An internal device having a lightguide which cooperates with an internal light source. A first light coupling element couples an external light source to the lightguide and a second light coupling element extracts the total internal reflection (TIR) from the lightguide. Between the first and second lightguides, an angular grating device and phase grating device are imposed. The angular grating device applies angular diversity to the rays of the TIR light, while the phase grating device applies phase diversity to the rays of the TIR light. Each of the grating devices has a plurality of electrically switchable grating pixels having a unique first and second diffracting state which varies based on the applied voltage.