Uniformity

Understanding Uniformity

Uniformity is a critical quality metric for LED displays, measuring how consistently the screen performs across its entire surface. Professional applications demand high uniformity to avoid distracting variations during content display.

Types of Uniformity

**Brightness Uniformity:** Consistency of luminance across the display when showing white or solid colors.

**Color Uniformity:** Consistency of color (hue, saturation) across the display surface.

**Angular Uniformity:** How consistent the display appears when viewed from different angles.

Measurement Standards

**Point Measurement:** Multiple measurement points (typically 9, 13, or more) across display surface.

**Calculation:** Uniformity % = (Minimum / Maximum) × 100

**Standards:**

• VESA FPDM (Flat Panel Display Measurements)
• IDMs (Information Display Measurements Standard)
• Manufacturer specifications

Factors Affecting Uniformity

**LED Binning:** Manufacturing variation in LED brightness and color wavelength.

**Calibration Quality:** How precisely individual LEDs have been adjusted.

**Panel Age:** Differential LED degradation across display.

**Temperature:** Uneven heating causes brightness/color shifts.

**Module Alignment:** Physical gaps or overlaps at panel seams.

Professional Requirements

**Virtual Production:**

• Brightness: 98%+
• Color: Delta E <2
• Critical for camera capture

**Broadcast:**

• Brightness: 97%+
• Color: Delta E <3
• On-camera appearance matters

**Corporate:**

• Brightness: 95%+
• Color: Delta E <4
• Acceptable for most content

**Concert/Event:**

• Brightness: 90%+
• Viewing distance is forgiving

Improving Uniformity

**Calibration:** Primary method for achieving uniformity:

• Pixel-level brightness adjustment
• Color correction per LED
• Regular recalibration

**Panel Selection:** Use panels from:

• Same manufacturing batch
• Similar operating hours
• Matched LED bins

**Environmental Control:**

• Even temperature distribution
• Adequate ventilation
• Warm-up time before critical use

Verification

**Test Patterns:**

• Solid white at various intensities
• Primary colors (R, G, B)
• Gray scale steps
• Moving window patterns

**Visual Inspection:**

• Check for visible seams
• Look for "hot spots"
• Evaluate gray scale smoothness

**Instrumented Measurement:**

• Colorimeter readings
• Camera-based uniformity analysis
• Documentation for quality records