IEC 62341-6-3:2012

IEC 62341-6-3 ®
Edition 1.0 2012-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Organic light emitting diode (OLED) displays –
Part 6-3: Measuring methods of image quality

Afficheurs à diodes électroluminescentes organiques (OLED) –
Partie 6-3: Méthodes de mesure de la qualité des images

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IEC 62341-6-3 ®
Edition 1.0 2012-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Organic light emitting diode (OLED) displays –

Part 6-3: Measuring methods of image quality

Afficheurs à diodes électroluminescentes organiques (OLED) –

Partie 6-3: Méthodes de mesure de la qualité des images

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX V
ICS 31.260 ISBN 978-2-83220-294-4

– 2 – 62341-6-3 © IEC:2012
CONTENTS
FOREWORD . 4

1 Scope . 6

2 Normative references . 6

3 Terms, definitions, symbols, units and abbreviations . 6

3.1 Terms, definitions, symbols and units . 6

3.2 Abbreviations . 6

4 Standard measuring equipment and coordinate system . 7
4.1 Light measuring devices . 7
4.2 Viewing direction coordinate system . 7
5 Measuring conditions . 8
5.1 Standard measuring environmental conditions . 8
5.2 Power supply . 9
5.3 Warm-up time . 9
5.4 Standard measuring dark-room conditions . 9
5.5 Standard set-up conditions . 9
6 Measuring methods of image quality . 10
6.1 Viewing angle range . 10
6.1.1 Purpose . 10
6.1.2 Measuring conditions . 10
6.1.3 Set-up . 10
6.1.4 Measurement and evaluation . 11
6.1.5 Reporting. 12
6.2 Cross-talk . 13
6.2.1 Purpose . 13
6.2.2 Measuring conditions . 13
6.2.3 Measurement and evaluation . 13
6.2.4 Reporting. 16
6.3 Flicker . 16
6.3.1 Purpose . 16
6.3.2 Measuring conditions . 16
6.3.3 Set-up . 16

6.3.4 Measuring method . 17
6.3.5 Evaluation method . 17
6.3.6 Reporting. 19
6.4 Static image resolution . 19
6.4.1 Purpose . 19
6.4.2 Measuring conditions . 20
6.4.3 Measuring method . 20
6.4.4 Calculation and reporting . 20
6.5 Moving image resolution . 21
6.5.1 Purpose . 21
6.5.2 Measuring conditions . 21
6.5.3 Temporal integration method . 23
6.5.4 Image tracking method . 25
6.5.5 Dynamic MTF calculation . 27

62341-6-3 © IEC:2012 – 3 –
6.5.6 Reporting. 27

Annex A (informative) Simple matrix method for correction stray light of imaging

instruments . 28

Bibliography . 30

Figure 1 – Representation of the viewing direction (equivalent to the direction of

measurement) by the angle of inclination, θ and the angle of rotation (azimuth angle),

φ in a polar coordinate system . 8

Figure 2 – DUT installation conditions . 9

Figure 3 – Geometry used for measuring viewing angle range . 11
Figure 4 – Standard measurement positions, indicated by P -P , are located relative
0 8
to the height (V) and display width (H) of active area. . 13
Figure 5 – Luminance measurement of 4 % window at P . 14
Figure 6 – Luminance measurement at P with windows A ,A , A and A . 15
0 W1 W2 B3 B4
Figure 7 – Luminance measurement at P with windows A , A , A and A . 15
0 W5 W8 B5 B8
Figure 8 – Apparatus arrangement . 16
Figure 9 – Temporal contrast sensitivity function . 18
Figure 10 – Example of flicker modulation waveform . 18
Figure 11 – Contrast modulation measurement . 21
Figure 12 – Peak luminance and amplitude of display test signal . 23
Figure 13 – Set-up for measurement of the temporal response of the DUT . 23
Figure 14 – Sinusoidal luminance pattern and corresponding gray level values . 24
Figure 15 – Input code sequences (left) and corresponding temporal luminance
transitions (right). 25
Figure 16 – Example of captured image . 26
Figure 17 – Example of Fourier transform . 27
Figure 18 – Example of limit resolution evaluation . 27
Figure A.1 – Result of spatial stray light correction for an imaging photometer used to
measure a black spot surrounded by a large bright light source. . 29

Table 1 – Temporal contrast sensitivity function . 17

– 4 – 62341-6-3 © IEC:2012
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-3: Measuring methods of image quality

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
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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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
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
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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 62341-6-3 has been prepared by IEC technical committee 110:

Flat panel display devices.
The text of this standard is based on the following documents:
FDIS Report on voting
110/374/FDIS 110/399/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.

