SIST EN 62341-5-3:2014

Organic light emitting diode (OLED) displays - Part 5-3: Measuring methods of image sticking and lifetime

This part of IEC 62341 specifies the standard measurement conditions and measurement methods for determining the image sticking and lifetime of organic light emitting diode (OLED) display panels and modules. It mainly applies to modules.

/

Afficheurs à diodes électroluminescentes organiques (OLED) - Partie 5-3: Méthodes de mesure de la durée de vie et de la rémanence d'images

La CEI 62341-5-3:2013 spécifie les conditions et les méthodes de mesure normalisées pour déterminer la durée de vie et la rémanence des images de modules et de panneaux d'affichage à diodes électroluminescentes organiques (OLED). Elle s'applique principalement à des modules.

Prikazovalniki z organskimi svetlečimi diodami (OLED) - 5-3. del: Metode za merjenje zadrževanja slike in življenjske dobe

Ta del standarda IEC 62341 določa standardne merilne pogoje in merilne metode za merjenje zadrževanja slike in življenjske dobe prikazovalnikov in modulov z organskimi svetlečimi diodami (OLED). Uporablja se zlasti za module.

General Information

• Status: Published
• Publication Date: 05-Dec-2013
• ICS: 31.120 - Electronic display devices
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 25-Nov-2013
• Due Date: 30-Jan-2014
• Completion Date: 06-Dec-2013
• Ref Project: EN 62341-5-3:2013 - Organic Light Emitting Diode (OLED) displays - Part 5-3: Measuring methods of image sticking and lifetime

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 62341-5-3:2014
01-januar-2014
3ULND]RYDOQLNL]RUJDQVNLPLVYHWOHþLPLGLRGDPL2/('GHO0HWRGH]D
PHUMHQMH]DGUåHYDQMDVOLNHLQåLYOMHQMVNHGREH
Organic light emitting diode (OLED) displays - Part 5-3: Measuring methods of image
sticking and lifetime
/
Afficheurs à diodes électroluminescentes organiques (OLED) - Partie 5-3: Méthodes de
mesure de la durée de vie et de la rémanence d'images
Ta slovenski standard je istoveten z: EN 62341-5-3:2013
ICS:
31.120 Elektronske prikazovalne Electronic display devices
naprave
SIST EN 62341-5-3:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 62341-5-3:2014

---------------------- Page: 2 ----------------------

SIST EN 62341-5-3:2014

EUROPEAN STANDARD
EN 62341-5-3

NORME EUROPÉENNE
October 2013
EUROPÄISCHE NORM

ICS 31.120; 31.260


English version


Organic Light Emitting Diode (OLED) displays -
Part 5-3: Measuring methods of image sticking and lifetime
(IEC 62341-5-3:2013)


Afficheurs à diodes électroluminescentes Anzeigen mit organischen Leuchtdioden
organiques (OLED) - (OLED) -
Partie 5-3: Méthodes de mesure de la Teil 5-3: Messverfahren für Nachbilder
durée de vie et de la rémanence d'images und Lebensdauer
(CEI 62341-5-3:2013) (IEC 62341-5-3:2013)





This European Standard was approved by CENELEC on 2013-09-30. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the CEN-CENELEC Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62341-5-3:2013 E

---------------------- Page: 3 ----------------------

SIST EN 62341-5-3:2014
EN 62341-5-3:2013 - 2 -
Foreword
The text of document 110/474/FDIS, future edition 1 of IEC 62341-5-3, prepared by IEC/TC 110
"Electronic display devices" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 62341-5-3:2013.

The following dates are fixed:
(dop) 2014-06-30
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2016-09-30
standards conflicting with the
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.

Endorsement notice
The text of the International Standard IEC 62341-5-3:2013 was approved by CENELEC as a
European Standard without any modification.

