Pebble-plate like louvre with specific domain characteristics
The present invention relates to a louvre lighting unit which contains a plurality of louvre cells for beam shaping the lighting unit light. The plurality of louvre cells comprises a plurality of n subsets, each comprising a respective plurality of m louvre cells. The louvre cells of each subset are configured as a domain of adjoining louvre cells, wherein a respective plurality of k louvre cells within each domain have mutually differing louvre cell cross-sections.
1. A louvre unit comprising a plurality of louvre cells for beam shaping a lighting unit light, wherein the plurality of louvre cells comprises a plurality of n subsets each comprising a respective plurality of m louvre cells, wherein the louvre cells of each subset are configured as a domain of adjoining louvre cells, wherein a respective plurality of k louvre cells within each domain have mutually differing louvre cell cross-sections, wherein 3≤n≤100000, wherein 5≤m≤21, and wherein 5≤k≤m,
wherein the louvre cells are formed as polygons bounded by a number Ne of louvre walls closing in a loop, wherein for each louvre cell the number Ne is in the range of 3≤Ne≤10,
wherein the plurality of louvre cells within the same domain only have C1 symmetry relative to a central point in said domain and each domain comprises at least three polygons of incongruent shape, and
wherein each louvre cell has a respective equivalent cross section, said equivalent cross section being a cross section of a circle having the same cross sectional area as the polygonal shape of the louvre cell, and wherein a ratio between equivalent cross-sections of louvre cells is in the range of 1:2.5.
2. The lighting unit comprising a plurality of LED light sources for generation of lighting unit light, and a light exit unit for escape of at least part of said lighting unit light from the lighting unit, wherein the light exit unit comprises a louvre unit according to claim 1 , the louvre unit being arranged in a light exit first face.
3. The lighting unit according to claim 2 , wherein each of the domains are regularly arranged in the light exit first face.
4. The lighting unit according to claim 2 , comprising a light mixing chamber, wherein the plurality of light sources are configured to provide light source light in the light mixing chamber which in turn provides said lighting unit light, wherein the light mixing chamber comprises as the light exit first face a light exit face for escape of the light source light from the light mixing chamber, wherein the light exit face is comprised said light exit unit or wherein said light exit unit is configured downstream of said light exit face.
5. The lighting unit according to claim 4 , wherein an air guide is configured as the light mixing chamber, and wherein the light exit face is comprised in said light exit unit.
6. The lighting unit according to claim 4 , wherein a waveguide is configured as the light mixing chamber, wherein the waveguide comprises said light exit face, and wherein said light exit unit is configured downstream of said light exit face.
7. The lighting unit according to claim 4 , wherein the light mixing chamber comprises one or more faces and an edge face, with the light mixing chamber having a height smaller than a first length of the light mixing chamber.
8. The lighting unit according to claim 7 , and wherein the light mixing chamber has a ratio of the first length to the height of 5≤L 1 /H≤100.
9. The lighting unit according to claim 7 , wherein the plurality of light sources are configured at the edge face and are configured to provide said light source light having an optical axis transverse to the height.
10. The lighting unit according to claim 7 , wherein at least one of the one or more faces comprises elements configured to redirect light source light within the light mixing chamber.
11. The lighting unit according to claim 2 , wherein the louvre cells are configured in a pseudo random pattern or in a phyllotaxis pattern.
12. The lighting unit according to claim 2 , wherein the louvre cells are tapering from a second louvre cell opening in the direction to a first louvre cell opening, with the first and second louvre cell opening having a ratio R 12 in the range of 0.5-1.1 and R 12 ≠1.
13. The lighting unit according to claim 2 , wherein the lighting unit comprises at least 10 light sources, wherein the light sources comprise solid state light sources, wherein the louvre cells have louvre heights selected from the range of 1-100 mm, wherein the light exit unit has a cross-sectional area, wherein the light exit unit comprises in the range of 0.05-10 louvre cells per cm′ cross-sectional area, wherein a part of the light exit unit occupied by the louvre walls defined by adjoining louvre cells is selected from the range of 9-17% of the cross-sectional area.
14. The lighting unit according to claim 2 , having a lighting unit length (L 3 ) and a lighting unit height ( 113 ) with a ratio of the lighting unit length to the lighting unit height of 5≤L 3 /H 3 ≤100.
15. The lighting unit according to claim 2 , wherein the louvre cells have a height H 2 and an equivalent diameter L 2 , with a ratio of H 2 /L 2 being ≥0.5.
16. The lighting unit according to claim 2 , wherein the louvre cells have a height H 2 and an equivalent diameter L 2 , with a ratio of H 2 /L 2 being ≥0.8.
17. The lighting unit according to claim 2 , wherein the louvre cells have a height H 2 and an equivalent diameter L 2 , with a ratio of H 2 /L 2 being ≥1.2.