IEC 62977-2-1:2021
(Main)Electronic displays - Part 2-1: Measurements of optical characteristics - Fundamental measurements
Electronic displays - Part 2-1: Measurements of optical characteristics - Fundamental measurements
IEC 62977-2-1:2021(E) specifies standard measurement conditions and measuring methods for determining the optical characteristics of electronic display modules and systems. These methods apply to emissive and transmissive direct view displays that render real 2D images on a flat panel. This document evaluates the optical characteristics of these displays under darkroom conditions. This document applies to the testing of display performance in response to standard analogue or digital input signals that are not absolute luminance encoded. The input signal is relative RGB without metadata information that codes for real luminance, colour space or colour coordinates. These methods are limited to input signals with typical OETFs such as defined in IEC 61966-2-1, ITU BT. Rec. 601, ITU BT. Rec.709, and ITU BT. Rec.2020. The tests in this document are not approved for use with HDR input signals.
NOTE A flat panel or flat panel display is a display with a flat surface and minimal depth that emits visible light from the surface. The display is subdivided into an array of electronically driven pixels which can be light valves modulating a backlight, or self-luminous. Emissive/transmissive/reflective hybrid displays can be flat panel or flat panel displays.
General Information
Standards Content (sample)
IEC 62977-2-1
Edition 1.0 2021-01
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-1: Measurements of optical characteristics – Fundamental measurements
IEC 62977-2-1:2021-01(en)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2021 IEC, Geneva, Switzerland
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 info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always
committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.
and withdrawn publications.Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 62977-2-1
Edition 1.0 2021-01
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-1: Measurements of optical characteristics – Fundamental measurements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-9225-9
Warning! Make sure that you obtained this publication from an authorized distributor.
® Registered trademark of the International Electrotechnical Commission---------------------- Page: 3 ----------------------
– 2 – IEC 62977-2-1:2021 © IEC 2021
CONTENTS
FOREWORD ........................................................................................................................... 6
INTRODUCTION ..................................................................................................................... 8
1 Scope .............................................................................................................................. 9
2 Normative references ...................................................................................................... 9
3 Terms, definitions and abbreviated terms ...................................................................... 10
3.1 Terms and definitions ............................................................................................ 10
3.2 Abbreviated terms ................................................................................................. 11
4 General ......................................................................................................................... 11
4.1 Measured basic quantities .................................................................................... 11
4.2 Electrical driving of the display (depending on the nature of the display) ............... 11
4.3 Data acquisition timing and display driving ............................................................ 12
4.3.1 Stationary measurements .............................................................................. 12
4.3.2 Properties of display under test ..................................................................... 12
5 Standard measuring conditions ...................................................................................... 12
5.1 Standard measuring environmental conditions ...................................................... 12
5.2 Standard measuring darkroom conditions ............................................................. 12
5.3 Standard setup conditions ..................................................................................... 12
5.3.1 General ......................................................................................................... 12
5.3.2 Adjustment of display .................................................................................... 12
5.3.3 Starting conditions of measurements ............................................................. 13
5.3.4 Conditions of measuring equipment ............................................................... 13
5.4 Location of measurement field .............................................................................. 15
5.5 Standard test patterns ........................................................................................... 16
5.6 Viewing direction coordinate system ..................................................................... 16
6 Simple box optical measurement methods ..................................................................... 17
6.1 General ................................................................................................................. 17
6.2 Test patterns......................................................................................................... 17
6.3 Luminance ............................................................................................................ 18
6.3.1 Purpose ......................................................................................................... 18
6.3.2 Measuring conditions ..................................................................................... 18
6.3.3 Measuring method ......................................................................................... 18
6.4 Darkroom contrast ratio ........................................................................................ 19
6.4.1 Purpose ......................................................................................................... 19
6.4.2 Measuring conditions ..................................................................................... 19
6.4.3 Measuring method ......................................................................................... 19
6.5 Luminance uniformity ............................................................................................ 20
6.5.1 Purpose ......................................................................................................... 20
6.5.2 Measuring conditions ..................................................................................... 20
6.5.3 Measuring method ......................................................................................... 20
6.6 Chromaticity .......................................................................................................... 21
6.6.1 Purpose ......................................................................................................... 21
6.6.2 Measuring conditions ..................................................................................... 21
6.6.3 Measuring method ......................................................................................... 22
6.7 White chromaticity and correlated colour temperature ........................................... 22
6.7.1 Purpose ......................................................................................................... 22
6.7.2 Measuring conditions ..................................................................................... 22
---------------------- Page: 4 ----------------------IEC 62977-2-1:2021 © IEC 2021 – 3 –
6.7.3 Measuring method ......................................................................................... 22
6.8 Chromaticity non-uniformity .................................................................................. 23