62341-6-3 © IEC:2012 – 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.
– 6 – 62341-6-3 © IEC:2012
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-3: Measuring methods of image quality

1 Scope
This part of IEC 62341 specifies the standard measurement conditions and measuring

methods for determining image quality of organic light emitting diode (OLED) display panels
and modules. More specifically, this standard focuses on five specific aspects of image quality,
i.e., the viewing angle range, cross-talk, flicker, static image resolution, and moving image
resolution.
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 62341-1-2:2007, Organic light emitting diode (OLED) displays – Part 1-2: Terminology
and letter symbols
CIE 015:2004, Colorimetry, 3rd Edition
ISO 11664-1/CIE S 014-1, Colorimetry – Part 1: CIE standard colorimetric observers
ISO 11664-5/CIE S 014-5, Colorimetry – Part 5: CIE 1976 L*u*v* Colour space and u', v'
uniform chromaticity scale diagram
3 Terms, definitions, symbols, units and abbreviations
3.1 Terms, definitions, symbols and units
For the purposes of this document, the terms, definitions, symbols and units given in
IEC 62341-1-2 apply.
3.2 Abbreviations
CCD Charge coupled device
CIE International Commission on Illumination
(Commission Internationale de L’Éclairage)
CFF Critrical flicker frequency
CIELAB CIE 1976 (L*a*b*) colour space
DUT Device under test
HVS Human visual system
LED Light emitting diode
LMD Light measuring device
OLED Organic light emitting diode
ppf pixels per frame
62341-6-3 © IEC:2012 – 7 –
PSF Point spread function
RGB Red, green, blue
SLSF Spectral line spread function

4 Standard measuring equipment and coordinate system

4.1 Light measuring devices
The system configurations and/or operating conditions of the measuring equipment shall

comply with the structure specified in each item.

To ensure reliable measurements, the following requirements apply to the light measuring
equipment, listed below:
a) Luminance meter [1] : the instrument's spectral responsivity shall comply with the CIE
’
photopic luminous efficiency function with a CIE-f value no greater than 3 % [2]; the
relative luminance uncertainty of measured luminance (relative to CIE illuminant A source)
shall not be greater than 4 % for luminance values over 10 cd/m and not be greater than
10 % for luminance values 10 cd/m and below.
b) Colorimeter: the detector’s spectral responsivity shall comply with the colour matching
functions for the CIE 1931 standard colorimetric observer (as defined in
ISO 11664-1/CIE S 014-1) with a colorimetric accuracy of 0,002 for the CIE chromaticity
coordinates x and y (relative to CIE illuminant A source). A correction factor can be used
for required accuracy by application of a standard source with similar spectral distribution
as the display to be measured.
c) Spectroradiometer: the wavelength range shall be at least from 380 nm to 780 nm, and
the wavelength scale accuracy shall be less than 0,5 nm. The relative luminance
uncertainty of measured luminance (relative to CIE illuminant A source) shall not be
greater than 4 % for luminance values over 10 cd/m and not be greater than 10 % for
luminance values 10 cd/m and below. Note that errors from spectral stray light within a
spectroradiometer can be significant and shall be corrected. A simple matrix method may
be used to correct the stray light errors, by which stray light errors can be reduced for one
to two orders of magnitudes. Details of this correction method are discussed in [3].
d) Goniophotometric mechanism: the DUT or LMD can be driven rotating around a horizontal
axis and vertical axis; angle accuracy shall be better than 0,5°.
e) Imaging colorimeter: number of pixels of the detector shall not be less than 4 for each
display sub-pixel within the colorimeter's measurement field of view; more than 12 bit
digital resolution; spectral responsivity complies with colour matching functions for the
CIE 1931 standard colorimetric observer with colorimetric accuracy of 0,004 for the CIE
’
coordinates x and y, and photopic vision response function with CIE-f no greater than
3 %.
f) Fast-response photometer: the linearity shall be better than 0,5 % and frequency
’
response higher than 1 kHz; and photopic vision response function with CIE-f no greater
than 5 %.
4.2 Viewing direction coordinate system
The viewing direction is the direction under which the observer looks at the spot of interest on
the DUT (see also IEC 62341-1-2:2007, Figure A.2). During the measurement, the LMD is
replacing the observer, looking from the same direction at a specified spot (i.e. measuring
spot, measurement field) on the DUT. The viewing direction is conveniently defined by two
angles: the angle of inclination θ (related to the surface normal of the DUT) and the angle of
rotation φ (also called azimuth angle) as illustrated in Figure 1. The azimuth angle is related to
—————————
Numbers in square brackets refer to the bibliography.

