Abstract: A light-transmitting substrate has parallel surfaces deployed with a first of the parallel surfaces in facing relation to an eye. An optical element is associated with the first surface and applies optical power to incident light of a first type so as to collimate the incident light, and applies substantially no optical power to incident light of a second type. An optical coupling configuration is associated with the substrate and is configured for coupling-in a proportion of collimated light of the first type incident on the first surface so as to propagate within the substrate, and for coupling-out a proportion of light of the second type propagating within the substrate. Optics associated with the substrate convert collimated light of the first type into converging beams of light, which are sensed by an optical sensor. A processor derives current gaze direction of the eye by processing signals from the optical sensor.

Abstract: A light-guide optical element (LOE) and methods of manufacture are disclosed. The LOE includes a transparent substrate having a first refractive index, the substrate having a pair of parallel external surfaces along a length thereof, and a plurality of mutually parallel at least partially reflective internal surfaces, the mutually parallel internal surfaces being angled obliquely relative to the pair of external surfaces; and a transparent polymer resin encapsulating at least a part of the substrate to form an encapsulated structure, the polymer resin having a second refractive index that is matched to the first refractive index; wherein the encapsulated structure comprises a pair of parallel external surfaces of optical quality formed from the resin.

Abstract: In an embodiment, an apparatus is disclosed that includes at least one processor configured to determine a target coupling-out facet, identify an optical path to the target coupling-out facet, identify an active wave plate corresponding to the optical path, determine a target state of the active wave plate that corresponds to the optical path, set the active wave plate to the identified target state and cause a projection device to project a light beam comprising an image field of view component along the identified optical path.

Abstract: In an embodiment, an apparatus is disclosed that includes at least one processor. The at least one processor is configured to select a light source from a plurality of lights sources based at least in part on a location of a pupil of an eye relative to an eye motion box. The selected light source is configured to illuminate a portion of the eye motion box that corresponds to the location of the pupil with a light beam. The at least one processor is further configured to activate the selected light source to illuminate the portion of the eye motion box.

Abstract: A method of fabricating a light-guide optical element having a plurality of partially reflecting surfaces is disclosed. The method includes providing a plurality of transparent plates, each plate polished on two opposite surfaces such that the surfaces are parallel to each other, coating a first of the surfaces of a subset of plates with a first coating, coating a second of the surfaces of the subset of plates with a second coating; bonding together the plurality of transparent plates to form a stack, and cutting the stack along parallel planes obliquely angled to the faces of the transparent plates so as to form the optical element, wherein the first coating is a partially reflective coating have a first set of mechanical properties, and the second coating is selected from the group consisting of: a coating similar to the first coating and a non-reflective coating having a second set of mechanical properties substantially similar to the first set of mechanical properties.

Abstract: In an embodiment, an apparatus is disclosed that includes at least one processor configured to determine a target portion of an eye motion box and to identify a facet of a light-guide optical element that is configured to direct a light beam comprising at least a portion of an image field of view toward the target portion of the eye motion box. The at least one processor is configured to identify a display region of an image generator that is configured to inject the light beam into the light-guide optical element at an angle that, in conjunction with the identified facet, is configured to direct the light beam toward the target portion of the eye motion box. The at least one processor is configured to selectively activate the identified facet and the identified display region to direct the light beam toward the target portion of the eye motion box.

Abstract: A collimated image projector that receives light from an illuminating source and propagates the light along a light path towards an exit pupil, the projector comprising: a first homogeneous dielectric polarizing beam splitter (PBS) deployed along the light path and defining a first transition from a first light path segment to a second light path segment; a second homogeneous dielectric PBS deployed parallel to the first PBS along the second light path segment and defining a second transition from the second light path segment to a third light path segment; and collimating optics deployed along the light path after the second PBS so as to direct a collimated image towards the exit pupil; wherein the first and second PBSs are deployed such that either the first and second transitions are both performed via transmission, or the first and second transitions are both performed via reflection.

