Micro-LED displays face significant color accuracy challenges due to inherent variations in emission spectra and quantum efficiency across different wavelengths. Current manufacturing processes achieve typical wavelength variations of ±2 nm for blue, ±3 nm for green, and ±5 nm for red micro-LEDs, while maintaining consistent brightness across millions of sub-pixels requires precise control over current density and thermal characteristics.

The fundamental challenge lies in balancing color uniformity and brightness while managing the thermal and electrical characteristics unique to each wavelength's semiconductor structure.

This page brings together solutions from recent research—including collimated emission systems with specialized reflectors, stacked RGB architectures that optimize pixel density, advanced driving circuits with separated digital and analog components, and precision transfer methods for consistent electrode orientation. These and other approaches focus on achieving uniform color reproduction while maintaining display efficiency and manufacturability.

1. Color Adjustment Method for LED Displays Using Ambient Light-Dependent EETF Curves

HUIZHOU ABSEN OPTOELECTRONIC CO LTD, SHENZHEN ABSEN OPTOELECTRONIC CO LTD, 2024

Color adjustment method for LED displays that improves color accuracy under varying ambient light conditions. The method involves collecting LED display data under different ambient lights, generating EETF curves for each light condition, and calling the appropriate EETF when ambient light changes to adjust display colors. This accounts for LED display gamut deviations and ambient light impact on color perception.

2. Color Cast Compensation Method in LED Displays Using Tristimulus Value Mapping for Grayscale Calibration

COLORLIGHT CLOUD TECH CO LTD, COLORLIGHT CLOUD TECHNOLOGY CO LTD, 2024

Method for compensating color cast in LED displays to improve efficiency and accuracy of full grayscale linear calibration. The method involves determining the original red, green, and blue tristimulus values for all gray levels, finding the target white tristimulus values for the reference gray scale, and mapping the corrected red, green, and blue values for each gray level by minimizing a distance function between the original and target whites. This allows finding the mapping to redisplay according to the input image gray scale for full gray scale linear calibration.

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3. Method for Determining Correction Coefficients in LED Displays Using Multi-Filtered Camera Image Analysis

HANGZHOU HIKVISION DIGITAL TEC, HANGZHOU HIKVISION DIGITAL TECHNOLOGY CO LTD, 2024

Method to determine correction coefficients for LED displays with mixed batches of LEDs to improve display quality. The method involves acquiring images of the display with multiple cameras having different filters, then determining the original and target color gamuts for each pixel based on the filtered images. By converting the original gamut to the target gamut for each set of colors, correction coefficients can be calculated for each pixel to correct brightness and chromaticity.

4. Device and System for Iterative Brightness Adjustment of Individual LEDs in Display Screens

SHENZHEN AOTO ELECTRONICS CO LTD, 2023

Single-point correction method, device and system for LED display screens to improve image quality without increasing costs for smaller pitch displays. The method involves iteratively adjusting the brightness of individual LEDs to correct color non-uniformity in a localized area. A correction device analyzes a small region of the display and identifies the brightness values of each LED. It then calculates optimal corrections to the brightness of specific LEDs to match a target color balance for that region. The corrected brightness values are sent to the LED controller to implement the adjustments. This iterative process is repeated for other regions to fine-tune the display's color uniformity.

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5. Display Color Calibration Method with Iterative Backlight Parameter Adjustment Based on Target Color Matching Coefficients

BEIJING QINGYUN INNOVATION TECH DEVELOPMENT CO LTD, BEIJING QINGYUN INNOVATION TECHNOLOGY DEVELOPMENT CO LTD, 2023

Color calibration method for displays that improves accuracy by adjusting the backlight color parameters based on the target display colors. The method involves determining initial backlight color matching parameters for a given display color, having the backlight produce color using those params, measuring the resulting display color, calculating color matching coefficients based on the initial and target display colors, and finally adjusting the backlight parameters using the computed coefficients to achieve the target display color. This iterative process improves calibration accuracy compared to starting with fixed backlight params.

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6. Micro-LED Display Pixels with Collimating Lenses and Reflectors for Sub-Pixel Light Containment and Cross-Talk Reduction

Plessey Semiconductors Limited, 2023

Micro-LED display pixels to improve color purity and efficiency by collimating emitted light and reducing cross-talk between sub-pixels. Each pixel has multiple sub-pixels with lenses and reflectors that contain and redirect the emitted light. The reflectors reflect pump light and transmit converted light. They also have apertures to limit cross-talk. This improves efficiency by preventing unconverted pump light from escaping the pixel. The lenses collimate the light to increase collection efficiency. The reflectors and lenses are designed to match and optimize the sub-pixel emissions.

