Micro-LED Display Repair

A manufacturing method for replacing defective light-emitting elements in dense arrays without damaging adjacent elements. The method involves irradiating the adhesive layers between the elements with ultraviolet light. The UV exposure reduces the adhesion of the irradiated areas. This allows selectively removing the defective element while leaving the adjacent elements attached due to the stronger adhesion.

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Display device with a blocker structure to prevent circuit substrate damage during repair of micro LED displays using laser removal. The display has a blocker on the substrate with pads for the micro LED electrodes. The blocker has sides aligned with the connecting pads. This prevents laser light from the micro LED removal process from reaching and damaging the substrate through the pads. The blocker shields the substrate while the micro LEDs are removed and replaced.

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Inspection apparatus and method for detecting and managing defective pixels in displays like LED panels. The apparatus uses an external device with a camera to capture images of the display, identify defective pixels based on low luminance, and store their locations. The display device can then limit electrical signals to those pixels to prevent incorrect lighting. This enables targeted mitigation of defective pixels without affecting normal ones.

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A component processing apparatus for efficiently transferring and repairing components during mass transfer of micro LED displays. The apparatus has a carrying unit to hold the object being processed, a control unit to define processing areas, and a processing module with a transfer unit and repair unit. The transfer unit arranges components in sequence across the areas, while the repair unit synchronously removes or replaces components in each area. This allows repairing transfer failures without separate steps, reducing time and costs compared to post-transfer repair.

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Backlight unit, display device, and driving method for detecting and recycling defective LEDs in an array. The backlight has a driver circuit with a sensing multiplexer (MUX) connected to the LED emitting nodes. By selectively sensing voltage on each node and comparing, it can determine if a specific LED is defective. This allows targeted replacement of just the bad LED rather than replacing the entire array when defects occur.

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Electroluminescence display with a repair structure that allows repairing defective pixels without darkening them. The repair involves connecting the defective pixel to a nearby normal pixel rather than making it black. When a pixel fails, a laser cuts the semiconductor layer of the defective pixel. Then, repair electrodes are connected between the cut semiconductor and the nearby normal pixel's driver. This allows the defective pixel to be driven by the normal pixel's transistor. The repair electrodes overlap the emission area to prevent damage to the LED. The laser used for cutting has low energy suitable for semiconductor processing, avoiding damage to the LED.

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In this work, the degradation in luminous characteristics of red, green, and blue (RGB) micro-LEDs (10 m 10 m) under electrical stress at 360 K has been investigated. After 280 h aging, AlGaInP-based red exhibit a 31.7% reduction maximum external quantum efficiency, which is significantly greater than reductions observed InGaN-based green micro-LEDs. Specifically, peak wavelength redshift by 0.6 nm, blueshift 1.0 0.5 nm for RGB micro-LEDs, respectively. The color purity decreases 3.6% 0.7%, respectively, resulting 7% gamut.

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A display device with improved yield by sensing and repairing defective subpixels in an LED display. The display has regular subpixels with LEDs and repair subpixels. In the regular subpixels, a sensing layer is placed between the LED and insulation layer. If an LED is not transferred, the sensing layer shorts to the high potential power line. In the repair subpixels, an additional LED is placed on the insulation layer. This allows detecting and repairing subpixel LED non-transfers without full display testing.

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A transparent display module and apparatus with improved manufacturing, inspection, and repairability for self-emitting transparent displays. The module has a grid pattern on a transparent substrate, with micro-pixel ICs and inorganic LEDs placed at the grid intersections. Transparent areas are left between the grids. This allows easier manufacturing, inspection, and repair compared to traditional dense pixel layouts. The transparent areas simplify inspection by providing clear areas to see through the display. The grid pattern allows efficient repair by isolating damaged pixels to just the grid surrounding them.

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Display panel and device design with reversible mini LED soldering for multiple repairs without damaging the substrate. The display uses conductive connectors made of a thermoplastic material with conductive particles distributed in it. These connectors are used to solder mini LEDs to the substrate pads. The thermoplastic property allows easy peeling of LEDs for repairs without damaging the substrate. When cooled, the connectors solidify and hold the LEDs securely. This enables repeat LED replacements without substrate damage.

