IEC TR 62977-2-5:2018

IEC TR 62977-2-5 ®
Edition 1.0 2018-11
TECHNICAL
REPORT
colour
inside
Electronic display devices –
Part 2-5: Transparent displays – Measurements of optical characteristics

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IEC TR 62977-2-5 ®
Edition 1.0 2018-11
TECHNICAL
REPORT
colour
inside
Electronic display devices –
Part 2-5: Transparent displays – Measurements of optical characteristics

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-6189-7

– 2 – IEC TR 62977-2-5:2018 © IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Measuring conditions . 7
4.1 Standard measuring environmental conditions . 7
4.2 Standard lighting conditions . 7
4.2.1 Darkroom conditions . 7
4.2.2 Ambient illumination conditions . 7
4.2.3 Ambient illumination spectra . 8
4.3 Standard setup conditions . 9
4.3.1 Starting conditions of measurements . 9
4.3.2 Standard measuring positions . 9
4.3.3 Conditions of measuring equipment . 9
5 Measuring methods of transparent properties . 11
5.1 Hemispherical transmittance factor with specular included . 11
5.1.1 Purpose . 11
5.1.2 Measuring conditions . 11
5.1.3 Measuring method . 12
5.2 Transmitted haze . 13
5.2.1 General . 13
5.2.2 Transmitted haze under hemispherical illumination . 13
5.2.3 Transmitted haze with directly incident light . 15
5.3 Directional transmittance factor . 18
5.3.1 Purpose . 18
5.3.2 Measuring conditions . 18
5.3.3 Measuring method . 19
5.4 Degree of clear distinction of see-through objects . 20
5.4.1 General . 20
5.4.2 Purity . 20
5.4.3 Clarity (measurement method using a stripe pattern with a rigid width.) . 23
5.4.4 Clarity (Measuring method using a stripe pattern with gradually changed
width) . 26
5.5 Colour variation caused by a transparent display . 28
5.5.1 Purpose . 28
5.5.2 Measuring conditions . 28
5.5.3 Measuring method . 28
6 Measuring methods of on-screen properties . 30
6.1 Ambient contrast ratio . 30
6.1.1 Purpose . 30
6.1.2 Measuring conditions . 30
6.1.3 Measuring method . 31
6.2 Display ambient colour measurement . 32
6.2.1 Purpose . 32
6.2.2 Measuring conditions . 32
6.2.3 Measuring method . 32

6.3 Contrast ratio and colour coordinate with the incident illumination originating
from objects behind the screen . 33
6.3.1 Purpose . 33
6.3.2 Measuring method with white light source . 35
6.3.3 Measuring method with collimated or directional light source . 37
Bibliography . 39

Figure 1 – Measurement points . 9
Figure 2 – Layout diagram of measurement setup . 10
Figure 3 – Side view of measuring concept for the hemispherical transmittance factor
measurement with specular included or excluded . 13
Figure 4 – Schematic arrangement of haze measurement . 15
Figure 5 – Schematic arrangement of the apparatus (TOP view) . 17
Figure 6 – Side view of measuring concept for the hemispherical transmittance factor
measurement with specular included or excluded . 20
Figure 7 – Measuring configuration for purity measurement . 22
Figure 8 – Test patterns for purity measurement . 22
Figure 9 – Measuring system and its configuration . 24
Figure 10 – Example reference object and its configuration . 25
Figure 11 – Luminance curve of reference object . 25
Figure 12 – Definition of test parameters . 26
Figure 13 – Reference object and its configuration. 27
Figure 14 – The relationship between stripe frequency and Michelson contrast ratio . 28
Figure 15 – Measuring configuration . 29
Figure 16 – Geometry of the transparent display and the bright background object . 34
Figure 17 – Case with bright background . 35
Figure 18 – Measurement configuration for transparent display with background object . 37

Table 1 – Standard ambient conditions . 8
Table 2 – Measuring conditions of the ports . 15
Table 3 – Measurements . 18
Table 4 – Measured example for purity . 23
Table 5 – Example of reported specification of two dimensional LMD . 23
Table 6 – Working example for colour variation index . 30

– 4 – IEC TR 62977-2-5:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC DISPLAY DEVICES –
Part 2-5: Transparent displays –
Measurements of optical characteristics

FOREWORD
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b
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