In order to generate mixed-colored, in particular white, light with light-emitting diode chips, it is possible to use conversion elements in the beam path of the primary radiation emitted by the light-emitting diode chip, in order to convert part of the short-wave primary radiation into longer-wave secondary radiation.
The intensity ratio of primary radiation to secondary radiation determines the emission color of the emitted light. In practice, firstly the wavelengths of the primary radiation from different light-emitting diode chips differ, even if the latter are produced jointly and originate from a single wafer, for example, and secondly the optical thicknesses of the conversion elements differ, such that an undesired distribution of the resulting emission color appears.
This problem could be solved by sorting light-emitting diode chips from a sufficiently large production volume by measuring light-emitting diode chips having emission colors within specific desired limits (so-called binning). The resultant rejects that cannot be utilized have the effect that this method can be implemented economically only in a restricted fashion.