LIGHTING SYSTEM WITH DICHROMATIC SURFACES

• Main Authors: CORNELISSEN, HUGO J, DUINE, PETER A, VAN GORKOM, RAMON P
• Format: Patent
• Language: English; French; German
• Published: 23.09.2009
• Subjects: BASIC ELECTRIC ELEMENTS; BLASTING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FREQUENCY-CHANGING; HEATING; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATINGELEMENTS; LIGHTING; MECHANICAL ENGINEERING; NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SEMICONDUCTOR DEVICES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; WEAPONS

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.