– 8 – 62341-6-3 © IEC:2012
the directions on a watch-dial as follows: φ = 0° is referred to as the 3 o'clock direction

("right"), φ = 90 ° as the 12 o'clock direction ("top"), φ = 180° as the 9 o'clock direction ("left")

and φ = 270 ° as the 6 o'clock direction ("bottom").

Normal direction
θ = 0°
Viewing direction
z
(θ , φ)
θ
12 o’clock
φ = 90°
Upside
y
φ
9 o’clock x′ x 3 o’clock
φ = 180° φ = 0°
Display plane
y′
Down side
6 o’clock
IEC  1573/12
z′
φ = 270°
Key
θ   incline angle from normal direction
φ   azimuth angle
3 o’clock right edge of the screen as seen from the user
6 o’clock bottom edge of the screen as seen from the user
9 o’clock left edge of the screen as seen from the user
12 o’clock top edge of the screen as seen from the user
Figure 1 – Representation of the viewing direction (equivalent to the direction of
measurement) by the angle of inclination, θ, and the angle of rotation (azimuth angle),

φ in a polar coordinate system
5 Measuring conditions
5.1 Standard measuring environmental conditions
Measurements shall be carried out under the standard environmental conditions:
• temperature:  25 ºC ± 3 ºC;
• relative humidity: 25 % RH to 85 % RH;
• atmospheric pressure: 86 kPa to 106 kPa.
When different environmental conditions are used, they shall be noted in the measurement
report.
62341-6-3 © IEC:2012 – 9 –
5.2 Power supply
The power supply for driving the DUT shall be adjusted to the rated voltage ± 0,5 %. In

addition, the frequency of power supply shall provide the rated frequency ± 0,2 %.

5.3 Warm-up time
Measurements shall be carried out after sufficient warm-up. Warm-up time is defined as the

time elapsed from when the supply source is switched on, and a 100 % gray level of input
signal is applied to the DUT, until repeated measurements of the display show a variation in

luminance of no more than 2 % per minute and 5 % per hour.

5.4 Standard measuring dark-room conditions
The luminance contribution from the background illumination reflected off the test display
shall be < 0,01 cd/m or less than 1/20 the display’s black state luminance, whichever is lower.
If these conditions are not satisfied, then background subtraction is required and it shall be
noted in the measurement report. In addition, if the sensitivity of the LMD is inadequate to
measure these low levels, then the lower limit of the LMD shall be noted in the measurement
report.
5.5 Standard set-up conditions
By default, the display shall be installed in the vertical position (Figure 2a), but the horizontal
alternative (Figure 2b) is also allowed. When the latter alternative is used, it shall be noted in
the measurement report.
Luminance, contrast and chromaticity of the white field and other relevant parameters of the
displays have to be adjusted to nominal status in the detailed specification and they shall be
noted in the measurement report. When there is no level specified, the maximum contrast
and/or luminance level shall be used. These adjustments shall be held constant for all
measurements, unless noted otherwise in the measurement report. Additional conditions are
specified separately for each measuring method.

