EN ISO 9241-333:2017

SLOVENSKI STANDARD
01-december-2017
(UJRQRPLMDPHGVHERMQHJDYSOLYDþORYHNVLVWHPGHO6WHUHRVNRSVNL]DVORQL]
XSRUDERRþDO,62
Ergonomics of human-system interaction - Part 333: Stereoscopic displays using glasses
(ISO 9241-333:2017)
Ergonomie der Mensch-System-Interaktion - Teil 333: Stereoskopische Displays unter
Verwendung von Brillen (ISO 9241-333:2017)
Ergonomie de l'interaction homme-système - Partie 333: (ISO 9241-333:2017)
Ta slovenski standard je istoveten z: EN ISO 9241-333:2017
ICS:
13.180 Ergonomija Ergonomics
35.180 Terminalska in druga IT Terminal and other
periferna oprema IT peripheral equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 9241-333
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2017
EUROPÄISCHE NORM
ICS 13.180; 35.180
English Version
Ergonomics of human-system interaction - Part 333:
Stereoscopic displays using glasses (ISO 9241-333:2017)
Ergonomie de l'interaction homme-système - Partie Ergonomie der Mensch-System-Interaktion - Teil 333:
333: Écrans stéréoscopiques utilisant des lunettes (ISO Stereoskopische Displays unter Verwendung von
9241-333:2017) Brillen (ISO 9241-333:2017)
This European Standard was approved by CEN on 6 April 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 9241-333:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
European foreword
This document (EN ISO 9241-333:2017) has been prepared by Technical Committee
ISO/TC 159 “Ergonomics” in collaboration with Technical Committee CEN/TC 122 “Ergonomics” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2017, and conflicting national standards
shall be withdrawn at the latest by November 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 9241-333:2017 has been approved by CEN as EN ISO 9241-333:2017 without any
modification.
INTERNATIONAL ISO
STANDARD 9241-333
First edition
2017-04
Ergonomics of human-system
interaction —
Part 333:
Stereoscopic displays using glasses
Ergonomie de l’interaction homme-système —
Partie 333: Écrans stéréoscopiques utilisant des lunettes
Reference number
ISO 9241-333:2017(E)
©
ISO 2017
ISO 9241-333:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
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Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms . 1
3.2 Human factors . 3
3.3 Performance characteristics. 4
4 Display technologies and their guiding principles . 4
5 Ergonomic requirements . 5
5.1 Viewing conditions . 5
5.1.1 General. 5
5.1.2 Design viewing distance . 5
5.1.3 Design viewing direction . 6
5.2 Luminance . 6
5.2.1 General. 6
5.2.2 Illuminance . 6
5.2.3 Display luminance . 6
5.3 Visual artefacts and fidelity. 6
5.3.1 General. 6
5.3.2 Luminance non-uniformity . 7
5.3.3 Interocular luminance difference . 7
5.3.4 Interocular crosstalk . 7
6 Optical laboratory test methods . 8
6.1 General . 8
6.1.1 Basic measurements and derived procedures . 8
6.1.2 Structure . 8
6.2 Measurement conditions . . 9
6.2.1 Preparations and procedures . 9
6.2.2 Test accessories .10
6.2.3 Test patterns .10
6.2.4 Alignment: measurement location and meter position .10
6.2.5 Light measuring device (LMD) .11
6.2.6 Measurement field . .12
6.2.7 Angular aperture .12
6.2.8 Meter time response .12
6.2.9 Test illumination .12
6.2.10 Other ambient test conditions .12
6.3 Measurement methods .13
6.3.1 Basic light measurements .13
6.3.2 P 333.1: Luminance angular distribution.15
6.3.3 P 334.1: Luminance angular uniformity .15
6.3.4 Luminance analysis .16
6.3.5 P 337.1: Interocular luminance difference .18
6.3.6 P 338.1: Interocular crosstalk .18
7 Analysis and compliance test methods .20
7.1 Compliance routes .20
7.1.1 Intended context of use .20
7.1.2 Design viewing direction range (angle of inclination and azimuth) .21
7.1.3 Information about the technology .22
7.1.4 Compliance assessment .22
7.2 Conformance .27
ISO 9241-333:2017(E)
Annex A (informative) Overview of the ISO 9241 series .28
Annex B (informative) Matrix of measurement procedures .29
Annex C (informative) Technical explanation of display technologies .30
Bibliography .32
iv © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 4,
Ergonomics of human-system interaction.
