Light source device

1. A light source device, comprising:

a lens having a light-emitting top surface which is flat and a bottom surface opposite to the light-emitting top surface, wherein the lens includes an outer wall surface extending from the bottom surface to the light-emitting top surface, wherein the outer wall surface includes a dome portion and a brim portion, the dome portion extends out from the light-emitting surface and is disposed on the brim portion, the brim portion extends out from the dome portion and extends to the bottom surface, wherein the light-emitting top surface and a top brim surface of the brim portion on the brim portion that is opposite to the bottom surface are flat surfaces, wherein the bottom surface concaves towards the light-emitting top surface to form a hole, and the bottom surface has a gouge surrounding the hole with an inclination towards the edge of the hole, and wherein the gouge has a curvature at an end of the inclination away from the hole and the curvature of the gouge substantially ends at the same distance away from a center axis as the dome portion and the curvature is lower than the top brim surface; and

a light source disposed below the bottom surface and corresponding to the hole, wherein the light source has an illumination area and the hole covers a projection area of the illumination area onto the bottom surface.

2. The light source device of claim 1 , wherein the hole is formed from the surrounding of a first inner wall surface and a second inner wall surface with an opening on the bottom surface.

3. The light source device of claim 2 , wherein the first inner wall surface and the second inner wall surface form a kettle gourd structure.

4. The light source device of claim 3 , wherein the angle between a normal line to the center of the opening and a line through the center of the opening and an intersection of the first inner wall surface and the second inner wall surface is between 10° and 80°.

5. The light source device of claim 2 , wherein an angle between a normal line to the center of the hole and a point on the first inner wall surface or the second inner wall surface is defined by the inverse tangent of the ratio of a radius of the hole to a height of the hole.

6. The light source device of claim 2 , wherein the first inner wall surface and the second inner wall surface form a bullet structure.

7. The light source device of claim 2 , wherein an angle between a normal line to the center of the opening and a line through the center of the opening and an intersection of the first inner wall surface and the second inner wall surface is between 1° and 85°.

8. The light source device of claim 1 , wherein the angle of the inclination is between 70° to 85°.

9. A light source device, comprising:

a lens having a center axis and having a light-emitting top surface, wherein the lens includes a bottom surface opposite to the light-emitting top surface, the bottom surface concaves towards the light-emitting top surface to form a hole, and the bottom surface has a gouge surrounding the hole with an inclination towards the edge of the hole, wherein the gouge has a curvature at an end of the inclination away from the hole, wherein the lens includes an outer wall surface extending from the bottom surface to the light-emitting top surface, wherein the outer wall surface includes a dome portion and a brim portion, the dome portion extends out from the light-emitting surface and is disposed on the brim portion, the brim portion extends out from the dome portion and extends to the bottom surface, wherein a top brim surface of the brim portion that is opposite to the bottom surface is a flat surface and the curvature is lower than the top brim surface, and wherein the curvature of the gouge substantially ends at the same distance away from the center axis as the dome portion; and

a light source for generating light and disposed below the lens; wherein the light from the light source is refracted by the lens to cause a maximum light intensity to form between an angle greater than or equal to 60° and less than or equal to 85° from the center axis and a center light intensity along the center axis to be between 0.1% and 40% of the maximum light intensity.

10. The light source device of claim 9 , wherein the hole is formed from the surrounding of a first inner wall surface and a second inner wall surface with an opening on the bottom surface.

11. The light source device of claim 10 , wherein the first inner wall surface and the second inner wall surface form a bullet structure.

12. The light source device of claim 10 , wherein the first inner wall surface and the second inner wall surface form a kettle gourd structure.

13. The light source device of claim 9 , wherein an angle between a normal line to the center of the hole and a point on the first inner wall surface or the second inner wall surface is defined by the inverse tangent of the ratio of a radius of the hole to a height of the hole.

14. The light source device of claim 13 , wherein the angle between a normal line to the center of the opening and a line through the center of the opening and an intersection of the first inner wall surface and the second inner wall surface is between 10° and 80°.

15. The light source device of claim 13 , wherein an angle between a normal line to the center of the opening and a line through the center of the opening and an intersection of the first inner wall surface and the second inner wall surface is between 1° and 85°.

16. The light source device of claim 9 , wherein the light-emitting top surface is a flat surface.

17. The light source device of claim 9 , wherein the light source is disposed below the bottom surface corresponding to the hole, the light source has an illumination area and the hole covers a projection area of the illumination area onto the bottom surface.

18. The light source device of claim 9 , wherein the dome portion, the first inner wall surface, and the second inner wall surface are curved surfaces, the curvature of the dome surface, the first inner wall, and the second inner wall increases towards the light-emitting top surface.

19. The light source device of claim 9 , wherein towards the light-emitting top surface, a rate of increase in curvature of the dome surface is greater than a rate of increase in curvature of the first inner wall surface.

20. The light source device of claim 9 , wherein a ratio of an emitting angle of light emitting from the light source and an incident angle of the emitting light being refracted by the outer wall surface changes as the emitting angle increases from 0° to 90° such that there is at least an interval in a range of the emitting angle where the ratio of the emitting angle between the incident angle will gradually increase before gradually decreasing.

21. The light source device of claim 9 , wherein the angle of the inclination is between 70° to 85°.