12 o’clock
φ = 90°
θ = 0°
LMD
y
Vertical
12 o’clock
z
φ = 90°
Vertical
9 o’clock
(normal) y
φ = 180°
Horizontal
9 o’clock
Horizontal
φ = 180°
x
3 o’clock
x
Normal
φ = 0°
3 o’clock
z
φ = 0°
LMD
θ = 0°
6 o’clock
6 o’clock
φ = 270°
φ = 270°
IEC  1574/12 IEC  1575/12
Figure 2a – Primary installation Figure 2b – Alternative installation
Figure 2 – DUT installation conditions

– 10 – 62341-6-3 © IEC:2012
6 Measuring methods of image quality

6.1 Viewing angle range
6.1.1 Purpose
The purpose of this method is to measure the viewing angle range of an OLED display module

in the horizontal (φ = 0˚, φ = 180˚) and vertical (φ = 90˚, φ = 270˚) viewing direction. Different

evaluation criteria are described with which the viewing angle range can be determined.

Several studies [4 – 8] have indicated that the contrast ratio (CR > 10:1) is, from a visual
quality point of view, not very useful to determine the viewing angle range for matrix displays.

When colour differences are included in a viewing angle metric, the correlation between the

metric value and a visual assessment value is significantly increased [9]. A more recent study

[10] revealed that a metric, combining viewing angle related luminance degradation and colour
deviation can accurately predict the relative change in visual assessment value. This
information is the basis for the determination of the image quality based viewing angle range,

which has relevance from a visual quality point of view.
6.1.2 Measuring conditions
Standard measuring is implemented under standard dark-room and set-up conditions.
6.1.3 Set-up
a) Apparatus: an LMD to measure luminance and chromaticity of the DUT; driving power
source; driving signal equipment; geometric mechanism illustrated in Figure 3.
b) Mount the display and LMD in a mechanical system that allows the display to be
measured along its vertical and horizontal plane, which lie normal to the display surface.
Figure 3 illustrates the geometry to be used in this measurement. The angle relative to the
display normal in the horizontal plane, 3 o’clock and 9 o’clock direction, is expressed as
θ , and the angle in the vertical plane, 6 o’clock and 12 o’clock direction, by θ . Either the
H V
display can be tilted to scan both planes, or the LMD can be moved within these planes.
During the measuring procedure, the LMD shall be directed at the same field of
measurement for all angles of inclination. In either case, the centre of the measurement
field shall remain at the same location on the DUT surface for all angles of inclination. The
angular positioning of the display in the goniophotometric system shall be accurate to ±
0,5°, and the measuring range shall be implemented from -90° to +90° both in vertical and
horizontal plane.
62341-6-3 © IEC:2012 – 11 –
y
Vertical
Viewing  θ
V
direction
θ
V
Horizontal
x
Normal θ
H
z
θ
H
LMD
IEC  1576/12 IEC  1577/12
Figure 3a – Geometric structure Figure 3b – Geometric system
of display to be measured
Figure 3 – Geometry used for measuring viewing angle range
c) Input signal to the DUT:
1) To determine the luminance (L) and CIE 1976 (as defined in ISO 11664-5/CIE S 014-5)
chromaticity coordinates (u’, v’) related viewing angle ranges, generate a full white
screen with a 100 % signal level (R = G = B = 255 for an 8 bit input signal) on the
display.
2) To determine the contrast ratio (CR) related viewing angle range, generate a full white
screen with a 100 % signal level (R = G = B = 255 for an 8 bit input signal) on the
display to measure the maximum display luminance (L ) and subsequently a full
max
black screen with 0 % signal level (R = G = B = 0 for an 8 bit input signal) to measure
the minimum luminance (L ). The contrast ratio is defined by:
min
L
max
CR =
(1)
L
min
3) To determine the image quality related viewing angle range, generate a full screen
grey pattern with a 78,,4 % signal level (R=G=B=200 for an 8 bit input signal) on the
display to measure the luminance (L) and the CIE 1976 chromaticity coordinates (u’,
v’) [11].
d) Align the LMD perpendicular to the display surface (θ = 0, φ = 0), and position it to the
centre of the display (position P in Figure 4).
6.1.4 Measurement and evaluation
Proceed as follows:
a) Apply the required input signal(s) to the DUT.
b) Measure the centre luminance (L ), chromaticity coordinates (u’ , v’ ) and contrast ratio
0 0 0
(CR ) perpendicular to the display surface (θ = 0°, φ = 0°). The measurement area shall
cover at least 500 pixels, or demonstrate equivalent results with fewer sampled pixels.
c) Take luminance (L ), chromaticity coordinates (u’ , v’ ) and contrast ratio (CR )
θ,φ θ,φ θ,φ θ,φ
measurements as the LMD steps through the various angles in the horizontal (φ = 0°,
φ = 180°) and vertical (φ = 90°, φ = 270°) viewing planes.

