IEC TR 62778:2014
(Main)Application of IEC 62471 for the assessment of blue light hazard to light sources and luminaires
Application of IEC 62471 for the assessment of blue light hazard to light sources and luminaires
IEC/TR 62778:2014 brings clarification and guidance concerning the assessment of blue light hazard of all lighting products which have the main emission in the visible spectrum (380 nm to 780 nm). By optical and spectral calculations, it is shown what the photobiological safety measurements as described in IEC 62471 tell us about the product and, if this product is intended to be a component in a higher level lighting product, how this information can be transferred from the component product (e.g. the LED package, the LED module, or the lamp) to the higher level lighting product (e.g. the luminaire). This second edition cancels and replaces the first edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical change with respect to the previous edition: inclusion of the photobiological assessment of LED arrays (Annex D). The contents of the corrigendum of July 2014 have been included in this copy.
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IEC TR 62778 ®
Edition 2.0 2014-06
TECHNICAL
REPORT
colour
inside
Application of IEC 62471 for the assessment of blue light hazard to light sources
and luminaires
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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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.
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and withdrawn publications. have been collected from earlier publications of IEC TC 37,
77, 86 and CISPR.
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IEC TR 62778 ®
Edition 2.0 2014-06
TECHNICAL
REPORT
colour
inside
Application of IEC 62471 for the assessment of blue light hazard to light sources
and luminaires
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
W
ICS 29.140 ISBN 978-2-8322-1615-6
– 2 – IEC TR 62778:2014 © IEC 2014
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General . 11
5 Spectrum, colour temperature, and blue light hazard . 12
5.1 Calculation of blue light hazard quantities and photometric quantities from
emission spectra . 12
5.2 Luminance and illuminance regimes that give rise to t values below
max
100 s . 15
6 LED packages, LED modules, lamps and luminaires . 17
7 Measurement information flow . 18
7.1 Basic flow . 18
7.2 Conditions for the radiance measurement . 20
7.3 Special cases (I): Replacement by a lamp or LED module of another type . 22
7.4 Special cases (II): Arrays and clusters of primary light sources . 22
8 Risk group classification . 22
Annex A (informative) Geometrical relations between radiance, irradiance and radiant
intensity . 23
Annex B (informative) Distance dependence of t for a certain light source . 25
max
Annex C (informative) Summary of recommendations to assist the consistent
application of IEC 62471 for the assessment of blue light hazard to light sources and
luminaires . 27
C.1 General . 27
C.2 Situation of RG0 or RG1 classification not requiring radiance or irradiance
measurement . 27
C.2.1 Boundary conditions . 27
C.2.2 True luminance values giving risk group not greater than RG1 . 27
C.2.3 Illuminance values giving risk group not greater than RG1 . 28
C.3 Situation for the classification of light sources larger than 2,2 mm and
luminaires using these light sources. 29
C.4 Situation for the classification of light sources smaller than 2,2 mm and
luminaires using these light sources. 30
C.5 Situation for the classification of light sources that pose practical difficulties
in measurements at 200 mm . 30
Annex D (informative) Detailed assessment of arrays and clusters of primary light
sources, comprised of LED packages . 31
D.1 General . 31
D.2 Approach . 31
D.2.1 Step by step assessment . 31
D.2.2 Type of arrays and additional steps . 32
D.2.3 Complete flowchart . 34
D.3 Derivation of the formula for average radiance of the full array . 35
Bibliography . 37
Figure 1 – Blue light hazard efficacy of luminous radiation, K , for a range of light
B,v
sources from different technologies, and for a few typical daylight spectra . 13
Figure 2 – Comparison between the curves involved in calculating K (the photopic
B,v
eye sensitivity curve and the blue light spectral weighting function) and the CIE 1931 Y
and Z curves involved in calculating the CIE 1931 x, y colour coordinates . 14
Figure 3 – Correlation plot between the quantity (1 – x – y)/y, calculated from the CIE
1931 x, y colour coordinates, and the value of K , for all the spectra analysed to
B,v
generate Figure 1 . 15
.
Figure 4 – Estimate of the luminance level where L = 10 000 W/(m sr), border
B
between RG1 (t > 100 s) and RG2 (t < 100 s) in the large source regime, as a
max max
function of CCT . 16
Figure 5 – Estimate of the illuminance level where E = 1 W/m , border between RG1
B
(t > 100 s) and RG2 (t < 100 s) in the small source regime, as a function of
max max
CCT 16
Figure 6 – Relation of illuminance E, distance d and intensity I . 20
Figure 7 – Flow chart from the primary light source (in blue) to the luminaire based on
this light source (in amber) . 21
Figure A.1 – Schematic image of the situation considered in Annex A . 23
Figure B.1 – General appearance of t as a function of viewing distance d, for any
max
light source with homogeneous luminance L and diameter D . 26
Figure C.1 – Luminance values from Table C.1 in relation to the RG1/RG2 border as
function of correlated colour temperature . 28
Figure C.2 – Illuminance values from Table C.2 in relation to the RG1/RG2 border as
function of correlated colour temperature . 29
Figure D.1 – Examples of secondary lenses with identical light distribution and
alignment . 32
Figure D.2 – Examples of LED arrays with bare LED packages . 33
Figure D.3 – Evaluation whether one or more LED elements fall in 11 mrad field of
view at distance d . 33
Figure D.4 – Complete flowchart of the detailed assessment of arrays and clusters of
primary light sources . 35
Table 1 – Correlation between exposure time and risk group . 10
Table C.1 – Luminance values giving risk group not greater than RG1 . 28
Table C.2 – Illuminance values giving risk group not greater than RG1 . 29
Table D.1 – Applicability of steps 1 to 6 . 31
– 4 – IEC TR 62778:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
APPLICATION OF IEC 62471 FOR THE ASSESSMENT OF
BLUE LIGHT HAZARD TO LIGHT SOURCES AND LUMINAIRES
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, ser
...
