Driving of multijunction multicolor display devices

Abstract

A lighting system and method of driving an array within the lighting system is disclosed. The array includes vertically stacked multi-color micro light emitting diode (micro LED) devices emitting different colors of light. Drive circuits and ground switch circuits are controlled by processing circuitry to sequentially emit the color of each micro LED by independently driving the pn junctions of the micro LEDs. Each drive circuit includes a multiplexer to receive sink / source current and selectively provide the sink / source current to a channel based on a control signal from the processing circuitry. Pulse width modulation (PWM) signals are used to implement dimming of a particular color to adjust the duty cycle of applying sink / source current to the channel. The ground switch circuit uses a multiplexer to select another channel and ground the channel so that current is limited to flow through one of the pn junctions at a time.

Description

[0001] Priority requirements This application claims the benefit of priority to U.S. Patent Application No. 18 / 383,698, filed October 25, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0002] Compared to conventional light sources, light-emitting diodes (LEDs) offer a highly efficient and relatively small light source. The applications of LEDs have evolved from systems providing pure illumination to more complex systems using light in displays, and they possess functions beyond simply illuminating a specific area. Therefore, there is ongoing effort to improve the technology using LED arrays and to find additional uses for them. Attached Figure Description

[0003] Figure 1 An example of a three-junction multicolor device is shown.

[0004] Figure 2A-2C It shows Figure 1 An example of sequential driving of a three-junction RGB multicolor device is shown.

[0005] Figure 3 Examples of multicolor matrices according to different embodiments of the disclosed subject are shown.

[0006] Figure 4 An example of a block diagram of a lighting system is shown.

[0007] Figure 5A It shows Figure 4 An example of a driving circuit for a lighting system.

[0008] Figure 5B It shows Figure 4 Another example of a driving circuit for a lighting system.

[0009] Figure 6A It shows Figure 4 An example of a grounding switch circuit for a lighting system.

[0010] Figure 6B It shows Figure 4 Another example of a grounding switch circuit in a lighting system.

[0011] Figure 7 An exemplary lighting system is shown.

[0012] Figure 8 Examples of electronic devices based on some embodiments of the disclosed subject matter are shown.

[0013] Figure 9 A block diagram is shown of an example of a visualization system that may include the light source described herein.

[0014] Figure 10 An exemplary method for driving a multicolor matrix is ​​shown.

[0015] Figure 11 An example of a multicolor matrix is ​​shown.

[0016] Figures 12A-12E The driving of LEDs in a multicolor matrix is ​​shown according to different embodiments of the disclosed subject matter.

[0017] Figure 13A Examples of active and inactive pixels according to different embodiments of the disclosed subject matter are shown.

[0018] Figure 13B Different embodiments based on the disclosed subject matter are shown. Figure 13A An instance of pixel coordinates.

[0019] Throughout these views, corresponding reference characters indicate the respective components. Elements in the accompanying drawings are not necessarily drawn to scale. The configurations shown in the drawings are merely examples and should not be construed as limiting in any way. Detailed Implementation

[0020] The use of LEDs in electronic devices has rapidly increased as the number and types of devices have expanded in various ways. Beyond displays alone, compact light sources have recently been incorporated into devices such as augmented reality (AR) and virtual reality (VR). Such devices can be enabled using microLED arrays.

[0021] MicroLED arrays can contain thousands to millions or more microscopic microLEDs, which can be controlled individually or in pixel groups (e.g., 5x5 pixel groups). MicroLEDs are relatively small (e.g., <0.07 mm on one side) and can provide monochromatic or multicolor light (typically red, green, blue, or yellow) using inorganic semiconductor materials. Other LEDs may have, for example, a diameter of approximately 4 mm. 2 Sizes of 250 micrometers x 250 micrometers or larger.

[0022] The active layer of a microLED can typically be formed from one or more inorganic materials (e.g., binary compounds such as gallium arsenide (GaAs); ternary compounds such as aluminum gallium arsenide (AlGaAs); quaternary compounds such as indium gallium phosphide (InGaAsP); gallium nitride (GaN); or other suitable materials), typically group III-V materials (defined by columns of the periodic table) or group II-VI materials.

[0023] MicroLEDs in different arrays can emit light in the visible spectrum (approximately 400 nm to approximately 800 nm) and / or emit light in the infrared spectrum (approximately greater than 800 nm). MicroLEDs can be formed by epitaxially growing active n-type and p-type semiconductors on a rigid or flexible substrate (which can be textured). The substrate may include, for example, sapphire alumina (Al2O3) or silicon carbide (SiC). Specifically, various layers are deposited and processed on the substrate during the fabrication of the microLEDs to form the microLED array. Before depositing the individual layers, the surface of the substrate may be pretreated to perform annealing, etching, polishing, etc. The original substrate may be removed and replaced with a thin, transparent rigid substrate (such as glass) or a flexible substrate (such as plastic). Generally, different active layers can be fabricated using epitaxial semiconductor deposition, metal deposition (e.g., by sputtering), oxide growth, and etching, stripping and cleaning, as well as other operations, to deposit one or more semiconductor layers.

[0024] In some aspects, the growth substrate can be removed from the microLED structure after fabrication and after contacts on a backplane are connected (e.g., electrically coupled) via metal bonding (such as wire bonding or ball bonding). The backplane can be a printed circuit board or wafer or other substrate containing integrated circuits (ICs), such as complementary metal-oxide-semiconductor (CMOS) IC wafers. Semiconductor deposition operations can be used to create microLEDs with active regions where electron-hole recombination occurs and light is generated from the microLEDs. The active regions can be, for example, one or more quantum wells. Metal contacts can be used to supply current from the IC on the backplane disposed on the microLED array to the n-type and p-type semiconductors. Methods for depositing materials, layers, and thin films can include, for example, sputtering deposition, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced atomic layer deposition (PEALD), plasma-enhanced chemical vapor deposition (PECVD), and combinations thereof, etc.

[0025] In some aspects, one or more other layers (such as a phosphor conversion layer containing phosphor particles) may be disposed on some or all of the microLEDs or microLED arrays to convert at least a portion of the light from the microLEDs into light of different wavelengths. For example, blue light can be converted into near-infrared light or white light by the phosphor conversion layer.

[0026] Recently, multi-junction multi-color microLED devices have been developed using InGaN, for example, as the active semiconductor. Multi-color InGaN devices are vertically stacked multi-color (typically RGB) devices, in which three pn junctions (for the three colors) are connected via tunnel junctions or otherwise electrically coupled. The term "vertical" as used herein refers to the direction of growth or deposition on the substrate (an array of such devices thus has devices arranged in a horizontal [or lateral] direction). Manufacturing details of the multicolor microLED device can be found in US10236409B2, US10749070B2, US10541352B2, US10804429B2, US10622206B2, US11069836B2, US11069524B2, US11069525B2, US11404599B2, US11081622B2, US11594572B2, US6822991B2, and US6847057B1, which are combined in full here.

[0027] Although a three-junction device is described here because it is perhaps the most basic color display engine, the number of junctions is not limited in this respect. Other devices can be fabricated using two-junction or four-junction (or more) devices when the junctions are vertically stacked. This vertical stacking allows for individual access to each junction by creating appropriate contacts via photolithography and etching, as well as deposition techniques.

[0028] Figure 1 An example of a triple-junction multicolor device is shown. The triple-junction multicolor device 100 has four electrical contact terminals 102a, 102b, 102c, and 102d, which allows for independent control of three current values. Each current value can be used to control different junctions 104a, 104b, and 104c of the triple-junction multicolor device 100. In some aspects, each junction 104a, 104b, and 104c of the multicolor device 100 can be a different color, for example... Figure 1 The red-green-blue (RGB) color scheme is shown. In other respects, at least one of the colors in the multicolor device 100 (regardless of whether three or more knots are manufactured) can be the same, which allows for more precise control over the relative intensity of the colors.

[0029] In some respects, junctions 104a, 104b, and 104c of the multicolor device 100 can be driven simultaneously to achieve color mixing. For example, to synthesize white from vertically stacked RGB emitters, current can flow through all three junctions 104a, 104b, and 104c simultaneously. The resulting color can be adjusted by changing the ratio of the current flowing through each of junctions 104a, 104b, and 104c. To adjust the ratio, current can flow into and out of different intermediate contact terminals 102a, 102b, 102c, and 102d. However, the independent control of different currents at any given moment is a cause for complexity in circuit design.

[0030] To reduce driving complexity, in some respects, multiple junctions 104a, 104b, 104c can be driven sequentially rather than simultaneously (i.e., simultaneous driving is avoided). Due to the persistence of human vision, color mixing can be achieved by switching primary colors at a rate relatively fast in the time domain (e.g., faster than the video frame rate of 24 or 30 frames per second), which is called sequential driving. One benefit of the driving circuitry, while achieving color mixing satisfactory to the human eye, is that by changing a small amount of current between the (primary color) pn junctions (micro-LEDs), the load on the circuit can be reduced by controlling and / or monitoring only one current. Additionally, sequential driving provides an extra dimension of color control because color tuning can be performed by adjusting the current for each single cycle (the same as simultaneous driving). In other respects, color control can also be achieved by adjusting the on-duration of each cycle (e.g., the on-duration of a pulse-width modulation (PWM) signal), a technique that is potentially more complex than the sequential approach described herein.

[0031] In some respects, sequential driving can be defined as at most one junction in a vertically stacked multicolor junction being driven at any given time. At any given time, the multicolor junction can be driven by a forward current. At some times, zero junctions can be driven, i.e., the multicolor device is off. As mentioned above, the triple-junction RGB multicolor device is merely an example of a vertically stacked junction LED device, and the number of individual microLEDs and therefore the colors may differ from those described herein.

[0032] Figure 2A-2C It shows Figure 1 An example of sequential driving of the triple-junction RGB multicolor device 100 shown. During the first period 200a of the driving cycle, as... Figure 2A As shown, the current from the current source 202 only passes through the first junction 204a (not through the second junction 204b or the third junction 204c).

[0033] The length of the drive cycle and the length of each time period can be selected as needed. Changing the drive cycle length affects how frequently the (RGB) units (pixels) in the panel are updated; the update rate depends on factors such as panel size and refresh rate. For example, if the panel has a 64x64 pixel array, 4096 pixels can be updated to form a frame (image). Additionally, the refresh rate can be set according to the expected content to be displayed. The minimum refresh rate at which the human eye perceives motion is 30 frames per second (FPS). Therefore, the minimum drive cycle length can be specified by 4096 pixels updated 30 times per second (1s / (4096*30) = 8.13μs). Higher refresh cycles (60FPS, 120FPS, 144FPS) allow highly dynamic content to appear smoothly on the screen.

[0034] On the other hand, within a driving cycle, the activation of a specific color can be adjusted for different time periods to achieve a desired brightness level. A specific color is a mixture of different brightness levels of different colors (e.g., red, green, and blue), which can be a specific mixture for each time period. Taking the example above (where each color is active for substantially the same number of time periods), each color can be active for one-third of the driving cycle (8.13 μs / 3 = 2.71 μs) to define how long the desired color mixture is provided within that time.

[0035] As mentioned above, although Figure 2A-2C The diagram shows that the first junction 204a, the second junction 204b, and the third junction 204c emit R, G, and B colors of light, respectively. However, in other respects, the number of junctions and / or the colors emitted by each junction may differ from those shown. Figure 2A As shown, during the first time period 200a, current enters the R+ terminal and leaves from the G+ (R-) terminal to reach ground 206. It should be noted that the terminals may be referred to as R+, G+ (R-), B+ (G-), and B-, where the G+ terminal is synonymous with the R- terminal because current flows from the R+ terminal to the G+ terminal, and the B+ terminal is synonymous with the G- terminal because current flows from the G+ terminal to the B+ terminal.

