Abstract: The present invention relates to a luminescent solar concentrator for a solar cell, comprising a collector with a luminescent substrate, and a wavelength selective filter, wherein the wavelength selective filter is arranged above the surface of the collector, wherein the luminescent substrate has an absorption edge which corresponds to a wavelength ?ex and emits radiation around a wavelength ?em, wherein the selective filter h a refractive-index contrast ?n with a negative or zero dispersion, and wherein the wavelength selective filter is designed to keep the emitted radiation inside the collector while shifting the reflection band of the incident radiation to angles ?25° and/or to narrow the reflection band to a range of ?10°.

Abstract: Display devices are used in portable computer systems, imaging systems, and other electronic devices. Many of these display devices require a source of light to illuminate a display screen. The invention relates to an illumination system for illuminating said display devices. The invention also relates to a display device provided with such an illumination system.

Abstract: A high efficiency lighting system (100) is described that has a small etendue. This can be used, for example, for backlighting a display device such as a liquid crystal display (LCD), projection displays, as well as for general lighting purposes. A portion of the light from a light emitting device die (101) falls onto a fluorescent material (105,106), such as phosphor. Dichroic mirrors (107,109) prevent the light generated by the fluorescent material to return to the light-emitting device. The mirrors may also provide collimation of the generated light and the remainder of the light from the light-emitting device. In this way a high efficiency system is realized because little or no generated light is absorbed and the generated light does not have to travel through a fluorescent material layer and thus has a high chance to go in the desired direction.

Abstract: The invention relates to a light emitting device comprising a light emitting element (100) and a light guide (101) arranged on a textile substrate (102). The light guide has a back surface (103) facing the textile substrate, a front surface (104) facing away from the substrate, and a light receiving surface (105). The light emitting element (100) is arranged such that at least part of the light emitted by the light emitting element (100) is coupled into the light guide (101) through the light receiving surface (105), and is subject to total internal reflection in the light guide (101). Furthermore, the light guide (101) is arranged such that at least part of the light coupled into the light guide (101) exits the light guide (101) through the front surface (104) and/or the back surface (103).

Abstract: To improve the illumination efficiency of hand-held illumination devices, this invention proposes a new illumination device having the “rolling” function, which is capable of illuminating the target area on which a user is currently focusing and rolling the illuminated area as the user is reading forward or backward. The illumination device comprises two pluralities of lighting elements, an illuminating body and a controller. The controller can control one plurality of lighting elements to emit light to illuminate a part of the illuminating body, which can further deflect the light to a part of the surface of the target.

Abstract: This invention relates to an illumination apparatus. The illumination apparatus comprises a light guide plate and a light source configured to emit light into the light guide plate through a first surface, and the light guide plate comprises a concentrator configured to direct incident light in the light guide plate so as to radiate in a direction substantially parallel to a preset plane. The preset plane is perpendicular to any one of the top surface and bottom surface of the light guide plate, and intersects the first surface and a second surface of the light guide plate or intersects the first surface and one of the side surfaces at an angle that is substantially larger than the critical angle of a total reflection. In this way, unwanted light loss in the light guide plate is reduced, and the distribution of the light intensity or luminance along the light guide plate is improved, i.e., a substantially uniform distribution of the light intensity can be achieved.

Abstract: It is disclosed an optical element (200) wherein one or more light-emitting diodes, LEDs, and additional optics may be provided in an integrated solution that may relatively easily be assembled and maintained in a desired position relatively each other. The optical element (200) may enable one or more LEDs and additional optics to be provided in an integrated solution that is relatively thin and compact in comparison with known devices, such that light from one or more LEDs may be injected into a thin light guide (205, 206) such as an optical fiber, an optical fiber array, a ribbon-shaped light-guiding structure, etc.

Abstract: The invention describes a light sensor (1) comprising a filter arrangement (11), which filter arrangement (11) comprises a number of spectral filters (F1, F2, . . . , Fn) for filtering incident light (L), wherein a spectral filter (F1, F2, . . . , Fn) is realized to pass a distinct component of the incident light (L), an aperture arrangement (12) for admitting a fraction of the incident light (L), and a sensor arrangement (13) realized to collect the admitted filtered light (L?), which sensor arrangement (13) comprises an array of sensor elements (130) for generating image-related signals (S, S1, S2, . . . , Sn) and which sensor array is sub-divided into a number of regions (R1, R2, . . . , Rn), wherein a region (R1, R2, . . . , Rn) of the sensor array is allocated to a corresponding spectral filter (Fi, F2, . . . , Fn) such that an image-related signal (S) generated by a sensor element (130) of a particular region (R1, R2, . . .

Abstract: A lighting system comprising a plurality of controllable light emitting elements 3 is disclosed. The lighting system further comprising a spreading optical element 5 arranged in front of the plurality of light emitting elements to shape the light emitted from the lighting elements, and a controller 7 for varying a light emission angle range of light emitted from the spreading optical element 5 by controlling each of the plurality of controllable light emitting elements. This allows the light emitted from the spreading optical element to be varied without varying any physical parts of the lighting system, because the controller now controls each of the light emitting elements, by e.g. dimming one or more of the light emitting elements or by switching one or more of the light emitting elements off.

