperating with a light modulating medium switchable between different states so as to act on light in ways which form an overall pattern of reflected, modulated light. The spatial light modulator also has an arrangement for switching the modulating medium between the different states in a controlled way so as to form the overall pattern. The overall assembly further includes an optics arrangement having a first member defining a light reflecting surface.

Abstract: A method and apparatus for display of a three dimensional virtual image is provided. The present invention allows one or more objects, real images and virtual images to be displayed at one or more of an arbitrary number of depth levels along a viewer's line of sight. The present invention uses a plurality of beam splitters organized as an optical labyrinth to combine a images with the proper perspective and parallax to result in a three dimensional image.

Abstract: An apparatus for displaying an image of an object comprises a beam splitter and retroreflectors between the object and the beam splitter on opposite sides of the object. Louvre films adjacent the beam splitter having oppositely directed slats allow observers on opposite sides of the apparatus to view the image but not the object.

Abstract: An image display apparatus, e.g., a head-mounted display apparatus, which uses a half-mirror or a beam splitter prism and yet has an even more compact structure and provides a favorably flat image surface. A half-mirror (S) is obliquely disposed in front of an observer's eyeball (1), and an image display device (3), e.g., a liquid crystal display device, and a magnifying reflecting mirror (4) are disposed to face each other across the half-mirror (S) and to extend parallel to the observer's line of sight. To widen the field angle without increasing the size and weight of the optical system considerably, at least one surface (L) having positive refractive power is interposed between the eyeball (1) and the half-mirror (S). An even more compact arrangement is obtained by using a beam splitter prism in place of the half-mirror (S).

Abstract: A combiner eyepiece with an enhancement imagery source and a collimating mirror is equipped with two oblique partially reflective mirrors. Both mirrors reflect some of the light impinging on their partially reflective sides and transmit substantially all of the rest of such light. The result is a collimated beam of light travelling toward the viewer along the viewing axis and expanded in vertical extent. This expanded vertical extent eases the requirement for the viewer to place his eyes in a precise location at the near end of the eyepiece. It also allows a smaller and lighter construction for an eyepiece where the vertical extent of the viewing area has been specified.

Abstract: Optical magnifying apparatus comprises an objective lens (11) from which light is directed to a beam splitting mirror (12). A portion of the light passes through the beam splitting mirror to a first concave mirror (13) and is reflected back via the beam splitting mirror through a viewing lens (5) to a first eye (16) of an observer. The remainder of the light is reflected by the beam splitting mirror to a second concave mirror (17) from which it is reflected back via the beam splitting mirror through the viewing lens to a second eye (19) of the observer. Focussed first and second images (14, 18) of an object (10) are produced respectively on the surfaces of the first and second concave mirrors. The optical axes of the concave mirrors are relatively offset such that the relayed pupils of the mirrors are separated horizontally by a distance approximately equal to the average interpupillary spacing of an observer.

Abstract: A vehicle structural accessory includes one or more electronic accessories. One electrical accessory which may be provided is an electronically trainable transmitter which is trainable to generate a control signal which will actuate a garage door opening mechanism. Another electronic accessory which may be included is an electronic compass. Yet another device is an electronically adjustable mirror having parameters set for each driver of a vehicle. The electronically adjustable rearview mirror and the electronically trainable garage door opener may be advantageously provided with a keyless entry system.

Abstract: An image display system wearable on the user's head is disclosed for displaying a magnified projected image. The image display system includes an image display element for displaying an image thereon, a right eye ocular optical system for forming a light path leading an image formed on the image display element onto the right eye of the viewer, a left eye ocular optical system for forming a light path leading an image formed on the image display element onto the left eye of the viewer, thereby viewing a spatially enlarged projection of the image by both the right and left eye ocular optical systems. The right eye ocular optical system for leading the image from the LCD 1 to the right eye 5R includes a half-mirror 3R and a convex lens 4R. The left eye ocular optical system for leading the image to the left eye 5L includes a half-mirror 3L and a convex lens. The LCD 1 is placed at a position at substantially equal distance from the right and left eyes.

Abstract: A helmet mounted display system comprising an eyepiece (3) through which a wearer of the helmet directly views a forward scene (13). The eyepiece also serves to combine an intensified image of the forward scene with the wearer's direct view of the scene. The intensified image is produced by an optical arrangement including an image intensifier (6) from which light is passed to the eyepiece via a prism (2). The prism serves to compensate for orientation of the intensified image in other parts of the optical arrangement so that the intensified image is in the same orientation as the wearer's direct view of the forward scene. In addition the prism allows the various components in the system light path to conform to the profile of the helmet thereby making the helmet more comfortable for a wearer.