[0036] Similarly, in Figure 2B During the second period 200b following the first period 200a shown, current only flows through the second junction 204b. (As shown...) Figure 2B As shown, during the second time period 200b, current enters the G+ terminal and exits from the B+ (G-) terminal to ground 206. Figure 2C As shown, during the third time period 200c following the second time period 200b, the current only passes through the third junction 204c. Figure 2CAs shown, during the second time period 200b, current enters the G+ terminal and exits from the B+ (G-) terminal to ground 206. In this way, the circuit has only one current to be controlled during a given time period. Color tuning can be performed by individually adjusting each current for a single drive cycle and / or by individually adjusting each on-time (for each junction 204a, 204b, 204c).

[0037] Figure 3 An example of a multicolor matrix is ​​shown. The multicolor matrix 300 may contain a large number (e.g., millions) of triple-junction multicolor devices 302, each addressable using individually addressable bus lines 304 that extend across the entire multicolor matrix 300 in some respects. Each cell 310 therefore includes four terminals to implement the addressable bus lines 304. Figure 3 The multicolor matrix 300 in the diagram can have a rectangular (square) shape. As mentioned above, in other respects, the number of addressable bus lines 304 can differ from the number of junctions.

[0038] To construct a display device, a multicolor device wafer or other type of substrate can be fabricated using photolithography techniques as described herein. Since unit 310 (also called a pixel or microLED device) has four terminals, and three junctions are designed for individual operation, Figure 3 The horizontal addressable bus lines of the addressable bus line 304 shown are R+ and B+ / G-, and the vertical addressable bus lines of the addressable bus line 304 are R- / G+ and B-. While the colors provided for the horizontal and vertical bus lines in the addressable bus line 304 are interchangeable in various aspects, the pairing of R+ and B+ / G- and the pairing of R- / G+ and B- are fixed due to the vertically stacked circuitry.

[0039] Figure 4 An example block diagram of a lighting system is shown. Lighting system 400 is shown as comprising multiple components to sequentially drive the junctions shown herein. Lighting system 400 includes a digital processing system (such as a field-programmable gate array (FPGA)) 410, driving circuitry 440, and a display unit 460. Display unit 460 may include a microLED array as indicated herein. In some aspects, in addition to display unit 460, Figure 4 The components shown can form a controller. The digital processing system 410 may include a field-programmable gate array (FPGA).

[0040] Digital processing system 410 may be a controller for controlling lighting system 400. Digital processing system 410 may include multiple components, including connector 412, high-speed pulse width modulator (PWM) circuit 414, communication bus 416, power supply 418 (voltage and ground), and standard input / output (I / O) bus 420. High-speed PWM circuit 414 is a high-speed communication module that, in some respects, allows communication at speeds up to, for example, approximately 24 MHz or up to, for example, approximately 155 Mbps. Signals on high-speed PWM circuit 414 may use low-voltage differential signaling (LVDS) with multiple duty cycles (e.g., three duty cycles, each for each junction to be driven). Communication bus 416 is a synchronous multi-controller / multi-target communication bus, a single-ended serial communication bus, for low-speed (approximately 0.1 Mbps to approximately 5 Mbps) communication. Communication bus 416 may carry, for example, two types of signals. Communication bus 420 may provide I / O signals for demultiplexing multiple bits (e.g., 4x6 bits for a 24-pin I / O bus). The digital processing system 410 can generate clock signals such as 23.6 MHz for the duty cycle of the PWM signal, 36.864 kHz for the pixel clock (the time the signal is applied to each pixel of the display unit 460), and 30 Hz for the frame clock (the time between each frame of each image provided by the display unit 460).

[0041] In some aspects, the digital processing system 410 can be connected to the drive circuit 440 via connector 412. Connector 412 can be connected to or otherwise electrically coupled to connector 452 of the drive circuit 440 using a ribbon cable or other flexible connector. This cable can provide signals from the digital processing system 410 to the drive circuit 440. The drive circuit 440 may also include a current sink / current source driver 454, drive circuits 442, 444, 446, a grounding switch circuit 448, and an LVDS receiver 450. Figure 4 As shown, signals from the communication bus 416 of the digital processing system 410 can be provided to the current sink / current source driver 454 of the drive circuit 440. The signals from the communication bus 416 can control the drive current provided by the current sink / current source driver 454 of the drive circuit 440.

[0042] Depending on the signal from the digital processing system 410 provided via connector 452, drive current from the sink current / source current driver 454 can be provided to each drive circuit 442, 444, 446 (B drive circuit 442, G drive circuit 444, R drive circuit 446). The sink current / source current driver 454 can provide bias current for each color, independent of the bias current used for any other color. Similarly, each drive circuit 442, 444, 446 can receive control signals from the digital processing system 410, provided via connector 452, to control the selection of the bus lines being driven in the display unit 460. Grounding switch circuit 448 ( Figure 3 The B-bus line shown can also be controlled based on control signals from the digital processing system 410 provided via connector 452. The grounding switch circuit 448 can be used to achieve sequential drive by moving the circuit ground synchronously with the active junction during specific time periods.

[0043] In operation, the digital processing system 410 can receive the frames to be displayed based on the panel size of the display unit 460 (e.g., 64×64) and generate digital signals provided to the driving circuit 440. The driving circuit 440 receives the signals and activates the analog switches in each driving circuit 442, 444, 446 to sequentially determine which microLED (i.e., which pn junction in the microLED device / unit / pixel) to activate and the activation duration. A current sink / source driver 454 can supply current to each driving circuit 442, 444, 446; the digital processing system 410 can thus manipulate the selected switches and turn on each pixel of the display unit 460. Along with the switch information, the digital processing system 410 can establish the duration of each pixel's active state by providing a duty cycle signal for each color. The duty cycle for each color can be set individually, or the duty cycle can be consistent for each color.

[0044] Figure 5A It shows Figure 4 An example of a system's drive circuit. Drive circuit 500a can be... Figure 4 One of the B-drive circuit 442, G-drive circuit 444, or R-drive circuit 446 shown. Drive circuit 500a includes a cascaded analog multiplexer 510 and an output stage 520 including one or more analog demultiplexers 516, 518. Analog circuits or switches allow the use of constant and / or controllable currents, unlike their digital counterparts. Using the cascaded analog multiplexer 510 and analog demultiplexers 516, 518, a constant current can be routed through the switches of drive circuit 500a (instead of a constant voltage typically routed by switches) to enable sequential driving of the microLEDs in each microLED device.

[0045] Cascaded analog multiplexer 510 can be a dual-channel analog multiplexer that receives signals from one input. Figure 4 The current-sinking / source-current driver 454 shown receives the current-sinking / source-current, while another input is grounded. The cascaded analog multiplexer 510 is activated based on the duty cycle for a specific period. This effectively allows PWM dimming of the light from the individual microLEDs of each microLED device by not driving the microLEDs during the off-duty period. The cascaded analog multiplexer 510 may include a multiplexer 512 that provides it with the duty cycle and a demultiplexer 514 that provides it with a control signal to select the path for routing the incoming duty cycle. The multiplexer 512 and demultiplexer 514 may be the same circuitry coupled back-to-back, with a single data port of the multiplexer 512 (used as an output) coupled to a single data port of the demultiplexer 514 (used as an input). The cascaded analog multiplexer 510 can thus act as a single-pole double-throw (SPDT) switch with a single input that can be connected to two outputs and switch between the two outputs (i.e., one input terminal and two output terminals). As shown in the figure, one input of the multiplexer 512 can provide sink current / source current, while the other input of the multiplexer 512 can be grounded.

[0046] The cascaded analog multiplexer 510 can be used to select inputs (i.e., such as...) Figure 5A The absorption current / source current or ground shown (as indicated) can be used to select which of the demultiplexers 516, 518 of the output stage 520 to provide input to. The output of demultiplexer 514 from the cascaded analog multiplexer 510 can be provided as a data input to one of the demultiplexers 516, 518 of the output stage 520. The demultiplexers 516, 518 of the output stage 520 can be multi-channel demultiplexers, wherein control signals (control bits) from the digital processing system 410 are provided as control inputs to the demultiplexers 516, 518 of the output stage 520. Providing control bits to the control inputs of the demultiplexers 516, 518 allows the demultiplexers 516, 518 to select the desired bus line of the display unit 460 for driving. In some aspects, the demultiplexers 516 and 518 of the output stage 520 may each provide, for example, 32 outputs, and thus sequentially address a total of 64 channels (to which sink current / source current is routed). In this case, the drive circuit 500a may receive 7 control bits: 6 bits for selecting one of the 64 channels; and a single bit for selecting between sink current / source current and ground.

[0047] Although the cascaded analog multiplexer 510 (along with multiplexer 512 and demultiplexer 514) is shown as a dual-channel demultiplexer (selected between two output channels), the cascaded analog multiplexer 510 can be an n-channel demultiplexer; or more than one multiplexer / demultiplexer pair can be used if a greater number of demultiplexers (channels) are connected to the cascaded analog multiplexer 510.

[0048] In operation, each driver circuit 500a can receive a unique constant current, which can be set according to the color (and pixel) of the driven microLED. The current is provided to multiplexer 512, which defines the duration for which the current drives the selected microLED device and a specific microLED within that device, where the activation time is the duty cycle. Output stage 520 determines which channel in the tree of cascaded demultiplexers 516, 518 will deliver current to the display panel. As described above, control signals may include duty cycles and multiplexer output address pins. These currents and / or duty cycles may be substantially the same (e.g., within variations caused by mismatched electronics) or may be different.

[0049] Figure 5B It shows Figure 4 Another example of a system's drive circuit. Drive circuit 500b can be... Figure 4 One of the B-drive circuit 442, G-drive circuit 444, or R-drive circuit 446 is shown. Drive circuit 500b includes a cascaded analog multiplexer 510 and an output stage 520 including one or more analog demultiplexers 516, 518. Analog circuits or switches allow the use of constant and / or controllable currents, unlike their digital counterparts. The use of cascaded analog multiplexers 510 and analog demultiplexers 516, 518 enables the routing of constant current through the switches of drive circuit 500b (instead of a constant voltage typically routed by switches), allowing the sequential driving of microLEDs in each microLED device.

[0050] Cascaded analog multiplexer 510 can be a dual-channel analog multiplexer that receives signals from one input. Figure 4The current-sinking / current-source driver 454 shown receives the current-sinking / current-source, while another input is grounded. The cascaded analog multiplexer 510 is activated based on the duty cycle for a specific period. This effectively allows PWM dimming of the light from individual microLEDs in each microLED device by not driving the microLEDs during the off-duty period. The cascaded analog multiplexer 510 may include a multiplexer 512 that provides it with the duty cycle and a demultiplexer 514 that provides it with control signals to select the path for routing the incoming duty cycle. The multiplexer 512 and demultiplexer 514 may be identical circuitry coupled back-to-back, with a single data port of the multiplexer 512 (used as an output) coupled to a single data port of the demultiplexer 514 (used as an input). The cascaded analog multiplexer 510 can thus act as a single-pole double-throw (SPDT) switch with a single input that can be connected to two outputs and switch between the two outputs (i.e., one input terminal and two output terminals). As shown in the figure, one input of the multiplexer 512 can provide sink current / source current, while the other input of the multiplexer 512 can be grounded.