A list of all parts in the ISO 9241 series can be found on the ISO website.
ISO 9241-333:2017(E)
Introduction
Recently, due to the improvement of display technologies, users can easily experience stereoscopic
displays using glasses, such as TVs with large screen, personal computers, etc. The displays are used
not only in the field of leisure, but also in business, education and medical applications.
This document presents the requirements for visual display units (VDUs) with stereoscopic displays
using glasses.
ISO 9241-303 covers the display hardware aspect and gives basic requirements for head-mounted
displays (HMDs). ISO/TR 9241-331 presents the optical characteristics of autostereoscopic displays.
These other documents are closely related to stereoscopic displays using glasses, but are not directly
applicable to them, because the need for special glasses or its absence is an important factor in
ergonomics. The visual factors of HMDs are also ergonomically different from those of other displays.
This document is not included in the current ISO 9241-300 subseries for 2D displays because stereoscopic
displays have unique features. The development of a separate document to cover stereoscopic displays
offers better understanding of its unique features. For an overview of the entire ISO 9241 series, see
Annex A.
[19]
Moreover, IWA 3:2005 was published (since withdrawn) to discuss the image contents aspect. This
ISO International Workshop Agreement described image safety issues and means of reducing the
incidence of undesirable biomedical effects caused by visual image sequences. Visual fatigue caused by
stereoscopic images (VFSI) is one of these undesirable effects.
With this document and the related International Standards, the purpose is to develop guidelines for
image content where activities are closely related to the use of stereoscopic displays with glasses.
To ensure effective and comfortable viewing, and to reduce VFSI, the standards will need to address
both display hardware and the displayed contents. However, as the first step, this document focuses on
the display hardware aspect in order to simplify the discussions.
vi © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 9241-333:2017(E)
Ergonomics of human-system interaction —
Part 333:
Stereoscopic displays using glasses
1 Scope
This document specifies ergonomic requirements for stereoscopic displays using glasses designed to
produce or facilitate binocular parallax. These requirements are stated as performance specifications,
aimed at ensuring effective and comfortable viewing conditions for users, and at reducing visual fatigue
caused by stereoscopic images on stereoscopic display using glasses. Test methods and metrology,
yielding conformance measurements and criteria, are provided for design evaluation. See Annex B for
measurement procedures.
This document is applicable to temporally or spatially interlaced types of display. These are implemented
by flat-panel displays, projection displays, etc.
Stereoscopic displays using glasses can be applied to many contexts of use. However, this document
focuses on business and home leisure applications (i.e. observing moving images, games, etc.). Only
dark environments are specified in this document.
For technical explanation of display technologies, see Annex C.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 General terms
3.1.1
stereoscopic display
3D display where depth perception is induced by binocular parallax (3.2.1)
[SOURCE: ISO/TR 9241-331:2012, 2.1]
3.1.2
temporally interlaced type
temporally multiplexed type
temporally multiplexed display
temporally multiplexed stereoscopic display
stereoscopic display (3.1.1) that shows each of stereoscopic images sequentially
ISO 9241-333:2017(E)
3.1.3
spatially interlaced type
spatially multiplexed type
spatially multiplexed display
spatially multiplexed stereoscopic display
stereoscopic display (3.1.1) that shows each of stereoscopic images divided in the screen
Note 1 to entry: As a result, each of stereoscopic images is shown simultaneously.
3.1.4
glasses
eye attachment for dividing stereoscopic images into each eye from a stereoscopic display (3.1.1) not
mounted on the user
3.1.5
active glasses
glasses (3.1.4) where the lenses differently change their optical properties synchronizing with the
stereoscopic display (3.1.1)
Note 1 to entry: Usually left and right images are displayed alternately on a screen. When a left image is displayed,
the left lens of active glasses is turned on to transmit the image and the right lens is turned off to cut off the image.
3.1.6
passive glasses
glasses (3.1.4) where the lenses have differently fixed optical properties
3.1.7
stereoscopic images
set of images with parallax shown on a stereoscopic display (3.1.1).