Abstract: An optical system for directing image illumination injected at a coupling-in region towards a user for viewing includes a light-guide optical element (LOE) (12) with a pair of parallel major external surfaces (24). A first region (16) of the LOE contains a first set of partially-reflecting surfaces (17) oriented to redirect image illumination propagating within the LOE towards a second region of the LOE (18), which contains a second set of partially-reflecting surfaces (19) oriented to couple out the image illumination towards the user. The first set of partially-reflecting surfaces (17) extend across at least 95 percent of a thickness of the LOE, while the second set of partially-reflecting surfaces (19) are contained within a subsection of the thickness spanning less than 95 percent of the thickness, so that the second set of partially-reflecting surfaces (19) are excluded from one or both surface layers of the second region (18).

Abstract: A light-guide optical element (LOE) for simultaneous viewing, of a real scene and of a projected image introduced into the LOE, having a transparent block along which light conveying a projected image propagates by internal reflection, and a plurality of internal partially reflecting surfaces obliquely oriented and configured so as to couple-out a part of said light, wherein the reflectance of each of the partially reflecting surfaces is such that the total power of the light that is coupled out is less than one third of the total power of the light that is introduced into the LOE. In some embodiments, the light of the projected image is polarized and the reflectance of the partially reflecting surfaces for light polarized in an orthogonal orientation is substantially reduced. In some embodiments, the reflectance of the partially reflecting surfaces for light not reaching the viewer is substantially reduced.

Abstract: An optical system may include (a) a light-guide optical element (LOE) formed from transparent material and having at least first and second mutually-parallel major external surfaces for supporting propagation of an image by internal reflection at the first and second major external surfaces, the LOE having a coupling-out arrangement for coupling out the image towards an eye of the user, the LOE having a coupling-in arrangement; and (b) an image projector comprising an image generator for generating an image and an image conjugate generator for generating a conjugate image, the image generator and the image conjugate generator disposed such as to project the image and the conjugate image, respectively, from directions not directly in front of the LOE.

Abstract: An optical system for displaying an image includes a light-guide optical element (LOE) having a coupling-in region and a propagation region, a coupling-out configuration associated with the propagation region of the LOE, an image projector for generating image illumination corresponding to a collimated image, and a beam-multiplication configuration external to the LOE. The beam-multiplier is a transparent plate bonded to the LOE adjacent to the coupling-in region. The transparent plate has a partially-reflective surface between the LOE and the plate, and a reflector at the opposite surface. The partially-reflective surface and the reflector multiply the beam from the projector so as to fully illuminate the propagation region of the LOE with both the collimated image and a conjugate of the collimated image.

Abstract: A display for providing an image to an eye of an observer is disclosed. An image generator provides image illumination corresponding to the image to a substrate having mutually-parallel major external surfaces for propagation within the substrate. An intermediate optical arrangement including at least one astigmatic optical element directs the image illumination from the image generator so as to propagate within the substrate in a first in-plane direction by internal reflection. A reflective optical arrangement having cylindrical optical power reflects the image illumination so as to propagate in a second in-plane direction by internal reflection. A coupling-out arrangement couples out the collimated image illumination towards an eye of an observer. The intermediate optical arrangement includes an element deployed to generate a corrective optical aberration that at least partially cancels out with a characteristic aberration introduced by the reflective optical arrangement.

Abstract: Head-mounted display with an eye-tracking system and including a light-transmitting substrate (20) having two major surfaces and edges, optical means for coupling light into said substrate (20) by total internal reflection, partially-reflecting surfaces (22a-22c) carried by the substrate (20) that are not parallel with the major surfaces of the substrate (20), a near-infrared light source (78) and a display source (92) projecting within the photopic spectrum, wherein light from the light source (78) and light from the display source (92) are coupled into the substrate (20) by total internal reflection.

Abstract: A near-eye display includes a light-guide optical element (LOE) (10) having first and second major external surfaces (11A, 11B) that are planar and mutually parallel. An image projector (2) introduces into the LOE illumination corresponding to an image so that the illumination propagates within said LOE by internal reflection at the major external surfaces. A coupling-out arrangement couples the illumination out of the LOE towards the eye of the observer. The coupling-out arrangement may be a set of mutually-parallel, partially-reflective surfaces (12A) deployed at an oblique angle within the LOE. Various arrangements for suppressing reflections of ambient light sources include obstructing baffles oriented so as to avoid reduction of peripheral field of view, various non-reflective coatings and various deployments of polarization filters.