[0051] The cascaded analog multiplexer 510 can be used to select inputs (i.e., such as...) Figure 5B The absorption current / source current or ground shown (as indicated) can be used to select which demultiplexer 516, 518 of the output stage 520 provides input to. The output of demultiplexer 514 from the cascaded analog multiplexer 510 can be provided to the input of one of the demultiplexers 516, 518 of the output stage 520. The demultiplexers 516, 518 of the output stage 520 can be multi-channel demultiplexers, wherein control signals (control bits) from the digital processing system 410 are provided to the control inputs of the demultiplexers 516, 518 of the output stage 520. Providing control bits to the control inputs of the demultiplexers 516, 518 allows the demultiplexers 516, 518 to select the desired bus line of the display unit 460 for driving. In some aspects, the demultiplexers 516 and 518 of the output stage 520 can each provide, for example, 32 outputs and thus sequentially address a total of 64 channels (to which sink current / source current is routed). In this case, Figure 5A The drive circuit 500a shown can receive 7 control bits: 6 bits for selecting one of the 64 channels; and a single bit for selecting between sink current / source current and ground.

[0052] Although the cascaded analog multiplexer 510 (multiplexer 512 and demultiplexer 514) is shown as a dual-channel demultiplexer (selected between two output channels), the cascaded analog multiplexer 510 can be an n-channel demultiplexer; or more than one multiplexer / demultiplexer pair can be used if more demultiplexers (channels) are connected to the cascaded analog multiplexer 510.

[0053] In operation, each drive circuit 500b can receive a unique constant current, which can be set according to the color (and pixel) of the driven microLED. The current is provided to multiplexer 512, which defines the duration for which the current drives the selected microLED device and a specific microLED within that device, where the activation time is the duty cycle. Output stage 520 determines which channel in the tree of cascaded demultiplexers 516, 518 will deliver current to the display panel. As described above, control signals may include duty cycles and multiplexer output address pins. These currents and / or duty cycles may be substantially the same (e.g., within the range of variations caused by mismatched electronics) or they may be different.

[0054] and Figure 5A The drive circuit 500a shown is different. Figure 5B The driving circuit 500b shown utilizes the enable inputs (ENB) to the demultiplexers 516 and 518. Specifically, an enable circuit 530 is used in the driving circuit 500b to control the activation of each demultiplexer 516 and 518 (the first demultiplexer 516, which controls the driving of n first channels; and the second demultiplexer 518, which controls the driving of n second channels) by providing control signals to the ENB inputs of the demultiplexers 516 and 518. The enable circuit 530 includes several circuit elements, including an inverter 532 and a pair of NAND gates 534a and 534b.

[0055] A busy signal is provided to the input of enable circuit 530. The busy signal is also provided to the input of each NAND gate 534a, 534b. The most significant bit provided to demultiplexer 514 is also directly provided to the input of one of the NAND gates 534b (the second NAND gate 534b), and after being inverted by inverter 532, is provided to the input of the other of the NAND gates 534a (the first NAND gate 534a). The output from the first NAND gate 534a is provided to the ENB input of the first demultiplexer 516, and the output from the second NAND gate 534b is provided to the ENB input of the second demultiplexer 518. Note that in other embodiments, the circuitry and / or connections may be different, as long as functionality is maintained.

[0056] Figure 6A It shows Figure 4An example of a system grounding switch circuit is provided. The grounding switch circuit 600a may be similar to the drive circuit 500a, containing demultiplexers 610, 612, and 614 but lacking multiplexer 512. The input of the first demultiplexer 610 is grounded, and a single control signal is used to select one of the second demultiplexer 612 and the third demultiplexer 614 to provide ground as an input. The second demultiplexer 612 and the third demultiplexer 614 are coupled to the control signal to select the desired bus line from the display unit to ground. In some aspects, the second demultiplexer 612 and the third demultiplexer 614 may each provide 32 outputs (as described above) and thus sequentially address a total of 64 channels. Similar to the drive circuit 500a, the grounding switch circuit 600a may receive 6 control bits to select one of the 64 channels. Although the first demultiplexer 610 is shown as a dual-channel demultiplexer (selecting between two output channels), the first demultiplexer 610 can be an n-channel demultiplexer; or, if a greater number of channels are used, more than one dual-channel demultiplexer can be used.

[0057] Therefore, in operation, the grounding switch circuit 600a, for example, determines when and where to switch (in this case, ground) the blue microLED to complete the individually addressable pixel method. As mentioned above, the grounding switch circuit 600a receives neither the current source drive line nor the duty cycle signal.

[0058] Figure 6B It shows Figure 4 Another example of a grounding switch circuit in the system. Grounding switch circuit 600b may be similar to drive circuit 500b, containing demultiplexers 610, 612, and 614 but lacking multiplexer 512. The input of the first demultiplexer 610 is grounded, and a single control signal is used to select one of the second demultiplexer 612 and the third demultiplexer 614 to provide ground as an input. The second demultiplexer 612 and the third demultiplexer 614 are coupled to the control signal to select the desired bus line from the display unit to ground. In some respects, the second demultiplexer 612 and the third demultiplexer 614 may each provide 32 outputs (as described above) and thus sequentially address a total of 64 channels. Similar to drive circuit 500b, grounding switch circuit 600b may receive 6 control bits to select one of the 64 channels. Although the first demultiplexer 610 is shown as a dual-channel demultiplexer (selecting between two output channels), the first demultiplexer 610 can be an n-channel demultiplexer; or, if a greater number of channels are used, more than one dual-channel demultiplexer can be used.

[0059] Therefore, in operation, the grounding switch circuit 600b, for example, determines when and where to switch (in this case, ground) the blue microLED to complete the individually addressable pixel method. As mentioned above, the grounding switch circuit 600b does not receive current source drive lines, and therefore does not receive duty cycle signals.

[0060] Similar to the above, but different Figure 6A The grounding switch circuit 600a shown in the figure, Figure 6B The grounding switch circuit 600b shown utilizes the enable inputs (ENB) to the second demultiplexer 612 and the third demultiplexer 614. Specifically, an enable circuit 630 is used in the drive circuit 500b to control the activation of each of the second demultiplexer 612 and the third demultiplexer 614 by providing control signals to the ENB inputs of the second demultiplexer 612 and the third demultiplexer 614. The enable circuit 630 includes a plurality of circuit elements, including an inverter 632 and a pair of NAND gates 634a, 634b.

[0061] A busy signal is provided to the input of enable circuit 630. The busy signal is also provided to the input of each of NAND gates 634a and 634b. The most significant bit provided to the first demultiplexer 610 is also directly provided to the input of one of the NAND gates 634b (the second NAND gate 634b) and, after being inverted by inverter 632, to the input of the other of the NAND gates 634a (the first NAND gate 634a). The output from the first NAND gate 634a is provided to the ENB input of the first demultiplexer 612, and the output from the second NAND gate 634b is provided to the ENB input of the second demultiplexer 614. Note that in other embodiments, the circuitry and / or connections may be different, as long as functionality is maintained.

[0062] Figure 7 An exemplary lighting system is illustrated. The lighting system 700 may include one or more light sources 710. The light source 710 may include one or more microLED arrays 712, including a single microLED array as described herein. As also described herein, the light source 710 may include driving circuitry 714. A photosensor 718 may include a photodiode array 716 that detects light from the microLED devices in the light source 710. The photodiode array 716 may be disposed within the device containing the light source 710 or may be separate from the light source 710.

[0063] The controller 730 may include a processor 732 (e.g., a hardware-based processor, or equivalently, processing circuitry) that can be used to control various functions of the lighting system 700. As also shown, the controller 730 may include other components, such as circuitry 734 configured to drive a photodiode array 716, such as that controlled by the processor 732. In some embodiments, circuitry 734 may also be configured to provide non-local driving of the micro-LED array 712 of the light source 710, and may include other circuitry, such as… Figure 4 The non-FPGA circuit shown (if there is no driver circuit in the light source 710, then the other circuit includes the driver circuit).

[0064] The light source 710 may include at least one lens and / or other optical elements (such as a reflector). In different embodiments, a single lens may be disposed on the microLED array 712, or multiple lenses may be disposed on the microLED array 712. The lens and / or other optical elements may guide the light emitted by the microLED array 712 to a target.

[0065] The processor 732 may also control one or more sensors 720, including a multi-pixel detector 722. Sensors 720 may sense light at one or more wavelengths emitted by the microLED array 712 and reflected by the target, radiation emitted by the target, and / or other wavelengths. Sensors 720 may be, for example, radar or lidar sensors, or the processor 732 may be used to determine the presence of a specific nearby object (e.g., other vehicles, people, road signs). Sensors 720 may include optical elements (e.g., at least one sensor lens) to capture radiation. The multi-pixel detector 722 may include, for example, photodiodes or one or more other detectors capable of detecting light in a wavelength range of interest. The multi-pixel detector 722 may contain multiple different arrays for sensing visible light and / or infrared light. Similar to the photodiode array 716, the multi-pixel detector 722 may have one or more segments (capable of sensing the same wavelength / wavelength range or different wavelengths / wavelength ranges).

[0066] In some embodiments, a multi-pixel detector may be provided in the photodetector 718 as an alternative or addition to the sensor 720. In some embodiments, the photodetector 718 and the sensor 720 may be integrated into a single module, while in other embodiments, the photodetector 718 and the sensor 720 may be separate modules mounted on a printed circuit board (PCB) or other mounting. In other embodiments, the photodetector 718 and the sensor 720 may be attached to different PCBs or mountings. Similarly, the light source 710 may be integrated into a single module with the photodetector 718, or it may be separate from the photodetector 718.

[0067] The microLEDs in the microLED array 712 can be driven as described herein. A power supply 740 (e.g., a battery) can be used. Figure 7 The components of the lighting system 700 shown are powered.

[0068] Figure 8 Examples of electronic devices 800 according to some embodiments are shown. Electronic device 800 may be, for example, a display, monitor, or screen, an AR / VR headset, a vehicle headlight, area lighting, or any other lighting arrangement. Various elements may be provided on the backplane indicated above, while other elements may be local or remote. As described herein, examples may include or be operable via logical components or components, modules, or mechanisms.

[0069] Modules and components are tangible entities (e.g., hardware) capable of performing specified operations and can be configured or arranged in a certain way. In an example, circuitry can be arranged as a module in a specified manner (e.g., internally or relative to external entities such as other circuitry). In an example, all or part of one or more computer systems (e.g., standalone, client-side, or server-side computer systems) or one or more hardware processors can be configured by firmware or software (e.g., instructions, application portions, or applications) to operate and perform specified operations. In an example, the software can reside on a machine-readable medium. In an example, when executed by the underlying hardware of the module, the software causes the hardware to perform the specified operations.

[0070] Therefore, the terms "module" (and "component") are understood to include tangible entities that are physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., momentarily) configured (e.g., programmed) to operate in a specified manner or perform part or all of the operations described herein. Consider an instance where modules are temporarily configured, where each module within a module does not need to be instantiated at any given time. For example, in the case where a module comprises a general-purpose hardware processor configured using software, the general-purpose hardware processor can be configured as different modules at different times. The software can accordingly configure the hardware processor to constitute a particular module at one time and different modules at different times.

