Street lighting device
In various embodiments, a street lighting device with a first light source for illuminating the street plane from above is provided. The device may include a second light source located at a closer position to the street plane than said first light source; a sensor sensitive to the occurrence of conditions of reduced ambient visibility; and a controller connected to said sensor and capable of activating said second light source in the presence of said conditions of reduced ambient visibility.
1. A street lighting device with a first light source for illuminating the street plane from above, the device comprising:
a second light source located at a closer position to the street plane than said first light source;
a sensor sensitive to the occurrence of conditions of reduced ambient visibility; and
a controller connected to said sensor and capable of activating said second light source in the presence of said conditions of reduced ambient visibility,
wherein said sensor is impinged upon by the light radiation emitted by said first light source and is capable of identifying the presence of said conditions of reduced ambient visibility when the intensity of the radiation emitted by said first light source and impinging upon said sensor falls below a given threshold level.
2. The device as claimed in claim 1 ,
wherein said second light source is located at a height in the range from 15 cm to 60 cm above the street plane.
3. The device as claimed in claim 1 ,
wherein said second light source is configured to project a lighting beam in a quasi-horizontal direction of propagation.
4. The device as claimed in claim 1 ,
wherein said second light source is configured to emit a warm white light radiation or a colored light radiation.
5. The device as claimed in claim 1 ,
wherein said first light source and said second light source are separate light generators.
6. The device as claimed in claim 5 ,
wherein said light generators are of the light emitting diode type.
7. The device as claimed in claim 1 , further comprising:
a single light generator, whose light radiation is distributed selectively toward said first light source and toward said second light source.
8. The device as claimed in claim 7 ,
wherein said single light generator is one of said first light source and said second light source.
9. The device as claimed in claim 7 ,
wherein said single light generator is of the LED type.
10. The device as claimed in claim 1 , further comprising:
a support structure of an illuminable material which can be activated by said controller in said conditions of reduced visibility.
11. A street lighting device with a first light source for illuminating the street plane from above, the device comprising:
a second light source located at a closer position to the street plane than said first light source;
a sensor sensitive to the occurrence of conditions of reduced ambient visibility; and
a controller connected to said sensor and capable of activating said second light source in the presence of said conditions of reduced ambient visibility, wherein said controller is configured for activating said second light source and reducing the intensity of the light radiation emitted by said first light source when said conditions of reduced ambient visibility are present.
12. The device as claimed in claim 11 ,
wherein said second light source is located at a height in the range from 15 cm to 60 cm above the street plane.
13. The device as claimed in claim 11 ,
wherein said second light source is configured to project a lighting beam in a quasi-horizontal direction of propagation.
14. The device as claimed in claim 11 ,
wherein said second light source is configured to emit a warm white light radiation or a colored light radiation.
15. The device as claimed in claim 11 ,
wherein said first light source and said second light source are separate light generators.
16. The device as claimed in claim 15 ,
wherein said light generators are of the light emitting diode type.
17. The device as claimed in claim 11 , further comprising:
a single light generator, whose light radiation is distributed selectively toward said first light source and toward said second light source.
18. The device as claimed in claim 17 ,
wherein said single light generator is one of said first light source and said second light source.
19. The device as claimed in claim 17 ,
wherein said single light generator is of the LED type.
20. The device as claimed in claim 11 , further comprising:
a support structure of an illuminable material which can be activated by said controller in said conditions of reduced visibility.