Light source lens, illumination unit, and display unit
An object of the present invention is to provide a light source lens that makes it possible to improve unevenness in a luminance distribution, an illumination unit, and a display unit. A light source lens ( 1 ) according to the present disclosure includes an incident surface on which light from a light-emitting device is incident, and an exit surface ( 20 ) that has a diffusing function at a center part ( 21 ) for light incident through the incident surface as well as a light-condensing function at at least a portion of an intermediate part ( 22 ) and a peripheral part ( 23 ) for the light incident through the incident surface.
1. A light source lens comprising:
an incident surface on which light from a light-emitting device is incident; and
an exit surface comprising:
a concave center part aligned with the incident surface,
a convexly curved intermediate part surrounding the center part, and
a peripheral part including a plurality of concavely curved shaped depression portions surrounding both the intermediate part and the center part,
wherein the concave shape of the center part terminates into the curved intermediate part;
wherein, in combination with the incident surface, the center part has a diffusing function for light incident through the incident surface, the intermediate part has a light-condensing function for light incident through the incident surface, and the peripheral part has a light-condensing function for light incident through the incident surface.
2. The light source lens according to claim 1 , wherein
the concave shape allows for the diffusing function for the incident light,
the curved section providing the light-condensing function for the incident light, and
the peripheral part of the exit surface includes a flat part, the curved section terminating into the flat part.
3. The light source lens according to claim 2 , wherein
the peripheral part has a quadrangular planar shape having four corners or four rounded corners as viewed from an optical-axis direction, and
the depressed part is formed near each of the four corners.
4. The light source lens according to claim 2 , wherein the center part and the intermediate part each have a circular planar shape as viewed from an optical-axis direction.
5. The light source lens according to claim 1 , wherein the incident surface has an aspherical shape that allows for diffusion of the light from the light-emitting device.
6. The light source lens according to claim 1 , wherein
an outer shape including the incident surface and the exit surface is a quadrangular shape having four corners or four rounded corners as viewed from an optical-axis direction.
7. The light source lens according to claim 1 , wherein light exited from the exit surface forms a quadrangular luminance distribution in a predetermined irradiation surface.
8. An illumination unit provided with a light-emitting device and a light source lens, the light source lens comprising:
an incident surface on which light from the light-emitting device is incident; and
an exit surface comprising:
a concave center part aligned with the incident surface,
a convexly curved intermediate part surrounding the center part, and
a peripheral part including a plurality of concavely curved shaped depression portions surrounding both the intermediate part and the center part,
wherein the concave shape of the center part terminates into the curved intermediate part;
wherein, in combination with the incident surface, the center part has a diffusing function for light incident through the incident surface, the intermediate part has a light-condensing function for light incident through the incident surface, and the peripheral part has a light-condensing function for light incident through the incident surface.
9. The illumination unit according to claim 8 , wherein
the light-emitting device comprises a plurality of light-emitting devices, and
the light source lens comprises a plurality of light source lenses that are provided respectively for the plurality of light-emitting devices.
10. The illumination unit according to claim 9 , wherein synthesized light of pieces of light that are exited from respective exit surfaces of the plurality of light source lenses forms a quadrangular synthesized luminance distribution in a predetermined irradiation surface.
11. A display unit provided with an illumination unit and a display panel, the illumination unit having a light-emitting device and a light source lens, the display panel displaying an image on a basis of illumination light from the illumination unit, the light source lens comprising:
an incident surface on which light from the light-emitting device is incident; and
an exit surface comprising:
a concave center part aligned with the incident surface,
a convexly curved intermediate part surrounding the center part, and
a peripheral part including a plurality of concavely curved shaped depression portions surrounding both the intermediate part and the center part,
wherein the concave shape of the center part terminates into the curved intermediate part;
wherein, in combination with the incident surface, the center part has a diffusing function for light incident through the incident surface, the intermediate part has a light-condensing function for light incident through the incident surface, and the peripheral part has a light-condensing function for light incident through the incident surface.
12. The display unit according to claim 11 , wherein
the concave shape allows for the diffusing function for the incident light,
the curved section providing the light-condensing function for the incident light, and
the peripheral part of the exit surface includes a flat part, the curved section terminating into the flat part.
13. The display unit according to claim 12 , wherein
the peripheral part has a quadrangular planar shape having four corners or four rounded corners as viewed from an optical-axis direction, and
the depressed part is formed near each of the four corners.
14. The display unit according to claim 12 , wherein the center part and the intermediate part each have a circular planar shape as viewed from an optical-axis direction.
15. The display unit according to claim 11 , wherein the incident surface has an aspherical shape that allows for diffusion of the light from the light-emitting device.
16. The display unit according to claim 11 , wherein
an outer shape including the incident surface and the exit surface is a quadrangular shape having four corners or four rounded corners as viewed from an optical-axis direction.
17. The display unit according to claim 11 , wherein light exited from the exit surface forms a quadrangular luminance distribution in a predetermined irradiation surface.