| 摘要 |
The invention relates to an apparatus for illumination with blue, green, yellow or red light-emitting diodes (LEDS), comprising one or more coloured LEDs and a light-scattering cover associated with the LED colour and composed of coloured plastic and having a base colour derived from one or more non-fluorescent dyes, characterized in that the light-scattering cover comprises, in addition to the base colour, at least one fluorescent dye associated in terms of colour with the base colour, where the dye mixture has been adjusted in such a way that the reflectance of the light-scattering cover is at least 28% at the wavelength of the energy maximum of the LED(S) used, where, based on the standard chromaticity diagram and on the colour loci of the reflected light from the light-scattering cover and on the colour locus of the LED(s) used, the following alternative relationship applies to the absolute value of the difference between the x value of the light-scattering cover and the x value of the LED and the absolute value of the difference between the y value of the light-scattering cover and the y value of the LED: a) for blue LED illumination: absolute value for x smaller than 0.03/absolute value for y smaller than 0.05 b) for green LED illumination: absolute value for x smaller than 0.05/absolute value for y smaller than 0.08 c) for yellow LED illumination: absolute value for x smaller than 0.0025/absolute value for y smaller than 0.02 d) for red LED illumination: absolute value for x smaller than 0.03/absolute value for y smaller than 0.003. |