[SOURCE: ISO/TR 9241-331:2012, 2.1.7]
3.1.8
stereoscopic views
pair of sights provided by a stereoscopic display (3.1.1), which induce stereopsis
Note 1 to entry: See Figure 1.
Note 2 to entry: Oxford Dictionary defines stereopsis as “the perception of depth produced by the reception in
the brain of visual stimuli from both eyes in combination”.
[SOURCE: ISO/TR 9241-331:2012, 2.1.8]
2 © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
Key
1 autostereoscopic display 4 monocular view (left eye)
2 monocular view (left eye) 5 stereoscopic views
3 monocular view (right eye) 6 stereoscopic images
Figure 1 — Relationship between stereoscopic images, stereoscopic views and monocular view
3.1.9
monocular view
one stereoscopic view (3.1.8)
[SOURCE: ISO/TR 9241-331:2012, 2.1.9]
3.2 Human factors
3.2.1
binocular parallax
apparent difference in the direction of a point as seen separately by one eye and the other, while the
head remains in a fixed position
Note 1 to entry: Binocular parallax is equivalent to the optic angle between the visual axes of both eyes, when
they are fixated to a single point.
[SOURCE: ISO/IWA 3:2005, 2.15 — modified.]
3.2.2
visual fatigue
eyestrain or asthenopia, which shows a wide range of visual symptoms, including tiredness, headache,
and soreness of the eyes, caused by watching images in a visual display
Note 1 to entry: See ISO 9241-302:2008, 3.5.3 for the definition of “asthenopia”.
[SOURCE: ISO/IWA 3:2005, 2.13 — modified.]
ISO 9241-333:2017(E)
3.3 Performance characteristics
3.3.1
interocular crosstalk
leakage of the stereoscopic images (3.1.7) from one eye to the other
Note 1 to entry: In some cases, interocular crosstalk is referred to as “3D crosstalk”. In stereoscopic display (3.1.1)
using glasses (3.1.4), the crosstalk means interocular effect and therefore this document uses “interocular”
instead of “3D”.
3.3.2
interocular luminance difference
difference between the luminance values of the left and right views of a stereoscopic presentation
[SOURCE: ISO 9241-392:2014, 3.16]
3.3.3
pseudoscopic images
pseudostereoscopic images
set of images with inverted parallax shown on a stereoscopic display (3.1.1)
4 Display technologies and their guiding principles
For a satisfying human–display interaction, a number of different requirements have to be met at
the same time in an appropriate balance. These requirements have been grouped into the following
subjects:
— viewing conditions; see 5.1;
— luminance; see 5.2;
— visual artefacts and fidelity; see 5.3.
Each subject includes the related performance characteristics (see Table 1) and the display performance.
This document focuses on the significant performance characteristics for stereoscopic display using
glasses, which are marked with an asterisk in Table 1. Other performance characteristics, such as
“gaze and head tilt angles”, “luminance adjustment”, etc. are common to the ordinary 2D display, and
ISO 9241-303 should be applied.
Table 1 — Performance characteristics by subject
Subject Performance characteristic
a
Viewing conditions Design viewing distance
a
Design viewing direction
Gaze and head tilt angles
a
Luminance Illuminance
a
Display luminance
Luminance balance
Luminance adjustment
a
This performance characteristic is a focus of this document.
4 © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
Table 1 (continued)
Subject Performance characteristic
a
Visual artefacts Luminance non-uniformity
Colour non-uniformity
Contrast uniformity
Geometric distortions
Screen and faceplate defects
Temporal instability (flicker)
Spatial instability (jitter)
Moiré effects
Other instabilities
Unwanted reflections
Unwanted depth effects
Unwanted velocity and acceleration effects
a
Interocular luminance difference
Interocular chromaticity difference
Interocular contrast difference
a
Interocular crosstalk
Fidelity Colour gamut and reference white
Gamma and grey scale
Rendering of moving images
Image formation time
Spatial resolution
Raster modulation or fill factor
Pixel density
a
This performance characteristic is a focus of this document.
5 Ergonomic requirements
5.1 Viewing conditions
5.1.1 General
When viewing the stereoscopic display using glasses, conditions such as design viewing distance, design
viewing direction and head rotation (in-plain rotation) angles affect the viewer. In order to achieve
a comfortable viewing condition, the design viewing distance and direction need to be determined
properly.
NOTE When the viewer rotates his/her head, stereopsis is affected due to the mismatch of displayed parallax.
