Segmented LED arrays with diffusing elements
Segmented LED arrays with various diffusing elements are disclosed. An example segmented LED array includes a plurality of LEDs arranged in a plurality of sections where a given section may include one or more LEDs and where each section may be aligned with a different respective optical element such as a lens. Each LED may be a wavelength-converting LED in that it may include a light emitter arrangement and a wavelength-converter structure. In various embodiments, diffusing elements in the form of one or more structures of a diffuser material may be provided over the wavelength-converter structure of one or more LEDs, the one or more structures being in a light path between the wavelength-converter structure and at least one of the plurality of optical elements, and configured to diffuse light emerging from the wavelength-converter structure.
1. An apparatus comprising:
an array of multiple light emitting elements arranged so as to emit array output light, the light emitting elements of the array being separated from one another by trenches filled with non-transparent material or with walls;
one or more optical elements arranged so as to direct at least a portion of the array output light to form an image of the array; and
one or more optical diffusers positioned in a light path between two or more light emitting elements of the array and one or more of the optical elements, the one or more optical diffusers being arranged so as to eliminate, in the image of the array, appearance of the trenches or walls.
2. The apparatus of claim 1 , surface roughness of one or more surfaces of the one or more optical diffusers, that face away from the light emitting elements of the array, being between 10 nanometers and 200 micrometers.
3. The apparatus of claim 1 further comprising a layer of transparent material positioned in the light path between the array of light emitting elements and the one or more optical diffusers.
4. The apparatus of claim 1 , the one or more optical diffusers including a continuous layer of optical diffuser material extending across multiple light emitting elements of the array.
5. The apparatus of claim 4 , the continuous layer of optical diffuser material being substantially flat.
6. The apparatus of claim 4 , the continuous layer of optical diffuser material having an irregular rough surface.
7. The apparatus of claim 4 , the continuous layer of optical diffuser material having a periodic rough surface including periodic shapes on a surface thereof.
8. The apparatus of claim 4 further comprising non-transparent walls that extending partly into the continuous layer of optical diffuser material.
9. The apparatus of claim 1 , the one or more optical diffusers including multiple dome-shaped volumes of diffuser material, each dome-shaped volume being positioned over a corresponding light emitting element of the array.
10. The apparatus of claim 9 , a convex portion of each dome-shaped volume facing the corresponding light emitting element.
11. The apparatus of claim 9 , a convex portion of each dome-shaped volume extending away from the corresponding light emitting element.
12. The apparatus of claim 1 , the one or more optical diffusers including multiple pluralities of columns of diffuser material, each plurality of columns being positioned over a corresponding light emitting element of the array.
13. The apparatus of claim 12 wherein, for at least one light emitting element, (i) a width of each of the columns is between 0.01% and 10% of a width of the corresponding light emitting element, or (ii) a height of each of the columns is between 0.1 and 500 micrometers.
14. The apparatus of claim 12 , a density of each plurality of columns being higher in a region centered around an optical axis of the corresponding light emitting element than in a region farther away from that optical axis.
15. The apparatus of claim 12 , the one or more optical diffusers further comprising a continuous layer of diffuser material in contact with the pluralities of columns and positioned either (i) between the pluralities of columns and the light emitting elements of the array or (ii) with the pluralities of columns between the continuous layer of diffuser material and the light emitting elements of the array.
16. The apparatus of claim 12 further comprising substantially optically transparent material between the columns.
17. The apparatus of claim 1 , each light emitting element including multiple semiconductor layers arranged as a light emitting diode (LED) with an active layer between a first semiconductor layer doped with dopants of a first type and a second semiconductor layer doped with dopants of a second type.
18. The apparatus of claim 1 further comprising one or more wavelength converter structures positioned in the light path between multiple light emitting elements of the array and the one or more optical diffusers.
19. The apparatus of claim 1 , the one or more optical elements including (i) one or more apertures arranged so as to guide array output light incident on the one or more apertures, or (ii) one or more lenses.