7. Display Device Uniformity Correction Using Calibration-Based Lookup Tables

GENERAL INTERFACE SOLUTION LTD, GIS OPTOELECTRONICS CO LTD, GIS OPTOELECTRONICS WUXI CO LTD, 2023

Uniformity correction method for display devices that improves color and brightness uniformity without requiring assembly sorting. The method involves characterizing the chromaticity and brightness uniformity of individual display panels and backlights using calibration methods. This data is then used to generate correction lookup tables for each panel and backlight. During display operation, the correction tables are applied to correct for any deviations in chromaticity and brightness across the display. This allows compensating for variations in components without discarding and replacing panels during assembly.

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8. Display Calibration Method with Combined Chromaticity and Brightness Targeting Using Variable Gamma Curve

BEIJING OULAIDE MICROELECTRONIC TECH CO LTD, BEIJING OULAIDE MICROELECTRONIC TECHNOLOGY CO LTD, 2023

Display calibration method that improves overall display quality by calibrating both chromaticity and brightness. The calibration involves determining target chromaticity coordinates for each grayscale value, along with the target gamma curve based on those chromaticities. This allows converting displayed grayscale data using the target gamma instead of a fixed gamma. By considering chromaticity as well as brightness, it enables more accurate calibration of display colors and brightness levels.

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9. Vision-Based Per-Pixel Color Correction System for Mini LED Displays with Degradation-Responsive Regional Adjustment

Shandong Dream Vision Intelligent Technology Co., Ltd., SHANDONG MENGHUANSHIJIE INTELLIGENT TECHNOLOGY CO LTD, 2023

Vision-based color correction for mini LED displays to mitigate graininess and maintain picture quality as LEDs degrade over time. The method involves determining per-pixel color correction curves based on the initial and degraded colors of each mini LED. The display is divided into regions based on these curves, and corrections are made within each region. This takes into account visual impact between nearby pixels.

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10. Display Color Gamut Calibration Method Using Reduced XYZ Value Mapping

BEIJING XIAOMI MOBILE SOFTWARE CO LTD, 2023

A method for calibrating display color gamut that improves accuracy, efficiency and cost compared to traditional methods. The calibration involves determining display XYZ values for some known RGB colors, then mapping those XYZ values to the RGB values of the colors to be calibrated. This allows calibrating the full display using fewer measured XYZ values. The mapping relationships can be linear or based on functions.

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11. Individual Emission Control Signal Method for Independent Subpixel Control in Micro-LED Displays

VueReal Inc., 2023

This method improves dynamic range, power consumption, and color and gamma correction of micro-LED displays. It involves providing individual emission control signals to each subpixel of each pixel to control emission time and duty cycle independently. This allows tuning color without affecting gamma.

12. Method for Automatic Display Parameter Calibration Using Chromaticity-Based Brightness Determination

MAOJIA TECH GUANGDONG CO LTD, MAOJIA TECHNOLOGY CO LTD, 2023

Calibrating display parameters of electronic displays to improve color accuracy and brightness without manual register adjustment. The method involves determining the maximum feasible brightness of the display based on its chromaticity coordinates. Then, target luminance and chromaticity are used to find the actual color parameters required. This allows accurate calibration without modifying RGB registers. It involves calculating actual white brightness components, converting pure color coordinates to brightness, and using preset relationships between luminance and color parameters.

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13. Micro-Nanofin LED Element Array with Vertically Stacked Subpixel Configuration

KOOKMIN UNIVERSITY INDUSTRY ACADEMY COOPERATION FOUNDATION, 2023

Full-color LED display using micro-nanofin LED elements that emit the same color for each subpixel. The display has subpixels with two or more vertically stacked micro-nanofin LED elements that emit the same color. The micro-nanofin LED shape increases the emission area compared to rod-shaped micro-LEDs. The micro-nanofin LEDs self-align on the subpixel electrodes when assembled. This allows high-resolution displays without individual LED placement. Micro-nanofin LEDs have higher efficiency and yield than nanorods.

