Multiple power supply circuits for LED arrays

Abstract

A power system for an LED pixel array includes at least two power supplies that are respectively connectable to sub-arrays in the LED pixel array and provide adjustable power. A controller is connected to the at least two power supplies, where the controller is capable of adjusting the power provided based on measured needs of the sub-arrays in the LED pixel array. In one embodiment, the LED pixel array is a micro-LED array.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 089653, entitled "Multiple Power Supply Circuit for a Micro-LED Array," filed October 9, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to power supplies for monolithic or segmented light-emitting diode (LED) dies. These power supplies can be used in general lighting or display systems based on microLED pixel arrays. Background Technology

[0004] The use of microLED displays or projectors is an emerging technology in the lighting and display industry. MicroLEDs can consist of arrays of thousands to millions of microscopic LED pixels that emit light and are individually controlled. Compared to other display technologies, microLEDs can offer higher brightness and better energy efficiency, making them attractive for a variety of applications, such as television displays or backlighting, automotive lights, or mobile phones. Summary of the Invention

[0005] In some embodiments, a power supply system for an LED pixel array includes at least two power supplies, each connectable to a subarray within the LED pixel array and providing adjustable power. A controller is connected to the at least two power supplies, wherein the controller is capable of adjusting the supplied power based on the measurement needs of the subarrays within the LED pixel array.

[0006] In some embodiments, the LED pixel array includes a microLED pixel array.

[0007] In some embodiments, at least two power supplies are set to factory defaults.

[0008] In some embodiments, the settings for at least two power supplies are dynamically configured.

[0009] In some embodiments, at least two power supplies are buck converters.

[0010] In some embodiments, at least two power sources are connected to a positive power supply voltage and share a common ground.

[0011] In some embodiments, at least two power supplies may be connected in parallel to corresponding subarrays in the LED pixel array.

[0012] In some embodiments, the microLED pixel array system includes a plurality of microLED pixels supporting independently powered subarrays. At least two power supplies are connected to each subarray of the plurality of microLED pixels, providing adjustable power. A controller is connected to the at least two power supplies and is capable of adjusting the supplied power based on the measurement needs of the subarrays within the plurality of microLED pixels.

[0013] In some embodiments, each of the plurality of microLED pixels is independently addressable to allow on / off operation.

[0014] In some embodiments, a method for controlling an LED array includes providing a plurality of microLED pixels arranged in a manner having at least two independently powered subarrays. Power suitable for efficient forward voltage offset matching is provided to each LED subarray. Power usage of at least some of the plurality of microLED pixels can be measured, and the power supplied to the independently powered subarrays is dynamically adjusted based on the measured power usage. Attached Figure Description

[0015] Figure 1 An LED display system including an LED array supporting multiple power supplies is shown;

[0016] Figure 2 An embodiment including powering multiple subarrays is shown;

[0017] Figure 3A and Figure 3B An embodiment of a power supply that uses multiple buck converters to supply power to LEDs in an array is shown;

[0018] Figure 4 The operation of an embodiment of a microLED control module supporting multiple dynamically adjustable power supplies is shown;

[0019] Figure 5 An example of a system with a microLED control module supporting multiple power supplies is shown; and

[0020] Figure 6 A detailed chip-level implementation of a system with a microLED control module that supports multiple power supplies is shown. Detailed Implementation

[0021] In an LED array, the color or intensity of the light emitted by the LEDs in the array is a function of the supplied LED current. Small variations in the current across the die or substrate supporting the microLEDs can lead to undesirable color or intensity changes. Undesirable color or intensity changes are variations inconsistent with the image to be provided by the array. Additionally, conventional power supply schemes are relatively electrically inefficient due to variations in the LED forward voltage across the microLEDs. When all pixels are connected in parallel and share the same power supply, the power supply voltage is designed for the maximum LED forward voltage in the array. However, pixels with lower LED forward voltages inevitably suffer higher voltage drops and losses at the pixel driver, resulting in lower system efficiency.

