Lighting device
View Patent ↗A lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface of the luminescent element being at least twice as large as the illumination surface of the light emitter. Also, a lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface of the luminescent element surface being at least twice as large as and substantially parallel to the illumination surface of the light emitter. Also, a lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface area of a projection of the luminescent element being at least twice as large as a surface area of a projection of the light emitter.
1. A lighting device comprising:
at least one solid state light emitter; and
at least one luminescent element,
the luminescent element comprising particles of at least a first luminescent material,
the luminescent element spaced from the solid state light emitter,
a content of luminescent material in the luminescent element not greater than about 15% by volume,
the particles of the first luminescent material having an average particle size of not greater than 50 microns, and
a thickness of the luminescent element not greater than 1 cm.
2. A lighting device as recited in claim 1 , wherein:
the solid state light emitter has an illumination surface,
the luminescent element has a luminescent element surface,
the luminescent element surface is at least twice as large as the illumination surface.
3. A lighting device as recited in claim 1 , wherein:
the solid state light emitter has an illumination surface,
the luminescent element is spaced from the solid state light emitter by a distance which is at least equal to a largest dimension of the illumination surface.
4. A lighting device as recited in claim 1 , wherein the solid state light emitter is a light emitting diode chip.
5. A lighting device as recited in claim 1 , wherein:
the solid state light emitter has an illumination surface,
the luminescent element has a luminescent element surface,
the luminescent element surface is at least five times as large as the illumination surface.
6. A lighting device as recited in claim 1 , wherein:
the solid state light emitter has an illumination surface,
the luminescent element has a luminescent element surface,
the luminescent element surface is at least ten times as large as the illumination surface.
7. A lighting device as recited in claim 1 , wherein:
the solid state light emitter has an illumination surface,
the luminescent element has a luminescent element surface,
the illumination surface is substantially planar, and
the luminescent element surface is substantially planar.
8. A lighting device as recited in claim 1 , further comprising at least one scattering layer.
9. A lighting device as recited in claim 1 , further comprising at least one brightness enhancing film.
10. A lighting device as recited in claim 1 , wherein the luminescent element is also a scattering layer.
11. A lighting device as recited in claim 1 , wherein the luminescent element is spaced from the solid state light emitter by a distance in the range of from about 100 micrometers to about 750 micrometers.
12. A lighting device as recited in claim 1 , wherein the luminescent element is spaced from the solid state light emitter by a distance in the range of from about 500 micrometers to about 750 micrometers.
13. A lighting device as recited in claim 1 , wherein the luminescent element comprises a matrix in which a luminescent material is contained.
14. A lighting device as recited in claim 13 , wherein the matrix comprises a polymeric material.
15. A lighting device as recited in claim 14 , wherein the polymeric material has been cured.
16. A lighting device comprising:
at least one solid state light emitter; and
at least one luminescent clement,
the luminescent element comprising at least one luminescent material, a content of the luminescent material in the luminescent element not greater than about 15% by volume,
the first luminescent material comprising particles having an average particle size of not greater than 50 microns,
the luminescent element spaced from the solid state light emitter,
the solid state light emitter having an illumination surface, and
the luminescent element having a luminescent element surface, and
the luminescent element surface at least twice as large as the illumination surface.
17. A lighting device as recited in claim 16 , wherein the luminescent element is spaced from the solid state light emitter by a distance which is at least equal to a largest dimension of the illumination surface.
18. A lighting device as recited in claim 16 , wherein:
the illumination surface is substantially planar, and
the luminescent element surface is substantially planar.
19. A lighting device as recited in claim 16 , wherein the luminescent element comprises a matrix in which a luminescent material is contained.
20. A lighting device as recited in claim 16 , wherein the luminescent element surface is at least five times as large as the illumination surface.