6.8.1 Purpose ......................................................................................................... 23
6.8.2 Measuring conditions ..................................................................................... 23
6.8.3 Measuring method ......................................................................................... 23
6.9 Chromaticity/colour gamut area............................................................................. 24
6.9.1 Purpose ......................................................................................................... 24
6.9.2 Measuring conditions ..................................................................................... 24
6.9.3 Measuring method ......................................................................................... 25
6.9.4 Chromaticity/colour gamut area in CIE 1931 and CIE 1976 chromaticitydiagram ......................................................................................................... 27
6.10 Luminance and colour variation with viewing direction .......................................... 28
6.10.1 Purpose ......................................................................................................... 28
6.10.2 Measuring conditions ..................................................................................... 28
6.10.3 Measuring method ......................................................................................... 28
7 Display multi-colour optical measuring methods ............................................................ 30
7.1 General ................................................................................................................. 30
7.2 Test patterns......................................................................................................... 30
7.3 Luminance ............................................................................................................ 33
7.3.1 Purpose ......................................................................................................... 33
7.3.2 Measuring conditions ..................................................................................... 33
7.3.3 Measuring method ......................................................................................... 34
7.4 Darkroom contrast ratio ........................................................................................ 35
7.4.1 Purpose ......................................................................................................... 35
7.4.2 Measuring conditions ..................................................................................... 35
7.4.3 Measuring method ......................................................................................... 35
7.5 Luminance uniformity ............................................................................................ 35
7.6 Chromaticity, tristimulus values, and spectra ........................................................ 35
7.6.1 Purpose ......................................................................................................... 35
7.6.2 Measuring conditions ..................................................................................... 36
7.6.3 Measuring method ......................................................................................... 36
7.7 White chromaticity and correlated colour temperature ........................................... 36
7.7.1 Purpose ......................................................................................................... 36
7.7.2 Measuring conditions ..................................................................................... 36
7.7.3 Measuring method ......................................................................................... 36
7.8 Chromaticity/colour gamut area............................................................................. 37
7.8.1 Purpose ......................................................................................................... 37
7.8.2 Measuring conditions ..................................................................................... 37
7.8.3 Measuring method ......................................................................................... 37
7.8.4 Chromaticity/colour gamut area in CIE 1931 and CIE 1976 chromaticitydiagram ......................................................................................................... 37
7.9 Chromaticity non-uniformity .................................................................................. 38
7.10 Luminance and colour variation with viewing direction .......................................... 38
7.10.1 Purpose ......................................................................................................... 38
7.10.2 Measuring conditions ..................................................................................... 38
7.10.3 Measuring method ......................................................................................... 38
8 CIELAB colour gamut volume ........................................................................................ 39
8.1 Purpose ................................................................................................................ 39
8.2 Measuring conditions ............................................................................................ 40
---------------------- Page: 5 ----------------------– 4 – IEC 62977-2-1:2021 © IEC 2021
8.3 Measuring method ................................................................................................ 40
Annex A (normative) RGB boundary colours for CIELAB colour gamut volumemeasurements ...................................................................................................................... 43
A.1 General ................................................................................................................. 43
A.2 Equally-spaced 98 boundary colours on the RGB cube ......................................... 43
A.3 Recommended 602 boundary colours on the RGB cube ........................................ 46
Annex B (informative) Calculation method for CIELAB gamut volume................................... 61
B.1 Purpose ................................................................................................................ 61
B.2 Procedure for calculating the colour gamut volume ............................................... 61
B.3 Number of sampled colours .................................................................................. 62
B.4 RGB cube surface subdivision method for CIELAB colour gamut volumecalculation ............................................................................................................ 62
B.4.1 General ......................................................................................................... 62
B.4.2 Assumption .................................................................................................... 62
B.4.3 Uniform RGB grid algorithm ........................................................................... 62
B.4.4 Software example execution .......................................................................... 65
Annex C (informative) Significance of Clause 6 .................................................................... 74
C.1 Summary .............................................................................................................. 74
C.2 Significance of Clause 6 during the research and development stage ................... 74
C.3 Significance of Clause 6 during the manufacturing stage ...................................... 75
C.4 Significance of Clause 6 during the evaluation of other test results ....................... 76
Annex D (informative) Colour-signal luminance .................................................................... 77
Annex E (informative) Gamut rings ...................................................................................... 78
E.1 General ................................................................................................................. 78
E.2 Visualization method ............................................................................................. 79