– 12 – 62341-6-3 © IEC:2012
d) Record the change in luminance and chromaticity coordinates from the perpendicular

direction.
1) The luminance change is defined in terms of the luminance ratio:

L
θ,φ
LR =
(2)
θ,φ
L
2) Colour shifts with viewing angle are to be determined relative to chromaticity

coordinates measured at the display normal. The change in colour is defined by the
colour difference equation using the CIE 1976 uniform colour space:

2 2
∆u'v' = (u' −u' ) + (v' −v' ) (3)
θ,φ 0 θ,φ 0 θ,φ
e) Determine in each of the four viewing directions (φ = 0°, φ = 180°, φ = 90°, φ = 270°), the
angles (θφ = 0°, θφ = 180°, θφ = 90°, θφ = 270°) at which the specified conditions are met:
1) For the luminance based viewing angle range, when the luminance ratio (LR),
calculated with Equation (2), equals 50 % or any other agreed upon value, specified in
the detail specification.
2) For the contrast ratio based viewing angle range, when the contrast ratio (CR ),
θ,φ
calculated with Equation (1), equals 100 or any other agreed upon value, specified in
the detail specification.
3) For the colour based viewing angle range, when the colour difference (∆u’v’),
calculated with Equation (3), equals 0,01 or any other agreed upon value, specified in
the detail specification.
4) For the image quality based viewing angle range, in which both the change in
luminance and the change in colour are considered, the condition specified in
Equation (4) applies:
IQ = LR − 28 × ∆u'v'≥ 0,36   (4)
θ,φ
where
L
θ,φ
LR =
θ,φ
L
and
2 2
∆u'v'= (u' −u' ) + (v' −v' )
0 θ,φ 0 θ,φ
NOTE Other measurement systems, such as conoscopic instruments, can also be used for the viewing angle
range measurement, if equivalent results can be demonstrated.
6.1.5 Reporting
The horizontal and vertical viewing angles ranges shall be calculated according to Equation (5)
on horizontal viewing angle range and Equation (6) on vertical viewing angle range.
θ = θ + θ (5)
VAR,H φ = 0° φ = 180°
θ = θ + θ (6)
VAR,V φ = 90° φ = 270°
The horizontal and vertical viewing angle ranges shall be noted in the measurement report,
together with the used criteria, e.g. LR ≥ 0,50, CR > 100, ∆u’v’ ≤ 0,01, or image quality based.

62341-6-3 © IEC:2012 – 13 –
6.2 Cross-talk
6.2.1 Purpose
The purpose of this method is to measure the cross coupling of electrical signals between
elements (cross-talk) of an OLED display module.

