A light emitting device (1) comprising at least one light source (2) adapted for, in operation, emitting first light (13) with a first spectral distribution, a light guide (4) made of a luminescent material and comprising a light input surface (41) and a light exit surface (42) extending in an angle different from zero to one another, the light guide further comprising a first further surface (46) extending parallel to and arranged opposite to the light exit surface, wherein the light guide is adapted for receiving the first light (13) with the first spectral distribution at the light input surface, converting at least a part of the first light with the first spectral distribution to second light (14) with a second spectral distribution, guiding the second light with the second spectral distribution to the light exit surface and coupling the second light with the second spectral distribution out of the light exit surface. The light emitting device further comprises a phosphor element (77) arranged adjacent to the first further surface and a reflective element (76) arranged adjacent the phosphor element opposite to the first further surface (46). The phosphor element is adapted for converting light incident from the light guide to third light (17) with a third spectral distribution and the light guide (40) is furthermore adapted for receiving the third light (17) with the third spectral distribution at the first further surface (46), guiding the third light (46) with the third spectral distribution to the light exit surface (42) and coupling the third light with the third spectral distribution out of the light exit surface.

A first light guide guides first light in a first light guiding path. The first light is of light irradiated from the light source to a sheet. A first detection unit receives reflected light from the sheet and outputs an image signal indicating an image of a surface of the sheet. A second light guide guides second light in a second light guiding path different from the first light guiding path. The second light is of the light irradiated from the light source and is different from the first light. A second detection unit receives the second light and output a detection signal corresponding to a light amount of the second light. A control unit controls a light emission amount of the light source based on the detection signal.

A film mirror having a metal reflective layer formed on a resin substrate may include, closer to a light incident side than the metal reflective layer, an interface reflective layer having at least one set of a high refractive index layer and a low refractive index layer that are adjacent to each other. At least one of the high refractive index layer and the low refractive index layer may include a water soluble polymer and metal oxide particles. A method for manufacturing the film mirror may include forming the interface reflective layer by simultaneous multilayer coating of materials of the high refractive index layer and the low refractive index layer.

A projection screen and a projection system. The projection screen includes a reflection layer and a light absorption layer for absorbing light which are sequentially arranged from an incident side of projection light; the reflection layer comprises multiple microstructure units; each microstructure unit comprises a first plane and a second plane which are opposite to each other at an angle in a first direction as well as a third plane and a fourth plane which are opposite to each other at an angle in a second direction.

An illumination system, including a light source module and a light uniformizing element, is provided. The light source module provides an illumination light beam. The light uniformizing element has a light incident surface and a light exit surface opposite to the light incident surface, and includes at least one light splitting surface. The light splitting surface is located inside the light uniformizing element. A normal vector of the light splitting surface is perpendicular to a central axis of the light uniformizing element. The illumination light beam is incident to the light incident surface of the light uniformizing element at an oblique angle, and the illumination light beam is split multiple times by the light splitting surface, so that the light uniformizing element outputs a uniformized illumination light beam at the light exit surface. A projection device and a light uniformizing element are also provided.

A method for molding a revolution paraboloid condenser, belongs to the field of condenser molding. The problems in the existing revolution paraboloid condensers, of high cost, difficult processing, and difficult assembly and transportation due to a complex overall structure are solved. The method includes determining a revolution paraboloid function of the condenser designed, determining a number of laminated structures that make up the condenser, and determining width functions of the laminated structures; deducing variable-thickness functions of the laminated structures; connecting multiple basic thin plate units in sequence to form each of the laminated structures; the multiple laminated structures are formed into a circle; punching holes in uppermost layers of the laminated structures, passing a rope through the holes and fixing other end of the rope to the vertical rod positioned at the center of the circle.

In some implementations, an optical device may include an aperture, one or more optical elements, an optical filter, and an optical sensor. The aperture may be configured to receive light. The one or more optical elements may be configured to diffuse the light received by the aperture, direct the diffused light to the optical filter via a folded optical path, wherein a length of the folded optical path is greater than a distance between the aperture and an input surface of the optical filter, and cause the diffused light to be distributed across the input surface of the optical filter. The optical filter may be configured to filter the diffused light distributed across the input surface of the optical filter to pass portions of the diffused light associated with one or more wavelengths to the optical sensor.

A curved display includes a display panel having a curved major surface and a light control film disposed proximate the display panel. The curved major surface is curved about a first axis, and a central portion of the curved major surface has a surface normal along a second axis substantially orthogonal to the first axis. The light control film includes a major surface having a substantially same shape as the curved major surface and includes a plurality of alternating optically transmissive and optically absorptive regions. In a cross-section orthogonal to the first axis, a transmissive region and adjacent absorptive regions define a central ray transmission direction through the optically transmissive region such that a light ray emitted by the display panel and transmitted through the optically transmissive region along the transmission direction is refracted upon exiting the curved display into a direction substantially parallel to the second axis.

An optical article for illuminating building interiors including a reflective grid panel, an LED light source positioned above the reflective grid panel and configured to illuminate the reflective grid panel at incidence angles ranging from a minimum angle of 0° to a maximum angle of at least 45°, a light diffusing sheet of an optically transmissive dielectric material approximately coextensive with and oriented generally parallel to the reflective grid panel, and a pair of reflective side walls flanking a space between the reflective grid panel and the light diffusing sheet. The reflective grid panel incorporates a plurality of parallel longitudinal walls and a plurality of parallel transverse walls joining the walls and defining a plurality of rectangular openings configured to transmit light. Each of the parallel transverse walls extends transversely with respect to a plane of the reflective panel and is configured to diffusely reflect a portion of the light being transmitted through the plurality of rectangular openings.

In some implementations, an optical device may include an aperture, one or more optical elements, an optical filter, and an optical sensor. The aperture may be configured to receive light. The one or more optical elements may be configured to diffuse the light received by the aperture, direct the diffused light to the optical filter via a folded optical path, wherein a length of the folded optical path is greater than a distance between the aperture and an input surface of the optical filter, and cause the diffused light to be distributed across the input surface of the optical filter. The optical filter may be configured to filter the diffused light distributed across the input surface of the optical filter to pass portions of the diffused light associated with one or more wavelengths to the optical sensor.