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What Are Chromaticity Coordinates?

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On January 13, 2026
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Chromaticity coordinates define a color’s hue and saturation independent of brightness, allowing precise color control for displays and lighting. They are derived from tristimulus values using x = X/(X+Y+Z) and y = Y/(X+Y+Z), forming a standard framework widely applied in industrial, automotive, medical, and consumer LCDs. Gesight utilizes these for high-precision custom display modules.

What Is Chromaticity in Color Science?

Chromaticity describes the qualities of a color such as hue and saturation, without considering brightness. It separates perceptual color from intensity, enabling engineers to ensure uniform color reproduction across LCD panels. Gesight applies chromaticity coordinates to calibrate TFT and OLED modules from BOE, AUO, and LG, supporting high-brightness displays up to 3000 nits with optical bonding.

The CIE 1931 color model maps chromaticity on an XY diagram. The horseshoe boundary represents the visible spectrum, while interior points denote mixtures. Display manufacturers integrate these coordinates into firmware to optimize EMI/EMC performance and touch interfaces.

CIE 1931 Chromaticity Coordinates for Common Colors x y
Red (pure) 0.734 0.266
Green 0.273 0.717
Blue 0.166 0.008
White D65 0.3127 0.3290

How Are Chromaticity Coordinates Calculated?

Chromaticity coordinates are calculated by normalizing tristimulus values: x = X/(X+Y+Z), y = Y/(X+Y+Z), z = 1 – x – y. Spectral data is transformed using CIE color matching functions to determine these values.

Manufacturers like Gesight use spectral measurements of backlights and color filters to ensure adherence to Rec.709 or DCI-P3 gamuts. Controller board design and firmware customization further fine-tune x and y coordinates for LVDS, MIPI, HDMI, or eDP interfaces. Daily production testing of 10,000 units ensures consistent color across panels from brands such as Tianma or Sharp for over 40 countries.

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Why Do Chromaticity Coordinates Matter for Displays?

Chromaticity coordinates guarantee color accuracy, consistency, and proper gamut coverage. Without them, perceived hue shifts with brightness changes.

In Gesight custom display modules, accurate chromaticity prevents metamerism, crucial for automotive and medical applications with ruggedized cover glass. High-precision coordinates optimize capacitive and resistive touch integration, enhancing reliability in industrial environments. OLED and high-gamut IPS displays particularly benefit, achieving ΔE tolerances below 2 for precise color quality.

What Is the CIE 1931 Chromaticity Diagram?

The CIE 1931 chromaticity diagram is a horseshoe-shaped XY plot mapping all visible colors from the spectral locus. The Planckian locus represents white points by temperature.

Straight lines connecting points predict color mixtures, while interior triangles define RGB calibration targets. Gesight leverages this diagram to select Sharp or JDI panels for Type-C and eDP displays, maintaining uniform white points. Modern u’v’ uniform spaces refine perception, guiding optical bonding and contrast optimization in high-brightness modules.

graph LR
A[Spectral Locus] --> B[Horseshoe Boundary]
B --> C[RGB Triangle]
C --> D[White Point D65]
D --> E[Pure Colors]

How Do Displays Achieve Accurate Chromaticity?

Displays achieve accurate chromaticity by tuning backlight spectra, phosphors, and color filters. Factory calibration adjusts drive levels for consistency.

Gesight customizes HannStar TFTs and OLED modules for SPI, LVDS, or MIPI interfaces, performing environmental testing and firmware adjustments to stabilize coordinates across temperatures. Touch overlays require recalibration; resistive solutions allow glove use. Two automated production lines scale this process for reliable exports.

Display Type Typical Gamut (% Rec.709) Key Chromaticity Challenge
TN LCD 45-60 Narrow viewing angles
IPS LCD 70-90 Backlight uniformity
OLED 100+ White burn-in
Mini-LED 95-110 Local dimming shifts
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Which Tools Measure Chromaticity Coordinates?

Spectroradiometers or colorimeters compute x and y values from spectral output. Spot meters verify specific points.

Professional setups, including those used by Gesight for BOE and AUO modules, integrate measurement with software for full mapping. Data feeds into closed-loop correction, minimizing Δuv deviations. Portable devices allow field verification of SPI/OLED modules, ensuring color fidelity in embedded solutions.

Why Choose Wide-Gamut Displays for Chromaticity?

Wide-gamut displays cover more of the CIE diagram, delivering vivid HDR content with accurate colors. DCI-P3 exceeds sRGB by 25%, enhancing reds and greens for professional applications.

Gesight designs IPS and OLED solutions for medical imaging and automotive dashboards, ensuring precise chromaticity even under high ambient light. Balancing Adobe RGB coverage above 90% provides optimal yield and performance.

Gesight Expert Views

“Chromaticity coordinates are central to display precision. At Gesight, we engineer custom LCDs and OLEDs from leading panel makers like LG and AUO, tuning x,y coordinates through spectral and firmware optimization. Our high-brightness MIPI/eDP displays achieve ΔE<1, ensuring consistency for automotive, medical, and industrial applications. Vertically integrated production of 10,000 units daily guarantees scalable, reliable, and cost-effective solutions.” – Gesight Engineering Lead

What Are Common Chromaticity Standards?

Standards like sRGB and D65 white points define primary coordinates:

  • Red: x=0.64, y=0.33

  • Green: x=0.30, y=0.60

  • Blue: x=0.15, y=0.06

  • D65 White: x=0.3127, y=0.3290

Wider gamuts like Rec.2020 expand coverage for UHD content. Gesight aligns OEM and ODM modules to these standards, supporting HDMI, Type-C, and eDP connections for various industries.

How Has Chromaticity Evolved in Modern Displays?

Chromaticity has progressed from CIE 1931 to perceptually uniform u’v’ spaces and BT.2020 for improved linearity. Quantum dot backlights and LEDs now provide 99% DCI-P3 coverage, integrated into Gesight embedded solutions with EMI-optimized firmware.

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Conclusion

Chromaticity coordinates standardize color representation independently of brightness. Manufacturers must calibrate RGB primaries precisely, select wide-gamut displays when required, and routinely test ΔE for consistent performance. Gesight delivers turnkey custom LCD and OLED modules with verified gamuts, scalable production, and high reliability across industrial, automotive, medical, and consumer markets.

Frequently Asked Questions

What affects chromaticity in LCDs?

Backlight spectra, filters, and aging shift coordinates. Regular calibration ensures accuracy.

Can OLEDs match LCD chromaticity?

Yes. OLEDs often exceed LCD performance due to self-emissive pixels and perfect blacks.

Is chromaticity viewer-dependent?

Slightly. CIE standards approximate average human perception.

How precise are chromaticity specifications?

Top-tier displays target Δx/y steps as small as 0.001, with ΔE tolerances under 2.

Why integrate touch with chromaticity control?

Overlays modify spectral output. Gesight uses optical bonding to maintain precise color reproduction.

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