Abstract: A pupil-replicating lightguide includes a slab of transparent material, a switchable out-coupling grating for out-coupling portions of image light to propagate towards an eyebox, and a switchable tracking grating for redirecting tracking light carrying an eye image towards an eye tracking camera. One of the two gratings may be turned ON while the other is turned OFF, in a time-sequential manner, allowing the combined use of the pupil-replicating lightguide for carrying image light and eye tracking light.

Abstract: A device includes a polymer stabilized blue phase liquid crystal (“PS-BPLC”) layer. The device also includes an alignment structure coupled with the PS-BPLC layer. LC molecules disposed in contact with the alignment structure are configured to have a spatially varying in-plane orientation pattern that is at least partially defined by the alignment structure. The PS-BPLC layer is configured to forwardly deflect a polarized light having a predetermined handedness, and transmit a polarized light having a handedness that is orthogonal to the predetermined handedness.

Abstract: A device includes a polymer stabilized blue phase liquid crystal (“PS-BPLC”) layer. The device also includes an alignment structure coupled with the PS-BPLC layer. LC molecules disposed in contact with the alignment structure are configured to have a spatially varying in-plane orientation pattern that is at least partially defined by the alignment structure. The PS-BPLC layer is configured to forwardly deflect a polarized light having a predetermined handedness, and transmit a polarized light having a handedness that is orthogonal to the predetermined handedness.

Abstract: A field of view of an imaging or ranging device may be increased multiple times by providing a switchable diffraction grating structure upstream of an imaging camera or ranging light source. The switchable diffraction grating changes the angle of propagating of incoming light by a fixed step, enabling the device to switch between several portions of a compound field of view. The switchable diffraction grating structure may be supported by a lightguide that guides the image light or ranging light by a series of reflections from opposed surfaces of the lightguide.

Abstract: An illuminator for a display panel includes a slab of transparent material for propagating illuminating light between outer surfaces of the slab, an out-coupler supported by the slab for out-coupling portions of the illuminating light along one of the outer surfaces of the slab, and a tunable microlens array for forming an array of light spots from the out-coupled illuminating light portions downstream of the focusing element for illuminating pixels of the display panel. The array of light spots may be repeated at a distance from the tunable microlens array due to Talbot effect. The display panel may be illuminated in a color-sequential manner, and the tunable microlens array may be used to adjust the focal plane position for each color channel individually.

Abstract: A switchable grating may be used to redirect illuminating light for illuminating a user’s eye in an eye tracking system, to facilitate the determination of eye position and/or orientation. The eye tracking system may be used in a near-eye display. An eye tracking camera obtains an eye image, and a controller performs an initial determination of the eye position. The controller may switch the switchable grating to direct the illuminating light beam onto the eye, for a better position and/or eye orientation determination.

Abstract: A pupil-replicating lightguide includes a slab of transparent material for guiding image light in the slab, and an out-coupling structure supported by the slab for out-coupling portions of the image light from the slab. The portions are laterally offset from one another along a path of the image light in the slab. The out-coupling grating structure has a switchable distribution of out-coupling efficiency for redirecting the portions of out-coupled light to a desired location such as a current location of an eye of the viewer determined by an eye tracking system. The out-coupling grating structure may include a plurality of diffraction gratings having different local slant angles of grating fringes.

Abstract: A pupil-replicating lightguide includes a slab of transparent material, a switchable out-coupling grating for out-coupling portions of image light to propagate towards an eyebox, and a switchable tracking grating for redirecting tracking light carrying an eye image towards an eye tracking camera. One of the two gratings may be turned ON while the other is turned OFF, in a time-sequential manner, allowing the combined use of the pupil-replicating lightguide for carrying image light and eye tracking light.

Abstract: A directional illuminator for a display apparatus includes a switchable diffuser for tuning a divergence of a light beam illuminating a display panel of the display apparatus. The tunable divergence of the illuminating light beam translates into a tunable exit pupil size at the eyebox of the display apparatus, which may be matched to a pupil size of a user’s eye, thus providing a configurable illumination of the eye pupil. A tiltable reflector in an optical path of the illuminating light beam may be used to shift the location of the exit pupil at the eyebox of the display apparatus.

Abstract: A device includes a first substrate and a second substrate. The device also includes a birefringent medium layer disposed between the first substrate and the second substrate. Orientations of directors of optically anisotropic molecules included in the birefringent medium layer varying periodically with an in-plane pitch tunable by an external field to adjust a diffraction angle of a light beam diffracted by the birefringent medium layer.