---------------------- Page: 4 ----------------------

SIST EN 62341-5-3:2014
- 3 - EN 62341-5-3:2013
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60050 Series International Electrotechnical Vocabulary - -
(IEV)


IEC 61966-2-1 1999 Multimedia systems and equipment - EN 61966-2-1 2000
Colour measurement and management -
Part 2-1: Colour management -
Default RGB colour space - sRGB


IEC 62087 2011 Methods of Measurement for the power EN 62087 2012
consumption of audio, video and related
equipment


IEC 62341-1-2 2007 Organic light emitting diode displays - EN 62341-1-2 2009
Part 1-2: Terminology and letter symbols


IEC 62341-6-1 2009 Organic light emitting diode (OLED) EN 62341-6-1 2011
displays -
Part 6-1: Measuring methods
of optical and electro-optical parameters


CIE 15 2004 Colorimetry - -

---------------------- Page: 5 ----------------------

SIST EN 62341-5-3:2014

---------------------- Page: 6 ----------------------

SIST EN 62341-5-3:2014




IEC 62341-5-3

®


Edition 1.0 2013-08




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Organic light emitting diode (OLED) displays –

Part 5-3: Measuring methods of image sticking and lifetime




Afficheurs à diodes électroluminescentes organiques (OLED) –

Partie 5-3: Méthodes de mesure de la durée de vie et de la rémanence d'images
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX U


ICS 31.120; 31.260 ISBN 978-2-8322-1045-1



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 7 ----------------------

SIST EN 62341-5-3:2014
– 2 – 62341-5-3 © IEC:2013
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Measuring configuration . 7
4.1 General . 7
4.2 Light measuring device (LMD) . 7
5 Standard measuring conditions . 7
5.1 Standard measuring environmental conditions . 7
5.2 Standard measuring dark-room condition . 7
5.3 Standard setup conditions . 7
5.3.1 General . 7
5.3.2 Adjustment of OLED display modules . 8
5.3.3 Starting conditions of measurements . 8
5.3.4 Test patterns . 8
5.3.5 Conditions of measuring equipment . 9
6 Measuring methods of image sticking . 9
6.1 Purpose. 9
6.2 Measuring method . 9
6.2.1 Measuring equipment . 9
6.2.2 Measuring procedure . 9
6.3 Analysis and report . 10
6.3.1 Analysis . 10
6.3.2 Report . 12
7 Measuring methods of the luminance lifetime . 13
7.1 Purpose. 13
7.2 Measuring method . 13
7.2.1 Measuring equipment . 13
7.2.2 Measuring procedure . 13
7.2.3 Estimation of luminance lifetime . 14
7.3 Analysis and report . 15
Annex A (informative) Calculation method of equivalent signal level . 17
Annex B (informative) Acceleration test of lifetime measurement . 23
Bibliography . 26

Figure 1 – Measuring system and arrangement . 7
Figure 2 – Test pattern for image sticking . 9
Figure 3 – An example of the burn-in image . 10
Figure 4 – An example of luminance behavior in operation for an OLED display panel
or module . 14
Figure 5 – An example of lifetime estimation with the extrapolation method . 15
Figure 6 – An example of estimated lifetime depending on the time elapsed . 15
Figure 7 – An example of Weibull distribution of lifetime . 16
2 2
Figure A.1 – Measured 10 mA/cm to 80 mA/cm OLED degradation values and
corresponding modelled functions with m = 1/1,7 . 18

---------------------- Page: 8 ----------------------

SIST EN 62341-5-3:2014
62341-5-3 © IEC:2013 – 3 –
Figure A.2 – Accumulated colour intensity of IEC 62087:2011 10-min video loop in
RGB subpixel format with equivalent signal distribution chart based on the left images,
respectively . 21
Figure A.3 – Accumulated colour intensity of the IEC 62087:2011 10-min video loop in
W, R, G, and B format, with equivalent signal distribution chart based on the left
images, respectively . 22
Figure B.1 – Examples of Weibull distributions of accelerated lifetime test . 23

