IEC 62341-6-2:2015

IEC 62341-6-2 ®
Edition 2.0 2015-12
INTERNATIONAL
STANDARD
colour
inside
Organic light emitting diode (OLED) displays –
Part 6-2: Measuring methods of visual quality and ambient performance
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC 62341-6-2 ®
Edition 2.0 2015-12
INTERNATIONAL
STANDARD
colour
inside
Organic light emitting diode (OLED) displays –

Part 6-2: Measuring methods of visual quality and ambient performance

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.260 ISBN 978-2-8322-3026-8

– 2 – IEC 62341-6-2:2015 © IEC 2015
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Abbreviations . 10
4 Structure of measuring equipment . 10
5 Standard measuring conditions . 10
5.1 Standard measuring environmental conditions . 10
5.2 Standard lighting conditions . 10
5.2.1 Dark-room conditions . 10
5.2.2 Ambient illumination conditions . 11
5.3 Standard setup conditions . 16
5.3.1 General . 16
5.3.2 Adjustment of OLED display modules . 16
5.3.3 Starting conditions of measurements . 16
5.3.4 Conditions of measuring equipment . 16
6 Visual inspection of static images . 17
6.1 General . 17
6.2 Classification of visible defects . 17
6.2.1 General . 17
6.2.2 Reference examples for subpixel defects . 17
6.2.3 Reference example for line defects . 19
6.2.4 Reference example for mura defects . 19
6.3 Visual inspection method and criteria . 20
6.3.1 Standard inspection conditions . 20
6.3.2 Standard inspection method . 21
6.3.3 Inspection criteria . 23
7 Electro-optical measuring methods under ambient illumination . 24
7.1 Reflection measurements . 24
7.1.1 Purpose . 24
7.1.2 Measuring conditions . 24
7.1.3 Measuring the hemispherical diffuse reflectance . 25
7.1.4 Measuring the reflectance factor for a directional light source . 26
7.2 Ambient contrast ratio . 28
7.2.1 Purpose . 28
7.2.2 Measuring conditions . 28
7.2.3 Measuring method . 28
7.3 Display daylight colour . 29
7.3.1 Purpose . 29
7.3.2 Measuring conditions . 29
7.3.3 Measuring method . 29
7.4 Daylight colour gamut volume . 30
7.4.1 Purpose . 30
7.4.2 Measuring conditions . 30
7.4.3 Measuring method . 31

7.4.4 Reporting . 32
Annex A (informative) Measuring relative photoluminescence contribution from
displays . 34
A.1 Purpose . 34
A.2 Measuring conditions . 34
A.3 Measuring the bi-spectral photoluminescence of the display . 34
A.4 Determining the relative PL contribution from the display . 34
Annex B (informative) Diagnostic for observing display luminance dependence from
ambient illumination . 37
B.1 Purpose . 37
B.2 Measuring method . 37
Annex C (informative) Calculation method of daylight colour gamut volume . 38
C.1 Purpose . 38
C.2 Procedure for calculating the colour gamut volume . 38
C.3 Surface subdivision method for CIELAB gamut volume calculation . 40
C.3.1 Purpose . 40
C.3.2 Assumptions . 40
C.3.3 Algorithm . 40
C.3.4 Software example execution . 40
Bibliography . 46

Figure 1 –Example of visual inspection room setup for control of ambient room lighting
and reflections . 11
Figure 2 –Example of measurement geometries for a uniform hemispherical diffuse
illumination condition using an integrating sphere and sampling sphere . 13
Figure 3 – Directional source measurement geometry using an isolated source . 15
Figure 4 – Directional source measurement geometry using a ring light source . 15
Figure 5 – Layout diagram of measurement setup . 16
Figure 6 – Classification of visible defects . 17
Figure 7 – Bright subpixel defects . 18
Figure 8 – Criteria for classifying bright and dark subpixel defects . 19
Figure 9 – Bright and dark line defects . 19
Figure 10 –Sample image of line mura . 20
Figure 11 – Example of spot mura . 20
Figure 12 – Setup condition for visual inspection of electro-optical visual defects . 22
Figure 13 – Shape of scratch and dent defect . 24
Figure 14 –Example of range in colours produced by a given display as represented
by the CIELAB colour space . 32
Figure A.1 – Scaled bi-spectral photoluminescence response from a display . 35
Figure A.2 – Decomposed bi-spectral photoluminescence response from a display . 35
Figure B.1 – Example of display luminance reduction caused by the high illuminance
from a high intensity LED flashlight directed at the display surface . 37
Figure C.1 – Analysis flow chart for calculating the colour gamut volume . 38
Figure C.2 – Graphical representation of the colour gamut volume for sRGB in the
CIELAB colour space . 39

Table 1 – Definitions for types of scratch and dent defects . 24

– 4 – IEC 62341-6-2:2015 © IEC 2015
Table 2 – Eigenvalues M and M for CIE daylight Illuminants D50 and D75 . 26
1 2
Table 3 – Example of minimum colours required for gamut volume calculation of a 3-
primary 8-bit display . 31
Table 4 – Measured tristimulus values for the minimum set of colours (see Table 3)
required for gamut volume calculation under the specified ambient illumination
condition .
...