6.2.2 Measuring conditions
The following measuring conditions apply:

a) Apparatus: an LMD that can measure luminance, a driving power source, and driving

signal equipment.
b) Standard measuring environmental conditions; dark-room condition; standard set-up
conditions.
c) The LMD shall be aligned perpendicularly to position P in Figure 4 to measure the
luminance.
H/2 H/10
P P P
1 5 2
P P P
8 0 6
P P P
4 7 3
H
IEC  1578/12
Figure 4 – Standard measurement positions, indicated by P - P , located
0 8
relative to the height (V) and display width (H) of active area
6.2.3 Measurement and evaluation
Proceed as follows:
a) Measure the maximum white level window luminance, L , at the centre of the active
w,max
area (position P in Figure 4).
Input signal is a 4 % white window pattern, with 100 % signal level, on a black background,
0 % signal level, in the centre of the active area, as shown in Figure 5. The 4 % window
has corresponding sides that are 1/5 the vertical and horizontal dimensions of the active
area. For a monochrome display, apply a signal at the highest grey level. For a colour
display, apply a white signal level of 100 %.
V/2
V/10
V
– 14 – 62341-6-3 © IEC:2012
IEC  1579/12
Figure 5 – Luminance measurement of 4 % window at P
b) Set the input signal to an 18 % grey level (R = G = B = 46), to measure the window
luminance, L ,18 %, at the centre of the active area (position P in Figure 4).
w 0
Input signal is a 4 % white window pattern, with 18 % signal level, on a black background,
0 % signal level, in the centre of the active area, as shown in Figure 5. The 4 % window
has corresponding sides that are 1/5 the vertical and horizontal dimensions of the active
area.
For a colour display, apply a white signal level of 100 %.
c) Measure the 18 % level window luminance, L ,18 %, at the centre of the active area
w
(position P in Figure 4).
Input signal is a 4 % white window pattern, with 18 % signal level, on a black background,
0 % signal level, in the centre of the active area, as shown in Figure 5. The 4 % window
has corresponding sides that are 1/5 the vertical and horizontal dimensions of the active
area.
d) Measure the 18 % level full-screen luminance, L , at the centre of the active area
FS,18 %
(position P in Figure 4).
Input signal is a full screen grey pattern, with 18 % signal level.
e) Measure the 18 % luminance signal L _ and L _ at the centre of the active area
W OFF B OFF
(position P in Figure 4).
In total, there are eight input patterns used in this step, which are indicated in Figure 6.
Figure 6 (left pattern) indicates the input signal pattern with the positions of the white
segments A which shall successively be activated to measure the luminance
wi,(i=1-4)
L at P . The signal level of the white blocks is 100 % white, while background
wi,(i=1-4) 0
luminance level is 18 % white.
Figure 6 (right pattern) indicates the input signal pattern with the positions of the black
segments A which shall successively be activated to measure the luminance
Bi,(i=1-4)
L at P . The signal level of the black blocks is 0 % white, while background
Bi,(i=1-4) 0
luminance level is 18 % white.
L and L are computed as follows.
W_OFF B_OFF
L + L + L + L
w1 w2 w3 w4
L = (7)
w_OFF
L + L + L + L
B1 B2 B3 B4
L = (8)
B_OFF
62341-6-3 © IEC:2012 – 15 –
IEC  1580/12
Figure 6 – Luminance measurement at P with windows A , A , A and A
0 W1 W2 B3 B4
f) Measure the 18 % luminance signal, L and L , at the centre of the active area
Wi_ON Bi_ON
(position P in Figure 4).
There are also two input patterns with 8 measuring points used in this step, which are
indicated in Figure 7.
Figure 7 (left pattern) indicates the input signal pattern with the positions of the white
segments A which shall successively be activated to measure the luminance
wi,(i=5-8)
L at P . The signal level of the white blocks is 100 % white, while background
wi_ON,(i=5-8) 0
luminance level is 18 % white.
Figure 7 (right pattern) indicates the input signal pattern with the positions of the black
segments A which shall successively be activated to measure the luminance
Bi,(i=5-8)
L at P . The signal level of the black blocks is 0 % white, while background
Bi_ON,(i=5-8) 0
luminance level is 18 % white.

IEC  1581/12
Figure 7 – Luminance measurement at P with windows A , A , A and A
0 W5 W8 B5 B8
g) Calculating cross-talk
L − L
Wi_ON W_OFF
CT = ×100 %(i = 5 to 8) (9)
for white windows A (i = 5 to 8), and
Wi
L − L
Bi_ON B_OFF
CT = ×100 % (i = 5 to 8) (10)
L
B_OFF
for black windows A (i = 5 to 8).
Bi
The maximum cross-talk value shall be noted in the measurement report.