[0071] Electronic device 800 may include a hardware processor (or equivalent processing circuitry) 802 (e.g., a central processing unit (CPU), GPU, hardware processor core, or any combination thereof) and a memory 804 (which may include main memory and static memory), some or all of which may communicate with each other via an interconnect (e.g., a bus) 808. Memory 804 may include any or all of removable and non-removable storage devices, volatile or non-volatile memory. Electronic device 800 may further include a light source 810 (such as a microLED as described above) or a video display, an alphanumeric input device 812 (e.g., a keyboard), and a user interface (UI) navigation device 814 (e.g., a mouse). In an example, the light source 810, input device 812, and UI navigation device 814 may be a touchscreen display. Electronic device 800 may additionally include a storage device (e.g., a drive unit) 816, a signal generation device 818 (e.g., a speaker), a network interface device 820, one or more cameras 828, and one or more sensors 830, such as a Global Positioning System (GPS) sensor, a compass, an accelerometer, or other sensors such as those described herein. Electronic device 800 may further include an output controller, such as serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.)) connection, to communicate with or control one or more peripheral devices (e.g., printers, card readers, etc.). Some components (such as one or more of the sparse array providing the light source 810) may be located remotely from other components and may be controlled by hardware processor 802.

[0072] Storage device 816 may include a non-transitory machine-readable medium 822 (hereinafter simply referred to as machine-readable medium) on which one or more sets of data structures or instructions 824 (e.g., software) are stored, which one or more sets embody or are utilized by any one or more of the techniques or functions described herein. Storage device 816 including non-transitory machine-readable medium should not be construed as meaning that the device or the machine-readable medium itself cannot have physical movement. During the execution of instructions 824 by electronic device 800, instructions 824 may also reside wholly or at least partially within memory 804 and / or hardware processor 802. Although machine-readable medium 822 is shown as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 824.

[0073] The term "machine-readable medium" can include any medium capable of storing, encoding, or carrying instructions executable by electronic device 800 and causing electronic device 800 to perform any or more of the technologies disclosed herein, or capable of storing, encoding, or carrying data structures used by or associated with such instructions. Examples of non-limiting machine-readable media include solid-state memory, as well as optical and magnetic media. Specific examples of machine-readable media can include: non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; random access memory (RAM); and CD-ROM and DVD-ROM disks.

[0074] The transmission medium 826 can be further used via the network interface device 820 to transmit or receive commands 824 on a communication network using any of a plurality of wireless local area network (WLAN) transmission protocols or SPI or CAN buses. Exemplary communication networks may include local area networks (LANs), wide area networks (WANs), packet data networks (e.g., the Internet), mobile phone networks (e.g., cellular networks), common old-style telephone (POTS) networks, and wireless data networks. Communication on the network may include one or more different protocols, such as the IEEE 802.11 standard family known as Wi-Fi, the IEEE 802.14 standard family known as WiMax, the IEEE 802.14.4 standard family, the Long Term Evolution (LTE) standard family, the Universal Mobile Telecommunications System (UMTS) standard family, point-to-point (P2P) networks, next-generation (NG) / 6th generation (6G) standards, etc. In an example, the network interface device 820 may include one or more physical jacks (e.g., Ethernet, coaxial, or telephone jacks) or one or more antennas for connection to the transmission medium 826.

[0075] Note that, as used herein, the term "circuit" refers to a hardware component, is part of a hardware component, or includes a hardware component such as electronic circuits, logic circuits, processors (shared, dedicated, or grouped) and / or memories (shared, dedicated, or grouped), application-specific integrated circuits (ASICs), field-programmable devices (FPDs) (such as field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), structured ASICs, or programmable SoCs), digital signal processors (DSPs), etc., which are configured to provide the described functions. In some embodiments, the circuit may execute one or more software or firmware programs to provide at least some of the described functions. The term "circuit" may also refer to a combination of one or more hardware elements and program code for performing the functions of the program code (or a combination of a circuit used in an electrical or electronic system and program code for performing the functions of the program code). In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0076] As used herein, the terms "processor circuit" or "processor" therefore refer to, are part of, or include circuits capable of sequentially and automatically performing a series of arithmetic or logical operations, or recording, storing, and / or transmitting digital data. The terms "processor circuit" or "processor" can also refer to one or more application processors, one or more baseband processors, a physical CPU, a single-core or multi-core processor, and / or any other means capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional procedures).

[0077] Camera 828 can sense light of one or more wavelengths emitted by at least the microLED. Camera 828 may include optical elements (e.g., at least one camera lens) capable of collecting reflected light from illumination reflected and / or emitted from the illuminated area. The camera lens can guide the reflected light onto a multi-pixel sensor (also known as a light sensor) to form an image on the multi-pixel sensor.

[0078] The processor 802 can control and drive the LEDs via one or more drivers. For example, the processor 802 can optionally control one or more microLEDs in the microLED array independently of other microLEDs in the array to illuminate an area in a specified manner.

[0079] Furthermore, sensor 830 can be integrated into camera 828 and / or light source 810. Sensor 830 can sense visible light and / or infrared light, and can sense ambient light and / or changes / flickers in ambient light in addition to receiving reflected light from LEDs. The sensor can have one or more segments similar to an LED array (capable of sensing the same wavelength / wavelength range or different wavelengths / wavelength ranges).

[0080] Figure 9 A block diagram of an example of a visualization system that may include the light source described herein is shown. The visualization system 910 may include a wearable housing 912, such as a head-mounted device or goggles. The housing 912 may mechanically support and house the elements detailed below. In some instances, one or more of the elements detailed below may be included in one or more additional housings that may be separate from the wearable housing 912 and may be wirelessly and / or coupled to the wearable housing 912 via a wired connection. For example, a separate housing may reduce the weight of the wearable goggles, for instance, by including batteries, radios, and other components. The housing 912 may include one or more batteries 914 that may power any or all of the elements detailed below. The housing 912 may include circuitry electrically coupled to an external power source, such as a wall outlet, to charge the batteries 914. The housing 912 may include one or more radios 916 for wireless communication with a server or network via a suitable protocol, such as WiFi.

[0081] The visualization system 910 may include one or more sensors 918, such as optical sensors, audio sensors, tactile sensors, thermal sensors, gyroscope sensors, time-of-flight sensors, triangulation-based sensors, etc. In some instances, one or more of the sensors may sense the user's point, position, and / or orientation. In some instances, one or more of the sensors 918 may generate sensor signals in response to the sensed point, position, and / or orientation. The sensor signals may include sensor data corresponding to the sensed point, position, and / or orientation. For example, the sensor data may include a depth map of the surrounding environment. In some instances, such as those used in augmented reality systems, one or more of the sensors 918 may capture real-time video images of the user's surrounding environment.

[0082] The visualization system 910 may include one or more video generation processors 920. The one or more video generation processors 920 may receive scene data from a server and / or storage medium. The scene data may represent a three-dimensional scene, such as a set of position coordinates of objects in the scene or a depth map of the scene. The one or more video generation processors 920 may receive one or more sensor signals from one or more sensors 918. In response to scene data representing the surrounding environment and at least one sensor signal representing the user's position and / or orientation relative to the surrounding environment, the one or more video generation processors 920 may generate at least one video signal corresponding to a view of the scene. In some instances, the one or more video generation processors 920 may generate two video signals (one for each of the user's eyes), representing views of the scene from the user's left and right eye viewpoints, respectively. In some instances, the one or more video generation processors 920 may generate more than two video signals and combine the video signals to provide a single video signal for both eyes, two video signals for both eyes, or other combinations.

[0083] The visualization system 910 may include one or more light sources 922, such as those described herein, which may provide light to the display of the visualization system 910. Suitable forms of the one or more light sources 922 may include microLEDs as described above, as an addition or alternative to monolithic LEDs, arrays of one or more microLEDs disposed on a common substrate, segmented microLEDs disposed on a single substrate (where the microLEDs are individually addressable and controllable (and / or controllable in groups and / or subsets)), etc. In some instances, one or more of the light sources 922 may include microLEDs disposed on a transparent flexible substrate, and a rigid substrate adhered to the transparent flexible substrate with an adhesive layer such that the microLEDs are located between the rigid substrate and the transparent flexible substrate.

[0084] One or more light sources 922 may include light-generating elements with different colors or wavelengths. For example, the light source may include a red microLED that can emit red light, a green microLED that can emit green light, and a blue microLED that can emit blue light. The red, green, and blue light are combined in a specific ratio to produce any suitable color that is visually perceptible in the visible portion of the electromagnetic spectrum.

[0085] The visualization system 910 may include one or more modulators 924. The modulators 924 may be implemented in at least one of two configurations.

[0086] In a first configuration, modulator 924 may include circuitry capable of directly modulating light source 922. For example, light source 922 may include an array of light-emitting diodes (LEDs), and modulator 924 may directly modulate the power, voltage, and / or current directed to each LED in the array to form modulated light. Modulation can be performed in analog and / or digital modes. In some instances, light source 922 may include an array of red microLEDs, an array of green microLEDs, and an array of blue microLEDs, and modulator 924 may directly modulate the red, green, and blue microLEDs to form modulated light to produce a specified image.

[0087] In a second configuration, modulator 924 may include a modulation panel, such as a liquid crystal panel. Light source 922 may generate uniform or near-uniform illumination to illuminate the modulation panel. The modulation panel may include pixels. Each pixel may selectively attenuate a corresponding portion of the modulation panel area in response to an electrical modulation signal to form modulated light. In some instances, modulator 924 may include multiple modulation panels capable of modulating different colors of light. For example, modulator 924 may include a red modulation panel capable of attenuating red light from a red light source such as a red microLED, a green modulation panel capable of attenuating green light from a green light source such as a green microLED, and a blue modulation panel capable of attenuating blue light from a blue light source such as a blue microLED.

[0088] In some instances of the second configuration, modulator 924 may receive uniform or nearly uniform white light from a white light source (such as a white microLED). The modulation panel may include wavelength-selective filters on each pixel of the modulation panel. Panel pixels may be arranged in groups (such as three or four groups), where each group may form pixels for a color image. For example, each group may include panel pixels with a red filter, panel pixels with a green filter, and panel pixels with a blue filter. Other suitable configurations may also be used.

[0089] The visualization system 910 may include one or more modulation processors 926, which may receive video signals, for example, from the one or more video generation processors 920, and in response may generate an electrically modulated signal. In a configuration where modulator 924 directly modulates light source 922, the electrically modulated signal may drive light source 922. In a configuration where modulator 924 includes a modulation panel, the electrically modulated signal may drive the modulation panel.

[0090] The visualization system 910 may include one or more beam combiners 928 (also referred to as beam splitters) that can combine beams of different colors to form a single polychromatic beam. For a configuration in which the light source 922 may include multiple microLEDs of different colors, the visualization system 910 may include one or more wavelength-sensitive (e.g., dichroic) beam combiners 928 that can combine light of different colors to form a single polychromatic beam.

[0091] The visualization system 910 can direct modulated light toward a viewer's eyes in at least two configurations. In a first configuration, the visualization system 910 can act as a projector and may include projection optics 930 that can project modulated light onto one or more screens 932. Suitable forms of projection optics 930 may include, for example, lenses, mirrors, or other optical elements. The screens 932 may be located at a suitable distance from the user's eyes. The visualization system 910 may optionally include one or more lenses 934 that can position a virtual image of the screens 932 at a suitable distance from the eyes, such as a near-focal distance, such as 500 mm, 750 mm, or another suitable distance. In some instances, the visualization system 910 may include a single screen 932 such that modulated light can be directed toward the user's eyes. In some instances, the visualization system 910 may include two screens 932 such that modulated light from each screen 932 can be directed toward the user's respective eyes. In some instances, the visualization system 910 may include more than two screens 932. In the second configuration, the visualization system 910 can direct modulated light directly into one or both eyes of the viewer. For example, the projection optics 930 can form an image on the retina of the user's eye, or on each retina of the user's two eyes.