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14. Method for Manufacturing Display Device Using Selective Transfer of Light-Emitting Units Based on Measured Optical Characteristics

INNOLUX CORP, 2023

A method for manufacturing a display device to align the color point of the display with a target color point. The method involves providing a mix of differently colored first and second light-emitting units, measuring the optical characteristics of each unit, presetting the target display color point, and selectively transferring a subset of the first and second units to the display based on their measured characteristics to achieve the target display color.

15. LED Display Color Gradation Correction via Iterative Gamma Curve Adjustment

LEYARD CO, 2023

Accurately correcting color gradations on LED displays without degrading image quality. The method involves determining the total color scale of the LED display, adjusting the initial color coordinate values of each color level to match the target values using a target gamma curve, and then adjusting the gamma curve based on the sample color levels to further refine the color correction. This iterative process precisely converts the initial color gamut to the target gamut for each color level.

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16. Display System with Calibration Parameters for RGB Channel Correction and Color Measurement Method

Suzhou Qisda Electronics Co., Ltd., Qisda Corporation, SUZHOU QISDA DENTSU CO LTD, 2023

Display system and color characteristic measurement method that provides accurate color characteristics for displays without requiring specialized equipment. The system involves storing calibration parameters for the RGB channels, measuring the displayed colors, and calculating the corrected RGB output percentages using the stored parameters. This allows obtaining accurate color characteristics for display algorithms without using expensive spectrometers. The calibration involves measuring monochrome spectra or CIE tristimulus values of the RGB channels, which are then used to derive the calibration parameters.

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17. Color Cast Correction Method for LED Displays Using Reference and Corrected Measurement Analysis

Xi'an NovaStar Tech Co., Ltd., XIAN NOVASTAR TECHNOLOGY CO LTD, 2023

Method to correct color cast distortion in LED displays. The method involves generating a set of reference measurements with known current amplitudes and acquiring corresponding images. It also involves generating a set of corrected measurements with unknown current amplitudes and acquiring corresponding images. From the known and unknown images, complementary color coefficients are calculated to correct the color cast in the unknown images.

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18. Method for Angle-Dependent Color Matching Function Selection in Self-Luminous Displays

BEIJING INST OF GRAPHIC COMMUNICATION, BEIJING INSTITUTE OF GRAPHIC COMMUNICATION, 2023

A method for accurately measuring and correcting colors between self-luminous display devices like displays and LEDs, by selecting the appropriate color matching function for different viewing angles. The method involves organizing observers to match colors between displays with different primary spectra at various angles using CIE recommended colors. By calculating the color difference at each angle, the optimal color matching function for accurate color perception between displays can be determined. This allows selecting the suitable CIE color matching function for color measurement and correction between self-luminous displays based on viewing angle.

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19. Micro-LED Display System with Independent Sub-Pixel Emission Time and Duty Cycle Control

VueReal Inc., 2023

Micro-LED display system and method to improve dynamic range, power consumption, color accuracy, and gamma correction. The method involves independently controlling each sub-pixel's emission times and duty cycles in a pixel using individualized control signals. This allows precise color adjustment without affecting gamma. It also enables optimizations like varying emission times/duty cycles by grayscale range to reduce power.

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20. Display Device with Region-Based Color Deviation Compensation Using Internal Coefficient Storage

Samsung Display Co., Ltd., 2023

Compensating for color deviation in display devices without requiring large external memory. The method involves dividing the display into regions, measuring optical characteristics in those regions, calculating region compensation coefficients, and storing them internally. When displaying an image, the region compensation coefficients are loaded, interpolated for the display resolution, and used to calculate pixel-level compensation coefficients. This allows compensating for color deviation without storing large per-pixel compensation data.

21. Silicon-Based Digital and IGZO-Based Analog Drive Circuit Separation for Micro-LED Displays

22. Dynamic Pixel-Based Color Gamut Adjustment Method for LED Displays Using Gray Level-Dependent Correction Coefficients

23. LED Display Calibration System with Iterative Gamma Correction and Temperature Drift Suppression

24. Backlight Module with Side-Mounted LEDs and Software-Adjustable Display Pixel Calibration

25. Multi-Emitter Light Source Apparatus with Mode-Switchable Color Gamut Emitters and Tuned Color-Conversion Materials

Because micro-LED technology offers a greater color gamut and better color accuracy, it is expected to have a substantial impact on the display market. Displays that can replicate content more closely to the original creator's vision will result from this. This development will result in improvements in color consistency, subpixel control, and light collimation.

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