Segmented LED arrays with diffusing elements
LED arrays with diffusing elements are disclosed. In various embodiments, diffusing elements in the form of one or more structures of a diffuser material may be provided between an LED array and an optical element that collects light emitted by the array and directs the light to an optical far field. The optical element may image or approximately image the LED array. The diffusing elements at least partially blur patterning in the far field illumination that may otherwise arise from the optical element imaging the array. Each LED may be a wavelength-converting LED in that it may include a light emitter arrangement and a wavelength-converter structure.
1. A light emitting device comprising:
an array of multiple LEDs arranged so as to emit array output light, the LEDs of the array being separated from one another by trenches filled with non-transparent material or by non-transparent 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 light diffusing structures 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 light diffusing structures being arranged so as to reduce or eliminate, in the image of the array, appearance of the trenches or walls.
2. The light emitting device of claim 1 , wherein the light diffusing structures are configured to diffuse but not absorb light emitted by the LEDs.
3. The light emitting device of claim 1 , wherein each LED is operable independently of at least one other LED.
4. The light emitting device of claim 1 , wherein each LED of the array is a segment of a monolithic structure.
5. The light emitting device of claim 4 , wherein each LED has nonzero dimensions in a plane of the array of less than or equal to 500 microns.
6. The light emitting device of claim 1 , wherein the trenches or walls separating adjacent LEDs have nonzero widths less than or equal to 200 microns.
7. The light emitting device of claim 1 , wherein the one or more light diffusing structures comprise a continuous layer of light diffusing material disposed over a plurality of the LEDs.
8. The light emitting device of claim 7 , wherein the continuous layer of light diffusing material is disposed on the LEDs.
9. The light emitting device of claim 7 comprising a layer of transparent material disposed on the LEDs, wherein the continuous layer of light diffusing material is disposed on the layer of transparent material opposite from the LEDs.
10. The light emitting device of claim 7 , wherein the continuous layer of light diffusing material is partially segmented at locations between adjacent ones of the LEDs.
11. The light emitting device of claim 1 , wherein the one or more light diffusing structures comprise a continuous layer of transparent material disposed over a plurality of the LEDs, the layer of transparent material comprising an irregularly rough light scattering surface opposite from the LEDs.
12. The light emitting device of claim 1 , wherein the one or more light diffusing structures comprise a continuous layer of transparent material disposed over a plurality of the LEDs, the layer of transparent material comprising a periodic textured light scattering surface opposite from the LEDs.
13. The light emitting device of claim 1 , wherein the one or more light diffusing structures comprise a plurality of discrete light diffusing structures each aligned with a corresponding one of the LEDs.
14. The light emitting device of claim 13 , wherein each discreet light diffusing structure is dome shaped.
15. The light emitting device of claim 14 , wherein each dome comprises a flat surface and an oppositely positioned convexly shaped surface, and the flat surface faces the LED.
16. The light emitting device of claim 14 , wherein each dome comprises a flat surface and a convexly shaped surface, and the flat surface faces the optical element.
17. The light emitting device of claim 1 , wherein the one or more light diffusing structures comprise columns of light diffusing material oriented with their columnar axes extending away from the LEDs.
18. The light emitting device of claim 17 , wherein the columns of light diffusing material are embedded in a layer of transparent material.
19. A mobile device comprising:
a camera; and
the light emitting device of claim 1 , the one or more optical elements of which are arranged to direct light from the array of LEDs into a field of view of the camera.
20. A display system comprising:
a display; and
the light emitting device of claim 1 , the one or more optical elements of which are arranged to couple light from the array of LEDs into the display.