[0092] For some configurations of the AR system, the visualization system 910 may include a display that is at least partially transparent, allowing the user to view their surroundings through the display. In such a configuration, the augmented reality system may generate enhanced modulated light corresponding to the surrounding environment, rather than the environment itself. For example, in the instance of a retail store showing chairs, the augmented reality system may direct modulated light corresponding to the chairs but not to the rest of the room toward the screen or toward the user's eyes.

[0093] Figure 10 Exemplary methods for driving multicolor matrices, as disclosed in different embodiments herein, are illustrated. In some aspects, Figure 10Process 1000 can be performed by the device or a portion thereof. At operation 1002, the process may include a processor determining driving parameters for the multicolor matrix. The processor may determine control signals to control the driving circuitry to drive each microLED of the three (or more) junction multicolor devices in the matrix. The parameters may each include a current and driving time or duty cycle for each microLED. At operation 1004, the process may further include using the driving circuitry to sequentially drive each microLED in the array. MicroLEDs in a particular microLED device of a pixel (or cell) may be sequentially driven using multiple bus lines provided to each pixel before moving to the next microLED device of another pixel. Pixels may be addressed sequentially or in any other manner as determined by the processing circuitry. Note that other operations may exist. The method operations may be performed substantially simultaneously or in a sequence different from that shown.

[0094] Figure 11 An example of a multicolor matrix is ​​shown. The multicolor matrix 1100 includes multiple cells 1102 (or pixels), each cell having multiple microLEDs 1104a, 1104b, 1104c connected in series to emit light. As shown, the microLEDs 1104a, 1104b, 1104c include a red microLED 1104a and a blue microLED 1104c. The cathode (R-terminal) of the red microLED 1104a is coupled to the anode (G+ terminal) of the green microLED 1104b, and the anode (B+ terminal) of the blue microLED 1104c is coupled to the cathode (G-terminal) of the green microLED 1104b. For convenience, only one row of cells 1102 of the multicolor matrix 1100 is shown. In cell 1102 (e.g., as... Figure 11 During the sequential driving of the leftmost unit shown, the anode of the green microLED 1104b is driven by the current source 1106 (green driver), while the anode of the red microLED 1104a, the cathode of the green microLED 1104b, and the anode and cathode of the blue microLED 1104c are grounded.

[0095] The sequential conduction of microLEDs 1104a, 1104b, and 1104c in a matrix configuration results in several inactive nodes, while a single device (in...) Figure 11 The green microLED 1104b shown in the image is always active. To ensure that no other unit 1102 is activated simultaneously, the non-participating ports should remain in a high-impedance state; therefore, these ports do not provide or absorb current. However, as Figure 11 As shown, when operating on the leftmost cell, current leaks from the green driver, causing the remaining cells to be unintentionally activated by connecting the inactive microLEDs to ground. Figure 11In the driving scheme shown, the green microLED 1104b of the first unit 1102 is driven by the G+ and B+ terminals (grounded), while the R+ and B- terminals are grounded. However, the inactive B- terminal also grounds adjacent units, where other green and blue microLEDs are unintentionally activated. The increased grounding creates a loop current, marked by a curved arrow terminating in the idle B- terminal.

[0096] To counteract this, driver control should operate from the final-level demultiplexer. Figure 5B The enable circuit shown is used to completely isolate the micro-LED to be turned on. Figure 5B The added NAND gates and inverters are highlighted, allowing only one output demultiplexer to drive a terminal or ground a terminal at a specific time. Furthermore, if the indicated terminal is not in use, then... Figure 5B The enable circuit in the circuit can alleviate or completely cut off the output circuit. Similarly, Figure 6B The enable circuit in the demultiplexer controls how the demultiplexer sets its high-impedance state by enabling the enable signal to turn off the inactive outputs.

[0097] Figures 12A-12E The diagram illustrates the driving of LEDs in a multicolor matrix according to different embodiments of the disclosed subject matter. Specifically, Figures 12A-12E The activation of different microLEDs 1204a, 1204b, and 1204c within individual cells 1200a and 1200b in array 1210 is illustrated using multiple current sources 1202a, 1202b and ground 1206. Due to the independent nature of the red and blue ports in the stackable LED structure shown herein, the fully sequential process can be improved to allow at least some colors to be active simultaneously. Figure 12A and Figure 12C Individual unit 1200a is shown, in which red microLED 1204a and blue microLED 1204c are simultaneously driven using multiple current sources 1202a, 1202b and ground 1206. Figure 12A Then, a current source 1202 and ground 1206 are used to sequentially drive the green microLED 1204b. Figure 12C ).

[0098] This reduces the original 3-level sequence (each activation of microLEDs 1204a, 1204b, and 1204c) to a 2-level process (each activation of a set of microLEDs 1204a, 1204b, and 1204c, where at least one set includes microLEDs of different colors). Figure 12B and 12D Show respectively Figure 12A and 12CThe activation order is shown in the form of rows (containing multiple rows) of array 1210. The activated microLEDs 1204a, 1204b, and 1204c are... Figure 12B and 12D The LEDs with circles are shown in the image. Figure 12B and 12D The activation of microLEDs 1204a, 1204b, and 1204c in the first unit of array 1210 is shown, while Figure 12E The simultaneous driving of the red microLED 1204a and blue microLED 1204c in the second unit of array 1210 is shown.

[0099] In a 64x64 multicolor array Figure 2A-2C The initial sorting method shown would activate 12,288 microLEDs (64x64x3). By pipelined the activation of blue microLEDs together with that of red microLEDs, this sorting uses 8,192 microLEDs (64x64x2), a reduction of 33.33%. Reducing the number of microLED activations allows each microLED to be activated for a longer period, resulting in improved brightness performance over the same total time compared to the initial sorting method.

[0100] One drawback of using a completely sequential method to turn on microLEDs is the brightness loss due to the low duty cycle. In the example above, Figure 12B , Figure 12D and Figure 12E The improved sequencing shown takes 64*64*2=8192 activations, meaning the maximum duty cycle for any LED translates to an effective ratio of 0.01%. Different methods of using sequencing strategies make their execution based on focusing the sequence only on the pixels to be powered, thus reducing the number of pixels scanned and increasing the effective duty cycle and brightness.

[0101] Figure 13A Examples of active and inactive pixels according to different embodiments of the disclosed subject are shown. Figure 13A In the exemplary image 1300 shown, the black areas marked as inactive pixels are not scanned, and only the pattern of micro-LEDs forming the word "LED" will be considered. In this example, only 351 pixels are marked as active. Because 351 pixels are marked as active, 351*2=702 red / blue and green pixels are used for activation, and the maximum duty cycle of each active pixel is 0.142% of the initial total sequential method, which is 14.24 times higher.

[0102] In this technology, when a new frame arrives, the driver control board (which includes drive circuitry and grounding switch circuitry) may also include a pre-calculation stage. This pre-calculation can be performed by a processor to generate a list of active pixels in the new frame. This allows the display engine to know which pixels should execute commands to turn on. Figure 13B Various embodiments based on the disclosed subject matter are shown. Figure 13A An instance of pixel coordinates. Figure 13B The pixel coordinates 1310 shown in the figure and Table 1 illustrate the target Figure 13A The operations performed in the exemplary image 1300. Project Number Activate Pixel X Activate pixel Y 1 10 24 2 11 24 3 12 24 * * * * * * * * * 349 52 38 350 53 38 351 54 38 Table 1: From Figure 13A and 13B A list of active pixels for the pattern in the image.

[0103] This pre-calculation phase collects the coordinates of each active pixel to feed a list of active pixels. Figure 13A and Figure 13B In this example, the top three pixels at the top left become the top three elements in the list in Table 1. The bottom three pixels at the bottom right become the bottom three elements in the list in Table 1. When a new frame is scheduled to be displayed in a subsequent cycle, the control system (e.g., processing circuitry) can dynamically perform pre-calculations. During the display phase, the system performs the turn-on sequence stepwise for each active element rather than the entire array. Therefore, when the processing circuitry determines that a new frame has arrived for display by the array, it uses a list of the xy coordinates of each of the identified active pixels to determine which pixels will be active to display the image indicated by the new frame. The processing circuitry controls the driving of the pixels by limiting the driving of the identified active pixels, specifically by driving the identified active pixels sequentially, and for each of these pixels, sequentially driving the first and second groups of microLEDs in the pixel (before moving to the next pixel indicated in the list).

[0104] Note that, although in Figures 12A-12E Only red, green, and blue microLEDs are shown, but other implementations can use microLEDs that emit different colors (e.g., saturated colors), additional colors (e.g., yellow and / or white), and / or replicated colors (e.g., multiple microLEDs having a specific color due to comparable emission efficiency). In embodiments using more than three colors, using techniques similar to those described, a set of two or more colors can be activated simultaneously.

[0105] Example Example 1 is a lighting system comprising: an array of vertically stacked multicolor microlight-emitting diodes (microLEDs), each microLED being configured to emit light of a different color; a plurality of drivers configured to independently drive each color of each microLED; and processing circuitry configured to control the plurality of drivers for each microLED to sequentially emit the color.

[0106] In Example 2, the subject matter as described in Example 1 includes: wherein the processing circuitry is configured to: control the plurality of drivers for each microLED device to avoid driving the microLED devices to emit the color simultaneously.

[0107] In Example 3, the subject matter as described in any one of Examples 1 to 2 includes: wherein each microLED device includes: a first terminal coupled to a first end of a first pn junction configured to emit a first color light; a second terminal coupled to a first end of a second pn junction, the first end of the second pn junction coupled to a second end of the first pn junction configured to emit a second color light different from the first color light; a third terminal coupled to a first end of a third pn junction, the first end of the third pn junction coupled to a second end of the second pn junction configured to emit a third color light different from the first and second color lights; and a fourth terminal coupled to a second end of the third pn junction.

[0108] In Example 4, the subject matter as described in Example 3 includes: wherein the processing circuit is configured to control the plurality of drivers to sequentially drive the first pn junction, the second pn junction, and the third pn junction by: routing a first constant current to the first terminal via the first driver and grounding the second terminal during a first time period of the cycle to limit the driving of the first microLED during the first time period; routing a second constant current to the second terminal via the second driver and grounding the third terminal during a second time period of the cycle to limit the driving of the second microLED during the second time period; and routing a third constant current to the third terminal via the third driver and grounding the fourth terminal during a third time period of the cycle to limit the driving of the third microLED during the third time period.

[0109] In Example 5, the subject matter as described in Example 4 includes: wherein the first constant current, the second constant current, and the third constant current are independent of each other and are the same.

[0110] In Example 6, the subject matter as described in any one of Examples 4 to 5 includes: wherein the first constant current, the second constant current, and the third constant current are independent of each other and different.

[0111] In Example 7, the subject matter as described in any one of Examples 4 to 6 includes: wherein, during the period, the conduction durations of the first constant current, the second constant current, and the third constant current are independent of each other and are the same.

[0112] In Example 8, the subject matter as described in any one of Examples 4 to 7 includes: wherein, during the period, the conduction durations of the first constant current, the second constant current, and the third constant current are independent of each other and are different.

[0113] In Example 9, the subject matter of any one of Examples 3-8 includes: wherein the array of the microLED device includes an array of bus lines coupled to the plurality of drivers, wherein in the array of bus lines: a first bus line is coupled to a first terminal, a third bus line is coupled to the third terminal and the first bus line is parallel to the third bus line, a second bus line is coupled to the second terminal, and a fourth bus line is coupled to the fourth terminal and the second bus line is parallel to the fourth bus line.

[0114] In Example 10, the subject matter as described in any one of Examples 1 to 9 includes: wherein each drive circuit is configured to receive a bias current from a sink current / source current driver and a control signal from the processing circuit.