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Apparatus and method for reworking ultra-small LED chips to quickly and accurately remove defective chips from a substrate and replace them with good chips. The rework involves using transfer technique with stick-shaped detach and attach press heads with adhesive layers of varying strengths. The detach head removes misaligned/defective chips from the weaker first adhesive layer on the substrate to a stronger second adhesive layer. The attach head replaces them from a weaker third adhesive layer onto the first layer. Driving units move the heads above the substrate in X,Y,Z. This allows efficient and precise reworking of ultra-small LED arrays without misalignment issues during chip transfer.

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Self-assembly apparatus for semiconductor microLED displays that allows resolving assembly defects after self-assembly. The apparatus has a fluid chamber to accommodate a fluid and microLEDs. An assembly substrate with electrodes is immersed in the fluid. A magnet array applies a magnetic force to guide microLED assembly. Power is supplied to the electrodes to attract microLEDs. After assembly, a repair substrate with pair electrodes is fed into the fluid. Power is applied to the pair electrodes to attract misplaced microLEDs from the assembly substrate. The repair substrate is then removed. This allows extracting and repositioning misassembled microLEDs without disassembling the display.

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Repairing techniques for micro LED displays to increase yield and reduce cost when defective micro LEDs are found after transfer to the system substrate. The techniques include replacing defective micro LEDs with spare ones, converting color of spares to match defects, mapping spare locations, and spatial coordinate variation to mitigate visual artifacts. It also involves calibration to correct for spatial non-uniformity induced by repair techniques.

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Repairing techniques for micro LED displays to increase yield and reduce costs by leveraging spare devices instead of physical replacement when micro LEDs fail. The repair techniques include remapping data from defective subpixels to surrounding spare subpixels, converting spare subpixels to match defective subpixel colors, and compensating for defective subpixel brightness in spare subpixels. The goal is to improve display quality without adding extra micro LEDs.

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Transferring micro-LEDs using a stamp with shape memory polymer nanotips to pick up and release the devices. The stamp has nanotips that can selectively adhere to the micro-LEDs due to shape memory properties. The nanotips heat to a critical temperature, contact the LED, press to attach, cool below critical temp, align on substrate, then heat again to transfer. This allows precise pickup, placement, and repair of micro-LEDs.

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MicroLED display technology with improved yield and production efficiency by selectively removing defective microLEDs before transfer to the final substrate. The method involves testing the microLEDs on a temporary substrate, removing any failures, and then transferring the remaining good microLEDs to the permanent display substrate. This prevents filling gaps with extra microLEDs, which can have lower yield. The key is controlling the transfer and removal rates so more defective microLEDs are removed than replaced.

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Method for manufacturing LED devices that enables efficient mass transfer, selective transfer, and repair of LEDs between substrates. The process involves attaching the LEDs from a source substrate to a carrier, removing the source substrate, and then transferring a portion of the LEDs from the carrier to the target substrate using laser lift-off. In selective transfer, the laser is focused only on the LEDs to be detached. This allows targeted replacement or repair of LEDs without disturbing the rest.

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An allGaNbased monolithic activematrix microLED system that integrates metalinsulatorsemiconductor highelectronmobility transistors (MIS HEMTs) with lightemitting diodes (LEDs) is demonstrated. The proposed structure employs direct electron injection from the 2D gas (2DEG) in a HEMT, serving as ntype layer, into quantum wells of LEDs. A 2HEMT1LED pixel configuration fabricated one epitaxial growth, enabling precise control LED light output through combination select and drive HEMTs. achieved maximum optical density 0.5 Wcm 2 . 2 matrix constructed row column lines connected via HEMTs, demonstrating capability for individual control.

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Abstract Microlight emitting diode (LED) based LED on silicon (LEDoS) is a promising candidate for nextgeneration AR and VR displays due to superior pixel performance potential high resolution. Traditional RGB pixels are placed single plane, which limits the To overcome this, vertically stacked using heterogeneous monolithic 3D integration (M3D) have been explored. However, previously reported vertical LED not considered heat dissipation capability of pixels, indeed important in future micro displays, utilized materials incompatible with standard CMOS processes, further limiting their practicality LEDoS. The critical regions constraint, bonding medium, typically organic polymer materials. Therefore, handle issue, fullcolor LEDs demonstrated oxide (SiO 2 ) yttrium (Y O 3 ), as mediums. These CMOScompatible offer thermal conductivity at least 10 times higher than conventional polymers. InGaN/GaN blue bonded oxides show improved management, leading external quantum efficiency (EQE) better color characteristics, including narrower full width half maximum (FWHM) purity. ... Read More

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Display device with improved reliability and repairability by preventing or substantially preventing dark spot defects in subpixels. The display has separate first and second conductive patterns that are electrically disconnected from each other. The subpixel electrodes are also disconnected from each other. This allows replacing a reversed connected defective LED without removing it. A laser is used to cut the connections between the electrodes and underlying conductive patterns, then connect them in the correct forward direction. This allows reusing the defective LED by changing its driving current direction. Having multiple sub-electrodes per end of the LED provides redundant current paths to improve reliability.

