Lumus Ltd.

Based on a rotational axis of symmetry for an output of a lightpipe coinciding with an input axis for projection optics, the lightpipe can be rotated around the rotational axis, in order to align the lightpipe with a frame of associated glasses, or correspondingly the temple of a wearer of the glasses. Thus, an improved or optimal aesthetic look of a display system can be approached. The lightpipe of the display system can be aligned with the frame of the glasses, or even hidden within the frame, depending on implementation details and requirements for image projection components. If a pantoscopic tilt of the lens (waveguide) changes, a rotation of the lightpipe can be applied to the lightpipe to bring the lightpipe in a position aligned with the temple again, thus avoiding the need for a lightpipe redesign.

A light-transmitting substrate has at least two major surfaces and is deployed with a first of the major surfaces in facing relation to an eye of a viewer. A light redirecting arrangement is associated with the light-transmitting substrate and deflects light from the eye toward an optical sensor that senses light, such that the light deflection occurs at the light-transmitting substrate and the deflected light that reaches the optical sensor is unguided by the light-transmitting substrate. A processor derives current gaze direction of the eye by processing signals from the optical sensor.

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.

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.

An image projector includes a spatial light modulator (SLM) with a two dimensional array of pixel elements controllable to modulate a property of light transmitted or reflected by the pixel elements. An illumination arrangement delivers illumination to the SLM. A collimating arrangement collimates illumination from the SLM to generate a collimated image directed to an exit stop. The illumination arrangement is configured to sequentially illuminate regions of the SLM, each corresponding to a multiple pixel elements. A controller synchronously controls the pixel elements and the illumination arrangement so as to project a collimated image with pixel intensities corresponding to a digital image.

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.

An optical system includes a partial-internal-reflection rectangular light guide (PRLG) ( 10 ) having three surfaces supporting internal reflection and a partially-reflecting fourth surface ( 34 ) with which a second light guide portion ( 30 ) is associated. A light beam redirecting arrangement, typically including a set of embedded partially-reflecting surfaces ( 12 ), in light guide portion ( 30 ) redirects light emerging from the PRLG towards a third light guide portion ( 20 ) that includes a coupling-out configuration ( 122 ), such as a further set of partially-reflecting surfaces ( 28 ), coupling-out light beams of an image towards the eye of a user.

A vehicular head-up display (HUD) for displaying an image to a user of a vehicle having a windshield ( 15 ) includes an image projector ( 14 ) outputting a collimated image and an optical aperture expander. The optical aperture expander includes a light-guide optical element (LOE) ( 10 ) having two major external surfaces ( 30 a, 30 b ). The image projector ( 14 ) injects the collimated image so as to propagate within the LOE by internal reflection at the major external surfaces. The LOE also has a set of parallel partially-reflecting internal surfaces ( 12 ) which progressively couple out the image illumination from the LOE. The optical aperture expander is deployed such that the image illumination coupled-out of the LOE ( 12 ) follows a light path including a reflection from a surface associated with the windshield ( 15 ) of the vehicle so as to be visible to the user while the user looks at a scene beyond the windshield.

An optical device includes a lightguide having a first pair of external surfaces parallel to each other, and at least two sets of facets. Each of the sets including a plurality of partially reflecting facets parallel to each other, and between the first pair of external surfaces. In each of the sets of facets, the respective facets are at an oblique angle relative to the first pair of external surfaces, and at a non-parallel angle relative to another of the sets of facets. The optical device is particularly suited for optical aperture expansion.

An image projector includes a spatial light modulator (SLM) with a two dimensional array of pixel elements controllable to modulate a property of light transmitted or reflected by the pixel elements. An illumination arrangement delivers illumination to the SLM. A collimating arrangement collimates illumination from the SLM to generate a collimated image directed to an exit stop. The illumination arrangement is configured to sequentially illuminate regions of the SLM, each corresponding to a multiple pixel elements. A controller synchronously controls the pixel elements and the illumination arrangement so as to project a collimated image with pixel intensities corresponding to a digital image.