Abstract: The present invention aims to provide a light guide apparatus based on diffraction gratings. The apparatus comprises a light guide plate (11) comprising a first diffraction grating (13) located on a first surface of or inside the light guide plate (11); a first light source (12), coupled to a first side of the light guide plate (11); wherein the first diffraction grating (11) is configured to extract the light generated by the first light source (12) from the first surface of the light guide plate (11). Since the first diffraction grating (13) is invisibly small, users hardly notice any change of the light guide (11). When the light guide apparatus of the present invention is used as a book reader, the dark area produced when lifting the book reader in a direction away from the objects to be read is smaller than that of existing light guide apparatus based on microstructures, since the light exit angle is relatively small when using a diffraction grating.

Abstract: The invention relates to a luminous window which can function both as a broad area light source and as a transparent window. The broad area light source is achieved by coupling light into a plate-shaped light guide, e.g. via the edges of the light guide, and extracting light from the light guide using geometric protrusions or diffraction gratings into a scattering layer which outputs the broad area light. The transparent window is achieved by switching the scattering layer into a non-scattering state, and possibly switching off the light source, so that light can propagate freely through the light guide and the scattering layer.

Abstract: The invention discloses a light guide apparatus which comprises a light guide (1). The light guide (1) comprises a plurality of diffraction gratings (2) on a first surface of the light guide (1), wherein each diffraction grating (2) has a pre-set pitch and is configured to diffract a portion of light emitted from a corresponding light source to one side of the light guide (1). As the plurality of diffraction gratings (2) is placed on the first surface of the light guide (1) facing the light sources, the light guide apparatus is more robust to damage and fingerprints.

Abstract: A lamp for emitting light, comprising a transparent sheet-like lightguide, with at least one light receiving side, a light emission front surface and a back surface opposite the front surface. The lamp further comprises a plurality of light sources, positioned in an array and optically coupled to at least one light receiving side. The back surface of said lamp comprises a plurality of optical extraction structures, for example provided in parallel curved lines. Furthermore, the lamp is substantially free from light scattering structures in a light path of the light to be emitted.

Abstract: The invention provides a method and system of controlling illumination characteristics of a plurality of lighting segments. According to the invention, there is provided an illumination system, comprising: a plurality of lighting segments; a detecting subsystem configured to detect an illumination intensity and/or color of lights emitted from each lighting segment; a controller configured to receive the detecting subsystem's output signals representing illumination intensity and/or color of lights emitted from each lighting segment and to generate sets of driving signals to respectively adjust the driving currents of each lighting segment in response to the output signals, so as to adjust the illumination intensity and/or color of the lights emitted from each lighting segment in accordance with a predetermined illumination setting, wherein each set of driving signals has a unique period feature which is distinguished from that of other sets of driving signals corresponding to other lighting segments.

Abstract: The invention relates to an illumination system (4) comprising at least one light source (10) for emitting light of a predominant wavelength (W), and a light-transmitting panel (14) which comprises a light-emitting window (16), a rear wall (18) situated opposite said light-emitting window, and edge walls (20) extending between the light-emitting window and the rear wall. Light from the LED is coupled into the light-transmitting panel and is transported substantially via total internal reflection. The rear wall is provided with a two-dimensional array of recesses (22, 24). A sub-set of recesses (22) is distributed substantially regularly on the rear wall. Each recess (22A, 22B, 22C) from the sub-set (22) comprises scattering material (26). When light from the light-transmitting panel reaches the scattering material of the recess, part of the light (W?) is coupled out of the light-transmitting panel via scattering.

Abstract: Display devices are used in portable computer systems, imaging systems, and other electronic devices. Many of these display devices require a source of light to illuminate a display screen. The invention relates to an illumination system for illuminating said display devices. The invention also relates to a display device provided with such an illumination system.

Abstract: A light output device comprises at least one discrete light source device (4) integrated into the structure of a substrate arrangement (1,2,5) and an electrophoretic switchable light control device (40,42; 50; 60,62; 80,82), comprising a controllable region or regions associated with the at least one light source device (4), the electrophoretic switchable light control device (40,42; 50; 60,62; 80,82) being stacked with the substrate arrangement. The electrophoretic device can be used to alter the light output of the light source array, for example providing focusing and/or redirection. This enables the structure of the light source array to be kept simple. The light source array can essentially function as the backlight for the electrophoretic control device.

Abstract: A lighting assembly has a light source emitting light, an angular filter having a main surface, and a light guide having a main surface. The main surface of the filter is parallel to the main surface of the light guide. The filter may be configured to reflect light rays originating from the light source that are incident at small angles with respect to a direction normal to the main surface of the filter, and to transmit light rays originating from the light source that are incident at larger angles with respect to the direction normal to the main surface of the filter.

Abstract: A lamp for emitting light, comprising a transparent sheet-like lightguide, with at least one light receiving side, a light emission front surface and a back surface opposite the front surface. The lamp further comprises a plurality of light sources, positioned in an array and optically coupled to at least one light receiving side. The back surface of said lamp comprises a plurality of optical extraction structures, for example provided in parallel curved lines. Furthermore, the lamp is substantially free from light scattering structures in a light path of the light to be emitted.

Abstract: This invention relates to thermal management for removing heat generated by a heat source (110). This is done by a combination of a heat conducting member (120), which is thermally connected to the heat source in one end and to a remotely arranged heat sink (130) in the opposite end, and a synthetic jet actuator (140). The synthetic jet actuator is arranged to provide active cooling directly onto the heat source by generating and directing an air flow towards the heat source. The synthetic jet actuator comprises a resonator cavity housing (150) and an oscillating member (160). The oscillator member is arranged at least partly inside said resonator cavity. The combination of the heat conducting member and the synthetic jet actuator provides a highly efficient cooling.