Abstract: A combiner is pivotally mounted for movement between an operating position in the line of sight of an operator and a storage position. A sector gear fixed to the combiner engages a slidable rack so that sliding the rack causes pivotal movement of the combiner. A control knob and stem are mounted for rotary movement and translation. A cam rotated by the knob engages followers on the rack to slide the rack upon knob translation or rotation. Knob translation effects movement of the combiner between operating and storage position, and when in operating position, knob rotation effects fine adjustment of the combiner to adjust image position.

Abstract: The system is designed to be mounted in a air pilot's helmet. It uses a confocal assembly with a first parabolic mirror and a second parabolic mirror, placed downline of a collimation objective which gives a collimated radiation. The first mirror is totally reflective and the second mirror is semi-transparent to simultaneously transmit, by reflection, the collimated radiation and, by transparency, for example the view of the external landscape. These two mirrors are integrated into the ends of a plate with two parallel faces. The collimated radiation penetrates the plate by one of the parallel faces, gets reflected on the first mirror, undergoes a succession of total reflections on the parallel faces and then gets reflected on the second mirror before leaving the plate, still doing so through one of the two faces.

Abstract: Automotive display apparatus in which a display image of the displayer is recognized from an eye range as a virtual image within a displaying range of a first reflector plate through a face plate which is disposed between the first reflector plate and the eye range.

Abstract: A compact, inexpensive and mass-producible optical display system for an automobile creates a dramatic and highly stylistic, sharp, high contrast and pleasing, multi-color or monochromatic 3-D magnified image of an instrument cluster, at least a portion of the 3-D image being located at a viewing distance greater than the actual optical distance between the dashboard and the driver's eyes. A non-pupil forming display system uses an off-axis aspherical narrow-band reflecting mirror with power to create a magnified virtual image of a miniaturized passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. A single mirror produces a single monochromatic virtual image, whereas a plurality of stacked and differently curved mirrors, each tuned to different wavelength bandwidth, produces a plurality of spatially separated virtual images of differing colors. The mirrors are holographic optical elements or graded index optical elements.

Abstract: An adjustable beam splitter includes a pentaprism type reflector unit including a housing, a splitter mirror positioned in the housing for transmitting a portion of an input energy beam and for reflecting a portion of the input energy beam, and a reflective mirror mounted within the housing for directing the reflected portion of the input energy beam at a fixed angle to the input energy beam regardless of the angle of incidence of the input energy beam to the splitter mirror and regardless of manufacturing tolerances of the splitter mirror. Translation of the reflected portion of the input energy beam is reduced and the split ratio adjusted by rotating the pentaprism type unit about a line corresponding to the intersection of a plane containing the splitter mirror and a plane containing the reflective mirror.

Abstract: An imaging system (10) for a Head-Mounted Display (HMD) comprises a projection screen (22) integrally formed with a headgear structure of the HMD. An image source is projected onto the projection screen (22) as an intermediate image. An optical sub-system (24), such as a lens, re-images the intermediate image to form a virtual image as viewed by a user's eye (26). The present invention provides improved imaging while reducing the weight and manufacturing cost of the HMD. In accordance with another aspect of the present invention, an optical spatial filter (28) is utilized in an HMD imaging system to remove unwanted image artifacts, and increase the depth of focus of an intermediate projected image.

Abstract: A compound prism including a plurality of unit prisms which have reflective interfaces defined by outer and/or inner surfaces thereof and which are arranged so that light is reflected by an inner surface of the interface of one of the unit prisms and by an outer surface of the interface of another unit prism.

Abstract: A head-mounted image display comprising a housing for covering both the eyes of the user, a support for mounting the housing on the head of the user, an image light emitting unit provided at a predetermined position in the housing for emitting image light, a pair of right and left convex lenses provided at both the eyes in the housing for enlarging the image produced by the image light emitting unit, and an optical system provided within the housing for guiding the image appearing on the image light emitting unit to the pair of right and left convex lenses.

Abstract: A display apparatus includes an image source displaying information and a magnifying mirror element reflecting the displayed information and projecting one or more images thereof viewable by the operator in one or more focal planes, the mirror element being partially light transmissive. A display data source is also provided so that, in a first mode, the display data is not visible and in a second mode the display data is visible to the operator through the mirror. A motor mechanism is operable to pivot the display between a stowed position and an unstowed operational position.

