IEC 61747-30-4:2016

IEC 61747-30-4 ®
Edition 1.0 2016-08
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –
Part 30-4: Measuring methods for liquid crystal display modules –
Dynamic backlight units
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IEC 61747-30-4 ®
Edition 1.0 2016-08
INTERNATIONAL
STANDARD
colour
inside
Liquid crystal display devices –

Part 30-4: Measuring methods for liquid crystal display modules –

Dynamic backlight units
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-3608-6

– 2 – IEC 61747-30-4:2016 © IEC 2016
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references. 6
3 Terms, definitionsand abbreviations . 6
3.1 Terms and definitions . 6
3.2 Abbreviations . 6
4 Standard measuring equipment . 7
5 Measuring conditions . 7
5.1 Standard measuring environmental conditions . 7
5.2 Power supply . 7
5.3 Warm-up time . 7
5.4 Standard measuring dark-room conditions . 8
5.5 Standard set-up conditions . 8
5.6 Signal patterns . 8
5.6.1 Full screen pattern . 8
5.6.2 Checkerboard patterns . 9
5.6.3 Increasing window patterns . 9
5.6.4 Line patterns . 10
5.6.5 Moving image . 10
5.6.6 Video signal . 11
6 Measuring methods . 11
6.1 Optical performance . 11
6.1.1 Luminance and uniformity . 11
6.1.2 Chromaticity and uniformity . 12
6.1.3 Window size dependence of luminance and chromaticity . 14
6.1.4 Contrast ratio . 15
6.1.5 Flicker . 16
6.1.6 Judder . 19
6.2 Power consumption . 21
6.2.1 Static power consumption . 21
6.2.2 Dynamic power consumption . 22
Annex A (informative) Example of flicker measurement . 23
Bibliography . 26

Figure 1 – DUT set-up conditions . 8
Figure 2 – Full screen pattern . 9
Figure 3 – Checkerboard patterns . 9
Figure 4 – Increasing window patterns . 10
Figure 5 – Line patterns . 10
Figure 6 – Moving image . 11
Figure 7 − Example of input signal level dependence on chromaticity . 13
Figure 8 – Window size dependence on luminance and chromaticity . 15
Figure 9 – Apparatus arrangement . 17
Figure 10 – Temporal contrast sensitivity function . 18
Figure 11 – Example of the luminance waveform by weighting TCSF . 19

Figure 12 – Dynamic curve of the judder . 21
Figure A.1 – Luminance as a function of time L(t) . 23
Figure A.2 – Power spectrum with Fourier Transform . 23
Figure A.3 – Perceptive power spectrum of example flicker . 24
Figure A.4 – Luminance of example screen flicker by weighting TCSF . 24

Table 1 – APL of increasing window patterns . 10
Table 2 – Temporal contrast sensitivity function . 18
Table A.1 – Luminance values of L'(t). 25

– 4 – IEC 61747-30-4:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIQUID CRYSTAL DISPLAY DEVICES –

Part 30-4: Measuring methods for liquid crystal
display modules – Dynamic backlight units

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
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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 61747-30-4 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
110/753/FDIS 110/769/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 parts in the IEC 61747 series, published under the general title Liquid crystal
display devices, can be found on the IEC website.
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.
– 6 – IEC 61747-30-4:2016 © IEC 2016
LIQUID CRYSTAL DISPLAY DEVICES –

Part 30-4: Measuring methods for liquid crystal
display modules – Dynamic backlight units

