IEC 62906-5-5:2022

IEC 62906-5-5 ®
Edition 1.0 2022-01
INTERNATIONAL
STANDARD
colour
inside
Laser displays –
Part 5-5: Optical measuring methods of raster-scanning retina direct projection
laser displays
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IEC 62906-5-5 ®
Edition 1.0 2022-01
INTERNATIONAL
STANDARD
colour
inside
Laser displays –
Part 5-5: Optical measuring methods of raster-scanning retina direct projection

laser displays
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.260 ISBN 978-2-8322-1068-6

– 2 – IEC 62906-5-5:2022 © IEC 2022
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Standard measuring conditions . 9
4.1 Standard measuring environmental conditions . 9
4.2 Coordinate system . 9
4.3 Standard conditions of RS-RDP laser displays and light measuring devices . 10
4.3.1 General . 10
4.3.2 Adjustment of RS-RDP laser display . 10
4.3.3 Requirements for light measuring device . 10
4.4 Laser-safety requirements for measurement . 12
5 Optical measuring methods . 12
5.1 General . 12
5.2 Optical power at the primary colour wavelength . 12
5.2.1 General . 12
5.2.2 Measurement at exit window (measurement point 1) . 12
5.2.3 Measurement at focal point (measurement point 2) . 13
5.2.4 Elimination of the effect of other spectral powers . 13
5.3 Eye-box . 14
5.3.1 General . 14
5.3.2 Eye-box measurement by 2D image sensor . 15
5.3.3 Eye-box measurement by goniometric spectroradiometer . 15
5.4 Field of view . 16
5.4.1 General . 16
5.4.2 FOV measurement by 2D image sensor . 16
5.4.3 FOV measurement by goniometric spectroradiometer . 17
5.5 Aspect ratio . 17
5.6 Effective angular image resolution . 18
5.6.1 General . 18
5.6.2 Measuring methods of effective angular image resolution . 19
5.7 Retinal free focus range . 22
5.7.1 General . 22
5.7.2 Retinal free focus range measured by direct method . 23
5.7.3 Retinal free focus range measured by imaging method . 24
5.8 Retinal white illuminance . 24
5.8.1 General . 24
5.8.2 Retinal white illuminance measurement using the method in 5.2.3 . 25
5.8.3 Retinal white illuminance measurement using spectral irradiance meter . 25
5.9 Luminance and chromaticity of virtual image . 25
5.9.1 General . 25
5.9.2 Measurement procedure . 25
5.10 White chromaticity nonuniformity . 26
5.10.1 General . 26
5.10.2 White chromaticity nonuniformity . 26

5.10.3 Virtual image chromaticity nonuniformity . 26
6 Report . 27
Annex A (informative) Structure of RS-RDP laser displays . 28
A.1 General . 28
A.2 Example of mechanical structure . 28
A.3 Example of fundamental electro-optical structure of RS-RDP laser display . 28
Annex B (informative) Maxwellian view of RS-RDP laser displays . 30
B.1 General . 30
B.2 Maxwellian view . 30
B.3 Pinhole image on the retina in the Maxwellian view . 31
B.4 Laser image on the retina in the Maxwellian view . 31
Annex C (informative) Eyeball model and use of planar 2D sensor for measuring
optical property . 32
C.1 Human eyeball structure, its optics and modelling for practical measurement . 32
C.2 Retinal sensor model . 36
C.3 Optical measuring method with planar 2D image sensor . 37
Annex D (informative) Comparison of retinal illuminance with other displays . 43
D.1 Projected area on retina . 43
D.2 Retinal illuminance estimation for the conventional displays using natural

viewing . 45
D.3 Retinal illuminance estimation for RS-RDP laser display using Maxwellian
viewing . 46
D.4 Comparison of retinal illuminance between RS-RDP laser displays and the
conventional displays . 46
Bibliography . 47

Figure 1 – Coordinate system and setup for planar measurements . 10
Figure 2 – Two measurement points of optical power . 14
Figure 3 – Measurement geometry of the eye-box . 16
Figure 4 – Measurement geometry of the FOV . 17
Figure 5 – Example of beam waist for Maxwellian view at the 2D image sensor plane. 18
Figure 6 – Example of measurement locations for effective angular image resolution . 19
Figure 7 – Setup for measuring effective angular image resolution and retinal free

focus range . 20
Figure 8 – Test patterns for resolution measurement . 21
Figure 9 – Example of contrast modulation plot . 22
Figure 10 – Example of the measured results of retinal free focus range. 24
Figure 11 – Nonuniformity measurement locations and box patterns . 27
Figure A.1 – Example of mechanical structure of RS-RDP laser display . 28
Figure A.2 – Example of electro-optical structure of RS-RDP laser display . 29
Figure B.1 – Maxwellian view (a) and normal viewing (b) . 30
Figure B.2 – Pinhole (a) and laser beam (b) in the Maxwellian view . 31
Figure C.1 – Cross-sectional human eyeball structure . 32
Figure C.2 – Schematic of the eye with geometrical and optical information . 33
Figure C.3 – Calculated refracted beam angle in the eye with respect to incident beam
angle for blue (465 nm), green (520 nm) and red (640 nm) . 33
Figure C.4 – Schematic eye optics . 35

– 4 – IEC 62906-5-5:2022 © IEC 2022
Figure C.5 – Example of beam spot radius calculation for the eye model as a function
of incident beam diameter . 36
Figure C.6 – Retinal sensor model with curved 2D image sensor . 37
Figure C.7 – Geometrical relationship between point A on the retina and B on the
fovea plane for the Cartesian coordinate system . 38
Figure C.8 – Cross-sectional view of the plane consisting of the z-axis and the line
segment OB in Figure C.7 . 38
Figure C.9 – Schematic diagrams of human eye . 39
Figure C.10 – Geometrical relation of point
...