In this case, the effect of the displayed contents is evaluated first, and therefore the detailed requirements are
omitted from this document.
5.1.2 Design viewing distance
The design viewing distance is dependent on the application and the display hardware, such as the
display area size and the screen resolution. Therefore, the supplier of the display shall specify the
design viewing distance. If it is not specified, 1,3D should be applied, where D is the diagonal
view view
ISO 9241-333:2017(E)
of the active display area. Shorter viewing distances can be used in the smaller display (smaller than
9 inches diagonal).
NOTE In stereoscopic displays, the depth sensation is affected by the viewing distance. Many contents for
stereoscopic display using glasses assume the viewing distance to be 3H . 3H is equivalent to 1,3D , and
view view view
1,3D is better for various aspect ratios of the active display area. When the viewing distance is shorter, the
view
perceived parallax is larger. This condition may increase discomfort and visual fatigue caused by stereoscopic
images (VFSI) and therefore needs to be avoided.
5.1.3 Design viewing direction
For general use, the stereoscopic display using glasses should be viewed from any angle of inclination
up to at least 40° from the normal to the surface of the display, measured in any plane. For personal use,
the display area as a whole should be viewed from at least the design viewing position determined by
the design viewing distance and direction. Therefore, the supplier of the display shall specify the design
viewing direction, and the specified value shall be applied. If it is not specified, the above requirements
should be applied.
5.2 Luminance
5.2.1 General
In order to obtain information from the display, sufficient display luminance is necessary. In addition,
a luminous environment to the screen contributes to the display luminance. When the stereoscopic
display using glasses is used, the display area and also the environment is viewed through the glasses.
Therefore, the display luminance shall be checked through the glasses.
NOTE With the glasses, both the display luminance and the screen illuminance are generally reduced.
5.2.2 Illuminance
The supplier shall specify the design screen illuminance, E .
S
5.2.3 Display luminance
In the ambient illumination for which the display is designed, the display luminance through glasses
shall exceed the minimum value for obtaining a sufficient recognizability of the displayed information
over the design viewing range and the intended lifetime of the visual display unit.
NOTE In the stereoscopic display using glasses, the display luminance through glasses is checked, because
the glasses transmittance affects the display luminance.
5.3 Visual artefacts and fidelity
5.3.1 General
When the display technology is not ideal, the viewer will perceive visual artefacts. In the stereoscopic
display using glasses, the visual artefacts are classified into monocular artefacts and binocular
artefacts. The monocular artefacts are perceived by one eye and contain screen non-uniformity in
luminance, temporal instability (flicker), etc. The binocular artefacts are typical of the stereoscopic
display using glasses, and interocular difference in luminance and interocular crosstalk are included.
In this document, the performance characteristics selected are those that are strongly related to
stereopsis. Performance characteristics where the current display technology can easily fulfil the
requirements (e.g. colour non-uniformity and contrast uniformity) are omitted. For example, the
requirements for colour non-uniformity for 2D display are described in ISO 9241-303. However, in some
cases the requirements cannot be directly applied to the stereoscopic display using glasses, because
the stereoscopic display is viewed through glasses. The effect of glasses should be taken into account.
6 © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
Moiré effects are also omitted because it is not peculiar to the stereoscopic display using glasses. In
the patterned retarder-type display, the moiré phenomenon can sometimes occur. However, this can be
evaluated from the luminance non-uniformity. In temporally or spatially interlaced types, interocular
chromaticity difference and interocular contrast difference can be omitted because the difference is
generally small.
In this document, the temporally instability (flicker) is not applied.
NOTE 1 The display flicker causes discomfort in general and therefore it needs to be avoided. However, in
order to establish the requirements, more investigations are necessary. For example, some academic papers
have described an asynchronous flicker effect with shutter glasses. If the flicker between both eyes is not
[6][7]
synchronized, it is said that the flicker perception can be reduced .
NOTE 2 See ISO 9241-305: 2008, P15.3 and P15.3A for the measurement method of flicker for 2D displays.
NOTE 3 When a non-inverter type of environmental illumination is observed through the shutter glasses, the
viewer sometimes perceives the flicker. In this case, the environmental illumination can be off or darkened. The
viewer needs to pay attention to the illumination.