Abstract: A display, for example, for a visor attached to a helmet, the visor having a partially reflecting semi-transparent portion in the view of the wearer and an optical projector for projecting an image onto the semi-transparent portion for reflection therefrom. The semi-transparent portion has a relatively higher reflectivity in a central area thereof and a relatively lower reflectivity in an annular area outside the central area. In one aspect of the invention, the head mounted display includes a projector having a display source whereon an image is formed and an optical system for focusing the image at separate sagittal and tangential foci between the image-forming surface and the semi-transparent portion.

Abstract: A projection unit for a car head-up display comprises a display source, a curved mirror which provides the optical power of the projection unit and, in use, receives light from the display source, and a Fresnel mirror extending generally between the display source and the curved mirror and disposed to receive reflected light from the curved mirror and to reflect that light in a desired direction. The curved mirror and the Fresnel mirror may be disposed on a solid block of transparent material having one curved end coated to provide the curved mirror, the display source being located at an opposite end of the block, and the Fresnel mirror being formed in a block face extending from the opposite end of the block to the curved end of the block.

Abstract: A virtual image display system for displaying a relatively large virtual image to a user derived from a relatively small image source. A lens group is provided for amplifying an image provided by the image source. A plurality of reflecting elements are provided for magnifying the image provided by the lens group and for displaying the relatively large virtual image. Several embodiments are provided that include on-axis and off-axis reflecting versions, and a holographic virtual image version. Conventional lenses and reflecting optics are used to provide the on- and off-axis versions of the system, while a holographic reflecting element is used to provide a holographic virtual image. A window element may also be employed to minimize ambient reflection viewed by the user and eliminates ambient reflection to reduce the user's eye fatigue. The display system improves a user's viewing comfort by positioning the image at a distance matching the visual requirements of the user's eye.

Abstract: An optical system for use in helmet mounted displays that consists of an image source, electronics that predistort the image emanating from the projector, a means for correcting for optical aberration that may be a lens or a fiber optic taper, and a reflective surface composed of a plurality of reflective surface elements with conic geometries. Light from the projector, corrected for optical aberrations, is directed into the first reflective surface element. Light from the first reflective surface element is reflected into a second reflective surface element and thereafter into the eye.

Abstract: A car head-up display projection unit has a substantially spherical concave mirror providing the optical power and which receives light at near axial incidence from a display source and reflects that light to an adjustable substantially plane mirror. Light from the projection unit is reflected from the car windshield to the driver's eyes.

Abstract: This invention is concerned with display apparatus of the Head-Up-Display (H.U.D.) type which finds utility in e.g. fighter aircraft. The invention is concerned with providing an H.U.D. which has a profile depth which is substantially and preferably much less than the diameter of the exit lens. The arrangements of the H.U.D. include a cathode ray tube (C.R.T.) display source, a collimating optical means having a plurality of lenses with at least an entrance lens and an exit lens together with a prism and combining means for combining displayed visual information with the view of the scene or object. The prism is so arranged in relationship to the display source that internal reflection of light from the display source within the prism and transmission of light towards the combining means is such as to enable the modular unit profile depth to be between 40% and 60% less than the exit lens diameter.

Abstract: Apparatus for producing a continuous line of light for a document scanner. An incoherent light beam is directed into one surface of an optical wedge device. The light beam is repeatedly reflected, back and forth, between input and output reflective surfaces on the wedge. The output surface is only partially reflective, thereby allowing a portion of the light to escape the wedge and provide the line of light which illuminates the document. Non-parallel sides extending between the reflective surfaces are used to provide total internal reflection and concentrate all of the incoherent light beams into a smaller area, Alignment of the incoherent light beam according to a predetermined angle causes the escaping light beams to be adjacent to each other and produce a uniform and continuous line of light free from destructive interference areas.

Abstract: A helmet sight comprises a collimator for projection of the image of a sighting graticule into the ocular field of the wearer of the helmet and sensors for measurement of the angular position of the helmet with respect to a structure, such as the cockpit of an aircraft. The collimator for projection gives the graticule a position whose angular deviation .DELTA.a, .DELTA.b with respect to a reference orientation linked to the helmet has remained an increasing function of the angular displacements of the helmet with respect to the reference structure.

Abstract: A display apparatus includes an image source displaying information and a magnifying mirror element reflecting the displayed information and projecting one or more images thereof viewable by the operator in one or more focal planes, the mirror element being partially light transmissive. A display data source is also provided so that, in a first mode, the display data is not visible and in a second mode the display data is visible to the operator through the mirror.

Abstract: The disclosed display device for simulators has an off-axis collimated display system: a spherical screen and a spherical mirror that are fixed to a helmet worn by the user. This device gives a wide horizontal field and a relatively low attenuation of the external view.