[0115] In Example 11, the subject matter as described in any one of Examples 1 to 10 includes: wherein each driving circuit includes an m-channel cascaded analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel cascaded analog multiplexer being configured to receive a sink current / source current at a first input and ground at a second input, and selectively providing the sink current / source current or ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers being configured to select the channel for routing the sink current / source current or ground based on other control signals from the processing circuitry.

[0116] In Example 12, the subject matter as described in Example 11 includes: wherein the m-channel cascaded analog multiplexer is further configured to receive a pulse width modulation (PWM) signal from the processing circuit to set the duty cycle for applying the absorb current / source current to the channel and to dim the illumination provided by the microLEDs coupled to the channel.

[0117] In Example 13, the subject matter as described in any one of Examples 1 to 12 includes: a grounding switch circuit configured to route a ground to one of a plurality of terminals of each microLED, the grounding switch circuit including an m-channel analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel analog multiplexer having a ground input and selectively providing the ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers being configured to select the channel for routing the ground based on other control signals from the processing circuitry.

[0118] In Example 14, the subject matter as described in any one of Examples 1 to 13 includes: wherein the microLED device is configured to emit red, green and blue light.

[0119] Example 15 is a controller comprising: a plurality of drivers configured to independently drive a plurality of bus lines of an array of vertically stacked multicolor microlight-emitting diodes (microLEDs), each microLED having a pn junction configured to emit light of a different color, each microLED having a terminal coupled to a different bus line to emit one of a different color; a grounding switch circuit configured to route a ground to one of the bus lines; and a processing circuit configured to control the plurality of drivers and the grounding switch circuit such that, for each microLED, the color of the microLED is sequentially driven by providing a drive current to one of the bus lines, and the ground is routed to another of the bus lines.

[0120] In Example 16, the subject matter as described in Example 15 includes: wherein the processing circuitry is configured to control the plurality of drivers and the grounding switch circuitry to drive each microLED device to avoid emitting the colors simultaneously.

[0121] In Example 17, the subject matter as described in any one of Examples 15 to 16 includes: wherein the processing circuitry is configured to control the constant currents routed to the bus lines to be independent and identical to each other.

[0122] In Example 18, the subject matter as described in any one of Examples 15 to 17 includes: wherein the processing circuitry is configured to control the constant currents routed to the bus lines to be independent and distinct from each other.

[0123] In Example 19, the subject matter as described in any one of Examples 15 to 18 includes: wherein the processing circuitry is configured to control the on-time duration of the constant current routed to the bus line to be independent and identical to each other.

[0124] In Example 20, the subject matter as described in any one of Examples 15 to 19 includes: wherein the processing circuitry is configured to control the on-time duration of the constant current routed to the bus line to be independent and different from each other.

[0125] In Example 21, the subject matter as described in any one of Examples 15-20 includes: wherein the bus lines are configured such that: a first bus line is coupled to a first terminal of the microLED, a third bus line is coupled to a third terminal of the microLED and the first bus line is parallel to the third bus line, a second bus line is coupled to a second terminal of the microLED, a fourth bus line is coupled to a fourth terminal of the microLED and the second bus line is parallel to the fourth bus line.

[0126] In Example 22, the subject matter as described in any one of Examples 15 to 21 includes: wherein each drive circuit is configured to receive a bias current from a sink current / source current driver and a control signal from the processing circuit.

[0127] In Example 23, the subject matter as described in any one of Examples 15 to 22 includes: wherein: each drive circuit includes an m-channel cascaded analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel cascaded analog multiplexer being configured to receive a sink current / source current at a first input and ground at a second input, and selectively providing the sink current / source current or ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers being configured to select the channel for routing the sink current / source current or ground based on other control signals from the processing circuitry.

[0128] In Example 24, the subject matter as described in Example 23 includes: wherein the m-channel cascaded analog multiplexer is further configured to receive a pulse width modulation (PWM) signal from the processing circuit to set the duty cycle for applying the absorb current / source current to the channel, and to dim the illumination provided by the micro-LEDs coupled to the channel.

[0129] In Example 25, the subject matter as described in any one of Examples 15 to 24 includes: wherein the grounding switch circuit includes an m-channel analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel analog multiplexer having a grounding input and selectively routing the grounding to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers being configured to select the channel for routing the grounding based on other control signals from the processing circuitry.

[0130] Example 26 is a method for providing light from a vertically stacked array of multicolor microlight-emitting diodes (microLEDs), each microLED device being configured to emit light of a different color, the method comprising: independently driving each color of each microLED device; and controlling the driving of each microLED device to drive the microLED device to emit colors sequentially.

[0131] In Example 27, the subject of Example 26 includes: driving each microLED device to avoid simultaneous emission of colors.

[0132] In Example 28, the subject matter of Example 26 includes: wherein each microLED device includes: a first terminal coupled to a first end of a first pn junction configured to emit a first color of light; a second terminal coupled to a first end of a second pn junction, the first end of which is coupled to a second end of the first pn junction configured to emit a second color of light different from the first color of light; a third terminal coupled to a first end of a third pn junction, the first end of which is coupled to a second end of the second pn junction configured to emit a third color of light different from both the first and second color of light; and a fourth terminal coupled to a second end of the third pn junction. Furthermore, controlling the driving of each microLED device includes controlling the drive to sequentially drive the first pn junction, the second pn junction, and the third pn junction in the following manner: providing a first constant current to the first terminal via a first driver and grounding the second terminal during a first time period of the cycle to limit the driving of the first pn junction during the first time period; providing a second constant current to the second terminal via a second driver and grounding the third terminal during a second time period of the cycle to limit the driving of the second pn junction during the second time period; and providing a third constant current to the third terminal via a third driver and grounding the fourth terminal during a third time period of the cycle to limit the driving of the third pn junction during the third time period.

[0133] In Example 29, the subject of Example 28 includes: wherein controlling the drive of each microLED device includes controlling a first constant current, a second constant current, and a third constant current to be independent of each other and identical.

[0134] In Example 30, the subject matter of any one of Examples 28-29 includes: wherein controlling the drive of each microLED device includes controlling a first constant current, a second constant current, and a third constant current to be independent and different from each other.

[0135] In Example 31, the subject matter of any one of Examples 28-30 includes: wherein controlling the driving of each microLED device includes controlling the conduction durations of the first constant current, the second constant current, and the third constant current to be independent of each other and the same during the cycle.

[0136] In Example 32, the subject matter of any one of Examples 28-31 includes: wherein controlling the driving of each microLED device includes controlling the conduction durations of a first constant current, a second constant current, and a third constant current to be independent and different from each other during the cycle.

[0137] In Example 33, the subject matter of any one of Examples 28-32 includes: wherein the array of microLED devices includes an array of bus lines, wherein: a first bus line is coupled to a first terminal, a third bus line is coupled to the third terminal and the first bus line is parallel to the third bus line, and a second bus line is coupled to the second terminal, and a fourth bus line is coupled to the fourth terminal and the second bus line is parallel to the fourth bus line.

[0138] In Example 34, the subject of Example 33 includes: wherein controlling the driving of each microLED device includes receiving a bias current from a current driver and receiving a control signal from a processing circuit.

[0139] In Example 35, the subject of Example 33 includes: wherein driving each microLED device includes using an m-channel cascaded analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel cascaded analog multiplexer receiving a sink current / source current at a first input and a ground at a second input, and selectively providing the sink current / source current or ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers selecting the channel for routing the sink current / source current or ground based on other control signals from the processing circuitry.

[0140] In Example 36, the subject of Example 35 includes: wherein driving each microLED device further includes: using the m-channel cascaded analog multiplexer to receive a pulse width modulation (PWM) signal from the processing circuit in order to set the duty cycle for applying the absorb current / source current to the channel and to dim the illumination routed by the microLEDs coupled to the channel.

[0141] In Example 37, the subject of Example 33 includes: wherein controlling the driving of each microLED device includes grounding one of a plurality of terminals of each microLED using an m-channel analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel multiplexer having a ground input and selectively providing ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers selecting the channel of grounding based on other control signals from the processing circuitry.

[0142] Example 38 is a non-transitory computer-readable storage medium storing instructions for execution by one or more processors of a lamp system, the one or more processors configuring the lamp system to: independently drive each color of each microlight-emitting diode (microLED) device in an array of vertically stacked multicolor microLED devices, each microLED device being configured to emit light of a different color; and control the driving of each microLED device to drive the microLED devices to emit colors sequentially.

[0143] In Example 39, the subject of Example 38 includes: wherein the one or more processors, when the instructions are executed, configure the lighting system to drive each microLED device to avoid emitting colors simultaneously.

[0144] In Example 40, the subject matter of any one of Examples 38 to 39 includes: wherein each microLED device includes: a first terminal coupled to a first end of a first pn junction, the first pn junction being configured to emit a first color light; a second terminal coupled to a first end of a second pn junction, the first end of the second pn junction being coupled to a second end of the first pn junction, the second pn junction being configured to emit a second color light different from the first color light; a third terminal coupled to a first end of a third pn junction, the first end of the third pn junction being coupled to a second end of the second pn junction, the third pn junction being configured to emit a third color light different from the first color light and the second color light; and a fourth terminal coupled to the second end of the third pn junction, and wherein the one or more processors, when executing the... The instruction configures the lamp system to control the drive of each microLED device by sequentially driving the first pn junction, the second pn junction, and the third pn junction through the following steps: providing a first constant current to the first terminal via a first driver and grounding the second terminal during the first time period of the cycle; routing a second constant current to the second terminal via the second driver and grounding the third terminal during the second time period of the cycle; and routing a third constant current to the third terminal via a third driver and grounding the fourth terminal during the third time period of the cycle to limit the drive of the third pn junction during the third time period.

[0145] In Example 41, the subject of Example 40 includes: wherein the one or more processors, when executing the instructions, configure the lighting system to control the driving of each microLED device by controlling the first constant current, the second constant current, and the third constant current to be independent of each other and the same.

[0146] In Example 42, the subject matter as described in any one of Examples 40 to 41 includes: wherein the one or more processors, when executing the instructions, configure the lighting system to control the driving of each microLED device by controlling the first constant current, the second constant current, and the third constant current to be independent and different from each other.

[0147] In Example 43, the subject matter as described in any one of Examples 40-42 includes: wherein, when the instructions are executed, the one or more processors configure the lamp system to control the driving of each microLED device by controlling the on-time of the first constant current, the second constant current and the third constant current to be independent and the same in that cycle.

[0148] In Example 44, the subject matter as described in any one of Examples 40-43 includes: wherein, when the instructions are executed, the one or more processors configure the lamp system to control the driving of each microLED device by controlling the on-time durations of the first constant current, the second constant current, and the third constant current to be independent and different from each other during the cycle.

[0149] In Example 45, the subject matter of any of Examples 40-44 includes: wherein the array of the microLED device comprises an array of bus lines, wherein: a first bus line is coupled to a first terminal, a third bus line is coupled to the third terminal and the first bus line is parallel to the third bus line, and a second bus line is coupled to the second terminal, and a fourth bus line is coupled to the fourth terminal and the second bus line is parallel to the fourth bus line.

[0150] In Example 46, the subject of any one of Examples 38-45 includes: wherein, when instructions are executed, the one or more processors configure the lighting system to control the driving of each microLED device by receiving a bias current from a current driver and a control signal from the processing circuitry.

[0151] In Example 47, the subject matter of any one of Examples 38-46 includes: wherein, when the instructions are executed, the one or more processors configure the lighting system to drive each microLED device using an m-channel cascaded analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel cascaded analog multiplexer receiving a sink current / source current at a first input and a ground at a second input, and selectively providing the sink current / source current or ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers selecting the channel for routing the sink current / source current or ground based on other control signals from the processing circuitry.

