IEC TR 62977-1-31:2021/AMD1:2022

Amendment 1 - Electronic displays - Part 1-31: Generic - Practical information on the use of light measuring devices

General Information

• Status: Published
• Publication Date: 13-Mar-2022
• ICS: 31.120 - Electronic display devices
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 13 - TC 110/WG 13
• Current Stage: PPUB - Publication issued
• Start Date: 13-Apr-2022
• Completion Date: 14-Mar-2022

Relations

• Amends: IEC TR 62977-1-31:2021 - Electronic displays - Part 1-31: Generic - Practical information on the use of light measuring devices
• Effective Date: 05-Sep-2023

Overview

IEC TR 62977-1-31:2021/AMD1:2022 (Amendment 1) is an IEC technical report amendment to Part 1‑31 of the electronic‑displays TR series. It provides additional, practical information on the use of light measuring devices (LMDs) for display metrology - in particular the influence of spectral stray light and the spectral bandwidth of spectroradiometers on chromaticity measurements. The amendment also corrects editorial errors and updates figures, notes and annex content of the 2021 edition.

Key topics and technical points

• Spectral stray light effects
  • Annex E gives experimental data showing how spectrometer stray light distorts measured spectral power distributions and computed CIE 1931 chromaticities.
  • Example: stray light magnitude was reduced from about 1:100–1:1 000 to 1:1 000–1:10 000 after correction.
  • Measured chromaticity differences (without minus with stray‑light correction): Red Δx = −0.0021, Δy = 0.0014; Green Δx = 0.0025, Δy = −0.0162; Blue Δx = 0.0008, Δy = 0.0006.
• Spectral bandwidth (instrument resolution)
  • Annex E demonstrates how increasing spectroradiometer bandwidth (FWHM) desaturates monochromatic (narrow‑linewidth) sources, with the green region most affected.
  • Presents synthetic‑spectrum simulations and explains how instrument bandwidth interacts with colour‑matching functions (CMFs) to bias tristimulus and chromaticity results.
• Measurement methods and corrections
  • Example measurement setup: integrating sphere + spectroradiometer used for retinal scanning projection display irradiance data (correction method valid for radiance as well).
  • Emphasises reducing background levels (stray light or electronic noise) to improve accuracy for saturated colours.
• Editorial and normative updates
  • Corrections to annexes on photometry/colorimetry (Annex A), colourimeter calibration (Annex B), input data and figures (Annex C), and the addition of Annex E.

Practical applications

• Ensures more accurate chromaticity and colour measurements for:
  • Display manufacturers (LCD, OLED, micro‑LED, laser projection, AR/VR retinal displays)
  • Test and calibration laboratories and NMI/metrology institutes
  • Instrument vendors (spectroradiometer/spectrometer designers)
  • Colour scientists and QA engineers performing production and R&D colorimetry
• Helps users decide appropriate LMD selection (wavelength accuracy, bandwidth, stray‑light performance), correction procedures, and interpretation of measurement uncertainty when testing highly saturated or narrow‑linewidth sources.

Related standards and references

• CIE 1931 colourimetry (used in chromaticity calculations) is cited throughout the amendment.
• The amendment sits within the IEC electronic‑displays TR series and complements instrument‑specific standards and manufacturer specifications for spectroradiometers and colourimeters.

Keywords: IEC TR 62977-1-31, amendment, electronic displays, spectroradiometer, spectral stray light, spectral bandwidth, chromaticity, colorimetry, display metrology, CIE 1931.

Standards Content (Sample)

IEC TR 62977-1-31 ®
Edition 1.0 2022-03
TECHNICAL
REPORT
colour
inside
AMENDMENT 1
Electronic displays –
Part 1-31: Generic – Practical information on the use of light measuring devices

IEC TR 62977-1-31:2021-04/AMD1:2022-03(en)

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IEC TR 62977-1-31 ®
Edition 1.0 2022-03
TECHNICAL
REPORT
colour
inside
AMENDMENT 1
Electronic displays –
Part 1-31: Generic – Practical information on the use of light measuring devices

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.120; 31.260 ISBN 978-2-8322-1087-8

– 2 – IEC TR 62977-1-31:2021/AMD1:2022
© IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC DISPLAYS –
Part 1-31: Generic – Practical information
on the use of light measuring devices

AMENDMENT 1
FOREWORD
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Amendment 1 to IEC 62977-1-31:2021 has been prepared IEC technical committee 110:
Electronic displays.
The text of this Amendment is based on the following documents:
Draft Report on voting
110/1380/DTR 110/1404A/DVDTR
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 Amendment is English.

© IEC 2022
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____________
INTRODUCTION to Amendment 1
This document provides additional information to IEC TR 62977-1-31:2021 regarding the
influence of spectral stray light and spectral bandwidth of a spectroradiometer on chromaticity
measurements. It is described in Annex E.
This document also provides the corrections of editorial errors of IEC TR 62977-1-31:2021. The
corrections are:
– Typos are fixed:
• “fiber” and “x(λ), y(λ), z(λ)” is replaced with “fibre” and “𝑥𝑥(𝜆𝜆),𝑦𝑦(𝜆𝜆),𝑧𝑧(𝜆𝜆)”, respectively in
Figure 2,
• “(%)” in the label of vertical axis is removed in Figure 9, Figure 10, and Figure 12,
• “0” label of the tick mark of vertical axis is replaced with “1” in Figure C.4.
– The lists for Formula (A.1) and Formula (B.1) are aligned.

– 4 – IEC TR 62977-1-31:2021/AMD1:2022
© IEC 2022
Figure 2 – Example of configurations for the input optics and detector
Replace, in Figure 2, Figure 2b) and Figure 2c) with the following new Figure 2b) and Figure
2c):
b) Colorimeter c) Spectroradiometer with spectrometer using
grating and array detector
5.5.2.1 General
Replace, in NOTE 2, the fourth sentence with the following new sentence:
Experimental data demonstrating the influence of spectral stray light in a specific application are shown in Annex E
[12].
Add, after NOTE 2, the following new NOTE 3:
NOTE 3 The influence of spectral bandwidth on chromaticity measurements of narrow spectral linewidth light is
shown in Annex E.
© IEC 2022
Figure 9 – Calculated chromaticity differences as a function of wavelength error
Replace Figure 9 with the following new figure:

a) DUT-1 (chromaticity coordinate, x) b) DUT-1 (chromaticity coordinate, y)

c) DUT-2 (chromaticity coordinate, x) d) DUT-2 (chromaticity coordinate, y)

e) DUT-3 (chromaticity coordinate, x) f) DUT-3 (chromaticity coordinate, y)

– 6 – IEC TR 62977-1-31:2021/AMD1:2022
© IEC 2022
Figure 10 – Calculated chromaticity differences as a function of spectral bandwidth
Replace Figure 10 with the following new figure:

a) DUT-1 (chromati
...