Light emitting module and optical lens thereof

1. An optical lens comprising:

an optical transparent body comprising:

an upper surface comprising a central upper concave portion, an outwardly-convex curved surface continuous from the central upper concave portion, and an inwardly-concave curved surface continuous from the outwardly-convex curved surface;

a lower surface;

a lateral surface connected between the inwardly-concave curved surface and the lower surface, wherein a first interface between the inwardly-concave curved surface and the lateral surface is closer to the lower surface than a curved interface between the outwardly-convex curved surface and the inwardly-concave curved surface, wherein the inwardly-concave curved surface is configured to refract light beams downwards; and

a lower concave portion recessed from the lower surface.

2. The optical lens of claim 1 , wherein the optical transparent body comprises a refractive index greater than 1.5.

3. The optical lens of claim 1 , wherein the upper surface is defined by a plurality of concentric circumferences disposed from the central upper concave portion to the lateral surface.

4. The optical lens of claim 3 , wherein a first concentric circumference of the plurality of concentric circumferences defines a second interface between the central upper concave portion and the outwardly-convex curved surface.

5. The optical lens of claim 4 , wherein a last concentric circumference of the plurality of concentric circumferences defines the first interface between the inwardly-concave curved surface and the lateral surface.

6. The optical lens of claim 5 , wherein one concentric circumference between the first and last concentric circumferences defines the curved interface between the outwardly-convex curved surface and the inwardly-concave curved surface.

7. The optical lens of claim 1 , wherein a point of inflection connects the outwardly-convex curved surface and the inwardly-concave curved surface.

8. The optical lens of claim 1 , wherein the lower concave portion is disposed centrally of the lower surface and aligned with the central upper concave portion.

9. A light emitting module comprising:

a substrate;

a light-emitting element disposed on the substrate; and

the optical lens of claim 1 , wherein the light-emitting element is housed within the lower concave portion of the optical transparent body.

10. The light emitting module of claim 9 further comprising an optical transparent media filled within the lower concave portion of the optical transparent body.

11. An optical lens comprising:

an optical transparent body comprising:

an upper surface comprising a central upper concave portion and a curved surface continuous from the central upper concave portion, wherein the curved surface comprises an outwardly-convex curved surface continuous from the central upper concave portion, and an inwardly-concave curved surface continuous from the outwardly-convex curved surface;

a lower surface;

a lateral surface connected between the curved surface and the lower surface;

a lower concave portion recessed from the lower surface, wherein the lower concave portion comprises a light incident surface, and the light incident surface has a top surface and a curved sidewall surface continuous from the top surface and connecting to the lower surface, wherein a curvature of the top surface is greater than that of the curved sidewall surface, the top surface surrounds and defines a first hollow space, and the curved sidewall surface surrounds and defines a second hollow space, wherein the inwardly-concave curved surface is configured to refract light beams from the light incident surface downwards; and

an optical transparent media filled within the second hollow space and not filled within the first hollow space.

12. The optical lens of claim 11 , wherein the top surface is a hemispherical surface.

13. The optical lens of claim 11 , wherein the lower concave portion is disposed centrally of the lower surface and aligned with the central upper concave portion.

14. The optical lens of claim 11 , wherein the lateral surface is substantially perpendicular to an edge of the lower surface.

15. The optical lens of claim 11 , wherein the lower concave portion is defined by a relatively small circumference and a relatively large circumference, wherein the relatively large circumference defines an interface between the curved sidewall surface and the lower surface.

16. The optical lens of claim 15 , wherein the relatively small circumference defines an interface between the top surface and the curved sidewall surface.

17. A light emitting module comprising:

a substrate;

a light-emitting element disposed on the substrate; and

the optical lens of claim 11 , wherein the light-emitting element is housed within the lower concave portion of the optical transparent body.

18. The light emitting module of claim 17 , wherein the optical transparent media comprises a refractive index smaller than that of the optical transparent body.

19. A light emitting module comprising:

a substrate;

a plurality of light-emitting diode chips disposed on the substrate in a flip-chip manner; and

a plurality of optical lenses respectively over the light-emitting diode chips and disposed in contact with the substrate, the optical lenses each having an optical transparent body comprising:

an upper surface comprising a central upper concave portion, an outwardly-convex curved surface continuous from the central upper concave portion, and an inwardly-concave curved surface continuous from the outwardly-convex curved surface;

a lower surface;

a lateral surface connected between the inwardly-concave curved surface and the lower surface, wherein a first interface between the inwardly-concave curved surface and the lateral surface is closer to the lower surface than a curved interface between the outwardly-convex curved surface and the inwardly-concave curved surface; and

a lower concave portion recessed from the lower surface, wherein a corresponding one of the light-emitting diode chips is housed within the lower concave portion of the optical transparent body.

20. The light emitting module of claim 19 , wherein the lower concave portion comprises a light incident surface, and the light incident surface has a top surface and a curved sidewall surface extending downwards from a bottom of the top surface to a bottom of the curved sidewall surface, the curved sidewall surface is continuously curved from a top to the bottom of the curved sidewall surface, the lower surface extends laterally from the bottom of the curved sidewall surface to a bottom of the lateral surface, and an entirety of the lower surface is flat.