IEC 62906-5-4:2018

Laser display devices - Part 5-4: Optical measuring methods of colour speckle

IEC 62906-5-4:2018(E) specifies the fundamental colour speckle distribution in CIE colour systems and the measuring methods of the colour speckle of laser display devices (LDDs).
The contents of the corrigendum of juin 2022 have been included in this copy.

General Information

• Status: Published
• Publication Date: 08-Jan-2018
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 01.040.29 - Electrical engineering (Vocabularies)
• ICS: 29.240 - Power transmission and distribution networks
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 10 - TC 110/WG 10
• Current Stage: PPUB - Publication issued
• Start Date: 02-Feb-2018
• Completion Date: 09-Jan-2018

Relations

• Corrected By: IEC 62906-5-4:2018/COR1:2022 - Corrigendum 1 - Laser display devices - Part 5-4: Optical measuring methods of colour speckle
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62906-5-4 ®
Edition 1.0 2018-01
INTERNATIONAL
STANDARD
colour
inside
Laser display devices –
Part 5-4: Optical measuring methods of colour speckle

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IEC 62906-5-4 ®
Edition 1.0 2018-01
INTERNATIONAL
STANDARD
colour
inside
Laser display devices –
Part 5-4: Optical measuring methods of colour speckle

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.260 ISBN 978-2-8322-5243-7

– 2 – IEC 62906-5-4:2018  IEC 2018
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, letter symbols and abbreviated terms . 7
3.1 Fundamental terms . 7
3.2 Terms related to colour speckle distribution . 7
3.3 Terms related to spatial variation . 8
3.4 Letter symbols . 8
3.5 Abbreviated terms . 9
4 Theory of colour speckle . 9
4.1 General . 9
4.2 Mechanism for generating colour speckle . 9
5 Calculation methods of colour speckle . 11
5.1 General . 11
5.2 Measuring method of spectral behaviour of BGR light sources . 12
5.3 Target chromaticity . 12
5.4 Adjustment of BGR power ratio . 14
5.5 Calculation method (a) using BGR speckle contrast C , C , C . 15
s-B s-G s-R
5.5.1 General . 15
5.5.2 Examples of measured distributions. 16
5.6 Evaluation metrics . 20
5.7 Calculation method (b) using the measured spatial distribution of BGR
monochromatic speckles . 21
5.7.1 General . 21
5.7.2 Examples of measured distributions. 21
5.7.3 Comparison between methods (a) and (b) . 23
5.7.4 Elimination of the background effects . 25
5.8 Error analysis based on data size . 28
6 Direct measuring methods of colour speckle . 32
6.1 General . 32
6.2 Fundamental design of LMD for colour speckle measurement . 33
6.3 Colour speckle measuring method using LMD with XYZ filters . 34
6.4 Colour speckle measuring method using LMD with BGR filters . 35
7 Measuring methods related to spatial variation . 36
7.1 General . 36
7.2 Angular colour speckle variation . 36
7.3 Photometric speckle contrast uniformity/non-uniformity . 37
7.4 Colour speckle variance/covariance non-uniformity . 38
Annex A (informative) Complementary explanation of colour speckle . 39
Annex B (informative) Examples of colour speckle distributions . 40
B.1 Colour speckle distributions (one of the BGR: 90 %, the others: 1 %) . 40
B.2 Colour speckle distributions (two of the BGR: 90 %, the other: 1 %). 43
Annex C (informative) Calibration of XYZ errors . 48
C.1 General . 48
C.2 Formulation of XYZ mismatches . 48

C.3 Calibration of the mismatched XYZ errors using the true BGR chromaticity
values . 50
Bibliography . 51

