Polygonally-shaped reflection member having inclined vertex portions for reflecting light from a light source
A reflection member includes at least one polygonal cell having a polygonally-shaped center bottom part in which a light source is disposed, vertex-part inclined surfaces provided so as to correspond to the respective vertexes of the polygonal shape, and side-part inclined surfaces provided between the corresponding vertex-part inclined surfaces, such that an inclination angle α of at least a part of the vertex-part inclined surfaces to the center bottom part is larger than an inclination angle β of the side-part inclined surfaces to the center bottom part.
1. A reflection member for reflecting light emitted from a light source, comprising:
at least one polygonal cell of a polygonal shape in plan view, which comprises:
a center bottom portion orthogonal to an optical axis and configured to receive the light source; and
an inclined portion inclined from the center bottom portion toward an outer rim;
wherein the inclined portion has a vertex-portion inclined surface provided correspondingly to each vertex of the polygonal shape, and a side-portion inclined surface provided between two of the vertex-portion inclined surfaces; and
in cross-sectional view, an acute inclined angle α of at least a part of the vertex-portion inclined surface to a reference plane orthogonal to the optical axis and coplanar with the center bottom portion is larger than an acute inclined angle β of the side-portion inclined surface to the reference plane.
2. The reflection member according to claim 1 , wherein:
the vertex-portion inclined surface has a plane with the inclined angle α.
3. The reflection member according to claim 1 , wherein:
the reflection member includes a plurality of the polygonal cells, and an outer rim of each polygonal cell is arranged to be adjacent to each other.
4. The reflection member according to claim 3 , wherein the vertex-portion inclined surface has a plane with the inclined angle α.
5. The reflection member according to claim 1 , wherein:
the highest point of the vertex-portion inclined surface of the polygonal cell is higher than the highest point of the side-portion inclined surface in cross-sectional view.
6. The reflection member according to claim 5 , wherein the vertex-portion inclined surface has a plane with the inclined angle α.
7. The reflection member according to claim 5 , wherein the reflection member includes a plurality of the polygonal cells, and an outer rim of each polygonal cell is arranged to be adjacent to each other.
8. The reflection member according to claim 7 , wherein the vertex-portion inclined surface has a plane with the inclined angle α.
9. An illumination device, comprising:
a light source; and
a reflection member for reflecting light emitted from the light source, the reflection member comprising at least one polygonal cell of a polygonal shape in plan view, and the polygonal cell comprises:
a center bottom portion orthogonal to an optical axis and on which the light source is arranged; and
an inclined portion inclined from the center bottom portion toward an outer rim, the inclined portion having a vertex-portion inclined surface provided correspondingly to each vertex of the polygonal shape, and a side-portion inclined surface provided between two of the vertex-portion inclined surfaces; and
wherein, in cross-sectional view, an acute inclined angle α of at least a part of the vertex-portion inclined surface to a reference plane orthogonal to the optical axis and coplanar with the center bottom portion is larger than an acute inclined angle β of the side-portion inclined surface to the reference plane.
10. The illumination device according to claim 9 , wherein:
the highest point of the vertex-portion inclined surface of the polygonal cell is higher than the highest point of the side-portion inclined surface in cross-sectional view.
11. The illumination device according to claim 9 , wherein:
the reflection member includes a plurality of the polygonal cells; and
an outer rim of each polygonal cell is arranged to be adjacent to each other.
12. A surface light source device, comprising:
the illumination device according to claim 9 ; and
a diffusion member provided on a light emission side of the illumination device.
13. A display device, comprising:
the surface light source device according to claim 12 ; and
an illuminated member which is irradiated with light from the surface light source device.
14. Electronic equipment, comprising the display device according to claim 13 as a display unit.
15. The illumination device according to claim 9 , comprising a light flux controlling member for controlling the light emitted from the light source to be a light flux of a predetermined distribution state.
16. The illumination device according to claim 15 , wherein the highest point of the vertex-portion inclined surface of the polygonal cell is higher than the highest point of the side-portion inclined surface in cross-sectional view.
17. The illumination device according to claim 15 , wherein:
the predetermined distribution state has a peak in direction of a predetermined angle from a reference surface; and
the predetermined angle is smaller than the inclined angle β of the side-portion inclined surface.
18. The illumination device according to claim 17 , wherein the highest point of the vertex-portion inclined surface of the polygonal cell is higher than the highest point of the side-portion inclined surface in cross-sectional view.