IEC TR 62778 ®
Edition 2.0 2014-06
TECHNICAL
REPORT
colour
inside
Application of IEC 62471 for the assessment of blue light hazard to light sources
and luminaires
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 14
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 55 000 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 TR 62778 ®
Edition 2.0 2014-06
TECHNICAL
REPORT
colour
inside
Application of IEC 62471 for the assessment of blue light hazard to light sources
and luminaires
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
W
ICS 29.140 ISBN 978-2-8322-1615-6
– 2 – IEC TR 62778:2014 © IEC 2014
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General . 11
5 Spectrum, colour temperature, and blue light hazard . 12
5.1 Calculation of blue light hazard quantities and photometric quantities from
emission spectra . 12
5.2 Luminance and illuminance regimes that give rise to t values below
max
100 s . 15
6 LED packages, LED modules, lamps and luminaires . 17
7 Measurement information flow . 18
7.1 Basic flow . 18
7.2 Conditions for the radiance measurement . 20
7.3 Special cases (I): Replacement by a lamp or LED module of another type . 22
7.4 Special cases (II): Arrays and clusters of primary light sources . 22
8 Risk group classification . 22
Annex A (informative) Geometrical relations between radiance, irradiance and radiant
intensity . 23
Annex B (informative) Distance dependence of t for a certain light source . 25
max
Annex C (informative) Summary of recommendations to assist the consistent
application of IEC 62471 for the assessment of blue light hazard to light sources and
luminaires . 27
C.1 General . 27
C.2 Situation of RG0 or RG1 classification not requiring radiance or irradiance
measurement . 27
C.2.1 Boundary conditions . 27
C.2.2 True luminance values giving risk group not greater than RG1 . 27
C.2.3 Illuminance values giving risk group not greater than RG1 . 28
C.3 Situation for the classification of light sources larger than 2,2 mm and
luminaires using these light sources. 29
C.4 Situation for the classification of light sources smaller than 2,2 mm and
luminaires using these light sources. 30
C.5 Situation for the classification of light sources that pose practical difficulties
in measurements at 200 mm . 30
Annex D (informative) Detailed assessment of arrays and clusters of primary light
sources, comprised of LED packages . 31
D.1 General . 31
D.2 Approach . 31
D.2.1 Step by step assessment . 31
D.2.2 Type of arrays and additional steps . 32
D.2.3 Complete flowchart . 34
D.3 Derivation of the formula for average radiance of the full array . 35
Bibliography . 37
Figure 1 – Blue light hazard efficacy of luminous radiation, K , for a range of light
B,v
sources from different technologies, and for a few typical daylight spectra . 13
Figure 2 – Comparison between the curves involved in calculating K (the photopic
B,v
eye sensitivity curve and the blue light spectral weighting function) and the CIE 1931 Y
and Z curves involved in calculating the CIE 1931 x, y colour coordinates . 14
Figure 3 – Correlation plot between the quantity (1 – x – y)/y, calculated from the CIE
1931 x, y colour coordinates, and the value of K , for all the spectra analysed to
B,v
generate Figure 1 . 15
.
Figure 4 – Estimate of the luminance level where L = 10 000 W/(m sr), border
B
between RG1 (t > 100 s) and RG2 (t < 100 s) in the large source regime, as a
max max
function of CCT . 16
Figure 5 – Estimate of the illuminance level where E = 1 W/m , border between RG1
B
(t > 100 s) and RG2 (t < 100 s) in the small source regime, as a function of
max max
CCT 16
Figure 6 – Relation of illuminance E, distance d and intensity I . 20
Figure 7 – Flow chart from the primary light source (in blue) to the luminaire based on
this light source (in amber) . 21
Figure A.1 – Schematic image of the situation considered in Annex A . 23
Figure B.1 – General appearance of t as a function of viewing distance d, for any
max
light source with homogeneous luminance L and diameter D . 26
Figure C.1 – Luminance values from Table C.1 in relation to the RG1/RG2 border as
function of correlated colour temperature . 28
Figure C.2 – Illuminance values from Table C.2 in relation to the RG1/RG2 border as
function of correlated colour temperature . 29
Figure D.1 – Examples of secondary lenses with identical light distribution and
alignment . 32
Figure D.2 – Examples of LED arrays with bare LED packages . 33
Figure D.3 – Evaluation whether one or more LED elements fall in 11 mrad field of
view at distance d . 33
Figure D.4 – Complete flowchart of the detailed assessment of arrays and clusters of
primary light sources . 35
Table 1 – Correlation between exposure time and risk group . 10
Table C.1 – Luminance values giving risk group not greater than RG1 . 28
Table C.2 – Illuminance values giving risk group not greater than RG1 . 29
Table D.1 – Applicability of steps 1 to 6 . 31
– 4 – IEC TR 62778:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
APPLICATION OF IEC 62471 FOR THE ASSESSMENT OF
BLUE LIGHT HAZARD TO LIGHT SOURCES AND LUMINAIRES
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) Al
...
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