Overview - IEC 62977-2-8:2025 for reflective displays
IEC 62977-2-8:2025 is an international standard that defines standard measurement conditions and methods for determining the optical characteristics of reflective direct‑view flat panel displays. It applies to flat panel displays operated in a reflective mode (with integrated light sources turned off) and covers input signals that represent monochrome or colour 2D images. The standard establishes how to measure reflectance, contrast, colour, and directional behaviour of reflective displays under defined illumination and viewing geometries.
Key topics and technical requirements
This part of IEC 62977 focuses on optical measurement methodology and includes:
- Illumination specifications: defined standard illumination spectra and configurations (directional, conical, ring/annulus, hemispherical diffuse and specular illumination).
- Light measuring devices (LMDs): requirements and recommended conditions for measurement instruments, including receiver inclination effects and measuring spot geometry.
- Measurement arrangements: coordinate systems and geometry for DUT (device under test), source and LMD positioning.
- Reflection and reflectance metrics:
- Reflectance factor under hemispherical diffuse illumination
- Off‑specular reflectance under directional illumination
- Specular reflectance using annulus and variable aperture sources
- Haze reflectance factor
- Contrast and colour measurements:
- Contrast ratio under specified illumination (diffuse, off‑specular, ambient)
- Colour measurement methods under defined illumination, including use of CIELAB and calculation of CIELAB colour gamut volume
- Viewing direction variation: methods to quantify viewing direction range and conditions for grey‑level inversion.
- Test methods and artefacts: standard test patterns, measurement fields, working standards (diffuse and specular reflectance standards), and temporal stability requirements.
- Informative annexes on illumination, BRDF considerations, and substitution methods for spectral irradiance/reflectance.
Practical applications and users
IEC 62977-2-8 is valuable for professionals involved in design, testing and certification of reflective displays, such as:
- Display manufacturers (e‑paper, transflective LCDs, microdisplay designers)
- Test laboratories and metrology facilities performing optical characterization
- R&D teams developing outdoor/low‑power display technologies
- Quality assurance and compliance engineers
- System integrators and OEMs specifying display performance for outdoor signage, wearable devices, instrument panels, and e‑readers
Using the standard ensures consistent, repeatable optical measurements that support product specification, competitive benchmarking, regulatory compliance and interoperability between suppliers and test labs.
Related standards
- IEC 62977 series (other parts covering emissive/transmissive measurements and test methods)
- References to colourimetry conventions (CIELAB) and BRDF measurement principles are used within the standard; users should align with relevant CIE/ISO guidance where appropriate.
Keywords: IEC 62977-2-8, reflective displays, optical measurements, reflectance, contrast ratio, CIELAB, light measuring device (LMD), illumination, BRDF.