IEC 62977-2-11:2023

Electronic displays - Part 2-11: Measurement of optical characteristics - Local luminance and uniformity

IEC 62977-2-11:2023 specifies the local luminance and uniformity measurement methods of emissive displays. The light measuring device’s (LMD) measurement field will cover more than 500 pixels of TVs, monitors or signage displays. The local luminance and uniformity measurement methods identify optical variations within the local block where over 500 emission pixels are regularly placed.

General Information

• Status: Published
• Publication Date: 12-Dec-2023
• ICS: 31.120 - Electronic display devices
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 13 - TC 110/WG 13
• Current Stage: PPUB - Publication issued
• Start Date: 13-Dec-2023
• Completion Date: 05-Jan-2024

Standards Content (Sample)

IEC 62977-2-11 ®
Edition 1.0 2023-12
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-11: Measurement of optical characteristics – Local luminance and
uniformity
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IEC 62977-2-11 ®
Edition 1.0 2023-12
INTERNATIONAL
STANDARD
colour
inside
Electronic displays –
Part 2-11: Measurement of optical characteristics – Local luminance and

uniformity
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-7955-7

– 2 – IEC 62977-2-11:2023 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, abbreviated terms, symbols and units . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
3.3 Symbols and units. 8
4 Standard setup conditions . 9
4.1 Light measuring devices . 9
4.2 Measuring conditions . 9
4.2.1 Standard measuring environmental conditions . 9
4.2.2 Power supply . 9
4.2.3 Warm-up time . 9
4.2.4 Standard measuring darkroom conditions . 10
4.3 Measuring direction setup condition . 10
5 Test pattern . 10
5.1 General . 10
5.2 Reference pattern . 10
5.3 Emissive ratio-variable test patterns . 11
5.3.1 Concept of test pattern . 11
5.3.2 Concept of arranged signal dots of the test pattern . 12
6 Measurement methods . 12
6.1 Local luminance consistency . 12
6.1.1 Purpose . 12
6.1.2 Measuring conditions . 12
6.1.3 Setup . 13
6.1.4 Test patterns for local luminance consistency . 13
6.1.5 Pixel numbers in the measurement field . 13
6.1.6 Measurement field coverage of test pattern . 13
6.1.7 Measurement procedure . 13
6.2 Local contrast consistency . 15
6.2.1 Purpose . 15
6.2.2 Measuring conditions . 15
6.2.3 Setup . 15
6.2.4 Measurement method of local contrast consistency . 15
6.3 Local luminance uniformity . 17
6.3.1 Purpose . 17
6.3.2 Measuring conditions . 17
6.3.3 Setup . 18
6.3.4 Test patterns for local luminance uniformity . 18
6.3.5 Measurement method of local luminance uniformity . 18
Bibliography . 20

Figure 1 – DUT installation conditions . 10
Figure 2 – Reference pattern (4 % white box pattern) . 11

Figure 3 – Examples of emissive ratio test patterns . 11
Figure 4 – Examples of test pattern with regularly arranged signal dots . 12
Figure 5 – Guided measurement points . 17

Table 1 – Letter symbols . 8
Table 2 – Example of measurement results for local luminance consistency . 15
Table 3 – Example of measurement results for local contrast consistency . 17
Table 4 – Example of measurement results for local luminance uniformity . 19

– 4 – IEC 62977-2-11:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC DISPLAYS –
Part 2-11: Measurements of optical characteristics –
Local luminance and uniformity

FOREWORD
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IEC 62977-2-11 has been prepared by of IEC technical committee 110: Electronic displays. It
is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
110/1566/FDIS 110/1591/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62977 series, published under the general title Electronic displays,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
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– 6 – IEC 62977-2-11:2023 © IEC 2023
INTRODUCTION
Emissive displays are emerging as the most advanced displays featuring a high dynamic range
from black to white luminance, as well as vivid colour for each pixel.
Various methods, which measure optical characteristics standardized in IEC TC 110, so far
consider only a specified measurement area that covers more than 500 pixels. It is likely that
optical performances reporting the spatially integrated data will have difficulty to represent the
optical characteristics of each pixel.
For that to be possible, standardization related to the method of measuring luminance and
uniformity from each pixel-to-pixel cluster within the specified local block which will cover at
least 500 emission pixels regularly placed, will be identified.
This document assesses the consistent luminance and uniformity in the local block (for example,
within a 4 % window box pattern and regularly scattered emission pixels) by comparing the
changes in luminance variation and emissive ratio, where an emissive sequence of each pixel
is controlled.
ELECTRONIC DISPLAYS –
Part 2-11: Measurements of optical characteristics –
Local luminance and uniformity