E.3 Software example ................................................................................................. 80
Bibliography .......................................................................................................................... 82
Figure 1 – Layout diagram of measurement setup with terminology....................................... 14
Figure 2 – Example of measurement locations with nine measurement locationsequally spaced in the display active area .............................................................................. 16
Figure 3 – Representation of the viewing direction, or direction of measurement .................. 17
Figure 4 – Example of centre box test patterns using the standard 4 % and 10 % area
boxes .................................................................................................................................... 18
Figure 5 – Example of uniformity measurement locations with nine measurementlocations ............................................................................................................................... 20
Figure 6 – Examples of a display with colour boundaries represented by the blacktriangle in two common chromaticity diagrams ...................................................................... 26
Figure 7 – Top view example of configurations for measuring luminance and colour in
the horizontal viewing direction ............................................................................................. 29
Figure 8 – Side view example of configurations for measuring luminance and colour in
the vertical viewing direction ................................................................................................. 30
Figure 9 – Standard medium APL loading version of the colour tile test pattern with red,
green, blue, and white boxes used for luminance and colour measurements ......................... 31
Figure 10 – Medium APL loading version of colour tile patterns illustrating thesequence of test patterns used for luminance and colour measurements .............................. 31
Figure 11 – Standard medium APL RGBCMY test pattern used for centre luminanceand colour measurements with 25 % APL ............................................................................. 33
---------------------- Page: 6 ----------------------IEC 62977-2-1:2021 © IEC 2021 – 5 –
Figure 12 – Sequence for measuring luminance at the nine display locations for all
coloured tile patterns ............................................................................................................ 34
Figure 13 – Example of range in colours produced by a given display as represented
by the CIELAB colour space ................................................................................................. 42
Figure B.1 – Analysis flow chart for calculating the CIELAB gamut volume ........................... 61
Figure B.2 – Example of tessellation using a 5 x 5 grid of surface colours on the
RGB cube ............................................................................................................................. 64
Figure B.3 – Example of tessellation for the RGB cube using a 3 x 3 grid ............................. 66
Figure B.4 – Example of tessellation for the CIELAB gamut volume using a 3 x 3 grid .......... 66
Figure C.1 – Example of conceptual scheme for the supply chain of displays and the
usage of the measurement methods (MM) of Clause 0 and Clause 0 .................................... 74
Figure C.2 – Conceptual example of the evaluation of the components ................................. 75
Figure C.3 – Example of a mechanical stress test ................................................................. 76
Figure E.1 – Example of transformation of the CIELAB gamut volume (top) illustrated
by L* slices into the concentric areas of the gamut ring representation (bottom) ................... 79
Figure E.2 – Example of calculation of gamut rings using the data from Table B.1 ................ 80
Table 1 – Summary of display characteristics ......................................................................... 8
Table 2 – Example of luminance of white, red, green, and blue measured at ninescreen locations and the resulting average luminance .......................................................... 21
Table 3 – Example of a white colour measured at nine screen locations and theresulting chromaticity non-uniformity ..................................................................................... 24
Table 4 – Standard digital-equivalent input signals for rendering the white, primary and
secondary colours in test patterns ......................................................................................... 25
Table 5 – Example of report format for CIELAB gamut volume .............................................. 42
Table A.1 – Equally-spaced 98 RGB boundary colours used for CIELAB colour gamutvolume measurements .......................................................................................................... 44
Table A.2 – Recommended RGB boundary colours used for CIELAB colour gamutvolume measurements .......................................................................................................... 46
Table B.1 – Example data format used for CIELAB colour gamut volumemeasurements ...................................................................................................................... 65
---------------------- Page: 7 ----------------------– 6 – IEC 62977-2-1:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC DISPLAYS –
Part 2-1: Measurements of optical characteristics –
Fundamental measurements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62977-2-1 has been prepared by IEC technical committee 110:
Electronic displays.The text of this International Standard is based on the following documents:
FDIS Report on voting
110/1256/FDIS 110/1275/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62977 series, published under the general title Electronic displays,
can be found on the IEC website.---------------------- Page: 8 ----------------------
IEC 62977-2-1:2021 © IEC 2021 – 7 –
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
---------------------- Page: 9 ----------------------– 8 – IEC 62977-2-1:2021 © IEC 2021
INTRODUCTION
This document describes the common optical measurement methods applicable in the field of
electronic display devices, which can overlap with some of the parts of existing documents
developed within TC 110 (IEC 61747-30-1 [1] , IEC 62341-6-1, IEC 61988-2-1 [2],IEC 62715-5-1 [3]), that describe the optical measurement methods of the individual
technologies, such as LCD, OLED, PDP and others. This document on common opticalmeasurement methods is intended to be used as the reference document in future documents
and in revisions of existing documents (e.g. IEC 61747-30-1, IEC 62341-6-1, IEC 61988-2-1,
IEC 62715-5-1). The existing documents will be revised in their maintenance time to refer to
this document to the largest extent possible.All documents in IEC TC 110 that are concerned with the measurement of optical properties of
electronic displays refer to a set of methods and procedures that are similar to each other, or
sometimes even identical. This document is intended to identify these methods and to describe
them, together with suitable precautions and diagnostics, as a reference for forthcoming
documents to make the work of the involved experts more efficient and to avoid duplication of
efforts.Introduction of the common optical measurement method (COMM) is also related to a structure
where each kind of optical measurement finds its unambiguous position for identification of
similarities to other methods or for clarification of distinctions. This structural classification
together with a general taxonomy is supposed to make the process of document production
easier, faster and thus more effective.The above characteristics are summarized in Table 1. The display characteristics that are
addressed in this part of IEC 62977 are indicated by a check mark √ in the table.
Table 1 – Summary of display characteristicsLocation D
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.