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Display device with improved transfer process for LED arrays to prevent defects when transferring the LEDs to the display panel. The display device has an adhesive layer on the panel with selective areas that adhere to the LEDs. During transfer, a mask is used to cure and prevent adhesion on the selective areas. This allows transferring only the LEDs in contact with the adhering areas while avoiding transfer of unplaced LEDs. The non-adhering areas provide space for LED repositioning. The adhesive force is higher on the LED contact areas. This prevents transfer defects like LEDs going to wrong positions.

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Transparent display device with improved resolution and repair capability. The display has sub-pixels containing red, green, and blue LEDs, along with a reserve sub-pixel with stacked red, green, and blue LEDs. If any LED in a normal sub-pixel fails, the reserve LEDs can replace them. Stacking the reserve LEDs reduces area compared to parallel LEDs. The reserve LED electrodes are transparent to allow light from lower LEDs to escape. This allows repair and area savings while maintaining light output.

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Display device with easily replaceable parts for improved repairability and recyclability compared to sealed devices. The display has a display panel sandwiched between an inner plate and a support plate. Coupling members connect the inner plate and support plate. This allows disassembly and replacement of just the inner panel or support plate without disturbing the rest of the display. The main frame holds the display panel and has features like guides, fasteners, and a bottom frame for securing the display. This enables easy removal and replacement of just the display panel or inner components, facilitating repair, recycling, and disassembly.

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Flexible electronic device with overlapping bumps for improved repairability of large display tiles. The device has a substrate with adjacent through holes and overlapping bumps. The bumps are adjacent along a direction. The electronic element is overlapped with the substrate and electrically connected to one of the bumps. The distance between the through holes is different from the distance between the bumps in the overlapped direction. This allows replacing a damaged bump without removing the undamaged bump and element. The substrate separates the replaced bump from the element.

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Transfer method for micro flip chips that allows reusing original bonding positions after defective chips are removed. The method uses conductive adhesive as the bonding material between the micro flip chips and substrate. Laser irradiation separates defective chips by causing gasification of the adhesive, without damaging the substrate contacts. The adhesive absorbs laser energy and expands, generating airflow to lift off the chips. This immediate separation prevents contact damage from prolonged laser exposure.

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Micro LED display element with reduced missing pixel defect and improved yield. The element has multiple LEDs packaged together with common electrodes and pads. This allows bonding all LEDs at once instead of separately. The shared electrodes and pads eliminate interference and misalignment issues during die bonding. It also reduces bonding time compared to individual LEDs. The larger element size enables repair through vacuum adsorption holes.

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Display panel and device design to save space and improve repairability by eliminating the need for backup electrodes in LED displays. The panel has electrode pads with three areas: a main area for the LED, and two connecting areas. If an LED fails, the connection between the main and connecting areas can be disconnected by melting the lower melting point connecting area. This allows moving the LED to the spare connecting area without needing a separate backup pad. The reduced width connecting areas save space compared to separate backup pads.

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Display panel design with improved yield and repairability. The display panel has an array of light-emitting elements on one side of a substrate. Each light-emitting element has a first binding electrode connected to a first pad and a second binding electrode connected to a second pad in the pixel region. The area of the first pad projection exceeds twice the first binding electrode projection, and the second pad projection exceeds twice the second binding electrode projection. This reduces alignment difficulties and enables bonding the replacement element within the original pixel region without repairing the pads. The larger pad areas simplify repair compared to redundant pads. The display has improved yield and repairability without impacting resolution.

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Display apparatus with improved diagnostics for microLED displays. It allows detecting panel issues during vertical blank periods when the display is off. The display has multiple microLED drivers with timings controlled by separate clock signals. During blanking, all clock signals go low to disable emitting in all pixels. This lets detecting abnormalities like stuck pixels.

