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IEC TR 62595-1-4
Edition 1.0 2020-07
TECHNICAL
REPORT
colour
inside
Display lighting unit –
Part 1-4: Glass light guide plate
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IEC TR 62595-1-4
Edition 1.0 2020-07
TECHNICAL
REPORT
colour
inside
Display lighting unit –
Part 1-4: Glass light guide plate
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-8618-0
– 2 – IEC TR 62595-1-4:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 6
4 Overview . 7
4.1 General . 7
4.2 Light guide plate technologies and its typical materials . 7
4.3 Advantages of and issues with GLGP . 8
5 Optical characteristics . 9
5.1 Factors affecting optical characteristics of GLGP . 9
5.2 Optical absorption of the glass materials for LGP . 9
5.3 Optical absorption and scattering loss caused by the dot pattern . 11
5.4 Incident loss . 11
5.5 Effect of the reflection tapes . 12
5.6 Discussions for possible future standardization . 12
5.6.1 Applicability of existing standards . 12
5.6.2 Mechanical structure and interface . 13
5.6.3 Hotspot influence caused by LED light source . 13
5.6.4 Non uniformity around edge . 13
5.6.5 Optical absorption of glass materials for LGP . 13
6 Mechanical and environmental characteristics . 13
6.1 General . 13
6.2 Rigidity . 14
6.3 Thermal expansion and heat resistance/noninflammability . 15
6.4 Humidity absorption . 17
6.5 Impact resistance . 18
6.6 Discussions for possible future standardization . 19
7 Additional functions and possible future standardization . 19
7.1 General . 19
7.2 Local dimming for HDR TV . 19
7.3 Curved GLGP for curved LCD . 20
7.4 Quantum dot coating and quantum dot coated film LCD . 21
7.5 Frontlight . 21
7.6 Transparent LCD . 21
7.7 Combination with PDLC . 22
Bibliography . 23
Figure 1 – Structure of edge-lit BLU and LGP . 7
Figure 2 – Light propagation in LGP . 8
Figure 3 – Examples of internal transmittance spectra at 50 cm in optical path length . 10
Figure 4 – Chromaticity gradient against the distance from incident edge . 10
Figure 5 – Variation of the relative BLU luminance against the thickness of the GLGP . 12
Figure 6 – Weight /thickness dependence of the rigidity of PMMA and glass for LGPs . 15
Figure 7 – Schematics of the simulation setup for the deformation calculation of the
LGP by pulling up one corner and fixing the other three corners . 15
Figure 8 – Horizontal bowing of polymeric LGPs under elevated temperature . 16
Figure 9 – Simulated temperature distribution of (a) GLGP and (b) PMMA LGP . 17
Figure 10 – Simulated thermal deformation of (a) GLGP and (b) PMMA LGP due to
LED lighting . 17
Figure 11 – Increase in the horizontal length of LGP with temperature change for a 65”
diagonal LGP . 18
Figure 12 – Example of curved LCD using a curved GLGP . 20
Figure 13 – Example of transparent LCD . 21
Figure 14 – Example of transparent LCD with GLGP including PDLC . 22
Table 1 – Comparison between polymers and glasses for LGP . 8
Table 2 – Physical properties of commercial glass for LGP and PMMA . 14
Table 3 – Comparison of thickness, weight, and calculated deformation between
GLGP, PMMA LGP, and PMMA combined with steel plate . 15
Table 4 – Comparison of GLGP and polymer LGP in confined structure under humid
condition . 18
Table 5 – Impact resistance with different machining . 19
– 4 – IEC TR 62595-1-4:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DISPLAY LIGHTING UNIT –
Part 1-4: Glass light guide plate
FOREWORD
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example "state of the art".
IEC TR 62595-1-4, 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
110/1174/DTR 110/1200/RVDTR
Full information on the voting for the approval of this technical report can be found in the
report on voting indicated in the above table.
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 light
...