IEC 62977-2-8:2025
(Main)Electronic displays - Part 2-8: Measurements of optical characteristics - Reflective displays
Electronic displays - Part 2-8: Measurements of optical characteristics - Reflective displays
IEC 62977-2-8:2025 specifies standard measurement conditions and methods for determining the optical characteristics of reflective direct view displays that render real 2D images on a flat panel. This document applies to flat panel displays operated in a reflective mode with any integrated light sources turned off during measurement. The input signal is unbounded and encodes either monochrome or colour images.
General Information
Standards Content (Sample)
IEC 62977-2-8 ®
Edition 1.0 2025-06
INTERNATIONAL
STANDARD
Electronic displays –
Part 2-8: Measurements of optical characteristics – Reflective displays
ICS 31.120; 31.260 ISBN 978-2-8327-0416-5
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– 2 – IEC 62977-2-8:2025 © IEC 2025
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
2 Normative references . 9
3 Terms, definitions, abbreviated terms and symbols . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms. 10
3.3 Symbols . 10
4 Specifications of illumination . 12
4.1 General . 12
4.2 Standard illumination spectra . 12
5 Light measuring devices (LMDs) . 13
5.1 General . 13
5.2 LMD conditions. 13
5.3 Effects of receiver inclination . 13
6 Arrangements of illumination source, DUT and LMD . 14
6.1 General . 14
6.2 Coordinate system for viewing direction and light source position . 14
6.3 Directional illumination . 16
6.4 Ring light illumination . 16
6.5 Conical illumination . 17
6.6 Hemispherical diffuse illumination . 19
6.7 Specular illumination . 20
6.7.1 Small and extended aperture sources . 20
6.7.2 Variable aperture source. 21
6.7.3 Annulus aperture source . 23
7 Measuring methods. 24
7.1 General . 24
7.2 Standard measuring environment conditions . 24
7.3 Temporal stability . 24
7.4 Standard test patterns . 24
7.4.1 General. 24
7.4.2 Solid colour patterns . 24
7.4.3 Simple box set . 24
7.5 Standard locations of measurement field . 25
7.6 Working standards and references . 25
7.6.1 Diffuse reflectance standard . 25
7.6.2 Specular reflectance standard . 25
7.7 Reflection measurement under defined illumination conditions . 26
7.7.1 General. 26
7.7.2 Measurement conditions . 26
7.7.3 Reflectance factor under hemispherical diffuse illumination . 28
7.7.4 Off-specular reflectance factor under directional illumination . 29
7.7.5 Specular reflectance under illumination from an annulus aperture
source . 30
7.7.6 Haze reflectance factor under specular reflection illumination from a
variable aperture source . 33
7.8 Contrast ratio under specified illumination . 34
7.8.1 General. 34
7.8.2 Contrast ratio under hemispherical diffuse illumination . 34
7.8.3 Contrast ratio under off-specular directional illumination . 35
7.8.4 Contrast ratio under ambient illumination . 36
7.9 Colour under specified illumination . 38
7.9.1 General. 38
7.9.2 Display colour under hemispherical diffuse illumination . 39
7.9.3 Display colour under off-specular directional illumination . 41
7.9.4 Display colour under ambient illumination . 42
7.9.5 CIELAB colour gamut volume . 44
8 Variations of viewing direction . 47
8.1 Purpose . 47
8.2 Viewing direction range . 48
8.2.1 Measuring method . 48
8.2.2 Determination methods . 48
8.2.3 Specified conditions . 48
8.3 Viewing direction range without grey-level inversion . 49
8.3.1 Calculation method . 49
8.3.2 Determination methods . 49
8.3.3 Specified conditions . 49
Annex A (informative) General remarks on illumination and measurement conditions. 50
A.1 General . 50
A.2 Illumination and measurement conditions . 50
A.3 Front-surface reflections of the DUT . 51
Annex B (informative) Measurement field on a slanted DUT . 52
Annex C (informative) Light source . 55
C.1 General . 55
C.2 Off-specular (diffuse) reflectance factor under directional illumination (7.7.4) . 55
C.3 Reflectance factor under hemispherical diffuse illumination (7.7.3) . 55
C.4 Specular characteristics . 55
Annex D (informative) Optical characteristic of hemispherical diffuse illumination . 56
Annex E (informative) Components of specular illumination . 58
Annex F (informative) Substitution method for determining the spectral irradiance and
the spectral reflectance factor at the measurement plane . 61
Annex G (informative) Chromaticity gamut area in CIE 1931 xy chromaticity diagram . 63
Bibliography . 64
Figure 1 – Shape of measuring spot of LMD . 14
Figure 2 – Illustration of spherical directions θ and φ for the light source and LMD . 15
Figure 3 – Polar coordinate system for specification of directions (illumination and
measurement) . 15
Figure 4 – Illustration of a directional illumination . 16
Figure 5 – Examples of conical illumination . 18
Figure 6 – Example of conical illumination device . 19
Figure 7 – Examples of hemispherical diffuse illumination (configuration B) . 20
Figure 8 – Example of specular illumination using 1° (a) and 15° (b) uniform sources . 21
– 4 – IEC 62977-2-8:2025 © IEC 2025
Figure 9 – VAS in specular (a) and off-specular (b) reflection configurations. 22
Figure 10 – Illustration showing the use of the annulus light source for measuring
reflections in the specular direction (a) and the idealized luminance profile (b) . 23
Figure 11 – Measurement points of the annulus source with opaque centre for spectral
radiance . 31
Figure 12 – Input RGB colour cube and corresponding CIELAB gamut volume. . 45
Figure 13 – Tetrahedral tessellation of the RGB colour cube with 5 × 5 samples on
each face (from IEC 62977-2-2, Annex B.4) . 47
Figure A.1 – Arrangement of illumination of the reflective display under measurement
(DUT) and the light measuring device (LMD) . 50
Figure A.2 – Illustration of reflection rays from the first surface and the modulated
reflection . 51
Figure B.1 – Schematic diagram of DUT measurement using a LMD and the shape of
the measurement fields on DUT . 53
Figure B.2 – Centre shift of the measurement field on the DUT for the data given in
Table B.1 . 54
Figure C
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