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Wiring substrate for mini LED displays that improves yield and manufacturing efficiency. The substrate has connection wires with adjacent pairs of ends arranged spaced apart. These pairs define bonding pad groups. The pads are sub-bonding pads from the adjacent pairs. This allows die bonding parallel to the pad groups for multiple LEDs at once. It reduces movement errors compared to bonding perpendicular to the pads. It also enables repositioning damaged pads by swapping LED pairs.

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Selective layer transfer technique to enable transferring specific areas of a layer from a donor substrate to a receiver substrate instead of full layer transfers. The technique uses a patterned bonding template on the receiver substrate and a reusable repair wafer with hydrophobic marks containing liquid droplets placed in areas matching the deficiencies of the donor wafer. The liquid capillary force between the droplets and deficient areas allows selective transfer of bad dies during a debonding process. The repair wafer can be reused for subsequent repairs on other donor wafers.

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Display apparatus with detachable display panel for easy replacement without damaging the display. The display has a rear chassis covering the back of the display panel. The panel has a holder on the rear facing the chassis. Wires connect the holder to the chassis. By separating the wires, the holder detaches from the chassis allowing the panel to be removed. This enables swapping out the display panel without disassembling the entire display.

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Compensating for luminance degradation of individual pixels in a display to improve image quality over time. The compensation is done by measuring the sensing current of each pixel during blank periods between frames. This current is compared to a reference value to calculate a deterioration weight for each pixel. This weight is then applied to the pixel's output image data to compensate for luminance degradation. By measuring and compensating for pixel degradation in real time based on usage, image quality is maintained as pixels age.

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Contactless micro LED inspection system that uses pulsed lasers to detect defective micro LEDs without direct electrical testing. The system emits pulsed lasers at the LEDs to generate photovoltaic radio frequency signals when radiated. An antenna receives these signals, which are amplified and analyzed by a processor to determine if the LED is functioning or defective. This allows high-efficiency, contactless testing of micro LED arrays without needing to electrically test each individual tiny LED.

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Display device with improved brightness uniformity, reduced staining, and higher charging efficiency at low brightness levels. The display has a bank layer surrounding the LED areas. The bank layer thickness varies between areas. A thinner bank area adjacent to the LEDs prevents residual films in the micro-lenses. A thicker bank area away from LEDs absorbs laser repair beams to block current. This prevents visual artifacts when repairing defective subpixels without affecting adjacent subpixels. The varying bank layer thicknesses balance brightness, staining, and repair isolation.

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A composite integrated film for high-resolution displays like microLEDs that allows eliminating defects and increasing pixel density. The composite integrated film has a base member thin film with penetrations, electrodes on one side, and an element on the other side. When bonded to a circuit board, the base member contacts the board first. This allows testing and separating the element side without damaging the circuit board electrodes. The penetrations connect the electrodes and element sides. By bonding the base member to the board first, defective elements can be removed and replaced without reworking the circuit board. This enables higher yield and pixel density compared to flip-chip bonding where board electrode damage prevents rework.

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Transparent display substrate with improved electrical connectivity and repairability. The display has a scanning line with outer ring portions extending from the non-display area into the display area. This reduces the scanning line resistance and allows shorted sections to be isolated. The data and power lines also extend into the display area to overlap the scanning lines. This allows repair of failed pixels in the display region by cutting off shorted lines. The outer ring portions also connect to the scanning lines to provide redundancy. The ring portions can have different configurations like closed loops or branches.

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Repair method for display panels that allows selective replacement of defective components in subpixels to improve yield and reduce repair costs. The repair involves electrically separating the cathode connections of adjacent subpixels, then connecting the cathode lines of those subpixels. This allows individual subpixel replacement without affecting the rest of the display. By isolating faulty subpixels and connecting good ones, repair processing can be optimized for each defect state. The repaired subpixels are then compensated for luminance to match the original display. This enables targeted repair of subpixel components without affecting the rest of the display, improving yield and reducing repair costs.

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Display device with a stacked transparent repair substrate to easily and cost-effectively repair defective micro LEDs in a display. The device has a base substrate with the main micro LEDs and a transparent repair substrate stacked on top. The repair substrate contains replacement micro LEDs at positions corresponding to defective LEDs on the base substrate. This allows repairing defects without removing and replacing individual micro LEDs on the base substrate.

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Light emitting display with test pixel to diagnose display defects. The display has areas for showing images and transmitting light. Each image pixel has a connected test pixel in the transparent area. If a regular pixel is defective, the test pixel shows the issue is the pixel device or circuit. This allows targeted repair versus replacing whole pixels.

