IEC 62679-3-3:2016

IEC 62679-3-3 ®
Edition 1.0 2016-09
INTERNATIONAL
STANDARD
colour
inside
Electronic paper displays –
Part 3-3: Optical measuring methods for displays with integrated lighting units
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IEC 62679-3-3 ®
Edition 1.0 2016-09
INTERNATIONAL
STANDARD
colour
inside
Electronic paper displays –
Part 3-3: Optical measuring methods for displays with integrated lighting units

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-3616-1

– 2 – IEC 62679-3-3:2016 © IEC 2016
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references. 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Standard measuring conditions . 8
4.1 Standard environmental measuring conditions . 8
4.2 Viewing direction coordinate system . 8
4.3 Standard lighting conditions . 9
4.3.1 General comments and remarks on the measurement of electronic
paper displays . 9
4.3.2 Dark room conditions . 9
4.3.3 Standard indoor ambient illumination spectra . 9
4.3.4 Standard illumination geometries . 10
4.4 Adjustment of the EPD . 11
4.5 Standard conditions of measuring equipment . 11
4.6 Working standards and references . 11
4.7 Standard locations of measurement field . 11
4.7.1 Matrix displays . 11
4.7.2 Segment displays . 12
5 Optical measuring methods . 12
5.1 Reflection measurements . 12
5.1.1 General . 12
5.1.2 Measuring conditions . 12
5.1.3 Measuring the hemispherical diffuse reflectance . 13
5.1.4 Measuring the reflectance factor for a directed light source . 15
5.2 Display photometric uniformity in a dark room . 16
5.2.1 Purpose . 16
5.2.2 Measuring equipment . 16
5.2.3 Measurement method . 16
5.2.4 Definitions and evaluations. 17
5.3 Dark room contrast ratio . 17
5.3.1 Purpose . 17
5.3.2 Measuring equipment . 17
5.3.3 Measurement method . 17
5.3.4 Definitions and evaluations. 17
5.4 Contrast ratio under indoor illumination . 18
5.4.1 Purpose . 18
5.4.2 Measurement conditions . 18
5.4.3 Measurement method . 18
5.5 Cross-talk . 19
5.5.1 Purpose . 19
5.5.2 Measuring equipment . 19
5.5.3 Greyscale matrix displays. 19
5.5.4 Black and white (two-level) matrix displays . 21

5.6 Display colour, colour gamut, and colour gamut area . 22
5.6.1 Purpose . 22
5.6.2 Measuring equipment . 22
5.6.3 Measurement method . 22
5.6.4 Display colour gamut . 22
5.6.5 Display colour gamut area . 23
5.7 Display colorimetric uniformity in a dark room . 25
5.7.1 Purpose . 25
5.7.2 Measuring equipment . 25
5.7.3 Measurement method . 25
5.7.4 Definitions and evaluations. 26
5.8 Display colour under indoor illumination . 26
5.8.1 Purpose . 26
5.8.2 Measurement conditions . 26
5.8.3 Measurement method . 27
5.8.4 Definitions and evaluations. 27
5.9 Colour gamut volume under indoor illumination . 28
5.9.1 Purpose . 28
5.9.2 Measurement conditions . 28
5.9.3 Measurement method . 28
5.9.4 Definitions and evaluations. 29
5.9.5 Recording . 30
5.10 Viewing direction dependence in a dark room . 30
5.10.1 Purpose . 30
5.10.2 Measuring conditions . 31
5.10.3 Measuring method . 31
5.10.4 Definitions and evaluations. 31
Annex A (informative) Calculation method of daylight colour gamut volume . 34
A.1 Purpose . 34
A.2 Procedure for calculating the colour gamut volume . 34
A.3 Surface subdivision method for CIELAB gamut volume calculation . 36
A.3.1 Purpose . 36
A.3.2 Assumptions . 36
A.3.3 Algorithm . 36
A.3.4 Software example . 36
Bibliography . 41

Figure 1 – Representation of the coordinate system used to specify the viewing or
measurement orientation . 9
Figure 2 – Standard measurement positions . 12
Figure 3 – Window pattern for cross-talk measurement . 20
Figure 4 – Example representation of the same primary colours in the CIE 1931 (left)
and CIE 1976 (right) chromaticity diagrams . 22
Figure 5 – Example of evaluation results for the colour gamut area on the a*b* plane
of the CIELAB colour space . 25
Figure 6 – An example of the range in colours produced by an sRGB display as
represented by the CIELAB colour space . 29
Figure 7 - Example of contrast ratio dependence on viewing direction . 32

– 4 – IEC 62679-3-3:2016 © IEC 2016
Figure A.1 – Analysis flow chart for calculating the colour gamut volume . 34
Figure A.2 – Graphical representation of the colour gamut volume for sRGB in the
CIELAB colour space . 35

Table 1 – Eigenvalues M and M for CIE daylight Illuminant D50 . 14
1 2
Table 2 – Input
...