| 摘要 |
The invention relates to a light source (1) comprising at least one LED (2) for emitting primary radiation (4) and at least one luminescent substance (6) for converting the primary radiation into secondary radiation (5). The light source is characterised in that secondary radiation has a decay time, which is greater that one second at room temperature, during which the luminescence intensity of the secondary radiation decreases by 50 %. The luminescent substance displays a phosphorescence effect. The luminescent substance emits secondary radiation over a long period of time after the LED is switched off and after excitation of the luminescent substance has ended. The light source can be seen after the LED has been switched off. Preferably, the decay time lasts from several minutes to several hours. The light source is used, for example, for the illumination of a flight path. |