1 Scope
This part of IEC 62977 specifies the local luminance and uniformity measurement methods of
emissive displays. The light measuring device’s (LMD) measurement field will cover more than
500 pixels of TVs, monitors or signage displays. The local luminance and uniformity
measurement methods identify optical variations within the local block where over 500 emission
pixels are regularly placed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. 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 (available at
www.electropedia.org)
IEC 62341-1-2, Organic light emitting diode (OLED) displays – Part 1-2: Terminology and letter
symbols
CIE 70-1987, The Measurement of Absolute Luminous Intensity Distributions
3 Terms, definitions, abbreviated terms, symbols and units
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-845,
IEC 62341-1-2, and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1.1
local block
area where at least 500 emission pixels are regularly arranged
3.1.2
local luminance
luminance not in the whole area but in a specified or designated local block, where regularly
arranged pixels are gathered, of the emissive display panel
3.1.3
local luminance consistency
luminance variation range within the local block

– 8 – IEC 62977-2-11:2023 © IEC 2023
3.1.4
local luminance uniformity
luminance variation among adjacent pixels in the local block of the emissive display panel
3.2 Abbreviated terms
APL average picture level
CCT correlated colour temperature
CIE Commission Internationale de l’Eclairage (International Commission on Illumination)
DUT device under test
iLMD imaging light measuring device
LMD light measuring device
3.3 Symbols and units
Table 1 describes the symbols and quantity units.
Table 1 – Letter symbols
No Name of quantity Symbol Unit Remark
01 Measuring distance between display and LMD d mm Formula (1)
02 Measurement-field angle a degree Formula (1)
Horizontal pixel pitch p mm Formula (1)
h
p
Vertical pixel pitch mm Formula (1)
v
05 Number of pixels in the measured area n - Formula (1)
Formula (2),
Average of local luminance (L = i 1, 2, …, m)
i L
cd/m
avg
Formula (3)
Luminance of arranged-pixels test pattern L Formula (2)
cd/m
i
08 Number of arranged-pixels test patterns m - Formula (2)
09 Local luminance consistency LLC % Formula (3)
10 Emissive ratio P % Formula (3)
L
11 Luminance of reference (4 % white box) Formula (3)
cd/m
ref
Luminance of 100 % black box L
12 Formula (3)
cd/m
K
Local contrast of reference CR - Formula (4)
Ref
14 Local contrast consistency LCC % Formula (6)
Correct measurement distance between iLMD
15 D mm Formula (7)
and display
Image luminance L
16 Formula (8)
cd/m
image
17 Local luminance uniformity LLU % Formula (9)
Minimum luminance of (L = i 1, 2, …, m) L Formula (9)
cd/m
i min
Maximum luminance of (L = i 1, 2, …, m) L Formula (9)
19 cd/m
i max
NOTE The pixel pitch is defined in ISO 9241-302:2008, 3.4.36 [9] .

___________
Numbers in square brackets refer to the Bibliography.

4 Standard setup conditions
4.1 Light measuring devices
The requirements of light measuring devices are specified in the IEC 62977-2-1:2021, Clause 5,
[1] and IEC 62341-6-1:2022, Clause 5 [2].
To ensure reliable measurements, the following requirements apply to the light measuring
equipment:
1) Luminance meter [3]: the instrument's spectral responsivity shall comply with the CIE
photopic luminous efficiency function with a CIE-f value no greater than 3 % (see CIE 70-
1’
1987); the relative luminance uncertainty of measured luminance (relative to the CIE
Illuminant A source) shall not be greater than 4 % for luminance values over 0,1 cd/m and
not be greater than 10 % for luminance values 0,1 cd/m and lower. If the luminance is lower
than the LMD’s lower limit of sensitivity it shall not be used for the measurement.
2) Colorimeter: the spectral responsivity shall comply with the colour matching functions for
the CIE 1931 standard colorimetric observer with a colorimetric accuracy of ±0,002 for the
CIE chromaticity coordinates x and y (relative to the CIE Illuminant A source) for luminance
values over 1 cd/m . A correction factor can be used for the required accuracy by application
of a standard source with similar spectral distribution as the display to be measured.
3) Spectroradiometer: the wavelength range shall be at least from 380 nm to 780 nm, and the
wavelength scale accuracy shall be less than 1 nm. The relative luminance uncertainty of
measured luminance (relative to the CIE Illuminant A source) shall not be greater than 4 %
for luminance values over 0,1 cd/m and not be grea
...