Figure 1 – Two speckle measuring methods and their flow charts . 12
Figure 2 – Target chromaticity and colour gamut . 13
Figure 3 – S (λ) with an FWHM of 2 nm. 13
B,G,R
Figure 4 – Adjustment method of BGR power ratio . 15
Figure 5 – Colour speckle distribution for C = 100 %, C = 100 %, C = 100 % . 16
s-B s-G s-R
Figure 6 – Photometric speckle distribution for C = 100 %, C = 100 %,
s-B s-G
C = 100 % . 17
s-R
Figure 7 – Colour speckle distribution for C = 50 %, C = 50 %, C = 50 % . 18
s-B s-G s-R
Figure 8 – Photometric speckle distribution for C = 50 %, C = 50 %, C = 50 % . 18
s-B s-G s-R
Figure 9 – Colour speckle distribution for C = 10 %, C = 10 %, C = 10 % . 19
s-B s-G s-R
Figure 10 – Photometric speckle distribution for C = 10 %, C = 10 %, C = 10 % . 20
s-B s-G s-R
Figure 11 – Colour speckle distribution for C = 9,2 %, C = 9,7 %, C = 9,2 %
s-B s-G s-R
obtained by method (b) . 22
Figure 12 – Colour speckle distribution for C = 9,2 %, C = 19,2 %, C = 23,2 %
s-B s-G s-R
obtained by method (b) . 23
Figure 13 – Colour speckle distribution for C = 9,2 %, C = 9,7 %, C = 9,2 %
s-B s-G s-R
obtained by method (a) . 24
Figure 14 – Colour speckle distribution for C = 9,2 %, C = 19,2 %, C = 23,2 %
s-B s-G s-R
obtained by method (a) . 24
Figure 15 – Raw data of BGR speckle distributions (upper row) and post-processed
data (lower row) for BGR monochromatic speckles (left: B, centre: G, right: R) . 26
Figure 16 – Colour speckle distribution directly using the raw data in Figure 15 . 26
Figure 17 – Colour speckle distribution for C = 16,2 %, C = 17,4 %, C = 17,3 %
s-B s-G s-R
obtained by indirect measuring method (a). 27
Figure 18 – Calculated average chromaticity values of the colour speckle distribution
with respect to data size for C = C = C = 80 % . 28
s-B s-G s-R
Figure 19 – Calculated average values of the normalized speckle illuminance speckle
distribution and the normalized monochromatic speckle intensity distribution with
respect to data size for C = C = C = 80 %. 29
s-B s-G s-R
Figure 20 – Calculated average chromaticity values of the colour speckle distribution
with respect to data size for C = C = C = 60 % . 29
s-B s-G s-R
Figure 21 – Calculated average values of the normalized speckle illuminance speckle
distribution and the normalized monochromatic speckle intensity distribution with
respect to data size for C = C = C = 60 %. 30
s-B s-G s-R
Figure 22 – Calculated average chromaticity values of the colour speckle distribution
with respect to data size for C = C = C = 40 % . 30
s-B s-G s-R
Figure 23 – Calculated average values of the normalized speckle illuminance speckle
distribution and the normalized monochromatic speckle intensity distribution with
respect to data size for C = C = C = 40 %. 31
s-B s-G s-R
Figure 24 – Calculated average chromaticity values of the colour speckle distribution
with respect to data size for C = C = C = 20 % . 31
s-B s-G s-R
Figure 25 – Calculated average values of the normalized speckle illuminance speckle
distribution and the normalized monochromatic speckle intensity distribution with
respect to data size for C = C = C = 20 %. 32
s-B s-G s-R
Figure 26 – Example of LMDs using XYZ filters for colour speckle measurement . 33

– 4 – IEC 62906-5-4:2018  IEC 2018
Figure 27 – Example of LMDs using BGR filters for colour speckle measurement . 34
Figure 28 – Example of measurement geometries for colour speckle using an LMD with
XYZ filters . 35
Figure 29 – Example of measurement geometries for colour speckle using an LMD with
BGR filters . 36
Figure 30 – Representation of the viewing direction, or direction of measurement,
ϕ ) in a
defined by the angle of inclination θ, and the angle of rotation (azimuth angle
polar coordinate system . 37
Figure A.1 – Photograph of colour speckle .
...