Table 1 – An example of measuring distance and radius size. 8
Table 2 – An example of typical value . 12
Table 3 – An example of the image sticking time with reference . 13
Table 4 – An example of the image sticking data at target time . 13
Table 5 – Examples of lifetime measurement . 16
Table A.1 – Examples of the maximum and the minimum equivalent signal levels (8
bits) . 20
Table B.1 – Summary of the acceleration test results in Figure B.1 . 24
Table B.2 – Statistical analysis results of the accelerated lifetime test in Figure B.1 . 24

---------------------- Page: 9 ----------------------

SIST EN 62341-5-3:2014
– 4 – 62341-5-3 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 5-3: Measuring methods of image sticking and lifetime


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 62341-5-3 has been prepared by IEC technical committee 110:
Electronic display devices.
The text of this standard is based on the following documents:
FDIS Report on voting
110/474/FDIS 110/501/RVD

Full information on the voting for the approval on 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 62341 series, under the general title Organic light emitting
diode (OLED) displays, can be found on the IEC website.

---------------------- Page: 10 ----------------------

SIST EN 62341-5-3:2014
62341-5-3 © IEC:2013 – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site 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.

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: 11 ----------------------

SIST EN 62341-5-3:2014
– 6 – 62341-5-3 © IEC:2013
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 5-3: Measuring methods of image sticking and lifetime



1 Scope
This part of IEC 62341 specifies the standard measurement conditions and measurement
methods for determining the image sticking and lifetime of organic light emitting diode (OLED)
display panels and modules. It mainly applies to modules.
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 (all parts), International Electrotechnical Vocabulary (available at
)
IEC 62087:2011, Methods of measurement for the power consumption of audio, video and
related equipment
IEC 62341-1-2:2007, Organic light emitting diode (OLED) displays – Part 1-2: Terminology
and letter symbols
IEC 62341-6-1:2009, Organic light emitting diode (OLED) displays – Part 6-1: Measuring
methods of optical and electro-optical parameters
IEC 61966-2-1:1999, Multimedia systems and equipment – Colour measurement and
management – Part 2-1: Colour management –Default RGB colour space – sRGB
CIE 15-2004, Colorimetry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62341-1-2:2007 and
IEC 60050-845:1987, as well as the following apply.
3.1
equivalent current density
average current density of a certain pixel calculated from a varying luminance per frame
image in a moving picture so that luminance degradation becomes similar at the same time
Note 1 to entry: See Annex A.
3.2
equivalent signal level
digital code value from 0 to 255 (in the case of 8 bits) transformed from the normalized
luminance of a certain pixel by a gamma function
Note 1 to entry: See Annex A.

---------------------- Page: 12 ----------------------

SIST EN 62341-5-3:2014
62341-5-3 © IEC:2013 – 7 –
4 Measuring configuration
4.1 General
The system diagrams and/or operating conditions of the measuring equipment shall comply
with the structure specified in each item. The measuring system and its arrangement are
shown in Figure 1. The details are referred to in Clause 5.

OLED
display
Display surface
module
Light measuring device
Driving
Driving
power
signal
source
IEC  2151/13

Figure 1 – Measuring system and arrangement
4.2 Light measuring device (LMD)
The LMD as defined in IEC 62341-6-1:2009 shall be used. Specifically, the accuracy of the
LMD at 1 degree of the measurement field angle is recommended as being ≤ ±3%, and with a
repeatability ≤ ±0,5%.
5 Standard measuring conditions
5.1 Standard measuring environmental conditions
The standard measuring environmental conditions specified in IEC 62341-6-1:2009, 5.1, shall
be applied. For image sticking measurements, the environmental temperature shall be
controlled at 25 °C ± 2 °C, otherwise a temperature controlled detector shall be used. (The
stability of the LMD shall be less than 1/5 of the intended detecting difference levels of
luminance and colour.)
5.2 Standard measuring dark-room condition
The standard measuring dark-room conditions specified in IEC 62341-6-1:2009, 5.2, shall be
applied.
5.3 Standard setup conditions
5.3.1 General
For the measurement area, the minimum radius for measurement with the distance and
aperture angle is explained in Table 1.

