IEC 62977-2-2:2020
(Main)Electronic displays - Part 2-2: Measurements of optical characteristics - Ambient performance
Electronic displays - Part 2-2: Measurements of optical characteristics - Ambient performance
IEC 62977-2-2:2020(E) specifies standard measurement conditions and measuring methods for determining the optical characteristics of electronic displays under indoor and outdoor illumination conditions. Standard illumination geometries are specified and the reflection properties of flat screens are determined under those conditions. Reference illumination levels and spectra are used to estimate the photometric and colorimetric characteristics of electronic displays under the same conditions. These methods apply to emissive, transmissive, and reflective displays, or combinations thereof, that render real 2D images on a flat screen.
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IEC 62977-2-2 ®
Edition 1.0 2020-09
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-2: Measurements of optical characteristics – Ambient performance
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IEC 62977-2-2 ®
Edition 1.0 2020-09
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-2: Measurements of optical characteristics – Ambient performance
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-8816-0
– 2 – IEC 62977-2-2:2020 © IEC 2020
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 Standard measuring conditions . 11
4.1 Standard measuring environmental conditions . 11
4.2 Viewing direction and light source coordinate system . 12
4.3 Standard lighting conditions . 12
4.3.1 General . 12
4.3.2 Standard measuring darkroom conditions . 13
4.3.3 Standard ambient illumination . 13
4.3.4 Standard illumination geometries . 14
4.4 Standard setup conditions . 20
4.4.1 General . 20
4.4.2 Adjustment of display . 20
4.4.3 Starting conditions of measurements . 21
4.4.4 General conditions of measuring equipment . 21
4.5 Reflection standards . 22
4.5.1 General . 22
4.5.2 Diffuse reflectance standard . 22
4.6 Locations of measurement field. 23
5 Darkroom luminance and spectra. 23
5.1 General . 23
5.2 Test pattern . 23
5.2.1 General . 23
5.2.2 Simple box test patterns . 23
5.2.3 Multi-colour test pattern . 24
5.2.4 Measuring conditions . 25
5.2.5 Measuring method . 25
6 Reflection measurements . 26
6.1 General . 26
6.2 Measuring conditions . 26
6.3 Measuring the hemispherical diffuse reflectance . 27
6.4 Measuring the reflectance factor for a directed light source. 28
7 Ambient optical performance . 30
7.1 General . 30
7.2 Ambient contrast ratio . 30
7.2.1 General . 30
7.2.2 Measuring conditions . 30
7.2.3 Measuring method . 30
7.3 Ambient display colour . 31
7.3.1 General . 31
7.3.2 Measuring conditions . 31
7.3.3 Measuring method . 31
7.4 Ambient colour gamut volume . 33
7.4.1 General . 33
7.4.2 Measuring conditions . 34
7.4.3 Measuring method . 34
Annex A (normative) RGB boundary colours for CIELAB gamut volume measurements . 37
A.1 General . 37
A.2 Equally-spaced 98 boundary colours on the RGB cube . 37
A.3 Recommended 602 boundary colours on the RGB cube . 40
Annex B (informative) Calculation method for CIELAB gamut volume. 54
B.1 Purpose . 54
B.2 Procedure for calculating the colour gamut volume . 54
B.3 Number of sampled colours . 55
B.4 RGB cube surface subdivision method for CIELAB gamut volume calculation . 55
B.4.1 General . 55
B.4.2 Assumption . 55
B.4.3 Uniform RGB grid algorithm . 55
B.4.4 Software example execution . 57
Bibliography . 67
Figure 1 – Representation of the viewing direction (direction of measurement) and
coordinate system used for light source configuration . 12
Figure 2 – Illustrated examples for directional illumination . 15
Figure 3 – Example of the measuring setup using directional illumination where
θ = 40° and θ = 30° . 16
S R
Figure 4 – Example of ring light illumination measuring setup where θ ± ∆ = 35 ± 5
S
and θ = 20° . 17
R
Figure 5 – Detailed schematic of ring light characteristics . 18
Figure 6 – Example of measurement geometries for hemispherical illumination using
an integrating sphere (left) or sampling sphere (right) . 19
Figure 7 – Layout diagram of measurement setup . 22
Figure 8 – Example of centre box test patterns using the standard 4 % and
10 % area boxes . 24
Figure 9 – Standard medium APL RGBCMYWx test pattern used for centre luminance
and spectra measurements with 25 % APL . 25
Figure 10 – Example of the range in colours produced by a display . 36
Figure B.1 – Analysis flow chart for calculating the CIELAB gamut volume . 54
Figure B.2 – Example of tessellation using 5 × 5 grid of surface colours on the
RGB cube . 57
Figure B.3 – Example of tessellation for the RGB cube using a 3 × 3 grid . 59
Figure B.4 – Example of tessellation for the CIELAB gamut volume using a 3 × 3 grid . 59
Table 1 – Measurement structure from optical quantities to evaluation and to results
(top down) . 8
Table 2 – Summary of symbols . 11
Table 3 – Eigenvalues M and M for CIE daylight Illuminants D50, D65, and D75 . 28
1 2
– 4 – IEC 62977-2-2:2020 © IEC 2020
Table A.1 – Equally-spaced 98 RGB boundary colours used for CIELAB gamut volume
measurements . 38
Table A.2 – Recommended RGB boundary colours used for CIELAB colour gamut
volume measurements . 41
Table B.1 – Example RGB boundary colours used to demonstrate how the CIELAB
colour gamut volume can be calculated . 58
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC DISPLAYS –
Part 2-2: Measurements of optical characteristics
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