[0152] In Example 48, the subject of Example 47 includes: wherein, when the instructions are executed, the one or more processors configure the lighting system to further use the m-channel cascaded analog multiplexer to receive pulse width modulation (PWM) signals from the processing circuitry to drive each microLED device in order to set the duty cycle for applying the absorb current / source current to the channel and to dim the lighting routed by the microLEDs coupled to the channel.

[0153] In Example 49, the subject matter of any one of Examples 38-48 includes: wherein, when the instructions are executed, the one or more processors configure the lighting system to control the driving of each microLED device by grounding one of a plurality of terminals of each microLED using an m-channel analog multiplexer and a plurality of n-channel analog multiplexers, the m-channel multiplexer having a ground input and selectively providing ground to one of the n-channel analog multiplexers based on control signals from the processing circuitry, the n-channel analog multiplexers selecting the channel for routing the ground based on other control signals from the processing circuitry.

[0154] Example 50 is a lighting system comprising: an array of multicolor microlight-emitting diode (microLED) devices, each microLED device having vertically stacked microLEDs configured to emit light of different colors; a plurality of drivers configured to independently drive each color of each microLED device; and processing circuitry configured to control the plurality of drivers for each microLED device to drive the microLED devices to emit the colors sequentially.

[0155] In Example 51, the subject of Example 50 includes: wherein the processing circuitry is configured to: control multiple drivers for each microLED device to avoid driving the microLED devices to emit colors simultaneously.

[0156] In Example 52, the subject matter of Examples 50-51 includes: wherein each microLED device includes: a first terminal coupled to a first end of a first microLED, the first microLED being configured to emit a first color light; a second terminal coupled to a first end of a second microLED, the first end of the second microLED being coupled to a second end of the first microLED, the second microLED being configured to emit a second color light different from the first color light; a third terminal coupled to a first end of a third microLED, the first end of the third microLED being coupled to a second end of the second microLED, the third microLED being configured to emit a third color light different from the first color light and the second color light; and a fourth terminal coupled to a second end of the third microLED.

[0157] In Example 53, the subject of Example 52 includes: wherein the processing circuitry is configured to control a plurality of drivers to sequentially drive a first microLED, a second microLED, and a third microLED by means of the following steps: during a first time period of the cycle, routing a first constant current to a first terminal via the first driver and grounding the second terminal to limit the driving of the first microLED during the first time period; during a second time period of the cycle, routing a second constant current to the second terminal via the second driver and grounding the third terminal to limit the driving of the second microLED during the second time period; and during a third time period of the cycle, routing a third constant current to the third terminal via the third driver and grounding the fourth terminal to limit the driving of the third microLED during the third time period.

[0158] In Example 54, the subject of Example 53 includes: wherein at least one of the following items in the cycle is independent of each other and substantially the same: a) the first constant current, the second constant current and the third constant current; or b) the conduction duration of the first constant current, the second constant current and the third constant current.

[0159] In Example 55, the subject matter of Examples 53-54 includes: wherein at least one of the following items in the cycle is independent of and distinct from each other: a) the first constant current, the second constant current and the third constant current; or b) the conduction duration of the first constant current, the second constant current and the third constant current.

[0160] In Example 56, the subject matter of Examples 52-55 includes: wherein the array of microLED devices includes an array of bus lines coupled to the plurality of drivers, wherein in the array of bus lines: a first bus line is coupled to a first terminal, a third bus line is coupled to the third terminal and the first bus line is parallel to the third bus line, a second bus line is coupled to the second terminal, and a fourth bus line is coupled to the fourth terminal and the second bus line is parallel to the fourth bus line.

[0161] In Example 57, the subject matter as described in Examples 50 to 56 includes: wherein each drive circuit is configured to receive a bias current from a current driver and a control signal from the processing circuit.

[0162] In Example 58, the subject matter as described in Examples 50 to 57 includes: wherein each driving circuit includes an m-channel cascaded analog multiplexer and a plurality of n-channel analog demultiplexers, the m-channel cascaded analog multiplexer being configured to receive a sink current / source current at a first input and ground at a second input, and selectively providing one of the sink current / source current and ground to one of the n-channel analog demultiplexers based on control signals from the processing circuitry, the n-channel analog demultiplexers being configured to select the channel for routing the one of the sink current / source current and ground based on other control signals from the processing circuitry.

[0163] In Example 59, the subject of Example 58 includes: wherein: the m-channel cascaded analog multiplexer includes a cascaded multiplexer and a cascaded demultiplexer, the cascaded demultiplexer being configured to receive the control signal from the processing circuit and to provide one of the absorb current / source current and ground to one of the n-channel analog demultiplexers, and the cascaded multiplexer being configured to receive a pulse width modulation (PWM) signal from the processing circuit to set the duty cycle for applying the absorb current / source current to the channel and to dim the illumination provided by the micro-LEDs coupled to the channel.

[0164] In Example 60, the subject of Example 59 includes: wherein each drive circuit further includes an enable circuit comprising a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate, the input of the inverter and the first input of the second NAND gate being configured to receive the control signal, the second input of the first NAND gate and the second input of the second NAND gate being configured to receive a busy terminal signal, and the output of the first NAND gate being coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate being coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

[0165] In Example 61, the subject of Examples 50-60 includes: a grounding switch circuit configured to route a ground to one of a plurality of terminals of each microLED, the grounding switch circuit including an m-channel analog demultiplexer and a plurality of n-channel analog demultiplexers, the m-channel analog demultiplexer having a ground input and selectively providing the ground to one of the n-channel analog demultiplexers based on control signals from the processing circuitry, the n-channel analog demultiplexers being configured to select the channel for routing the ground based on other control signals from the processing circuitry.

[0166] In Example 62, the subject matter of Example 61 includes: wherein the grounding switch circuit further includes an enable circuit, the enable circuit including a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate, the input of the inverter and the first input of the second NAND gate being configured to receive the control signal, the second input of the first NAND gate and the second input of the second NAND gate being configured to receive an active grounding signal, and the output of the first NAND gate being coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate being coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

[0167] In Example 63, the subject matter of Examples 50-62 includes: wherein the processing circuit is configured to: control the plurality of drivers to sequentially drive a first group of microLEDs comprising a plurality of microLEDs and a second group of microLEDs comprising a single microLED disposed between the plurality of microLEDs for each microLED device.

[0168] In Example 64, the subject of Example 63 includes: wherein the first group of microLEDs includes microLEDs emitting different colors, and the second group of microLEDs includes another microLED emitting a different color from the microLEDs in the first group of microLEDs.

[0169] In Example 65, the subject of Example 64 includes: wherein the processing circuitry is further configured to: determine that a new frame has arrived for display by the array; use a list of xy coordinates of each microLED device determined to be active; determine which microLED devices will be activated to display the image indicated by the new frame; control the driving of the microLED devices to limit the driving of the determined active microLED devices; sequentially drive the determined active microLED devices; and for each of the determined active microLED devices, sequentially drive the first group of microLEDs and the second group of microLEDs.

[0170] Example 66 is a controller comprising: a plurality of drivers configured to independently drive a plurality of bus lines of an array of multicolor microlight-emitting diode (microLED) devices, each microLED device having vertically stacked microLEDs configured to emit light of a different color, each microLED device having a terminal coupled to a different bus line to emit one of the different colors; a grounding switch circuit configured to route a ground to one of the bus lines; and a processing circuit configured to control the plurality of drivers and the grounding switch circuit such that, for each microLED device, the colors of the microLED devices are sequentially driven by providing a constant current to one of the bus lines, and the ground is routed to another of the bus lines.

[0171] In Example 67, the subject matter of Example 66 includes: wherein the bus lines are configured such that: a first bus line is coupled to a first terminal of the microLED, a third bus line is coupled to a third terminal of the microLED and the first bus line is parallel to the third bus line, a second bus line is coupled to a second terminal of the microLED, a fourth bus line is coupled to a fourth terminal of the microLED and the second bus line is parallel to the fourth bus line.

[0172] In Example 68, the subject matter as described in Examples 66 and 67 includes: wherein each driving circuit includes an m-channel cascaded analog multiplexer and a plurality of n-channel analog demultiplexers, the m-channel cascaded analog multiplexer being configured to receive: an absorber current / source current at a first input, and a ground at a second input, the m-channel cascaded analog multiplexer being configured to selectively provide one of the absorber current / source current and the ground to one of the n-channel analog demultiplexers based on a control signal from the processing circuitry, the n-channel analog demultiplexer being configured to select a channel for routing the absorber current / source current and the ground based on other control signals from the processing circuitry, and the m-channel cascaded analog multiplexer being further configured to receive a pulse width modulation (PWM) signal from the processing circuitry to set the duty cycle for applying the absorber current / source current to the channel and to dim the illumination provided by microLEDs coupled to the channel.

[0173] In Example 69, the subject matter as described in Example 68 includes: wherein each drive circuit further includes an enable circuit comprising a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate, the input of the inverter and the first input of the second NAND gate being configured to receive the control signal, the second input of the first NAND gate and the second input of the second NAND gate being configured to receive a busy terminal signal, and the output of the first NAND gate being coupled to an enable input of a first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate being coupled to an enable input of a second demultiplexer of the n-channel analog demultiplexer.

[0174] In Example 70, the subject of Examples 66-69 includes: wherein the grounding switch circuit includes an m-channel analog demultiplexer and a plurality of n-channel analog demultiplexers, the m-channel analog demultiplexer having a grounding input and selectively routing the grounding to one of the n-channel analog demultiplexers based on control signals from the processing circuitry, the n-channel analog demultiplexers being configured to select the channel for routing the grounding based on other control signals from the processing circuitry.

[0175] In Example 71, the subject matter as described in Example 70 includes: wherein the grounding switch circuit further includes an enable circuit comprising a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate, the input of the inverter and the first input of the second NAND gate being configured to receive the control signal, the second input of the first NAND gate and the second input of the second NAND gate being configured to receive an active grounding signal, and the output of the first NAND gate being coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate being coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

[0176] In Example 72, the subject matter of Examples 66-71 includes: wherein the processing circuit is configured to: for each microLED device, control the plurality of drivers to sequentially drive a first group of microLEDs comprising a plurality of microLEDs and a second group of microLEDs comprising a single microLED disposed between the plurality of microLEDs.

[0177] In Example 73, the subject matter as described in Example 72 includes: wherein the processing circuitry is further configured to: determine that a new frame has arrived for display by the array; determine, using a list of xy coordinates of each of the microLED devices determined to be active, which of the microLED devices will be activated to display the image indicated by the new frame; control the driving of the microLED devices to limit the driving of the microLED devices determined to be active; sequentially drive the microLED devices determined to be active; and for each of the microLED devices determined to be active, sequentially drive the first group of microLEDs and the second group of microLEDs.

[0178] Example 74 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement any one of Examples 1 to 73.

[0179] Example 75 is an apparatus that includes means for implementing any one of Examples 1 to 73.

[0180] Example 76 is a system for implementing any one of Examples 1 through 73.

[0181] Example 77 is a method for implementing any one of Examples 1 through 73.

[0182] The subject matter may be referred to individually and / or collectively by the term "embodiment" for convenience only and is not intended to actively limit the scope of this application to any single concept (if more than one concept is actually disclosed). Therefore, while specific embodiments have been shown and described herein, it should be understood that any arrangement contemplated to achieve the same purpose may replace the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of different embodiments. Upon review of the above description, combinations of the above embodiments with other embodiments not specifically described herein will become apparent to those skilled in the art.

