Transparent display device, manufacturing method and controlling method thereof are provided. The transparent display device includes a light guide plate with a rectangular light exit, and a liquid crystal unit including multiple strip electrodes arranged in parallel and a black matrix; the black matrix includes a first and second strip-shaped light-shielding layers; an arrangement direction of the multiple strip electrodes is not parallel to any edge of the light exit; an orthographic projection of the first strip-shaped light-shielding layer on the light guide plate covers at least a center of the light exit and an extension direction of which is parallel to a first edge of the light exit, and an orthographic projection of the second strip-shaped light-shielding layer on the light guide plate covers at least the center of the light exit and an extension direction of which is parallel to another edge perpendicular to the first edge.

Techniques for eye-tracking in a near-eye display system are disclosed. One example of a near-eye display system includes a substrate transparent to visible light and configured to be placed in front of a user's eye, one or more light sources configured to emit illumination light invisible to the user's eye, one or more input couplers configured to couple the illumination light into the substrate, and one or more grating couplers each configured to couple a portion of the illumination light out of the substrate and towards the user's eye at a different direction. The illumination light coupled into the substrate propagates within the substrate through total internal reflection. The one or more grating couplers include at least one of a chirped surface-relief grating coupler or a volume Bragg grating coupler.

A light guide assembly, comprising: a substrate and a light guide disposed on the substrate, wherein the top surface of the body comprises a first protrusion having a first slanting surface and a second slanting surface opposite to the first slanting surface for reflecting lights entering into the body, wherein a first outer surface of the body extends from a first lateral surface to the first slanting surface, wherein a highest point of the first slanting surface is located between the first lateral surface and a second lateral surface opposite to the first lateral surface, and a highest point of the second slanting surface is located between the first lateral surface and a lowest point of the second slanting surface.

An optical grating component may include a substrate, and an optical grating, the optical grating being disposed on the substrate. The optical grating may include a plurality of angled structures, disposed at a non-zero angle of inclination with respect to a perpendicular to a plane of the substrate, wherein the plurality of angled structures are arranged to define a variable depth along a first direction, the first direction being parallel to the plane of the substrate.

A light guide plate, a backlight module and a display device are provided. The light guide plate includes a main body and plural prism portions. The main body has a first extending direction and a second extending direction. The main body includes a light-incident surface extending along the first extending direction and an optical surface connected to the light-incident surface. The optical surface has a first region, a second region and a third region which are arranged along the second extending direction. The prism portions are disposed on the optical surface and extend along the second extending direction. An occupied area ratio of the prism portions located in the first region is greater than an occupied area ratio of the prism portions located in the second region and is smaller than an occupied area ratio of the prism portions located in the third region.

An optical system includes a light-transmitting substrate having at least two external major surfaces and edges and an optical element for coupling light waves into the substrate, by total internal reflection. At least one partially reflecting surface is located in the substrate for coupling light waves out of the substrate, and at least one transparent layer, having a refractive index substantially lower than the refractive index of the light transmitting substrate is optically attached to at least one of the major surfaces of the substrate, defining an interface plane. The light waves coupled inside the substrate are substantially totally reflected from the interface plane between the major surface of the substrate and the transparent layer.

A backlight module, a manufacturing method thereof, a display device and a light guide device are provided. The backlight module includes: a light guide structure, including a volume grating layer, the volume grating layer including a plurality of volume grating portions and a light guide portion between adjacent volume grating portions, the plurality of volume grating portions being configured to introduce a beam of a specific wavelength into the light guide portion; and a light extraction structure, located on a light exit side of the light guide structure, wherein a refractive index of the light guide structure is greater than a refractive index of the light extraction structure, and an incident angle of the beam introduced into the light guide portion on a plane where the light guide portion is located is not less than a total reflection critical angle of the light guide structure.

Embodiments of the present disclosure provide backlight module, display device and driving method. The backlight module comprises: light guide plate for emitting light from light-exiting surface of the light guide plate along light-exiting direction; monochromatic light sources of different colors located on a side of the light guide plate on which incident surface is located; optical path adjusting portion located on the incident surface of the light guide plate, for making light emitted by the monochromatic light sources be incident to the light guide plate from the incident surface of the light guide plate at different incident angles, wherein the light incident to the light guide plate is propagated with a total reflection; and light extracting gratings arranged in an array, located on the light-exiting surface of the light guide plate, for extracting the light with same preset angle.

An optical system including a light-guide optical element (LOE) with a first set of mutually-parallel, partially-reflecting surfaces and a second set of mutually-parallel, partially-reflecting surfaces at a different orientation from the first set. Both sets of partially-reflecting surfaces are located between a set of mutually-parallel major external surfaces. Image illumination introduced at a coupling-in location propagates along the LOE, is redirected by the first set of partially-reflecting surfaces towards the second set of partially-reflecting surfaces, where it is coupled out towards the eye of the user. The first set of partially-reflecting surfaces are implemented as partial surfaces located where needed for filling an eye-motion box with the required image. Additionally, or alternatively, spacing of the first set of partially-reflecting surfaces is varied across a first region of the LOE. Additional features relate to relative orientations of the projector and partially reflecting surfaces to improve compactness and achieve various adjustments.

A face-lit waveguide illumination system employing a planar sheet of an optically transmissive material. A strip of side-emitting LEDs is positioned adjacent to a major surface of the planar sheet and optically coupled to the planar sheet. The planar sheet is configured to guide light using optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the planar sheet and emit the light towards a surface normal direction.