Abstract: A display and method for providing an image to an eye of a viewer is provided. The display comprises at least two projector assemblies. Each projector assembly comprises a light-guide optical element (LOE), and an image projector arrangement for generating a partial image and being deployed to introduce the partial image into the LOE for coupling out towards the eye of the viewer. The at least two projector assemblies cooperate to display the image to the eye of the viewer with partial overlap. The display further comprises a controller associated with the image projector arrangements and configured to reduce a pixel intensity of selected pixels in a region of partial overlap between the first and second part of the image so as to enhance a perceived uniformity of the image.

Abstract: An optical system may include (1) a light-guide optical element formed from transparent material and having at least first and second mutually-parallel major external surfaces for supporting propagation of an image by internal reflection, and (2) a mediating layer adjacent at least one of the at least first and second mutually-parallel major external surfaces, the mediating layer configured such that (1) reflectivity, averaged over the visible spectrum, of light coupled into the LOE and transmitted between the at least first and second mutually-parallel major external surfaces at angles below the critical angle is higher than the reflectivity that would have been expected absent the mediating layer and (2) reflectivity of purely white light lies closer to a purely white color point for an angular range from angles below the critical angle to the critical angle than the reflectivity that would have been expected absent the mediating layer.

Abstract: There is disclosed an optical device, including a light-transmitting substrate having an input aperture, an output aperture, at least two major surfaces and edges, an optical element for coupling light waves into the substrate by total internal reflection, at least one partially reflecting surface located between the two major surfaces of the light-transmitting substrate for partially reflecting light waves out of the substrate, a first transparent plate, having at least two major surfaces, one of the major surfaces of the transparent plate being optically attached to a major surface of the light-transmitting substrate defining an interface plane, and a beam-splitting coating applied at the interface plane between the substrate and the transparent plate, wherein light waves coupled inside the light-transmitting substrate are partially reflected from the interface plane and partially pass the through.

Abstract: Disclosed herein is a method including: providing a light guiding arrangement (LGA) configured to redirect light, incident thereon in a direction perpendicular to an external surface of the sample, into or onto the sample, such that light impinges on an internal facet of the sample nominally normally thereto; generating a first incident light beam (LB), directed at the external surface normally thereto, and a second incident LB, parallel to the first incident LB and directed at the LGA; obtaining a first returned LB by reflection of the first incident LB off the external surface, and a second returned LB by redirection by the LGA of the second incident LB into or onto the sample, reflection thereof off the internal facet, and inverse redirection by the LGA; measuring an angular deviation between the returned LBs and deducing therefrom an actual inclination angle of the internal facet relative to the external surface.

Abstract: An optical system may include (1) a light-guide optical element formed from transparent material and having at least first and second mutually-parallel major external surfaces for supporting propagation of an image by internal reflection, and (2) a mediating layer adjacent at least one of the at least first and second mutually-parallel major external surfaces, the mediating layer configured such that (1) reflectivity, averaged over the visible spectrum, of light coupled into the LOE and transmitted between the at least first and second mutually-parallel major external surfaces at angles below the critical angle is higher than the reflectivity that would have been expected absent the mediating layer and (2) reflectivity of purely white light lies closer to a purely white color point for an angular range from angles below the critical angle to the critical angle than the reflectivity that would have been expected absent the mediating layer.

Abstract: Disclosed herein is a method for validating parallelism of internal facets of a sample. The method includes: (i) providing a sample including a light transmissive substrate and internal facets, nominally parallel and nominally inclined at an angle ?nom relative to a flat surface of the sample; (ii) providing a prism having a substantially same refractive index as the substrate and including a flat, first surface and a flat, second surface, opposite to the first surface and inclined relative thereto at substantially the angle ?nom; (iii) positioning the sample and the prism, such that the surface of the sample is parallel and adjacent to the second surface of the prism; (iv) projecting on the first surface of the prism, substantially normally thereto an incident light beam; (v) sensing light returned from the prism following reflection off the internal facets; and (vi) computing deviation from parallelism between the internal facets.