---------------------- Page: 13 ----------------------

SIST EN 62341-5-3:2014
– 8 – 62341-5-3 © IEC:2013
Table 1 – An example of measuring distance and radius size
Radius of measurement
Distance Aperture angle
field
(mm) (degree)
(mm)
2 10
1 5
500
0,2 1
0,1 0,5

5.3.2 Adjustment of OLED display modules
The adjustment of OLED display modules specified in IEC 62341-6-1:2009, 5.3.1, shall be
applied.
5.3.3 Starting conditions of measurements
Warm-up time is defined as the time elapsed from the moment of switching on the supply
voltage until repeated measurements of the display show a variation in luminance of less than
2 % per minute. Repeated measurements shall be taken for at least a period of 15 minutes
after starting. The luminance variations shall also not exceed 5 % during the total
measurement.
5.3.4 Test patterns
The test patterns for display devices such as mobile phones, table PCs, monitors and TVs are
shown in Figure 2. In the case of mobiles and tablet PCs, depending on the size of the OLED
display panels or modules and measurement distance between the display and the LMD, if the
pattern size is a smaller area than a 10 mm radius at a 500 mm measurement distance with a
2-degree aperture angle of the LMD, then the aperture angle of the LMD should be set to
cover the pattern area as set in Table 1. The measuring distance and the aperture angle may
be adjusted to achieve a measuring field greater than 500 pixels if the setting of the aperture
angle is difficult. For all applications, the test pattern is used in Figure 2a), and usage method
case for monitors and TVs such as Figure 2b) may be used. In order to get repeatability of
measurement, the measuring location from P to P for TVs type as shown in Figure 2c) are
0 4
set, considering the uniformity of the OLED display panels or modules.

---------------------- Page: 14 ----------------------

SIST EN 62341-5-3:2014
62341-5-3 © IEC:2013 – 9 –


IEC  2152/13 IEC  2153/13

a) – The test pattern for display b) – The test pattern for monitor
devices except monitors and TV devices
and TVs



IEC  215413

c) – Image sticking measuring location
Figure 2 – Test pattern for image sticking
5.3.5 Conditions of measuring equipment
The general conditions in IEC 62341-6-1:2009, 5.3.3.1, shall be applied.
6 Measuring methods of image sticking
6.1 Purpose
The purpose of this method is to measure the image sticking of OLED display panels or
modules.
6.2 Measuring method
6.2.1 Measuring equipment
The following equipment defined in IEC 62341-6-1:2009, 6.1.2, shall be used:
a) power supplies and signal sources for driving,
b) LMD.
6.2.2 Measuring procedure
The OLED display modules shall be set in dark-room conditions for measurement.
1) Initial measurements on full screen pattern

---------------------- Page: 15 ----------------------

SIST EN 62341-5-3:2014
– 10 – 62341-5-3 © IEC:2013
Apply a full white screen driving signal to the OLED display modules over the full screen,
and set all power supplies to the standard operation conditions. However, for some display
applications, the full screen luminance can be reduced, according to 7.3.1 of IEC 62341-6-
1:2009.
Measure the initial spectral radiance or tristimulus values of white at P to P as shown in
0 4
Figure 2c). The initial spectra radiance or tristrimulus values of the primary colours may
also be measured individually.
2) Image burn-in using test pattern
For the test pattern for display devices (except monitors and TVs), set the test input signal
to the OLED display modules to generate a 0 % luminance level over the full screen and a
peak luminance at the test pattern which is located at the centre of the display as shown in
Figure 2a). For monitor and TV, set the peak luminance level over the 4 % window pattern
located in the centre of the display with a 15 % luminance level of the peak luminance
over the background area. For information about guidance, see Annex C of
IEC 62087:2011. If the other pattern is used, it should be based on Annex A of this
document and reported.
Keep the test pattern until the specified time, considering the luminance degradation curve.
For example, the measurement time can be every 1 hour during the first 6 hours, and
every 24 hours during the first 120 hours; then every 72 hours until the target time in the
standard measurement condition. Alternatively keep the test pattern until the target time in
the standard measurement condition.
3) Measurements on full screen pattern
Apply a full white screen driving signal to the OLED display modules over the full screen.
Measure the spectral radiance or the tristimulus values at the same measuring location as
the initial measurement. The initial and final spectra radiance or tristrimulus values of the
individual primary colours may also be measured and reported.
All measurements shall be done at the target time of 400 and 500 hours and shall be reported.
In Figure 3, an example of the burn-in image is shown.