[0022] Figure 1 An LED display system 100 including an LED array 110 is shown. As shown, each cell in the LED array 110 defines a pixel 102 that can be controlled using a system controller 120. The system controller 120 may include a connection or combination of multiple power supplies, one or more power drivers, and control software. The multiple power supplies, one or more power drivers, and control software allow for the measurement and control of the current and voltage supplied to the LED array 110 by the multiple power supplies. Control can be dynamically adjusted after deployment or can be set during calibration. Using the system controller 120, the regulation of the power supplied to the LED array 110 can allow for changes in the pixel intensity, color, and on / off state of individual pixels or selected groups of pixels.

[0023] In some embodiments, the LED array 110 may be formed from an array of one or more microLEDs (sometimes referred to as "µLEDs" or "uLEDs"). MicroLEDs can support high-density pixels with a lateral dimension of less than 100 micrometers (µm) by 100 µm. In some embodiments, microLEDs with a diameter or width of about 50 µm or less may be used. Such microLEDs can be used in color displays by closely aligning microLEDs containing red, blue, and green wavelengths. In other embodiments, microLEDs may be defined on a monolithic gallium nitride (GaN) or other semiconductor substrate, formed on segmented, partially or completely separate semiconductor substrates, or formed individually or assembled into groups of microLEDs. In some embodiments, the LED array 110 may include a small number of microLEDs located on a substrate with an area of ​​centimeters or larger. In some embodiments, the LED array 110 may support a microLED pixel array with hundreds, thousands, or millions of LEDs located together on a substrate with an area of ​​centimeters or smaller. In some embodiments, microLEDs may include light-emitting diodes with dimensions between 30 micrometers and 500 micrometers. In some embodiments, the microLED pixel array may be formed from light-emitting elements of various types, sizes, and layouts. In some embodiments, a one-dimensional or two-dimensional matrix array of individually addressable light-emitting diodes (LEDs) can be used. Typically, an N×M array can be used, where N and M are between two and one thousand, respectively. Individual LED structures can have square, rectangular, hexagonal, polygonal, circular, arcuate, or other surface shapes. The array of LED components or structures can be arranged in geometrically straight rows and columns, staggered rows or columns, curves, or a semi-random or random layout. LED components are also supported, which can include multiple LEDs formed as an array of individually addressable pixels. In some embodiments, radial or other non-rectangular grid arrangements of wires to the LEDs can be used. In other embodiments, bent, wound, meandering, and / or other suitable non-linear arrangements of electrical wires to the LEDs can be used.

[0024] Figure 2Embodiment 200 is illustrated, showing n corresponding power supplies 220, 222, 224 that provide independent power to corresponding n subarrays 226, 228, 230 of the entire LED array 210. Instead of using a common power supply to power all pixels in the LED array 210 (e.g., which may be a microLED matrix or a similar LED display / light projector), each of the power supplies 220, 222, 224 is connected to a corresponding subarray n. Advantageously, because each individual power supply 220, 222, 224 can provide a reduced amount of power, rather than providing total power to the entire LED array 210, the size of each power supply 220, 222, 224 can be much smaller than the size of a single power supply in the microLED array 210. Furthermore, Figure 2 The configuration shown makes the configuration of power supplies 220, 222, and 224 more flexible because there are more options in the power components that form power supplies 220, 222, and 224 that operate at relatively low power levels.

[0025] In some embodiments, each power supply voltage can be fixed or dynamically adjusted to provide different voltages to the individual LED subarrays 226, 228, 230 in LED array 210 based on a determined LED forward voltage. Fixed power supply voltages can be calibrated and set at the factory or after deployment. Dynamically adjusted power supplies can also be calibrated at the factory or dynamically set when the LED array is turned on, and can be scheduled intermittently or continuously during operation to regulate the voltage supply based on direct measurements of power usage or simulations or estimates of the power to be used by each subarray 226, 228, 230. For example, continuous scheduling can be used in instances where energy efficiency is more important. If energy efficiency is less important, fewer power measurements or adjustments to the voltage supply can be used. This allows, for example, subarray 1 to be powered with a voltage that effectively matches the forward voltage of the LEDs used, which may differ from the voltage used by subarray 2. The power supply voltage can be set based on the maximum value, average value, etc., of the forward voltage of the LEDs in subarrays 226, 228, 230.