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Display device with LEDs that improves luminance and allows individual LED replacement. The display has a display board with LEDs supported by it. The LEDs are electrically connected through an electrode body. The LEDs have a peak wavelength difference of 5 nm or less. This allows them to appear as a single light source when illuminated. The LEDs have a light transmitting layer with a ragged region formed on the side facing the LEDs. This allows light refraction and improves luminance. The LED electrodes are connected to separate electrodes on the display board. This allows individual LED replacement. The display can also have markers with exposed LED electrodes and light emitter holes of different sizes or spacing to reveal specific LEDs.

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A method for repairing flexible transparent LED displays without having to replace the entire display if faulty components are found. The method involves softening the encapsulation layer surrounding the faulty component, accessing and repairing the component, then curing the softened encapsulation layer. The softening is done by heating the display to a temperature that melts the encapsulation material but avoids damaging other components. This allows repairing individual faulty components in flexible transparent LED displays without needing to replace the entire display.

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Display panel with improved optical performance, reliability and production yield, using a cluster-based approach. The panel is built by connecting clusters of LEDs on interposers using hub boards. Each cluster is a self-contained unit with LEDs, driver IC, and encapsulation. This allows replacing defective clusters instead of individual LEDs or whole panels. The encapsulation protects against moisture and contamination. The clusters are manufactured using techniques like overmolding to form light-shielding layers.

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Method for manufacturing micro LED displays with high yield and low cost after transferring the micro LEDs from the growth substrate. The method involves repairing defective or missing micro LEDs by filling vacancies or replacing failed micro LEDs in some areas, rather than retransferring the entire display. This allows using the original substrate with intact micro LEDs alongside repaired areas. The repaired micro LEDs have their own substrate, electrical connections, and pins. The connections between the repaired and original areas use solder, glue, wire bonding, or PCB pads. This avoids retransfer issues and reduces cost compared to replacing all defective micro LEDs.

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Maintenance method for Mini/Micro LED integrated package display devices to repair defective pixels without compromising reliability and adding a matte surface finish. The method involves replacing the failed LED chip, partially filling the repair area with regular resin and curing, then completely filling and curing with modified resin containing boron trifluoride-monoethylamine. The modified resin cures faster internally compared to the surface, creating stress that causes an orange peel texture for a matte finish.

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LED display panel with consistent packaging surface and method for preparing and maintaining it. The panel has a glossy outer layer over the encapsulation layer. This glossy layer is formed by molding with a glossy release film. The glossy layer is then treated and coated with a thermosetting anti-glare coating. This provides a consistent surface without pattern issues. To maintain consistency during repairs, the damaged area is dug out, filled, and polished to match the surrounding encapsulation level. Then the treated area is coated with anti-glare coating and cured. This prevents a visible repair seam with inconsistent light emission.

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Method for inspecting and repairing micro LED displays to reduce rework and improve yield. The method involves using a probe card with micro spring tips to test micro LEDs after transfer. Defective pixels are identified by EL inspection. Replacement micro LEDs are mounted using a stamping process. This avoids rework issues that can occur with traditional repair methods.

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Display unit with improved repairability and a method to repair it. The display unit has cutting lines around the edge with identification points. This allows precise machine processing of excess material during repairs. The identification points cover the edges around the display circuitry. By cutting along these lines, excess encapsulation can be removed without affecting the functional area. The width of the cuts is greater than 200um. This allows accurate secondary processing after removing and replacing faulty components. It avoids issues like misalignment or overcutting when reworked.

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Driving backplane, display screen, and display repair method that allows efficient repair of mini LED and micro LED displays without removing failed pixels. The backplane has spare contact pairs and overlapping electrodes for each pixel area. When a main LED fails, the overlapping electrode is connected to the spare contact to replace the main LED without removing it. This is done by detecting failed LEDs, identifying the faulty main color and location, and swapping it with a backup of the same color. The repair is done on the backplane without touching the main LED, improving repair efficiency and success rate compared to removing and reattaching a new LED.

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Device, method, control system and electronic equipment to repair blind spots on a real pixel display screen. The repair involves actively controlling individual subpixels in a display to compensate for blind spots. When a subpixel is lit, the brightness of the other two subpixels is set to zero. This creates a virtual pixel arrangement where all lit subpixels form a larger effective pixel. This is done using a data processing module between decoding and encoding the display signal. By actively controlling subpixels instead of replacing modules, it allows repairing a few blind spots without replacing the entire screen.

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