| 摘要 |
An illumination panel is provided, for example for use as a backlight for illuminating an at least partially transmissive display (1). The panel comprises a light source (18), for example in the form of a light emitting diode which emits light in a relatively narrow waveband. A light guide (3) receives the light from an edge surface and guides light by total internal reflection. Combined light extraction and phosphor elements (19) on at least one of the major surfaces of the light guide (3) permit extraction of the light but also convert at least some of the light from the light source (18) to a different visible waveband. By locating the combined phosphor and extraction features at least partially inside the lightguide (3) it is possible to control the angular distribution of the extracted light and, in particular, to arrange for the variation of intensity with angle of light extracted without wavelength conversion to be substantially the same as the variation of intensity with angle of light emitted with wavelength conversion.
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