[0026] Figure 3A and Figure 3B An embodiment of a power supply system 300 using multiple buck converters 330, 332, and 334 is illustrated. The buck converters 330, 332, and 334 can provide digitally controlled output voltages. Controller 120 (see...) Figure 1The output voltage can be set based on the maximum positive voltage of the subarrays to which the buck converters 330, 332, and 334 supply power. Therefore, each of the buck converters 330, 332, and 334 can provide a different positive power supply. The buck converters 330, 332, and 334 shown include output ports, one of which provides a negative voltage common to all buck converters 330, 332, and 334, and another of which provides a positive voltage depending on the electrical characteristics of the subarrays.

[0027] The power supply system 300 is connected to the LED array 210 (at least in Figure 3B As shown in the diagram, the LED array 210 represents an LED array comprising n (e.g., 10,000) pixels 336, 338, 340, divided into m (e.g., ten (10)) segments of 1000 pixels each. Each segment may have a different number of pixels. Each of the pixels 336, 338, 340 is part of a different pixel segment of array 210. Each segment is powered by a separate positive voltage from system 300. Figure 3A and Figure 3B There are m power supplies 220, 222, and 224, each including a corresponding buck converter 330, 332, and 334. These buck converters 330, 332, and 334 convert a 12V input voltage to a 3.5V output voltage from Vout1+ to Vout10+. Power supplies 220, 222, and 224 share a common ground Vout-. Figure 3B In this configuration, all microLED subarrays share a common ground Vout-, while each subarray is connected to its own positive power supply voltage from Vout1+ to Vout10+. Within each segment, all pixels are connected in parallel and share the same power supply 220, 222, 224. Each pixel includes a current source, a pulse width modulation (PWM) switch, and a microLED.

[0028] Figure 4Operation 400 of an embodiment of a micro-LED control module (e.g., local control module 502 or command control module 616) supporting multiple dynamically adjustable power supplies 220, 222, 224 is illustrated. In operation 402, calibration is performed, for example, at the factory, when the LED array is turned on, or intermittently or continuously during operation. In some embodiments, calibration includes determining operational dependencies based on at least one of LED design, manufacturing factors, or supply current. Based at least in part on calibration measurements, in operation 404, each LED subarray power supply 220, 222, 224 is supplied with power suitable for efficient forward voltage offset matching. In operation 406, power usage for each pixel or selected pixel subarray is measured. The measurement can be a one-time event, intermittently set during operation, or continuously scheduled. In operation 408, dynamically adjusted power is supplied, and this process can be repeated as desired. Power can be adjusted based on the power usage measured in operation 406.

[0029] Figure 5 An example of a lighting matrix control system 500 is shown, which has suitable lighting logic and control modules and / or pulse width modulation modules to allow individual control and adjustment of pixel intensity by setting appropriate ramp times and pulse widths. Addressable LED pixel activation can be used to provide patterned lighting, reduce color or intensity variations, and provide various pixel diagnostic functions. (See also: [link to relevant documentation]). Figure 1 The topics discussed, such as Figure 5 The microLED array shown can comprise thousands to millions of individually controlled microLED pixels that actively emit light. To emit light in a pattern or sequence that results in an image display, the current level of each microLED pixel at a different location on the array is individually adjusted according to the specific image. This may involve pulse width modulation (PWM), which turns the pixels on and off at a specific frequency. During PWM operation, the average direct current (DC) through the pixel is the product of the current amplitude and the PWM duty cycle, which is the ratio between the on-time and the period or cycle time.

