MicroLED array with yellow sub-pixels
A lighting system and method of driving an array of micro light emitter (microLED) pixels are disclosed. Each pixel contains a blue sub-pixel configured to emit blue light, a red sub-pixel configured to emit red light, a green sub-pixel configured to emit green light, and a yellow sub-pixel configured to emit yellow light. A processor selects, for each pixel to produce white light, between driving the blue sub-pixel and yellow sub-pixel to produce the white light and driving the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel to produce the white light.
1 . A micro light-emitting diode (microLED) device comprising:
an array of pixels, each pixel containing a plurality of sub-pixels that each contain a microLED, the sub-pixels including a blue sub-pixel configured to emit blue light, a red sub-pixel configured to emit red light, a green sub-pixel configured to emit green light, and a yellow sub-pixel configured to emit yellow light; and
a processor configured to:
select, for each pixel to produce white light, between driving the blue sub-pixel and yellow sub-pixel to produce the white light and driving the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel to produce the white light,
select, for each pixel to produce white light, driving of the sub-pixels to produce the white light dependent on at least one characteristic of the pixel, the at least one characteristic selected from a group of characteristics that include brightness, efficiency of the white light produced, and power source used to generate the white light, and
in response to a determination that a brightness of the white light is to exceed a predetermined threshold, drive all of the sub-pixels to produce the white light.
2 . The microLED device of claim 1 , wherein the sub-pixels are limited to the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel.
3 . The microLED device of claim 1 , wherein the processor is further configured to drive the yellow sub-pixel in response to driving the red sub-pixel and at least one other sub-pixel.
4 . The microLED device of claim 1 , wherein a yellow junction configured to emit yellow light to form the yellow sub-pixel is disposed between a red junction configured to emit red light to form the red sub-pixel and a green junction configured to emit green light to form the green sub-pixel.
5 . The microLED device of claim 1 , wherein, for each pixel, each of the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel are disposed in a different lateral area of the pixel.
6 . The microLED device of claim 1 , wherein the white light is substantially D65 white.
7 . The microLED device of claim 1 , wherein the yellow light has a dominant wavelength (LDOM) of about 572 nm.
8 . The microLED device of claim 1 , wherein, for each pixel, the processor is further configured to:
determine whether at least one of the red sub-pixel and the green sub-pixel has failed, and
in response to a determination that the at least one of the red sub-pixel and the green sub-pixel has failed, maintain at least a subset of a total color gamut to be generated by the pixel using the yellow sub-pixel in place of the at least one of the red sub-pixel and the green sub-pixel.
9 . The microLED device of claim 8 , wherein, to produce a color within the at least the subset of the total color gamut to be generated by the pixel, the processor is further configured to determine a current to drive the yellow sub-pixel using a reference, the reference selected from a group of references that include a D65 color chart, Correlated Color Temperature (CCT), and a distance (Duv) above or below a blackbody curve.
10 . The microLED device of claim 1 , wherein the processor is configured to:
determine that the power source is a battery and the microLED device is operating on battery power, and
select the sub-pixels to be driven based on a determination that the microLED device is operating on battery power.
11 . The microLED device of claim 1 , wherein the processor is configured to:
determine that the power source is a battery,
determine whether battery power of the battery is below a predetermined power threshold, and
select the sub-pixels to be driven based on a determination of whether the battery power is below the predetermined power threshold.
12 . The microLED device of claim 1 , wherein the processor is configured to adjust relative emission intensities among the sub-pixels dependent on which pixels are activated.
13 . The microLED device of claim 1 , wherein relative positions of the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel are independent in each pixel or set of pixels.
14 . A non-transitory machine-readable medium that stores instructions for execution by one or more processors of a micro light-emitting diode (microLED) device, the one or more processors configure the microLED device to, when the instructions are executed perform operations comprising:
selecting, for each pixel to produce white light in an array of pixels, a set of sub-pixels that each contain a microLED, the sub-pixels including a blue sub-pixel configured to emit blue light, a red sub-pixel configured to emit red light, a green sub-pixel configured to emit green light, and a yellow sub-pixel configured to emit yellow light, the set of sub-pixels selected from a group of sets that include a first set that contains the blue sub-pixel and the yellow sub-pixel and a second set that contains the blue sub-pixel, the red sub-pixel, the green sub-pixel, and the yellow sub-pixel, the selecting comprising selecting, for each pixel to produce white light, driving of the sub-pixels to produce the white light dependent on at least one characteristic of the pixel, the at least one characteristic selected from a group of characteristics that include brightness, efficiency of the white light produced, and power source used to generate the white light; and
controlling driving of the set of sub-pixels to produce the white light, the controlling comprising controlling driving of all of the sub-pixels to produce the white light in response to a determination that a brightness of the white light is to exceed a predetermined threshold.
15 . The non-transitory machine-readable medium of claim 14 , wherein the one or more processors further configure the microLED device to perform operations comprising, when the instructions are executed, controlling driving of the yellow sub-pixel in response to driving the red sub-pixel and at least one other sub-pixel.
16 . The non-transitory machine-readable medium of claim 14 , wherein the one or more processors further configure the microLED device to perform operations comprising, when the instructions are executed, for each pixel:
determining whether at least one of the red sub-pixel or green sub-pixel has failed, and
in response to a determining that the at least one of the red sub-pixel or green sub-pixel has failed, maintaining at least a subset of a total color gamut to be generated by the pixel using the yellow sub-pixel in place of the at least one of the red sub-pixel or green sub-pixel.
17 . A micro light-emitting diode (microLED) device comprising:
an array of pixels; and
a processor configured to, for each pixel:
determine a gamut of pixel chromaticity for a particular color to be produced by the pixel, each gamut defined by a different triad of colors in a color space chromaticity diagram, the pixel containing sub-pixels that each contain a microLED, the sub-pixels including a blue sub-pixel configured to emit blue light, a red sub-pixel configured to emit red light, a green sub-pixel configured to emit green light, and a yellow sub-pixel configured to emit yellow light;
determine a bias of each sub-pixel based on the gamut determined; and
control driving of the sub-pixels based on the bias to produce the particular color, the driving comprising:
selecting, for each pixel to produce white light, driving of the sub-pixels to produce the white light dependent on at least one characteristic of the pixel, the at least one characteristic selected from a group of characteristics that include brightness, efficiency of the white light produced, and power source used to generate the white light, and
driving of all of the sub-pixels to produce the white light in response to a determination that a brightness of the white light is to exceed a predetermined threshold.
18 . The microLED device of claim 17 , wherein the processor is further configured to, for each pixel, select the gamut from a plurality of gamuts defined by red, green, yellow, and blue cornerpoints, the gamuts containing sets of gamuts that include a first gamut defined by blue, green, and yellow cornerpoints and a second gamut defined by red, blue, and yellow cornerpoints.
19 . The microLED device of claim 17 , wherein the processor is further configured to, for each pixel, select the gamut from a plurality of gamuts defined by virtual cornerpoints along a color line connecting red, yellow, and green that are linear combinations of red, green, and yellow.