Fidelity is an attribute for indicating the correspondence between displayed images and their original
images, and includes colour gamut, reference white, gamma, grey scale, resolution, rendering of moving
images, etc. In this document, fidelity is not applied for the same reasons as for visual artefacts.
NOTE 4 ISO 9241-303 suggests that it is uncertain whether images with the highest fidelity will be those
preferred by the viewers. The requirements in ISO 9241-303 cannot be directly applied to the stereoscopic
display using glasses, because the effect of glasses needs to be considered. For example, the glasses may affect
the colour gamut and reference white.
5.3.2 Luminance non-uniformity
For an intended uniform display luminance, the luminance non-uniformity, either step-wise or smooth,
in ambient illumination shall not exceed the threshold for reduced visual performance, with a maximum
of 1,4:1.
5.3.3 Interocular luminance difference
The luminance differences in the left- and right-eye views should not exceed 25 % and shall not
exceed 40 %.
NOTE In the stereoscopic display using glasses, the interocular luminance difference is caused by the glasses
influence. For example, in the shutter glasses type, the difference occurs if the shutter timing is not appropriate,
because the transmittance between both lenses will be different. Generally, the limit of interocular luminance
[8][9]
difference is around 50 % .
5.3.4 Interocular crosstalk
The interocular crosstalk of each eye should not exceed 5 % and shall not exceed 10 %.
NOTE 1 Interocular crosstalk is the leakage of the stereoscopic images from one eye to the other. When
interocular crosstalk occurs a double image can be viewed. It is generally said that 1 % to 2 % crosstalk can
[10]
be perceived, and therefore the perception limit is around 2 % . When crosstalk increases, stereopsis is
[11]
disturbed, and then it causes discomfort and VFSI. Generally, the tolerance limit is around 10 % and less than
[12]
5 % is recommended . Using the current display technology, in the perpendicular direction the stereoscopic
display has lower crosstalk but angular dependence exists. Therefore, the interocular crosstalk is checked across
the design viewing angles.
NOTE 2 The displayed contents are strongly related to the perception of interocular crosstalk. Generally,
white-and-black interocular crosstalk is used, because its influence is large. However, many kinds of grey
[13][14][15][16][17][18]
level crosstalk measurement are recently proposed . When the measurement is applied, the
relation between the grey level crosstalk level and its influence is evaluated.
ISO 9241-333:2017(E)
NOTE 3 Pseudostereoscopy can be regarded as the state where interocular crosstalk is over 100 %, because
visual images to be presented to the right and left eyes for stereopsis are presented to the left and right eyes,
respectively. This means that reducing interocular crosstalk can prevent pseudostereoscopy.
6 Optical laboratory test methods
6.1 General
6.1.1 Basic measurements and derived procedures
The optical laboratory test methods in this document adopt the same format as that of ISO 9241-305.
The collection of optical measurements necessary for the compliance evaluations is divided into basic
measurements, identified by M and a measurement number, and measurement procedures, identified
by P and a procedure number (and letter in the case of supplementary procedures), as described in
6.1.1.1 and 6.1.1.2.
6.1.1.1 Basic measurements (or evaluation): method M
Basic measurements should describe a fundamental method as simply as possible. Most of the essential
measurement parameters (such as screen location, viewing direction, test pattern, etc.) are not
specified. The specified result is a physical quantity or some other directly measured property, and
does not involve any processing of the collected data. These results are usually not directly used in a
compliance procedure, as specified in Clause 7. Instead, following a compound measurement procedure
(see 6.1.1.2), a basic measurement will be used to achieve sets or collections of data.
These basic measurements define the types of meters acceptable for use, meter parameters, and any
default parameters (“fixed measurement conditions”), and list the parameters that are to be varied
by the compound measurement procedure (“configurable measurement conditions”). These latter
parameters are often defined by the compliance procedure (see Clause 7).
6.1.1.2 Compound measurement procedures: procedure P
Compound measurement procedures are methods that collect and evaluate physical quantities that were
measured using a basic method (see 6.1.1.1). These procedures reference basic measurements, and may
specify the specific requirements for the “configurable measurement conditions”. They also include any
special preparation procedures. The result of a procedure is a collection of basic quantities (e.g. area
or angular distribution of luminance), or derived quantities (e.g. crosstalk, interocular difference). In
many cases, the measurement procedures could have some of the configurable measurement conditions
defined by the compliance procedure (see Clause 7).