[0030] Processing modules that contribute to the effective use of System 500, such as Figure 5 As shown. System 500 includes a control module 502 capable of pixel-level or group-pixel-level control of the amplitude and duty cycle of the microLED array. In some embodiments, the system further includes: an image processing module 504 for generating, processing, or transmitting images; and a digital control interface 506, such as an internal integrated circuit (I... 2 C)(I 2C (a synchronous, multi-leader, multi-follower, packet-switched, single-ended, serial communication bus) is configured to transmit the required control data or instructions. The digital control interface 506 and control module 502 may include a system microcontroller and any type of wired or wireless module configured to receive control input from external devices. For example, the wireless module may include Bluetooth, Zigbee, Z-wave, mesh, WiFi, near-field communication (NFC), and / or a peer-to-peer module may be used. The microcontroller may be any type of dedicated computer or processor, which may be embedded in the LED lighting system and configured or configurable to receive input from the wired or wireless module or other modules in the LED system, and based on this, provide control signals to other modules. The algorithm implemented by the microcontroller or other suitable control module 502 may be implemented in a computer program, software, or firmware, which is incorporated in a non-transitory computer-readable storage medium for execution by a dedicated processor. Examples of non-transitory computer-readable storage media include read-only memory (ROM), random access memory (RAM), registers, cache memory, and semiconductor memory devices. The memory can be included as part of the microcontroller, or it can be implemented elsewhere, either on or off the printed circuit board or electronic board.

[0031] As used herein, the term "module" can refer to electrical and / or electronic components mounted on a separate circuit board that can be soldered to one or more electronic boards. However, the term "module" can also refer to electrical and / or electronic components that provide similar functionality but can be soldered separately to one or more circuit boards, either in the same area or in different areas.

[0032] As previously mentioned, the local control module 502 may further include: an image processing module 504; and a digital control interface 506, such as I... 2C. Serial Peripheral Interface (SPI), Controller Area Network (CAN), Universal Asynchronous Receiver / Transmitter (UART), Universal Serial Bus (USB), etc. In some embodiments, image processing calculations can be performed by control module 502 by directly generating modulated images. Alternatively, standard image files can be processed or otherwise converted to provide modulation matching the image. Image data, primarily consisting of PWM duty cycle values, can be processed for all pixels in image processing module 504. Since the amplitude is a fixed or rarely changing value, amplitude-related commands can be given separately via a digital interface (e.g., a digital interface mentioned elsewhere herein). Control module 502 interprets all digital data, which is then used by the PWM generator to generate PWM signals 510 for the pixels and by the digital-to-analog converter (DAC) signal 512 to generate control signals for obtaining the desired current source amplitude. In some embodiments, discrete temperature sensors (T1-T4) can be used for temperature monitoring, which can supplement or provide calibration for the described pixel-level temperature monitoring system and method. In one embodiment, Figure 5 The pixel matrix 520 may include m pixels capable of supporting pixel-level temperature measurement. In one example embodiment, the pixels are connected to multiple current sources and PWM switches, as previously referenced. Figure 4 As stated above.

[0033] Figure 6 A chip-level implementation of system 600 is shown in more detail, which supports, for example, regarding... Figures 3A-3B , Figure 4 and Figure 5 The functions discussed. System 600 includes a command and control module 616 capable of calibrating and providing different power levels to the LED subarray, controlling monitoring, and controlling, as well as implementing pixel-level or group-pixel-level control of the amplitude and duty cycle of the circuit. In some embodiments, system 600 also includes a frame buffer 610 for storing images that can be provided to the active LED matrix 620 for generation or processing. Other modules may include digital control interfaces, such as I... 2 The C serial bus 612 or SPI 614 is configured to transmit the required control data or instructions.

[0034] In operation, system 600 can accept images or other data from vehicles or other sources arriving via SPI 614. Continuous image or video data can be stored in image frame buffer 610. If no image data is available, one or more backup images stored in backup image buffer 611 can be routed to image frame buffer 610. Such backup images may include, for example, intensity and spatial patterns consistent with legally permitted low beam headlight radiation patterns for vehicles, or default light radiation patterns used for architectural lighting or displays.

[0035] In operation, pixels in the image are used to define the response of the corresponding active LED pixel, where the intensity and spatial modulation of the LED pixel are based on the image(s). To mitigate data rate issues, in some embodiments, pixel groups (e.g., 5×5 blocks) can be controlled as a single block. In some embodiments, high-speed and high-data-rate operation is supported, where pixel values ​​from consecutive images can be loaded as consecutive frames in an image sequence at rates between 30Hz and 100Hz (where 60Hz is a typical rate). PWM can be used to control each pixel to emit light with a pattern and intensity at least in part dependent on the image stored in the image frame buffer 610.

