IEC 62906-5-2:2016

IEC 62906-5-2 ®
Edition 1.0 2016-06
INTERNATIONAL
STANDARD
colour
inside
Laser display devices –
Part 5-2: Optical measuring methods of speckle contrast
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IEC 62906-5-2 ®
Edition 1.0 2016-06
INTERNATIONAL
STANDARD
colour
inside
Laser display devices –
Part 5-2: Optical measuring methods of speckle contrast

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.260 ISBN 978-2-8322-3455-6

– 2 – IEC 62906-5-2:2016 © IEC 2016
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references. 6
3 Terms, definitions and abbreviations . 6
3.1 Terms and definitions . 6
3.2 Abbreviations . 6
4 Standard measuring conditions . 7
4.1 General . 7
4.2 Standard measuring environmental conditions . 7
4.3 Measurement coordinate system . 7
4.4 Darkroom conditions . 8
4.5 Standard conditions of measuring equipment . 8
4.5.1 General . 8
4.5.2 Adjustment of LDD . 9
4.5.3 Conditions of measuring equipment . 9
4.6 Screen conditions . 10
4.6.1 General . 10
4.6.2 Report . 10
5 Measuring methods of speckle contrast . 10
5.1 Speckle contrast measurement of still image . 10
5.1.1 Purpose . 10
5.1.2 Measuring conditions . 10
5.1.3 Measuring the monochromatic speckle contrast of front projection . 10
5.1.4 Measuring the monochromatic speckle contrast of rear projection . 12
5.2 Calibration and diagnosis of the LMD . 12
5.2.1 General . 12
5.2.2 Calibration procedure and diagnosis for the highest C . 13
s
5.2.3 Calibration procedure and diagnosis for the lowest C . 13
s
Annex A (informative) Spectral behaviour of the LD . 15
A.1 Spectral behaviour of a single-longitudinal mode LD . 15
A.2 Spectral behaviour of a multi-longitudinal mode LD . 15
Annex B (informative) Recommendation on imaging sensor pixel size . 16
Annex C (informative) Fundamental formulation of speckle contrast and the effects of
measurement variables . 18
C.1 Fundamental formulation . 18
C.2 Effect of observation distance and iris radius . 18
Annex D (informative) Possible errors and their sources . 20
Bibliography . 21

Figure 1 – Coordinate system for projection direction and viewing direction. 8
Figure 2 – Example of measurement geometries for monochromatic speckle contrast
of front projection . 11
Figure 3 – Example of measurement geometries for monochromatic speckle contrast
of rear projection . 12
Figure 4 – Example of measurement geometries for C calibration . 13
s
Figure A.1 – Example of spectral behaviour of a single-longitudinal mode LD . 15
Figure A.2 – Example of spectral behaviour of a multi-longitudinal mode LD . 15
Figure B.1 – Minimum subjective speckle grain size as a function of the F-number . 17
Figure C.1 – Measurement result of C by changing NA . 19
s screen-Iris
Table B.1 – Example of s . 16
subj
– 4 – IEC 62906-5-2:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LASER DISPLAY DEVICES –
Part 5-2: Optical measuring methods of speckle contrast

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62906-5-2 has been prepared by IEC technical committee 110:
Electronic display devices.
The text of this standard is based on the following documents:
FDIS Report on voting
110/760/FDIS 110/768/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62906 series, published under the general title Laser display
devices, can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

– 6 – IEC 62906-5-2:2016 © IEC 2016
LASER DISPLAY DEVICES –
Part 5-2: Optical measuring methods of speckle contrast

1 Scope
This part of IEC 62906 specifies the standard measurement conditions and measurement
methods for determining the monochromatic speckle contrast of laser display devices (LDDs).
The LDDs may include hybrid types using both a laser or lasers, and spontaneous emission-
based light sources, such as LEDs.
NOTE The monochromatic speckle contrast measurements do not include image quality issues.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
unda
...