IEC TR 62715-6-21:2022

IEC TR 62715-6-21 ®
Edition 1.0 2022-11
TECHNICAL
REPORT
colour
inside
Flexible display devices –
Part 6-21: Mechanical test methods – Foldable durability test for foldable display
set
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IEC TR 62715-6-21 ®
Edition 1.0 2022-11
TECHNICAL
REPORT
colour
inside
Flexible display devices –
Part 6-21: Mechanical test methods – Foldable durability test for foldable

display set
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120 ISBN 978-2-8322-6013-5

– 2 – IEC 62715-6-21:2022 © IEC:2022
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Foldable devices technology . 6
4.1 General . 6
4.2 Classification of folding product . 6
4.2.1 General . 6
4.2.2 In-folding products . 6
4.2.3 Out-folding products . 7
4.2.4 Multi-folding products . 7
4.2.5 In and out-folding products . 8
4.3 Hinge structure . 8
4.3.1 General . 8
4.3.2 Role of the hinge structure . 9
4.3.3 Types of hinge structure . 12
5 Durability items of folding products . 12
5.1 General . 12
5.2 Angle of folding and unfolding . 13
5.3 Radius of curvature of folding area . 13
5.4 Folding angular speed . 13
Bibliography . 14

Figure 1 – Example of in-folding product . 6
Figure 2 – Example of out-folding product . 7
Figure 3 – R comparison of in-folding versus out-folding . 7
Figure 4 – Example of multi-folding Z-type product . 8
Figure 5 – Example of multi-folding G-type product . 8
Figure 6 – In and out-folding products . 8
Figure 7 – General hinge structure . 9
Figure 8 – Flip phone . 9
Figure 9 – Angle of folding and unfolding . 10
Figure 10 – Constant R type hinge . 12
Figure 11 – Varying R type hinge . 12

IEC 62715-6-21:2022 © IEC:2022 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FLEXIBLE DISPLAY DEVICES –
Part 6-21: Mechanical test methods –
Foldable durability test for foldable display set

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
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IEC TR 62715-6-21 has been prepared by IEC technical committee 110: Electronic displays. It
is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
110/1426/DTR 110/1435A/RVDTR
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 Technical Report is English.

– 4 – IEC 62715-6-21:2022 © IEC:2022
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/standardsdev/publications.
A list of all parts in the IEC 62715 series, published under the general title Flexible display
devices, 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
 reconfirmed,
 withdrawn,
 replaced by a revised edition, or
 amended.

IMPORTANT – The "colour inside" logo on the cover page of this document 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.

IEC 62715-6-21:2022 © IEC:2022 – 5 –
FLEXIBLE DISPLAY DEVICES –
Part 6-21: Mechanical test methods –
Foldable durability test for foldable display set

1 Scope
This part of IEC 62715, which is a technical report, provides information about various folding
types and hinge structures of foldable products which can affect the durability of a foldable
panel. This document focuses only on the issues concerning the foldable products and will not
include product parts that do not affect display durability such as speakers, batteries,
communication ports.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
foldable panel
flexible display panel which can be folded
3.2
foldable display set
foldable product
device to which a foldable panel is applied
3.3
in-folding
method used to fold the light emitting surface inward
3.4
out-folding
method used to fold the light emitting surface outward
3.5
multi-folding
method used to fold more than once in different positions
EXAMPLE The different folding positions can be in-out Z type or in-in G type.
3.6
in and out-folding
method used to fold in both the inward and outward direction

– 6 – IEC 62715-6-21:2022 © IEC:2022
3.7
R value
radius of curvature of the folding area
3.8
folding area
curved section of the panel due to folding
4 Foldable devices technology
4.1 General
The foldable product market has been growing steadily and the demand for foldable display
panels is expected to increase in the future. The first foldable product was launched in 2019
and since then, various types of foldable products have been released during the past three
years.
In 4.2, some of the techniques of the foldable product which affect the durability of the foldable
panels are discussed.
4.2 Classification of folding product
4.2.1 General
The foldable product can be classified acc
...