IEC  2155/13

Figure 3 – An example of the burn-in image
6.3 Analysis and report
6.3.1 Analysis
6.3.1.1 Luminance and chromatic deviation method
Image sticking can be characterized by luminance and chromatic deviation.
The image sticking of luminance IS(t) for white is calculated as follows:

---------------------- Page: 16 ----------------------

SIST EN 62341-5-3:2014
62341-5-3 © IEC:2013 – 11 –
4
 
 
L t) / L (t)
 
i 0
∑
 
i=1
 
 (1)
IS(t)= 1− ×100(%)
4
 
 
L (t ) / L (t )
 
i 0 0 0
∑
 
i=1
 
where
t is the specified measurement time;
t is the initial measurement time;
0
L  is the luminance of measurement location from P .
i i
∆u’v’(t) caused by image sticking at P over time for white is calculated
Chromatic deviation
0 0
as follows:
2 2
∆u'v'(t) = {u'(t)− u'(t )} +{v'(t)− v'(t )}
  (2)
0 0 0
where
t is the specified measurement time;
t is the initial measurement time;
0
(u’(t), v’(t)) is the white chromaticity value at the specified time;
(u’(t ),v’(t )) is the white chromaticity value at the initial time.
0 0
The average of chromatic deviation ∆u’v’(t) caused by image sticking between different
AVG
measuring locations from P to P for white is calculated as follows:
1 4
4
 
2 2
 
∆u'v'(t) = {u' (t)− u' (t)} +{v' (t)− v' (t)} / 4 (3)
AVG ∑ i 0 i 0
 
 i=1 
where
t is the specified measurement time;
(u’ (t), v’ (t)) is the chromaticity coordinates of measuring locations of P (i = 1, 2, 3, 4).
i i i
The value of u' and v' can be calculated from the tristimulus value X, Y, and Z using the
following equations:
u'= 4X /(X+ 15Y+ 3Z)
 (4)
v'= 9Y /(X+ 15Y+ 3Z)
6.3.1.2 Colour difference method
The image sticking shall be analyzed with ∆E* of the three-dimensional, CIE 1976 L*a*b*
ab
colour space (see CIE 15-2004) following the procedure in 6.2.2. Additional three-dimensional
uniform colour spaces and colour spaces may also be used and identified in the test report.
Each colour point can be plotted on the L*, a*, and b* axes of the CIE L*a*b* colour space by
referencing the peak white tristimulus value (X , Y , Z ) in measuring location P at initial time
n n n 0
t and using the following transformation equations:
0

---------------------- Page: 17 ----------------------

SIST EN 62341-5-3:2014
– 12 – 62341-5-3 © IEC:2013
L * (t)= 116 f (Y (t)/ Y )−16
i i n
a * (t)= 500[f (X (t)/ X )− f (Y (t)/ Y )] (5)
i i n i n
b * (t)= 200[f (Y (t)/ Y )− f (Z (t)/ Z )]
i i n i n
where
1/ 3 3

x x> (6 / 29)

f (x)=

1 29 4
2
( ) x+ otherwise

3 6 29
t is the specified measurement time;
L*a*b* is the CIELAB colour coordinates of measuring locati
...