[0036] In some embodiments, system 600 may receive logic power via Vdd and Vss pins. The active matrix receives power for LED array control via multiple VLED and VCathode pins. SPI 614 may provide full-duplex communication using a leader-follower architecture with a single leader. The leader device initiates frames for reading and writing. Multiple follower devices are supported by utilizing individual slave select (SS) lines for selection. Input pins may include leader-output-follower-in (MOSI), leader-in-follower-output (MISO), chip select (SC), and clock (CLK), all of which are connected to SPI 614. SPI 614 is connected to an address generator, a frame buffer, and a spare frame buffer. Pixels may have parameters set by command and control modules and modified signals or power (e.g., power-gated before input to the frame buffer, or pulse-width modulation or power-gated after output from the frame buffer). SPI 614 may be connected to address generation module 618, which in turn provides row and address information to active matrix 620. The address generator module 618 can then provide the frame buffer address to the frame buffer 610.

[0037] In some embodiments, the command and control module 616 can be accessed via I 2 The C-series bus 612 is used for external control. It supports clock (SCL) and data (SDA) pins with 7-bit addressing. The command and control module 616 may include a DAC and two analog-to-digital converters (ADCs). These are used to set the V for the connected active matrix. bias Help determine the maximum V fThe system temperature is determined, or the power supplied to the corresponding LED pixel subarray is set. An oscillator (OSC) is also connected to set the pulse width modulation oscillation (PWMOSC) frequency of the active matrix 620. In one embodiment, a bypass line is also provided to allow addressing of individual pixels or pixel blocks in the active matrix for diagnostic, calibration, or testing purposes. The active matrix 620 may be further supported by row and column selection for addressing individual pixels, which are provided with data lines, bypass lines, PWMOSC lines, Vbias lines, and Vf lines.

[0038] It will be understood that, in some embodiments, the circuitry and active LED matrix 620 may be packaged and may optionally include a connected base or printed circuit board for powering and controlling the light generated by the semiconductor LEDs. In some embodiments, the printed circuit board may also include electrical vias, heat sinks, ground planes, electrical traces, and flip-chip or other mounting systems. The base or printed circuit board may be formed of any suitable material, such as ceramic, silicon, aluminum, etc. If the base material is conductive, an insulating layer is formed on the substrate material, and a pattern of metal electrodes is formed on the insulating layer. The base may act as a mechanical support, provide an electrical interface between the electrodes and power supply on the LEDs, and also provide heat dissipation.

[0039] More generally, active light-emitting matrix pixel arrays, such as those described herein, can support applications that benefit from fine-grained intensity, spatial, and temporal control of light distribution. This can include, but is not limited to, precise spatial patterning of light emitted from pixel blocks or individual pixels. Depending on the application, the emitted light can be spectrally distinct, time-adaptive, and / or environmentally responsive. The emitting pixel array can provide pre-programmed light distributions with various intensity, spatial, or temporal patterns. The emitted light can be at least partially based on received sensor data and can be used for optical wireless communication. The associated optics can be distinct at the pixel, pixel block, or device level. Example emitting pixel arrays may include a device with a central block of high-intensity pixels sharing associated common optics, while edge pixels may have individual optics. Common applications supported by emitting pixel arrays include video lighting, automotive headlights, architectural and area lighting, street lighting, and information displays.

[0040] Emitting pixel arrays can be used to selectively and adaptively illuminate buildings or areas to improve visual presentation or reduce lighting costs. Additionally, emitting pixel arrays can be used to project media facades for decorative motion or video effects. Combined with tracking sensors and / or cameras, selectively illuminating areas around pedestrians is possible. Pixels with distinctly different spectra can be used to adjust the color temperature of the lighting, as well as support specific wavelengths of horticultural lighting.

[0041] Street lighting is an application that can greatly benefit from the use of luminescent pixel arrays. A single type of luminescent array can be used to simulate various street light types, allowing switching between Type I linear streetlights and Type IV semi-circular streetlights, for example, by appropriately activating or deactivating selected pixels. Additionally, street lighting costs can be reduced by adjusting the beam intensity or distribution based on environmental conditions or usage time. For example, when there are no pedestrians, the light intensity and distribution area can be reduced. If the pixels in the luminescent pixel array are spectrally distinct, the color temperature of the light can be adjusted according to the corresponding daytime, dusk, or nighttime conditions.

