IEC 62341-6-7:2024

Organic light emitting diode (OLED) displays - Part 6-7: Measuring methods of optical characteristics for display with under-screen feature

IEC 62341-6-7:2024 specifies the standard measuring conditions and measuring methods for determining the optical characteristics of an OLED display with under-screen camera; other under-screen features, such as under-screen fingerprint or under-screen time of flight (TOF) can also be applied. This document applies to OLED displays such as mobile phone, monitor and TV with under-screen features.
NOTE Under-screen feature will want the display to be partially transparent and partially non-transparent, and this can be achieved only by certain types of display technology, for example OLED. This document mainly focuses on OLED display with under-screen feature.

General Information

• Status: Published
• Publication Date: 02-Oct-2024
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 18 - TC 110/WG 18
• Current Stage: PPUB - Publication issued
• Start Date: 03-Oct-2024
• Completion Date: 25-Oct-2024

Standards Content (Sample)

IEC 62341-6-7 ®
Edition 1.0 2024-10
INTERNATIONAL
STANDARD
colour
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Organic light emitting diode (OLED) displays –
Part 6-7: Measuring methods of optical characteristics for display with under-
screen feature
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IEC 62341-6-7 ®
Edition 1.0 2024-10
INTERNATIONAL
STANDARD
colour
inside
Organic light emitting diode (OLED) displays –

Part 6-7: Measuring methods of optical characteristics for display with under-

screen feature
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.260  ISBN 978-2-8322-9754-4

– 2 – IEC 62341-6-7:2024 © IEC 2024
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 8
4 Measuring conditions . 8
4.1 Standard measuring environmental conditions . 8
4.2 Standard darkroom conditions . 9
4.3 Standard measurement locations . 9
5 Measuring methods of display performance . 10
5.1 Reflectance difference . 10
5.1.1 General . 10
5.1.2 Measuring equipment . 10
5.1.3 Measuring procedure . 10
5.2 Uniformity . 11
5.2.1 General . 11
5.2.2 Measuring apparatus . 11
5.2.3 Measuring procedure . 11
5.3 Gamma . 12
5.3.1 General . 12
5.3.2 Measuring apparatus . 12
5.3.3 Measuring procedure . 12
5.4 Angular chromaticity shift . 13
5.4.1 General . 13
5.4.2 Measuring apparatus . 13
5.4.3 Measuring procedure . 13
5.5 Luminance degradation . 14
5.5.1 General . 14
5.5.2 Measuring apparatus . 15
5.5.3 Measuring procedure . 15
6 Measuring methods of transmittance performance . 16
6.1 Transmittance . 16
6.1.1 General . 16
6.1.2 Measuring apparatus . 16
6.1.3 Measuring procedure . 17
6.2 Clarity . 18
6.2.1 General . 18
6.2.2 Measuring method of modulation transfer function (MTF) . 18
6.2.3 Measuring method of spatial frequency response (SFR) . 20

Figure 1 – Example of measurement locations . 9
Figure 2 – Measurement geometries for reflectance . 11
Figure 3 – Example tone curve of the display . 13
Figure 4 – Viewing angle set up . 14

Figure 5 – Example of luminance decreases versus operating time . 15
Figure 6 – Example of the decrease of a luminance difference curve . 16
Figure 7 – Measurement geometry . 17
Figure 8 – Diffraction phenomenon of under-screen camera . 18
Figure 9 – Reference test pattern . 19
Figure 10 – Measurement configuration . 20

Table 1 – Measurement results . 14
Table 2 – Example of measured data . 16

– 4 – IEC 62341-6-7:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-7: Measuring methods of optical characteristics for
display with under-screen feature

FOREWORD
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IEC 62341-6-7 has been prepared by 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
110/1667/FDIS 110/1691/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 62341 series, published under the general title Organic light emitting
diode (OLED) 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.
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– 6 – IEC 62341-6-7:2024 © IEC 2024
INTRODUCTION
A display has originally been conceived to show content or images on the screen and been
designed to be blocked on its back-plate, except for a transparent display. Along with advances
in display technologies, various screen forms with the display are available, such as a notch
type for the camera and sensors area, a pin-hole area, a teardrop shape, and a dual punch-
hole for the front camera.
The display has changed and consistently improved its pixel structures to make it easier for a
user to use multimedia without physical interference, for example, putting cameras and sensors
under the display screen to achieve the functions of finger touch, taking photos, 3D sensing
and so on; these technologies can be called under-screen features.
This document introduces mainly measuring conditions and measuring methods for the impact
of these developing under-screen features.

ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-7: Measuring methods of optical characteristics for
display with under-screen feature

1 Scope
This part of IEC 62341 specifies the standard measuring conditions and measuring methods for
determining the optical characteristics of an OLED display with under-screen camera; other
under-screen features, such as under-screen fingerprint or under-screen time of flight (TOF)
can also be applied. This document applies to OLED displays such as mobile phone, monitor
and TV with under-screen features.
NOTE Under-screen feature will want the display to be partially transparent and partially non-transparent, and this
can be achieved only by certain types of display technology, for example OLED. This document mainly focuses on
OLED display with under-screen feature.
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 62341-1-2, Organic light emitting diode (OLED) displays – Part 1-2: Terminology and letter
symbols
IEC 62341-5-3, Organic light emitting diode (OLED) displays – Part 5-3: Measuring methods of
image sticking and lifetime
IEC 62341-6-2, Organic light emitting diode (OLED) displays – Part 6-2: Measuring methods of
visual quality and ambient performance
IEC TR 62977-2-5, Electronic displays devices – Part 2-5: Transparent displays –
Measurements of optical characteristics
IEC 62977-3-7, Electronic displays – Part 3-7: Evaluation of optical performance – Tone
characteristics
ISO 12233, Photography – Electronic still picture imaging – Resolution and spatial frequency
responses
– 8 – IEC 62341-6-7:2024 © IEC 2024
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in 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
under-screen feature
feature placed under the display screen to achieve the functions of finger touch, taking photos,
3D sensing and so on
3.1.2
under-screen area
display area with special pixel structure and circuit design so that the under-screen feature can
be achieved
3.1.3
normal display area
display area with normal pixel structure and circuit design except for the under-screen area
3.2 Abbreviated terms
CCD charge coupled device
CCT correlated colour temperature
CTF contrast transfer function
DUT device under test
LMD light measuring device
MTF modulation transfer function
SFR spatial frequency response
TOF time of flight
4 Measuring conditions
4.1 Standard measuring environmental conditions
Measurements shall be carried out under the standard environmental conditions as follows:
– temperature: 25 °C ± 3 °C
– relative humidity: 25 % to 85 %
– atmospheric pressure: 86 kPa to 106 kPa
When different environmental conditions are used, they shall be noted in the report.

4.2 Standard darkroom conditions
The luminance contribution from the background illumination reflected off the test display shall
be ≤ 0,01 cd/m or less than 1/20 of 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 test report. In addition, if the sensitivity of the LMD is inadequate to measure at these low
levels, then the lower limit of the LMD shall be noted in the test report.
4.3 Standard measurement locations
Measurement shall be undertaken at several specified locations on the surface of the DUT. P
is the centre of the whole display area, P is the centre of the under-screen area, P , P , P ,
1 2 3 4
P are the centre of the adjacent display area, and m is the distance between test points which
is determined by the display
...