LED color displays with multiple LEDs connected in series and parallel in different sub-pixels of a pixel
A multi-color LED display comprises pixels, each comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel. The first sub-pixel comprises a first light-emitting diode (LED) that emits a first color of light, the second sub-pixel comprises second LEDs that emit a second color of light different from the first color of light, and the third sub-pixel comprises third LEDs that emit a third color of light different from the first color of light and different from the second color of light. The second LEDs are electrically connected in parallel and the third LEDs are electrically connected in series.
1. A multi-color LED display, comprising:
pixels, each of the pixels comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel, the first sub-pixel comprising a first light-emitting diode (LED) that emits a first color of light, the second sub-pixel comprising second LEDs that emit a second color of light different from the first color of light, and the third sub-pixel comprising third LEDs that emit a third color of light different from the first color of light and different from the second color of light,
wherein the second LEDs are electrically connected in parallel and the third LEDs are electrically connected in series.
2. The multi-color LED display of claim 1 , wherein the second sub-pixel comprises only two second LEDs that are electrically connected in parallel.
3. The multi-color LED display of claim 1 , wherein the third sub-pixel comprises only two third LEDs that are electrically connected in series.
4. The multi-color LED display of claim 1 , wherein the third sub-pixel comprises only three third LEDs that are electrically connected in series.
5. The multi-color LED display of claim 1 , wherein the third sub-pixel comprises only four third LEDs that are electrically connected in series.
6. The multi-color LED display of claim 1 , wherein the second sub-pixel comprises pairs of serially connected second LEDs, wherein the pairs are pair-wise electrically connected in parallel.
7. The multi-color LED display of claim 1 , wherein the first LED, the second LEDs, and the third LEDs are inorganic micro-LEDs with at least one of a width and a length that is no greater than 500 microns.
8. The multi-color LED display of claim 7 , wherein the first LED, the second LEDs, and the third LEDs are inorganic micro-LEDs with at least one of a width and a length that is no greater than 200 microns.
9. The multi-color LED display of claim 1 , wherein the first LED is a blue LED that emits blue light, the second LEDs are green LEDs that emit green light, and the third LEDs are red LEDs that emit red light.
10. The multi-color LED display of claim 1 , wherein the first LED is more efficient than the second LEDs and the second LEDs are more efficient than the third LEDs.
11. The multi-color LED display of claim 1 , wherein the first LED has a first efficiency that is current or current density dependent, the second LEDs each have a second efficiency that is current or current density dependent, and the second efficiency of each of the second LEDs reaches a maximum at a smaller current or current density than the first efficiency.
12. The multi-color LED display of claim 1 , wherein the second LEDs each have a second efficiency that is current or current density dependent, the third LEDs each have a third efficiency that is current or current density dependent, and the second efficiency of each of the second LEDs reaches a maximum at a smaller current or current density than the third efficiency of each of the third LEDs.
13. The multi-color LED display of claim 1 , wherein the first LED has a first efficiency that is current dependent, the third LEDs have a third efficiency that is current dependent, and the first efficiency reaches a maximum at a smaller current than the third efficiency of each of the third LEDs.
14. The multi-color LED display of claim 1 , comprising a display controller electrically connected to the pixels that is operable to control the first LED, the second LEDs, and the third LEDs.
15. The multi-color LED display of claim 14 , wherein a voltage provided to each of the third LEDs is less than a voltage provided to the first LED or to each of the second LEDs.
16. The multi-color LED display of claim 14 , wherein a current provided to the third LEDs is no less than twice a current provided to the first LED or to each of the second LEDs.
17. The multi-color LED display of claim 14 , wherein the controller is operable to provide a current source at a fixed voltage to the first LED, the second LEDs, and the third LEDs, and wherein a quantity of light emitted by the first LED, the second LEDs, and the third LEDs is controlled by the current provided to the first LED, the second LEDs, and the third LEDs, respectively.
18. The multi-color LED display of claim 1 , comprising:
a display substrate on, in, or over which the pixels are disposed; and
a controller electrically connected to each of the pixels that is operable to control the pixels.
19. The multi-color LED display of claim 15 , wherein the voltage provided to each of the third LEDs is no greater than one half the voltage provided to the first LED or to each of the second LEDs.
20. A multi-color LED display, comprising:
pixels, each of the pixels comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel, the first sub-pixel comprising first light-emitting diodes (LEDs) that emit a first color of light, the second sub-pixel comprising second LEDs that emit a second color of light different from the first color of light, and the third sub-pixel comprising third LEDs that emit a third color of light different from the first color of light and different from the second color of light,
wherein at least two of the first LEDs are electrically connected in series, at least two of the second LEDs are electrically connected in parallel, and at least two of the third LEDs are electrically connected in series,
and wherein the second sub-pixel comprises more second LEDs than first LEDs in the first sub-pixel and the third sub-pixel comprises more third LEDs than first LEDs in the first sub-pixel.