[0042] Illuminated arrays are also well-suited for applications requiring direct display or projected display. For example, warnings, emergency signals, or information signs can be displayed or projected using illuminated arrays. This allows for, for example, projecting color-changing or flashing exit signs. If the illuminated array consists of a large number of pixels, it can display text or numerical information. Directional arrows or similar indicators can also be provided.

[0043] Vehicle headlights are an application requiring a large number of pixels and a high data refresh rate for the light-emitting array. Motor vehicle headlights that actively illuminate only selected portions of the road can reduce problems associated with glare or blindness for oncoming drivers. Using an infrared camera as a sensor, the light-emitting pixel array activates only those pixels needed to illuminate the road, while deactivating pixels that could glare pedestrians or drivers of oncoming vehicles. Additionally, pedestrians, animals, or signs outside the road can be selectively illuminated to improve driver environmental awareness. If the pixels in the light-emitting pixel array are spectrally distinct, the color temperature of the light can be adjusted according to corresponding daytime, dusk, or nighttime conditions. Some pixels can be used for optical wireless vehicle-to-vehicle communication.

[0044] Additional notes and examples

[0045] Example 1 may include a power supply system for a light-emitting diode (LED) pixel array, comprising: at least two power supplies configured to provide adjustable power to respective LED subarrays in the LED pixel array; and a controller for the at least two power supplies configured to measure the forward voltage of a respective LED pixel in the LED subarray and adjust the power provided by the at least two power supplies based on the measured forward voltage of the respective LED pixel in the LED subarray.

[0046] In Example 2, Example 1 may further include, wherein the LED pixel array comprises a micro-LED pixel array.

[0047] In Example 3, at least one of Examples 1-2 may further include that the at least two power supplies are set to factory settings.

[0048] In Example 4, at least one of Examples 1-3 may further include that the settings of the at least two power supplies are dynamically configured.

[0049] In Example 5, at least one of Examples 1-4 may further include, wherein the at least two power supplies include buck converters.

[0050] In Example 6, at least one of Examples 1-5 may further include, wherein the at least two power supplies comprise a plurality of ports, a first port of the plurality of ports provides an independent positive power supply, and a second port of the plurality of ports provides a common ground voltage to all subarrays in the LED pixel array.

[0051] In Example 7, at least one of Examples 1-6 may further include, wherein each of the at least two power supplies may be connected in parallel to a corresponding subarray in the LED pixel array.

[0052] Example 8 includes a micro light-emitting diode (LED) pixel array system comprising: a plurality of micro LED pixels arranged as independently powered subarrays; at least two power supplies respectively connected to one of the subarrays and configured to provide adjustable power to the subarray; and a controller for the at least two power supplies configured to measure the electrical characteristics of the respective LED pixels of the subarrays and adjust the power provided by the at least two power supplies based on the measured electrical characteristics.

[0053] In Example 9, Example 8 may further include that each of the plurality of microLED pixels is independently addressable.

[0054] In Example 10, at least one of Examples 8-9 may further include, wherein the settings of the at least two power supplies are factory-set or dynamically set after deployment.

[0055] In Example 11, at least one of Examples 8-10 may further include, wherein the measured electrical characteristics include the forward voltage of the pixels of the LED subarray.

[0056] In Example 12, at least one of Examples 8-11 may further include, wherein the at least two power supplies include buck converters.

[0057] In Example 13, at least one of Examples 8-12 may further include, wherein the at least two power sources provide independent positive power supply voltages and provide a shared common ground voltage.

[0058] In Example 14, at least one of Examples 8-13 may further include, wherein the at least two power supplies are electrically connected in parallel with each other, and each of the at least two power supplies is electrically connected to a corresponding subarray in a corresponding subarray of the LED pixel array.

[0059] Example 15 includes a method for controlling a light-emitting diode (LED) array, the method comprising providing a plurality of microLED pixels arranged to include at least two independently powered subarrays, each subarray including different microLED pixels from the plurality of microLED pixels, supplying power to each subarray based on a forward voltage offset matching, measuring power usage of at least some of the plurality of microLED pixels, and dynamically adjusting the power supplied to the independently powered subarrays based on the measured power and the forward voltage offset.

