摘要 |
A lighting system, typically a vehicle signaling light has a light source (S) and lens (18). The lens has an internal radial rib with optical fibre (20) which acts as a light guide and channels light from the lens center through a further optical fibre to a photosensitive sensor (30) located at the periphery. If the luminous flux received by the sensor falls below a threshold a lighting failure signal is emitted. |