Abstract: The automotive headup display apparatus contains an indicator and a reflection member and has an opening directed toward a reflection surface as on a windshield. A Fresnel lens is installed in the opening for enlarging a display image of the indicator. The reflection member is disposed facing and between the indicator and the reflection surface. The reflection member is coated with a hologram emulsion layer to have a wavelength selection capability such that only the rays of light with almost the same wavelength as display light of the indicator are reflected by the reflection membeer. With this arrangement, when external light should enter the indicator unit from the reflection surface on the windshield, those rays of light different in wavelength from the display light are not reflected toward the indicator, preventing the display of the indicator from being obscured as in the conventional apparatus.

Abstract: A multi-element, air-spaced prism system for use in a reflective-type optical media device having a light source to provide an incident light beam provides an achromatic, anamorphic prism which corrects for astigmatism and ellipticity in the light beam from the light source. One embodiment of the prism system provides at least two reflections of a return beam from the reflective-type optical media. The return prism provides these reflections from various optical surfaces in the multi-element prism system. In one embodiment, the prism system also provides a reflection of a portion of the incident beam. This reflection is directed to a detector which can, for instance, monitor the intensity of the light beam.

Abstract: Disclosed is an optic device designed to enable an observer to look simultaneously at what is normally in his visual field and at a collimated image that is introduced so as to be superimposed on his visual field. The optic device has a plate with parallel faces in which the light rays coming from an image generator, through an access point, get propagated by total reflection on the parallel faces. A slab, formed by a stacking of plane mirrors, reconcentrates the light rays and directs them towards two successive, semi-reflecting mirrors which reflect them partially towards the observation pupil. The semi-reflecting mirrors are in the visual field of an observer's eye placed at the observation pupil.

Abstract: A portable, battery powered, self-levelling alignment tool for simultaneously indicating level, plumb and square. A projection unit including a laser diode, a collimator, and an optical system is located in a projection unit which is pendulously suspended inside a housing. The optical system divides a collimated beam from the laser diode and the collimator into output beams having a generally perpendicular relationship with each other. The projection unit may be balanced such that at least one of the output beams is substantially level and other beams thus indicate plumb or square.

Abstract: In one embodiment of the present invention, the automotive display apparatus has two concave mirrors arranged below the windshield in such a way that light from the display of an indicator which shows driving condition information such as car speed is reflected by one of the concave mirrors toward the other concave mirror, which then reflects the light toward the windshield that further directs it toward the driver's seat. A drive can thus see a remotely formed virtual display image within a viewing field of the windshield. The first concave mirror, which directly receives light from the indicator and reflects it toward the second concave mirror, is mounted on a plane mirror in such a manner that it can be moved into or out of a light path that extends from the indicator to the second concave mirror. When the first concave mirror is in the light path, the display image is magnified and hence the virtual display image is formed at a remote position from the driver.

Abstract: Optical multiplexer configurations are designed to minimize the volume of the multiplexer or minimize back focal distance of the lens of a multi-color projection system. The multiplexer employs three liquid crystal modulators under computer control to respectively and selectively transmit beams of three different colors for combination within the multiplexer which projects the combined modulated beams to a projection lens for focusing an image on a display screen. Optical light paths are chosen within the multiplexer by arrangement and configuation of mirrors and dichroic filters to direct the beams along folded paths within the multiplexer for combination and projection through a multiplexer exit window. For minimized volume of the multiplexer all beams are folded within the multiplexer, but two of the color beams are each folded twice in a single common plane which is perpendicular to a plane of folding of the third beam.

Abstract: The disclosed display device for simulators has, for the display of a zone of interest, a visual unit fixed to a helmet, essentially constituted by mirrors and spherical screens and, for the peripheral vision, a system of wide-angle projection on a sphere.

Abstract: A split mirror vision augmentation system for high performance aircraft is disclosed comprising a transparency, an adjustable external mirror, a first internal mirror, and at least a second internal mirror. The external mirror is positionable at a stowed position adjacent to the transparency and substantially flush with the outer skin and is also positionable at at least one deployed position for reflecting light received from a field-of-view exterior to the aircraft. The first internal mirror is located within the aircraft, at an orientation substantially parallel to the external mirror. It receives a first portion of the light reflected from the external mirror and through the transparency. When the external mirror is deployed, the first internal mirror is constructed and arranged to redirect the reflected first portion of light toward a crew member of the aircraft. Thus, a first view is provided from the vantage of a first "apparent eye" position located aft of the external mirror.