An edge-lit back light unit for a backlit display includes a reflector, an edge-lit light guide film, a diffuser film, and a pair of crossed brightness enhancement films with increased efficiency. The diffuser film has an angular light distribution output that is matched to light acceptance angles of the pair of crossed brightness enhancement films to provide increased on-axis brightness without having to increase power to the edge-lit back light unit.

A device comprises a film with an adhesive layer on a first side of a core layer, a major sheet area of the film bounded by edges of the film with a light extracting region positioned to receive and extract light propagating by total internal reflection within the core layer out of the major sheet area, and a minor sheet between the major sheet area and an array of strips. The strips extend from the minor sheet area of the film, and each strip of the array of strips is folded within a fold region and stacked. The device further comprises a component extending a width of the array of strips where they extend from the minor sheet area, wherein the adhesive layer adheres the component to the film between fold region and the light extracting region. In some embodiments, the adhesive layer is a cladding layer.

There is provided a light source arranged to output light at a first wavelength. The light source comprises a luminescent concentrator having a slab-shaped geometry. The luminescent concentrator comprises: an input port arranged to receive light and define a first area; an output port arranged to transmit light and define a second area which is smaller than the first area; and surfaces arranged to direct light inside the luminescent concentrator to the output port. The luminescent concentrator further comprises lumophores arranged to receive light at a second wavelength and emit light at the first wavelength; and a pump light supply coupled to the input port and arranged to illuminate the input port with light at the second wavelength.

A vehicle interior lighting apparatus for illuminating the interior of a vehicle, being equipped with a first lighting section having a light source emitting light and a light guide plate emitting light by virtue of the light from the light source, wherein the first lighting section has a planar light emitting section emitting light emitted from the light source in a planar manner and a linear light emitting section integrated with the planar light emitting section and emitting light emitted from the light source linearly.

A backlight unit includes a light guide plate; a light source provided on a side surface of the light guide plate, and configured to inject light into the light guide plate; a circular polarizing reflective layer provided on a front surface of the light guide plate, and configured to reflect a first polarizing component and transmit a second polarizing component among components of light emitted from the light guide plate; and a cholesteric liquid crystal layer provided on the front surface of the circular polarizing reflective layer and including a plurality of regions, and configured to reflect or transmit the second polarizing component that has passed through the circular polarizing reflective layer according to a voltage applied to each of the plurality of regions.

A method of producing a partial luminaire includes arranging at least one semiconductor chip that emits electromagnetic radiation on a substrate, and applying an elastic waveguide, disposed downstream of the at least one semiconductor chip in an emission direction, such that the elastic waveguide projects at at least one of its side surfaces beyond the substrate.

A method for adjusting brightness includes detecting whether damage occurs on a light guide plate of the display device, determining a damage position and a damage extent of the light guide plate when the damage occurs on the light guide plate, and compensating for a change value of brightness generated due to the damage by adjusting the brightness of the display device corresponding to the damage position, according to a predetermined correspondence between damage extents and change values of brightness. The method for testing a display device includes applying a destructive operation to the display device to be tested, detecting a damage extent generated by the destructive operation and a change value of brightness correspondingly generated in a damage region, and creating and storing a correspondence between the damage extent and the change value of brightness.

A head mounted device includes a transparent display, an infrared light source, and an infrared light receiver. The transparent display has a transparent waveguide and a first and second optical component connected to the transparent waveguide. The infrared light source generates an infrared light directed at the second optical component. The transparent waveguide receives the infrared light from the second optical component and transmits the infrared light to the first optical component. The first optical component directs the infrared light to an eye of a user of the head mounted device and receives a reflection of the infrared light off the eye of the user. The infrared light receiver receives the reflection of the infrared light via the second optical component and generates reflection data based on the received reflection of the infrared light. A position of the eye of the user is identified based on the reflection data.

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

An instrument cluster, in particular for a vehicle, has a dial with a plurality of graphic areas, which are backlit by a device provided with at least one light source, with a front light-guiding element having a front face at least partially covered by a back surface of the dial, and with a rear light-guiding element; the latter has a receiving portion facing said light source and a transmitting portion, which transmits and guides the light received by the receiving portion and is spaced apart from and faces a rear face of the front light-guiding element; the rear face of the front light-guiding element has an optical compensation system, having curved convex or curved concave lens surfaces, for varying the intensity of the light transmitted from said transmission portion to the different graphic areas.