1 Scope
This part of IEC 61747 specifies the standard measurement conditions and measuring
methods for determining the optical performance and power consumption of active matrix
liquid crystal display modules with dynamic backlight units.
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 61747-1-2, Liquid crystal display devices – Part 1-2: Generic – Terminology and letter
symbols
IEC 61747-30-1:2012, Liquid crystal display devices – Part 30-1: Measuring methods for liquid
crystal display modules – Transmissive type
IEC 62087, Methods of measurement for the power consumption of audio, video and related
equipment
ISO 11664-1, Colorimetry – Part 1: CIE standard colorimetric observers
3 Terms, definitionsand abbreviations
For the purposes of this document, the terms, definitions, symbols and units given in
IEC 61747-1-2, as well as the following apply.
3.1 Terms and definitions
3.1.1
judder
motion-dependent temporal instability of a moving pattern
Note 1 to entry: Rather than smooth motion, there may be hesitations, inconsistencies, or other interruptions of
the smooth motion of the moving content.
3.2 Abbreviations
APL average picture level
CCD charge coupled device
CIE Commission Internationale de l’Eclairage (International Commission on
Illumination)
CIELAB CIE 1976 (L*a*b*) colour space
DUT device under test
HVS human visual system
LED light emitting diode
LMD light measuring device
PSF point spread function
RGB red, green, blue
SLSF spectral line spread function
TCSF temporal contrast sensitivity function
4 Standard measuring equipment
The system configuration and operating conditions of the measuring equipment shall comply
with the structures specified in each item.
To ensure reliable measurements, the following requirements shall apply to the light
measuring equipment, listed below:
a) Luminance meter: the instrument's spectral responsivity shall comply with the relative
luminance uncertainty of the measured luminance and 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) Colourimeter: the detector’s spectral responsivity shall comply with the colour-matching
functions for the CIE 1931 standard colourimetric observer with a chromaticity accuracy of
0,004 for x y. A correction factor can be used for the required accuracy by application of a
standard source with a similar spectral distribution as the module to be measured.
c) Imaging colourimeter: the number of pixels within the measurement field of view of the
colourimeter's detector shall not be less than 4 for each display subpixel and not be less
than a 12-bit digital resolution. The spectral responsivity shall comply as colour-matching
functions for the CIE 1931 standard colourimetric observer with a chromaticity accuracy of
0,004 for x y.
d) Fast-response photometer: the linearity shall be better than 0,5 % in a measured dynamic
range. A –3 dB cut-off frequency shall be higher than1 kHz.
5 Measuring conditions
5.1 Standard measuring environmental conditions
Measurements shall be carried out under the standard environmental conditions:
• temperature: 25 °C ± 3 °C,
• relative humidity: 25 % to 85 % RH,
• atmospheric pressure: 86 kPa to 106 kPa.
When different environmental conditions are used, they shall be noted in the measurement
report.
5.2 Power supply
The power supply for driving the DUT shall be adjusted to the rated voltage, ±0,5 %. The
frequency of the power supply shall also provide the rated frequency, ±0,2 %.
5.3 Warm-up time
Measurements shall be carried out after sufficient warm-up. Sufficient warm-up is defined as
the time elapsed from when the supply source is switched on, and a 100 % grey level of input
signal is applied to the DUT, until repeated measurements of the module show a variation in

– 8 – IEC 61747-30-4:2016 © IEC 2016
luminance of no more than 1 % per 5 min for at least 5 sampling points; the warm-up duration
should be no less than 15 min.
5.4 Standard measuring dark-room conditions
The luminance contribution from the background illumination reflected off the test module in a
direction perpendicular to the test module shall be less than 0,03 cd/m . If these conditions
are not satisfied, then background subtraction is required and it shall be noted on the report.
In addition, if the sensitivity of the LMD is inadequate to measure these low levels of
luminance from the background illumination reflected off the test module, then the lower limit
of the LMD shall be noted in the measurement report.
5.5 Standard set-up conditions
By default, the module shall be installed in the vertical position (Figure 1a)), but the horizontal
alternative (Figure 1b)) 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
modules 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°
Vertical Y LMD
12 o'clock
Vertical Z
φ = 90°
(Normal)
Y
9 o'clock
Horizontal
φ = 180°
Horizontal
9 o'clock
X φ = 180°
3 o'clock
Normal Z
X
ϕ = 180°
3 o'clock
φ = 0°
LMD
θ = 0°
6 o'clock
6 o'clock
φ = 270°
φ = 270° IEC
IEC
a) Primary set-up b) Alternative set-up
Figure 1 – DUT set-up conditions
5.6 Signal patterns
5.6.1 Full screen pattern
The pattern is applied with different grey levels or different colours on the full screen.

IEC
Figure 2 – Full screen pattern
5.6.2 Checkerboard patterns
There are different columns and different rows (for example 3-by-3, 5-by-5) in checkerboard
patterns. For a monochromatic display, apply a signal to make the white rectangle box emit at
the highest grey level and the black rectangle box emit at the lowest grey level. For a colour
display, apply a white signal level of 100 % on a white rectangle box and a black signal level
of 0 % on a black rectangle box.
IEC IEC
a) b)
IEC IEC
c) d)
Figure 3 – Checkerboard patterns
Stray-light management should be used as indicated in the International Display
Measurements Standard version 1.03:2012, Annex A, while using the checkboard patterns.
5.6.3 Increasing window patterns
Display a full screen black (0 % grey level) background and a white (100 % grey level) window
with the specified dimension in the centre of the screen. The dimensions of the windows can
be n/10 (n = 1 to 10) of the full screen area. A total of 10 patterns is valid for this kind of
pattern as shown in Figure 4. The APL of the area is shown in Table 1.

– 10 – IEC 61747-30-4:2016 © IEC 2016

IEC
Figure 4 – Increasing window patterns
Table 1 – APL of increasing window patterns
All
STEP 1 2 3 4 5 6 7 8 9 10
black
Horizontal 0 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 %
Vertical 0 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 %
Area (APL) 0,0 % 1,0 % 4,0 % 9,0 % 16,0 % 25,0 % 36,0 % 49,0 % 64,0 % 81,0 % 100,0 %

5.6.4 Line patterns
Line patterns are composed of horizontal or vertical lines with n white or black pixels, where
n = 1 to 5 as in Figure 5.
IEC
...