IEC TR 62595-1-3:2019

IEC TR 62595-1-3 ®
Edition 1.0 2019-04
TECHNICAL
REPORT
colour
inside
Display lighting unit –
Part 1-3: Lighting units with arbitrary shapes

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IEC TR 62595-1-3 ®
Edition 1.0 2019-04
TECHNICAL
REPORT
colour
inside
Display lighting unit –
Part 1-3: Lighting units with arbitrary shapes

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-6721-9

– 2 – IEC TR 62595-1-3:2019  IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Flexible lighting units . 8
4.1 General . 8
4.2 FLSs possessing arbitrary curvature . 9
5 Single-curvature FLS model. 10
6 FLS light emission directionality . 12
7 Measurement field projection on a curved FLS . 14
8 Discussion and conclusions . 17
Bibliography . 18

Figure 1 – Examples of curved FLS and curved display . 8
Figure 2 – FLS with an arbitrary curvature and measurement system . 9
Figure 3 – FLS element with curvature and change of measurement field contour due
to curvature . 10
Figure 4 – Curved FLS with convex and concave curvatures . 12
Figure 5 – Radiation pattern of FLSs with nearly Lambertian luminous intensities (n =
0,8, 1, 1,2) and collimated light intensities (n = 5, 10, 15) in a spherical coordinate
system . 13
Figure 6 – Radiation pattern profiles of FLSs with nearly Lambertian luminous
intensities (n = 0,8, 1, 1,2) . 13
Figure 7 – Confined flux in solid angles (θ = 0° to 90°) for intensity distributions with n
= 0,8, 1, 1,2 and 15 . 14
Figure 8 – LMD’s cone cross section nearly equal to that of the FLS’s diameter . 14
Figure 9 – Contour of projected measurement field’s cone cross section on a
cylindrical FLS . 15
Figure 10 – Contour of a cone’s cross section of the measurement field on a large
radius cylindrical FLS R = ∞ (flat) . 15
FLS
Figure 11 – Off-axis measurement and cone’s cross section contour on the DUT (right
half expanded and left half contracted) . 15
Figure 12 – Measurement field cone’s cross section contour on a cylindrical FLS
versus the angle between the LMD and DUT axes (δ) . 16
Figure 13 – Cross section of the measurement field (cone's cross section) with the
angle (δ) between the LMD and DUT axes, on a concave cylindrical FLS . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DISPLAY LIGHTING UNIT –
Part 1-3: Lighting units with arbitrary shapes

FOREWORD
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The main task of IEC technical committees is to prepare International Standards. However, a
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data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 62595-1-3, which is a technical report, has been prepared by IEC technical
committee 110: Electronic displays.
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
110/1018/DTR 110/1064/RVDTR
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.

– 4 – IEC TR 62595-1-3:2019  IEC 2019
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62595 series, published under the general title Display lighting
unit, 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.
A bilingual version of this publication may be issued at a later date.

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INTRODUCTION
Recent developments in materials for flexible lighting sources (FLSs) with arbitrary shapes
such as organic light emitting devices (OLEDs) have boosted their fabrication process as well
as expanding their applications in various fields, for example electronic displays and wearable
display devices. Since FLSs can emit light in a curved and deformed shape even under
external stress, which is different from that of the devices with rigid substrates, these
characteristics and performances require new evaluation and measurement methods. This
document focuses on common issues of light emission from FLSs such as spatial uniformity of
luminance and colour, and angular distribution of luminance and colour. This document
delivers an archetype of a curved FLS's light emission and its measurement. The intent of this
document is to provide guidance for the development of future measurement standards.

– 6 – IEC TR 62595-1-3:2019  IEC 2019
DISPLAY LIGHTING UNIT –
Part 1-3: Lighting units with arbitrary shapes

1 Scope
This part of IEC 62595 focuses on common issues of light emission such as spatial uniformity
of luminance and colour, and angular distribution of luminance and colour, from lighting units
with arbitrary shapes like flexible lighting sources (FLSs). This document provides a model of
light emission from a curved FLS and of light measurement on a curved FLS. Because the
development of flexible liquid crystal panels is in progress (see the notes), the intent of this
document is to provide guidance for the development of future measurement standards. This
document is applicable to FLSs either as light sources, products or elements with arbitrary
shapes of geometrical curvature having different spectral and spatial characteristics of light
emission.
NOTE 1 Almost 20 years ago plastic LCDs were developed and used in a few applications.
NOTE 2 Flexible BLUs have been used for bendabl
...