– 16 – 62341-6-3 © IEC:2012
6.2.4 Reporting
The following information shall be noted in the measurement report:

a) the maximum cross-talk in per cent with 100 % white window and black window;

b) the position of window that affect the maximum cross-talk at P ;
c) luminance at P with following conditions
– L
W,max,
– L
W,18 %,
– L
FS,18 %,
– L and L in case of the maximum cross-talk with white window,
W_OFF Wi_ON
– L and L in case of the maximum cross-talk with black window.
B_OFF Bi_ON
6.3 Flicker
6.3.1 Purpose
The purpose of this method is to measure the potential of an observable flicker from an OLED
display module.
6.3.2 Measuring conditions
The following measuring conditions apply:
a) apparatus: a signal generator，a frequency analyser, and an LMD with the following
characteristics to record the luminance as a function of time
1) CIE photopic vision spectral response,
2) capable of producing a linear response to rapid changes in luminance,
3) frequency response: greater than 1 kHz,
4) field angle of view: less than 5°,
5) the LMD shall be dark field (zero) corrected;
b) standard measuring environmental conditions; dark-room illumination; standard set-up

conditions.
6.3.3 Set-up
6.3.3.1 Geometric arrangement
DUT
LMD
Frequency analyser
Signal generator
IEC  1582/12
Figure 8 – Apparatus arrangement

62341-6-3 © IEC:2012 – 17 –
a) Optical axis of the LMD is in accordance with central normal line of the DUT (see

Figure 8).
b) Measurement region: larger than 500 pixels.

c) Measuring distance: twice the diagonal distance of DUT. The minimum distance shall be

500 mm.
6.3.3.2 Pattern
The nominal test pattern is constant full screen white at specified level (L ), which shall be
W
noted in the measurement report. If other empirically or analytically derived worst-case test

patterns are used, the changed colour, drive level, pattern, and/or viewing direction shall be

noted in the measurement report.
6.3.4 Measuring method
Proceed as follows:
a) Set the DUT under the standard measuring conditions.
b) Display the selected test pattern, and wait until the test pattern is stable.
c) Measure the luminance as a function of time L( ) with the LMD.
t
6.3.5 Evaluation method
6.3.5.1 Flicker modulation amplitude
a) Analyse the luminance and perform a Fourier transform with the array of data L( ), to
t
acquire the power spectrum P(F).
b) Weight the power spectrum P(F) with temporal contrast sensitivity function, see Figure 9,
to obtain perceptive power spectrum P’(F).
c) Transform the P’(F) to the luminance as a function of time L’( ) with the inverse Fourier
t
transform
Table 1 – Temporal contrast sensitivity function
Frequency CR Frequency CR
CS CS
Hz Hz
% %
1, 6
17,8 19,8 78,8
2, 7 17,9 24 59,8
4 28
32,9 29,9
5, 1 32 23
45,3
6, 8 40
50,3 5,89
8, 8 54
72,5 1,23
10, 7 64
96,7 0,79
12, 7 75
101,5 0,60
16, 2
91,3
– 18 – 62341-6-3 © IEC:2012
2,00
1,00
0,50
0,20
0,10
0,05
0,02
0,01
2       5    10    20     50
Temporal frequency  (Hz)
IEC  158 3/12
Figure 9 – Temporal contrast sensitivity function
Subsequently, calculate the flicker modulation amplitude (A ) as follows:
FM
a) determine the main flicker frequency f from the maximum of P'(f);
m
b) determine the flicker modulation amplitude A in per cent from L'(t) as follows:
FM
c) obtain the average luminance, L' , the maximum luminance L' , and the minimum
ave max
luminance L' of L'(t), see Figure 10.
min
Calculate A via:
FM
 L' −L' 
max min
A =   ×100 %    (11)
FM
 
L'
ave
 
L′
max
L′
min
IEC  1584/12
Figure 10 – Example of flicker modulation waveform
Luminance L′ (t)
Contrast sensitivity
L′
ave
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