Lens and lighting device
Disclosed is a lens ( 100 ) for a lighting device ( 10 ) comprising a solid state lighting element ( 20 ), the lens comprising a light exit surface ( 110 ); a central lens portion ( 120 ) opposite said light exit surface; an inner annular reflective element ( 130 ) opposite said light exit surface and extending away from said light exit surface by a first distance (d 1 ), said inner annular reflective element delimiting said central lens portion; and a side surface defined by an outer annular reflective element ( 140 ) opposite said light exit surface and extending away from said light exit surface by a second distance (d 2 ) that is larger than the first distance such that the outer annular reflective element extends beyond the inner annular reflective element. A lighting device such as a light bulb including such as lens is also disclosed.
1. A lighting device comprising at least one solid state lighting element and a lens which comprises:
a light exit surface;
a central lens portion opposite said light exit surface;
an inner annular reflective element opposite said light exit surface and extending away from said light exit surface by a first distance, said inner annular reflective element delimiting said central lens portion; and
a side surface defined by an outer annular reflective element opposite said light exit surface and extending away from said light exit surface by a second distance that is larger than the first distance such that the outer annular reflective element extends beyond the inner annular reflective element;
wherein the inner annular reflective element and the outer annular reflective element are directly adjacent to each other;
wherein the lens is placed over the at least one solid state lighting element such that the outer annular reflective element is in contact with a surface of the lighting device carrying the at least one solid state lighting element, wherein an outer surface of the outer annular reflective element is angled, wherein a luminous surface area of the solid state lighting element is enclosed by the outer annular reflective element; and
wherein said luminous surface area extends beyond the central lens portion.
2. The lighting device of claim 1 , wherein the central lens portion of the lens has a convex surface.
3. The lighting device of claim 1 , wherein the central lens portion of the lens comprises a Fresnel refractive surface.
4. The lighting device of claim 1 , wherein at least one of the inner annular reflective element and the outer annular reflective element comprises a tapered outer surface defined by a plurality of rings of facets.
5. The lighting device of claim 1 , wherein said light exit surface of the lens comprises a stepped profile.
6. The lighting device of claim 1 , wherein said light exit surface of the lens is textured.
7. The lighting device of claim 1 , wherein the lens further comprises a microlens array on said light exit surface.
8. The lighting device of claim 1 , wherein the lens is made of a polymer material.
9. The lighting device of claim 8 , wherein the polymer material is polycarbonate or poly(methyl methacrylate).
10. The lighting device of claim 1 , further comprising a cavity over said at least one solid state lighting element, said cavity housing said lens.
11. The lighting device of claim 1 , wherein the at least one solid state lighting element on said carrier is a chip on board solid state lighting element.
12. The lighting device of claim 1 , wherein the at least one solid state lighting element is a light emitting diode.
13. The lighting device of claim 1 , wherein the lighting device has a beam angle not exceeding 15°.