IEC 62595-1-2:2016
(Main)Display lighting unit - Part 1-2: Terminology and letter symbols
Display lighting unit - Part 1-2: Terminology and letter symbols
IEC 62595-1-2:2016(E) gives the preferred terms, their definitions and symbols for display lighting units (DLUs) such as backlight units (BLUs) of transmissive and transflective LCDs, and frontlight units (FLUs) of reflective LCDs and electronic paper (E-paper) displays, with the object of using the same terminology when publications are prepared in different countries. This edition includes the following significant technical changes with respect to the previous edition:
a) change in the series title in order to handle frontlight units;
b) new terms are added considering recent advances in display lighting unit (DLU) technology;
c) some of terms and definitions are corrected and revised, particularly to be consistent with IEC 62595-2;
d) some of the terms and definitions are corrected and revised, particularly to be consistent with IEC 60050 policy;
e) clause structure is rectified for categorizing terms correctly;
f) some of figures in Annex A are added or revised for better understanding.
General Information
Relations
Standards Content (Sample)
IEC 62595-1-2 ®
Edition 2.0 2016-02
INTERNATIONAL
STANDARD
colour
inside
Display lighting unit –
Part 1-2: Terminology and letter symbols
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 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 15 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. 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 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. 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 62595-1-2 ®
Edition 2.0 2016-02
INTERNATIONAL
STANDARD
colour
inside
Display lighting unit –
Part 1-2: Terminology and letter symbols
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-3170-8
– 2 – IEC 62595-1-2:2016 IEC 2016
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references. 5
3 Terms and definitions . 5
3.1 Classification of terms . 5
3.2 Fundamental terms . 5
3.3 Terms related to passive optical components . 9
3.4 Terms related to solid-state light sources . 13
3.4.1 Light-emitting diode (LED) . 13
3.4.2 LED light bar . 14
3.5 Terms related to frontlight units . 15
3.6 Terms related to performances and specifications . 16
3.7 Terms related to backlight dimming . 18
4 Letter symbols (quantity symbols / unit symbols) . 20
Annex A (informative) Supplementary figures . 21
Figure A.1 – Backlighting concept for transmissive and transflective LCDs . 21
Figure A.2 – Examples of edge-lit backlight units . 21
Figure A.3 – Example of a direct-lit backlight unit . 22
Figure A.4 – Visual definition of the terms related to passive optical components such
as bezel and case . 22
Figure A.5 – Luminance uniformity on a backlight unit . 23
Figure A.6 – Polar coordinate system for evaluation of the angular luminance
distribution. 23
Figure A.7 – Angular luminance on a backlight unit . 24
Figure A.8 – Examples of spectral power distribution of a display lighting unit . 24
Figure A.9 – Incoherent light spread function for evaluation of optical characteristics of
a block in a block-wise dynamic backlight unit . 24
Figure A.10 – Light spread functions of three BLUs with different optical structures . 25
Figure A.11 – Checkerboard pattern for evaluation of the luminance uniformity
in a BLU . 26
Table 1 – Letter symbols (quantity symbols / unit symbols) . 20
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DISPLAY LIGHTING UNIT –
Part 1-2: Terminology and letter symbols
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 62595-1-2 has been prepared by IEC technical committee 110:
Electronic display devices.
This second edition cancels and replaces the first edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) change in the series title in order to handle frontlight units;
b) new terms are added considering recent advances in display lighting unit (DLU)
technology;
c) some of terms and definitions are corrected and revised, particularly to be consistent with
IEC 62595-2;
d) some of the terms and definitions are corrected and revised, particularly to be consistent
with IEC 60050 policy;
– 4 – IEC 62595-1-2:2016 IEC 2016
e) clause structure is rectified for categorizing terms correctly;
f) some of figures in Annex A are added or revised for better understanding.
The text of this standard is based on the following documents:
FDIS Report on voting
110/720/FDIS 110/734/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 62595 series, under the general title Display lighting unit, can
be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
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.
DISPLAY LIGHTING UNIT –
Part 1-2: Terminology and letter symbols
1 Scope
This part of IEC 62595 gives the preferred terms, their definitions and symbols for display
lighting units (DLUs) such as backlight units (BLUs) of transmissive and transflective LCDs,
and frontlight units (FLUs) of reflective LCDs and electronic paper (E-paper) displays, with the
object of using the same terminology when publications are prepared in different countries.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-845, International Electrotechnical Vocabulary – Part 845: Lighting
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-845 as well
as the following apply.
3.1 Classification of terms
Terms for display lighting units (DLUs), such as backlight units (BLUs) and frontlight units
(FLUs) are classified as follows:
a) fundamental terms related to display lighting units (3.2);
b) terms related to passive optical components used in display lighting units (3.3);
c) terms related to solid-state light sources used in display lighting units (3.4);
d) terms related particularly to frontlight units (3.5);
e) terms related to performances and specifications (3.6);
f) terms related to backlight dimming (3.7).
The following definitions are applied for international standardization of the backlight units.
3.2 Fundamental terms
3.2.1
display lighting unit
DLU
lighting unit for recognition of the displayed images on a non-emissive electronic display
device
____________
Identical to CIE 17.4.
–
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.