Overview
IEC TR 62977-2-5:2018 is a Technical Report from the International Electrotechnical Commission (IEC) that specifies conditions and measurement methods for the optical characteristics of transparent direct‑view displays. It covers both transparent LCD and OLED display modules and defines how to measure both on‑screen properties (the displayed image) and through‑screen properties (objects seen behind the display). This report is part of the IEC 62977 series on electronic display devices and provides standardized test setups, ambient lighting conditions, and measurement positions to ensure repeatable optical characterization of transparent displays.
Key topics and technical requirements
The document organizes measurement guidance into two main groups-through‑screen (transparent) properties and on‑screen (displayed) properties. Major technical topics include:
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Measuring conditions and setup
- Standard environmental and ambient illumination conditions
- Darkroom and ambient lighting spectra
- Standard measurement positions and instrument conditions
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Through‑screen optical metrics
- Hemispherical transmittance factor (specular included/excluded)
- Transmitted haze (under hemispherical and direct illumination)
- Directional transmittance factor
- Degree of clear distinction (metrics such as purity and clarity using stripe patterns)
- Colour variation caused by the transparent display
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On‑screen optical metrics
- Ambient contrast ratio and contrast measurement in ambient light
- Display ambient colour measurement
- Contrast and colour coordinates with background illumination (including methods for white and collimated directional background sources)
The report references related test procedures (for example IEC 62341 parts on OLED measurement methods) and includes figures and tables detailing measurement geometries and sample configurations.
Practical applications and users
IEC TR 62977-2-5:2018 is useful for anyone needing consistent, repeatable optical characterization of transparent displays:
- Display manufacturers developing transparent LCD or OLED modules
- Test and calibration laboratories performing optical performance verification
- System integrators specifying transparent displays for retail, automotive HUDs, AR windows, signage, or architectural applications
- Procurement and QA teams defining acceptance criteria and comparing supplier claims
- R&D teams evaluating tradeoffs between transparency, haze, and on‑screen visibility
Using this standard helps ensure objective comparisons of transmittance, haze, clarity, colour shift and ambient contrast-critical for user experience in transparent display applications.
Related standards
- IEC 62341-6-4:2017 - OLED displays: measuring transparent properties
- IEC 62341-6-2 - OLED displays: visual quality and ambient performance
- Other parts of the IEC 62977 series on electronic display devices
Keywords: IEC TR 62977-2-5:2018, transparent displays, measurements of optical characteristics, transmittance, haze, clarity, purity, ambient contrast ratio, LCD, OLED.