6.1.2 Structure
The measurement methods given in this clause are structured as follows:
a) objective: describes the purpose and quantities measured;
b) applicability: describes the type of displays (or applications) in which the particular measurement
is relevant;
c) preparation and set-up: describes fixed and configurable measurement conditions, optional
accessory equipment and any special preliminary requirements;
d) procedure: describes the measurement or references basic measurement method;
e) analysis: describes calculation of the measured data with mathematical models;
f) reporting: describes the form of reporting, including the number of significant digits, where
appropriate;
8 © ISO 2017 – All rights reserved

ISO 9241-333:2017(E)
g) comments: describes any special concerns or relevant information not contained elsewhere.
6.2 Measurement conditions
6.2.1 Preparations and procedures
6.2.1.1 Display warm-up
Allow sufficient time for the display luminance to stabilize, with a minimum of 20 min. When indicated
by the manufacturer, the display should be warmed up for the specified time (not to exceed 1 h).
6.2.1.2 Technology dependent parameters
Testing should be conducted under normal user conditions for power supply. The bias settings (if any)
of the display should be set to those expected under typical use.
One adjustment setting shall be used for each complete test sequence. If multiple settings are provided,
this implies multiple complete test sequences.
6.2.1.3 Cleaning
Ensure that the display is clean.
6.2.1.4 Alignment
The display screen should be aligned such that a plane tangential to the screen centre is parallel to the
axes of the measurement system(s). The alignment tolerance should be within 1°.
For tilt, the active display area shall be aligned such that a horizontal line through the screen
centre is parallel to the horizontal axis of the measurement instrument and/or of the measurement
instrument travel.
6.2.1.5 Brightness and contrast control settings
The display should be adjusted to its default or preset brightness and contrast. The controls should
remain at these settings for all measurements.
NOTE The default or preset mode is most likely to be used.
6.2.1.6 Image size
Use the factory setting or the default, if available. Otherwise, adjust to a specified size.
6.2.1.7 Video drive levels
A digital interface is applied. If the display only uses an analogue interface, then the drive level(s) should
be specified for video signal lines. The value used should be specified.
6.2.1.8 Display resolution
The display should be tested in its natural resolution if not otherwise specified by the supplier.
ISO 9241-333:2017(E)
6.2.2 Test accessories
6.2.2.1 Mirror standards
Mirror standards are mainly used for checking the geometrical alignment and for redirecting light from
a source into a light-measuring device (LMD).
6.2.2.2 Data acquisition
LMD samples as a function of time are typically collected, stored, processed and displayed by a storage
device such as a computer or storage oscilloscope.
6.2.2.3 Ruler
Use of a steel ruler (mm resolution) or equivalent linear or digital micrometre can be used for small
measurements. For large measurements, such as a steel tape measure (with mm resolution) can be
used for determining large area dimensions, such as the size of a projected image.
6.2.2.4 Graduated scales
Linear and rotational scales are recommended for achieving accurate alignment.
6.2.3 Test patterns
The test patterns that are used by the measurement procedures are described below.
— All pixels are white (all white).
— All pixels are black (all black).
— One of stereoscopic images is white, others are black.
— One of stereoscopic images is grey, others are grey in a different level.
— Colour test images (red, green, blue).
— Grey and colour levels will be expressed accordingly.
Box (window) patterns are also used in some measurements.
EXAMPLE 1 For RGB, red is R = 100 %, G = 0 %, B = 0 %.
EXAMPLE 2 50 %, grey is R = 50 %, G = 50 %, B = 50 %.
NOTE 1 In some cases, grey patterns are used.
NOTE 2 For preparing the test patterns, the supplier specifies which pixels are used for measurement. Or
alternatively, the supplier can prepare the test patterns.
6.2.4 Alignment: measurement location and meter position
6.2.4.1 Standard five locations
Five standard measurement locations are defined for making measurements of various types (see
Figure 2).
The locations are at
a) the centre (i.e. at the intersection of the two diagonals of the addressable area), and
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ISO 9241-333:2017(E)
b) the locations on the diagonals that are 10 % of the diagonal length in from the corners of the
addressable area of the display.
Figure 2 — Standard five locations
6.2.4.2 Standard
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