An embodiment of the present invention discloses a backlight module and a display device. The backlight module includes a circuit board. A side surface of the circuit board is provided with a plurality of light emitting elements spaced apart from each other. A light output surface of at least one of the light emitting elements is covered with a first encapsulation layer. A side surface of the first encapsulation layer away from the at least one light emitting elements is a curved surface.

The present invention comprises a light emissive display comprising one or more photoluminescent printed waveguides. The waveguides are coated with one or more layers of an overprint varnish. The overprint varnish eliminates surface texture produced by the photoluminescent printing, rendering the waveguides transparent when in the non-energized state.

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

The invention relates to a diffractive exit pupil expander arrangement for display applications. The arrangement comprises a first lightguide element (51) comprising an exit pupil expander (53) and arranged in a first plane and a second lightguide element (41) comprising an in-coupler (42) and arranged in a second plane. The in-coupler is optically coupled with the exit pupil expander (53). Further, the first lightguide element (51) is arranged to confine propagation of light laterally in said first plane by reflections, and the first plane and the second plane are arranged at an angle (a) with respect to each other.

Systems, devices, and methods for eyebox expansion in wearable heads-up displays (“WHUDs”) are described. The WHUDs described herein each include a projector and an optical waveguide positioned in an optical path between the projector and an eye of the user. For any given light signal from the projector, the optical waveguide receives the light signal at an input coupler and outputs multiple instances or copies of the light signal from multiple discrete, spatially-separated output couplers. The multiple instances or copies of the light signal may be converged by the optical waveguide directly to respective exit pupils at the user's eye or may be routed by the optical waveguide to a holographic combiner in the user's field of view from which the light signals may be converged to respective exit pupils at the user's eye. The optical waveguide employs exit pupil replication to expand the eyebox of the WHUD.

Embodiments provide systems and methods for providing a dynamically variable focal plane in a waveguide-based display. Generally speaking, embodiments described herein provide an optical system that allows variable control of the focal length of the image emerging from the display engine into the waveguide. This can be a dynamic system that is controlled based upon the content being projected on the display. For a stereoscopic system, individual control of each eye can be provided. More specifically, embodiments comprise an electrically tunable lens element interposed between the output of the projection engine and the optical waveguide and a control unit to dynamically the tunable lens element to vary the focal length of the images provided to the waveguide display.

Methods and systems for reductions in switching between depth planes of a multi-depth plane display system are disclosed. The display system may be an augmented reality display system configured to provide virtual content on a plurality of depth planes using different wavefront divergence. The system may monitor the fixation points based upon the gaze of each of the user's eyes, with each fixation point being a three-dimensional location in the user's field of view. Location information of virtual objects to be presented to the user are obtained, with each virtual object being associated with a depth plane. In some embodiments, the depth plane on which the virtual object is to be presented is modified based upon the fixation point of the user's eyes. For example, where the user is switching their fixation between virtual objects on two different depth planes, the display system may be configured to modify the presentation of one of the objects such that both objects are placed on the same depth plane.

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

According to one embodiment, a display device includes a display panel, a first light guide, and a second light guide. In the first light guide, a first main surface includes a first plane and first grooves between the first plane and a first side surface, a second main surface includes second grooves orthogonal to the first grooves, and a second plane between the second grooves and the first side surface. In the second light guide, a third main surface includes a third plane and third grooves located between the third plane and a fourth side surface, a fourth main surface includes fourth grooves orthogonal to the third grooves, and a fourth plane located between the fourth grooves and the fourth side surface.

One embodiment provides an apparatus for displaying an image comprising: a first optical substrate comprising at least one waveguide layer configured to propagate light in a first direction, wherein the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction; and a second optical substrate comprising at least one waveguide layer configured to propagate the light in a second direction, wherein the at least one waveguide layer of the second optical substrate comprises at least one grating lumina configured to extract light from the second substrate along the second direction, wherein the at least one grating lamina of at least one of the first and second optical substrates comprises an SBG in a passive mode.