[0060] In Example 16, Example 15 may further include, wherein the supply of power includes providing an independent positive power source and a shared common ground.

[0061] In Example 17, at least one of Examples 15-16 may further include, wherein each of the plurality of microLED pixels includes a current source, a pulse width modulation switch and an LED connected in series.

[0062] In Example 18, at least one of Examples 15-17 may further include the arrangement of at least two power sources supplying power at the manufacturing facility.

[0063] In Example 19, at least one of Examples 15-18 may further include operations that independently change each of the plurality of microLED pixels.

[0064] In Example 20, at least one of Examples 15-19 may further include, wherein at least two power sources supplying power each include a buck converter.

[0065] Having already benefited from the teachings presented in the foregoing description and associated drawings, those skilled in the art will conceive of many modifications and other embodiments of the invention. Therefore, it should be understood that the invention is not limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. It should also be understood that other embodiments of the invention may be practiced without elements / steps not specifically disclosed herein. In those embodiments supporting software-controlled hardware, the methods, processes, and implementations described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROMs and digital versatile discs (DVDs).

Claims

1. A power supply system for a microLED pixel array system, the microLED pixel array system comprising a microLED pixel array arranged as multiple independently powered subarrays, wherein all microLED pixels in the subarrays are connected in parallel, the power supply system comprising: Multiple power sources are configured to provide adjustable power to pixel subarrays in the microLED pixel array, each microLED pixel including a current source and a microLED; and A controller for the plurality of power supplies, the controller being configured to: The forward voltage of the microLED pixels in the subarray is measured, and the power supplied by the plurality of power sources is adjusted based on the measured forward voltage.

2. The power supply system according to claim 1, wherein the plurality of power supplies are configured at the factory settings.

3. The power supply system according to claim 1, wherein the configuration of the plurality of power supplies is dynamically configured.

4. The power supply system of claim 1, wherein the plurality of power supplies includes a buck converter.

5. The power supply system of claim 1, wherein the plurality of power supplies comprises a plurality of ports, a first port of the plurality of ports provides an independent positive power supply, and a second port of the plurality of ports provides a common ground voltage to all subarrays.

6. The power supply system of claim 1, wherein the output voltage of each power supply is set based on the maximum or average value of the forward voltage of the microLED pixels in the subarray.

7. The power supply system of claim 1, wherein the plurality of power supplies can be connected in parallel to different subarrays.

8. A micro-LED pixel array system, comprising: A microLED pixel array arranged as multiple independently powered subarrays, wherein all microLED pixels in the subarrays are connected in parallel and each microLED pixel includes a current source and a microLED; Multiple power supplies, each connected to a subarray in the microLED pixel array, are configured to provide adjustable power to the subarray; and A controller for the plurality of power supplies, the controller being configured to: Measure the forward voltage of the microLED pixels in the subarray, and The power supplied by the plurality of power sources is adjusted based on the measured positive voltage.

9. The microLED pixel array system of claim 8, wherein each of the plurality of microLED pixels is independently addressable.

10. The microLED pixel array system of claim 8, wherein the output voltage of the power supply is set by the controller based on the maximum positive voltage of the subarray to which the power supply supplies power.

11. The microLED pixel array system of claim 8, wherein the plurality of power supplies provide independent positive power supply voltages and share a common ground voltage.

12. The microLED pixel array system according to claim 8, wherein the plurality of power supplies are connected in parallel.

13. A control method for a microLED pixel array system, the microLED pixel array system comprising a microLED pixel array arranged as multiple independently powered subarrays, wherein all microLED pixels in the subarrays are connected in parallel and each microLED pixel includes a current source and a microLED, the control method comprising: Measure the forward voltage of the micro-LED pixels in the sub-array; and Based on the measured positive voltage, the power supplied to the independently powered microLED pixel subarray is dynamically adjusted.

14. The control method of claim 13 further includes providing an independent positive power supply and a shared common ground.

15. The control method of claim 13 further includes the provision of a plurality of power sources for supplying power at the manufacturing facility.

16. The control method according to claim 13 further includes independently changing the operation of each of the plurality of microLED pixels.

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