A lighting device includes a light source and a photoconversion layer including a perovskite compound represented by Formula 1. The perovskite compound absorbs at least part of light emitted from the light source and emits light having a different wavelength range from the absorbed light:

[A][B][X].sub.3  <Formula 1>

In Formula 1, A is at least one monovalent organic cation, at least one a monovalent inorganic cation, or any combination thereof, B is at least one divalent inorganic cation, and X is at least one monovalent anion.

A light source apparatus according to the present disclosure includes: a plurality of light sources; a plurality of collimator lenses that outputs, as parallel light, divergent light from each of the plurality of light sources; a diffuser plate that diffuses output light from each of the plurality of collimator lenses; a fly-eye lens having a plurality of lens cells, and in which the output light from each of the plurality of collimator lenses enters each of the plurality of lens cells through the diffuser plate; a fluorescence emission section having a phosphor face; and a condenser optical system that condenses output light from each of the plurality of lens cells of the fly-eye lens toward the phosphor face.

A tileable display panel includes a screen layer, an illumination layer and a display layer. The screen layer is for displaying a unified image to a viewer. The illumination layer includes at least one light source emitting lamp light into a diffusing region of the illumination layer. The illumination layer also includes a plurality of emission apertures that are each configured to emit the lamp light from the diffusing region in a divergent projection beam. The display layer is disposed between the screen layer and the illumination layer. The display layer includes a plurality of pixelets corresponding to the plurality of emission apertures. The pixelets in the plurality of pixelets are positioned to be illuminated by the divergent projection beams from the corresponding emission apertures.

A light engine for a lighting fixture includes a bracket, with multiple mounting surfaces configured at different angles to form a substantially concave region, and a plurality of light emitting diode (LED) modules mounted to the multiple mounting surfaces to project an axis of a light beam from each of the plurality of LED modules along substantially a same illuminating plane. The light engine includes a first set of lenses with a first type of optical surface for focusing a first portion of the plurality of LED modules and a second set of lenses with a second type of optical surface, different than the first type, for focusing a second portion of the plurality of LED modules.

An LED device includes a plurality of LED dies, a plurality of lens, a diffuser plate and a collimator lens. The collimator lens is positioned between the diffuser plate and the lens. The collimator lens includes a plurality of fresnel lenses. A focus of each fresnel lens is equal to a distance between a plane where the fresnel lens places and a light outputting surface of the LED die. Light emitted from the LED dies is adjusted to collimator light and striking perpendicularly into the diffuser plate.

A double-sided LED light structure includes a casing that includes a base and a front chip arranged in the casing and electrically connected to the base and comprising an LED illuminant, wherein the casing has a rear end on which a rear chip that is electrically connected to the base and comprises an LED illuminant is mounted and a light-transmittable rear cover is set on and houses the rear chip. The front end of the light achieves concentrated illumination and the rear end achieves projection of supplemental light so that the LED light has a function of emitting light from two sides thereof to achieve a bettered three-dimensional illumination effect and also reduce the number of lights used.

A light source device and a projection display system are provided. The light source device includes a first light source configured to emit first light, a wavelength conversion unit having at least one region, a second light source configured to emit second light, and a light combining element. The at least one region is configured to receive the first light and be excited to generate excited light. The light combining element is configured to converge excited light emitted from the wavelength conversion device and the second light.

A light source device includes a light source unit with at least one set of light sources, wherein each of the at least one set of light sources emits a light of a predetermined wavelength band; an optical waveguide unit that multiplexes light from the at least one set of light sources; and an incident unit, wherein on an incident surface of the incident unit, with an optical axis on the incident unit as a reference position, an installation state of each light source is adjusted such that the maximum separation distances are set equal to each other from the reference position to a maximum incident angle of an incident position of the respective light from the at least one set of light sources incident on the incident unit.

A light source device includes a light source unit with at least one set of light sources, wherein each of the at least one set of light sources emits a light of a predetermined wavelength band; an optical waveguide unit that multiplexes light from the at least one set of light sources; and an incident unit, wherein on an incident surface of the incident unit, with an optical axis on the incident unit as a reference position, an installation state of each light source is adjusted such that the maximum separation distances are set equal to each other from the reference position to a maximum incident angle of an incident position of the respective light from the at least one set of light sources incident on the incident unit.

A low beam optical module includes a lens, a light-shielding sheet and at least one light concentrating portion. The light-shielding sheet includes a light-shielding sheet body. An upper edge of a front end of the light-shielding sheet body comprises a low beam cutoff line structure. A front end surface and the rear end surface of the light-shielding sheet body are transparent. The light concentrating portion is connected to a rear end of the light-shielding sheet. The lens is arranged in front of the light-shielding sheet, and an outer contour surface of the at least one light concentrating portion is engaged with a lower surface of the light-shielding sheet body—the light-shielding sheet body can receive emitted light of the light concentrating portion and refract the light from the front end surface to the lens. The projected light forms a low beam region III beam shape. A low beam illumination module, a vehicle lamp and a vehicle includes the low beam optical module.