[0183] In this document, as is common in patent documents, the terms “a” or “an” are used to include one or more, independent of any other instances or uses of “at least one” or “one or more.” In this document, unless otherwise specified, the term “or” is used to mean a non-exclusive “or,” such that “A or B” includes “A but not B,” “B but not A,” and “A and B.” In this document, the terms “comprising” and “wherein” are used as concise English equivalents to the corresponding terms “including” and “wherein.” Furthermore, in the following claims, the terms “comprising” and “including” are open-ended, meaning that a system, UE, article, composition, formulation, or process that includes elements other than those listed after such terms in the claims is still considered to fall within the scope of the claims. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc., are used only as designations and are not intended to impose numerical requirements on their objects. For example, the term "processor" configured to perform a particular operation includes: a single processor configured to perform all operations; and multiple processors each configured to perform some or all operations (which may overlap) such that a combination of processors performs all operations. It should be noted that, unless otherwise specified, the term "about x" and similar terms (e.g., substantially) as used herein can be understood as being within 10% of x or within a range known to those skilled in the art to be within the tolerances of the described quantity or quality.

[0184] An abstract of this disclosure has been submitted; it should be understood that this abstract is not intended to interpret or limit the scope or meaning of the claims. Furthermore, as can be seen in the above detailed description, different features are combined in a single embodiment for the purpose of simplification. This method of disclosure should not be construed as reflecting an intention that the claimed embodiment needs to have more features than those expressly stated in each claim. Rather, as reflected in the following claims, the subject matter lies in fewer than all features in the embodiments of a single disclosure. Therefore, the following claims are included in the detailed description, wherein each claim is an independent, separate embodiment.

Claims

1. A lighting system, comprising: An array of multicolor micro-light-emitting diode (micro-LED) devices, each micro-LED device having vertically stacked micro-LEDs configured to emit light of different colors; Multiple drivers are configured to independently drive each color of each microLED device; as well as The processing circuit is configured to control the plurality of drivers for each microLED device to drive the microLED devices to emit the color sequentially.

2. The lighting system according to claim 1, wherein, The processing circuit is configured to control the plurality of drivers for each microLED device to avoid driving the microLED devices to emit the color simultaneously.

3. The lighting system according to claim 1 or 2, wherein, Each microLED device includes: A first terminal is coupled to a first end of a first microLED, which is configured to emit light of a first color. The second terminal is coupled to the first terminal of the second microLED, and the first terminal of the second microLED is coupled to the second terminal of the first microLED. The second microLED is configured to emit a second color light different from the first color light. The third terminal is coupled to the first terminal of the third microLED, which is coupled to the second terminal of the second microLED. The third microLED is configured to emit a third color light that is different from the first and second color lights. The fourth terminal is coupled to the second terminal of the third micro-LED.

4. The lighting system according to claim 3, wherein, The processing circuit is configured to control the plurality of drivers to sequentially drive the first microLED, the second microLED, and the third microLED through operations including the following steps: During the first time period of the cycle, a first constant current is routed to the first terminal via the first driver, and the second terminal is grounded to limit the driving of the first micro-LED during the first time period. During the second time period of the cycle, a second constant current is routed to the second terminal via the second driver, and the third terminal is grounded to limit the driving of the second microLED during the second time period. During the third period of the cycle, a third constant current is routed to the third terminal via a third driver, and the fourth terminal is grounded to limit the driving of the third microLED during the third period.

5. The lamp system of claim 4, wherein at least one of the following is independent of each other and substantially the same in the cycle: a) the first constant current, the second constant current and the third constant current; or b) the conduction duration of the first constant current, the second constant current and the third constant current.

6. The lamp system of claim 4, wherein at least one of the following is independent of and different from each other in the cycle: a) the first constant current, the second constant current and the third constant current; or b) the conduction duration of the first constant current, the second constant current and the third constant current.

7. The lighting system according to any one of claims 3 to 6, wherein, The array of microLED devices includes an array of bus lines coupled to the plurality of drivers, wherein: A first bus line is coupled to the first terminal, a third bus line is coupled to the third terminal, and the first bus line is parallel to the third bus line. The second bus line is coupled to the second terminal, the fourth bus line is coupled to the fourth terminal, and the second bus line is parallel to the fourth bus line.

8. The lighting system according to any one of claims 1-7, wherein, Each drive circuit is configured to receive a bias current from a current driver and a control signal from the processing circuit.

9. The lighting system according to any one of claims 1-8, wherein, Each drive circuit includes an m-channel cascaded analog multiplexer and a plurality of n-channel analog demultiplexers. The m-channel cascaded analog multiplexer is configured to receive a sink current / source current at a first input and ground at a second input, and selectively provides one of the sink current / source current and ground to one of the n-channel analog demultiplexers based on control signals from the processing circuit. The n-channel analog demultiplexer is configured to select the channel that routes the sink current / source current and ground based on other control signals from the processing circuit.

10. The lighting system according to claim 9, wherein: The m-channel cascaded analog multiplexer includes a cascaded multiplexer and a cascaded demultiplexer. The cascaded demultiplexer is configured to receive the control signal from the processing circuit and provide one of the sink current / source current and ground to one of the n-channel analog demultiplexers. The cascaded multiplexer is configured to receive a pulse width modulation (PWM) signal from the processing circuit to set the duty cycle for applying the absorb current / source current to the channel and to dim the illumination provided by the microLEDs coupled to the channel.

11. The lighting system according to claim 10, wherein: Each drive circuit also includes an enable circuit. The enabling circuit includes a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate. The input of the inverter and the first input of the second NAND gate are configured to receive the control signal. The second inputs of the first NAND gate and the second NAND gate are configured to receive a busy terminal signal, and The output of the first NAND gate is coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate is coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

12. The lighting system according to any one of claims 1-11, further comprising a grounding switch circuit configured to route a ground to one of a plurality of terminals of each microLED, the grounding switch circuit including an m-channel analog demultiplexer and a plurality of n-channel analog demultiplexers, the m-channel analog demultiplexer having a ground input and selectively providing the ground to one of the n-channel analog demultiplexers based on a control signal from the processing circuitry, the n-channel analog demultiplexer being configured to select the channel for routing the ground based on other control signals from the processing circuitry.

13. The lighting system according to claim 12, wherein: The grounding switch circuit also includes an enable circuit. The enabling circuit includes a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate. The input of the inverter and the first input of the second NAND gate are configured to receive the control signal. The second inputs of the first NAND gate and the second NAND gate are configured to receive an active ground signal, and The output of the first NAND gate is coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate is coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

14. The lighting system according to any one of claims 1-13, wherein, The processing circuit is configured to control the plurality of drivers to sequentially drive a first group of microLEDs comprising a plurality of microLEDs and a second group of microLEDs comprising a single microLED disposed between the plurality of microLEDs for each microLED device.

15. The lighting system according to claim 14, wherein, The first group of microLEDs includes microLEDs that emit different colors, and the second group of microLEDs includes another microLED that emits a different color than the microLEDs in the first group of microLEDs.

16. The lighting system according to claim 15, wherein, The processing circuit is further configured to: A new frame has arrived for display by the array. Using a list of the xy coordinates of each microLED device identified as active, it is determined which microLED devices will be activated to display the image indicated by the new frame. Controlling the driving of the microLED devices to limit the driving of microLED devices identified as active, sequentially driving the microLED devices identified as active, and for each of the microLED devices identified as active, sequentially driving the first group of microLEDs and the second group of microLEDs.

17. A controller, comprising: Multiple drivers are configured to independently drive multiple bus lines of an array of multicolor micro light-emitting diode (microLED) devices, each microLED device having vertically stacked microLEDs configured to emit light of different colors, each microLED device having a terminal, each terminal being coupled to a different bus line to emit one of the different colors; A grounding switch circuit is configured to route a ground to one of the bus lines; as well as The processing circuitry is configured to control the plurality of driver and ground switch circuits, thereby sequentially driving the color of each microLED device by providing a constant current to one of the bus lines and routing the ground to the other of the bus lines for each microLED device.

18. The controller according to claim 17, wherein, The bus line is configured such that: A first bus line is coupled to a first terminal of the micro-LED, and a third bus line is coupled to a third terminal of the micro-LED, with the first bus line parallel to the third bus line. The second bus line is coupled to the second terminal of the micro LED, and the fourth bus line is coupled to the fourth terminal of the micro LED, with the second bus line and the fourth bus line being parallel.

19. The controller according to claim 17 or 18, wherein: Each driver circuit includes an m-channel cascaded analog multiplexer and multiple n-channel analog demultiplexers. The m-channel cascaded analog multiplexer is configured to receive: The absorption current / source current at the first input, and Grounding at the second input, The m-channel cascaded analog multiplexer is configured to selectively provide one of the sink current / source current and ground to one of the n-channel analog demultiplexers based on a control signal from the processing circuitry. The n-channel analog demultiplexer is configured to select a channel for routing one of the sink current / source current and ground based on other control signals from the processing circuitry, and The m-channel cascaded analog multiplexer is further configured to receive pulse width modulation (PWM) signals from the processing circuit in order to set the duty cycle for applying the absorb current / source current to the channel and to dim the illumination provided by the micro-LEDs coupled to the channel.

20. The controller according to claim 19, wherein: Each drive circuit also includes an enable circuit. The enabling circuit includes a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate. The input of the inverter and the first input of the second NAND gate are configured to receive the control signal. The second inputs of the first NAND gate and the second NAND gate are configured to receive a busy terminal signal, and The output of the first NAND gate is coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate is coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

21. The controller according to any one of claims 17 to 20, wherein, The grounding switch circuit includes an m-channel analog demultiplexer and a plurality of n-channel analog demultiplexers. The m-channel analog demultiplexer has a grounding input and selectively routes the grounding to one of the n-channel analog demultiplexers based on control signals from the processing circuit. The n-channel analog demultiplexers are configured to select the channel for routing the grounding based on other control signals from the processing circuit.

22. The controller according to claim 21, wherein: The grounding switch circuit also includes an enable circuit. The enabling circuit includes a first NAND gate, a second NAND gate, and an inverter, the inverter having an output coupled to a first input of the first NAND gate. The input of the inverter and the first input of the second NAND gate are configured to receive the control signal. The second inputs of the first NAND gate and the second NAND gate are configured to receive an active ground signal, and The output of the first NAND gate is coupled to the enable input of the first demultiplexer of the n-channel analog demultiplexer, and the output of the second NAND gate is coupled to the enable input of the second demultiplexer of the n-channel analog demultiplexer.

23. The controller according to any one of claims 17 to 22, wherein: The processing circuit is configured to control the plurality of drivers to sequentially drive a first group of microLEDs comprising a plurality of microLEDs and a second group of microLEDs comprising a single microLED disposed between the plurality of microLEDs for each microLED device.

24. The controller according to claim 23, wherein, The processing circuit is further configured to: A new frame has arrived for display by the array. Using a list of the xy coordinates of each of the microLED devices identified as active, it is determined which of the microLED devices will be activated to display the image indicated by the new frame, and Controlling the driving of the microLED devices to limit the driving of the microLED devices determined to be active, sequentially driving the microLED devices determined to be active, and for each of the microLED devices determined to be active, sequentially driving the first group of microLEDs and the second group of microLEDs.

25. A method for providing light from an array of multicolor microlight-emitting diodes (microLEDs), the method comprising: Each color of each microLED device in the array is driven independently, and each microLED device has vertically stacked microLEDs configured to emit light of different colors; as well as Control the drive of each microLED device to drive the microLED device to emit colors sequentially.

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