Overview
IEC 61747-30-4:2016 specifies standardized measurement conditions and methods for determining the optical performance and power consumption of active-matrix liquid crystal display (LCD) modules that include dynamic backlight units (DBUs). The standard defines test environments, signal patterns, required measuring equipment and procedures to ensure repeatable, comparable results for luminance, chromaticity, uniformity, flicker, judder and both static and dynamic power use.
Key Topics and Technical Requirements
- Standard measuring conditions
- Temperature: 25 °C ± 3 °C; Relative humidity: 25 %–85 % RH; Pressure: 86–106 kPa.
- Power supply tolerance: ±0.5 % voltage, ±0.2 % frequency.
- Warm-up: apply 100 % grey input until luminance variations ≤ 1 % per 5 min for at least five samples; minimum 15 min warm-up.
- Dark-room: reflected background luminance perpendicular to module < 0.03 cd/m² (otherwise apply background subtraction).
- Required measuring equipment
- Luminance meter: spectral responsivity limits such that relative uncertainty ≤ 4 % for luminance > 10 cd/m² and ≤ 10 % for ≤ 10 cd/m².
- Colourimeter / imaging colourimeter: chromaticity accuracy 0.004 (x,y); imaging device should sample ≥4 pixels per display subpixel and be ≥12-bit.
- Fast-response photometer: linearity better than 0.5 %, –3 dB cut-off frequency > 1 kHz.
- Measured optical characteristics
- Luminance and uniformity, chromaticity and uniformity, window-size dependence, contrast ratio, flicker (with TCSF weighting), and judder (motion-dependent temporal instability).
- Power consumption
- Procedures for static and dynamic power measurement of DBUs, including test signal patterns (full screen, checkerboard, increasing window, line patterns, moving image, video).
Practical Applications and Users
- Who uses it: display manufacturers, test laboratories, OEMs, product validation teams, compliance engineers, and procurement/specification writers.
- Why it matters:
- Ensures reproducible comparison of DBU performance across vendors and models.
- Supports energy-efficiency evaluation, product datasheets and regulatory reporting.
- Enables objective assessment of visual artifacts (flicker, judder) that affect user experience and accessibility.
- Guides R&D and quality control when optimizing dynamic backlight algorithms for power vs. visual fidelity.
Related Standards
Keywords: IEC 61747-30-4, dynamic backlight units, liquid crystal display modules, measuring methods, luminance, chromaticity, flicker, judder, power consumption.
Open preview (PDF)Liquid crystal display devices - Part 30-4: Measuring methods for liquid crystal display modules - Dynamic backlight units
