ISO INTERNATIONAL STANDARD 9241-303 Second edition 2011-11-15 Ergonomics of human-system interaction - Part 303: Requirements for electronic visual displays Ergonomiedel'interactionhomme-systeme- Partie303:Exigencesrelativesaux écransde visualisation électroniques Reference number ISO 9241-303:2011(E) @ISO2011 Copyright Intemational Organization for Standardization vithout license from IHS Not for Resale ISO 9241-303:2011(E) COPYRIGHTPROTECTEDDOCUMENT ISO2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, Iso's member body in the country of the requester. ISO copyright office Case postale 56.CH-1211Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ ISO 2011 All rights reserved without ficense from IHS Not for Resale ISO9241-303:2011(E) Contents Page Foreword. Introduction ..vili 1 Scope.. 2 Normative references 3 Terms and definitions.. 4 Guiding principles... 5 Ergonomicrequirementsand recommendations 5.1 Viewing conditions... 5.1.1 5.1.2 5.1.3 Design viewing direction.. 5.1.4 Gaze and head tilt angles 5.1.5 Displays for virtual images.. 5.2 Luminance.... 5.2.1 General 5.2.2 Illuminance.. 5.2.3 Display luminance 5.2.4 Luminancebalanceandglare 5.2.5 Luminance adjustment. 5.3 Special physical environments.. 5.3.1 General ....... 5.3.2 Vibration 5.3.3 Wind and rain 5.3.4 Excessivetemperatures 5.4 Visual artefacts.... 5.4.1 General 5.4.2 Luminance non-uniformity 5.4.3 Colour nonuniformity.... 5.4.4 Contrast uniformity 5.4.5 Geometric distortions.. 5.4.6 Screenandfaceplatedefects 5.4.7 Temporal instability (flicker) 5.4.8 Spatial instability (jitter).. 5.4.9 Moiré effects 5.4.10 Other instabilities .... 5.4.11 Unwanted reflections. 10 Unintended depths effects .10 5.4.12 5.5 Legibility and readability. 11 5.5.1 General 5.5.2 Luminance contrast 11 5.5.3 Image polarity.. 1 5.5.4 Character height... 5.5.5 Text size constancy. 12 5.5.6 Character strokewidth 13 5.5.7 Character width-to-height ratio 13 5.5.8 Character format.... 5.5.9 Between-character spacing. 13 5.5.10 Between-word spacing 13 5.5.11 Between-line spacing... 13 ili Copyright Intemallinal Oorganization fcrStandardalon'ghts reserved lout ficense from IHS Not for Resale ISO9241-303:2011(E) 5.6 Legibility of information coding.... 5.6.1 General.. ..14 5.6.2 Luminance coding .14 5.6.3 Blink coding 5.6.4 Colour coding. 5.6.5 Geometrical coding .14 5.7 Legibility of graphics. .14 5.7.1 General.. Monochromeandmulticolour object size. .14 5.7.2 5.7.3 Contrastforobjectlegibility... 5.7.4 Colour considerationsfor graphics .15 5.7.5 Background and surrounding image effects.... 5.7.6 Number of colours.. .16 5.8 Fidelity 5.8.1 5.8.2 Colourgamutandreferencewhite .17 5.8.3 Gamma and grey scale... 1> 5.8.4 Rendering of moving images. .18 5.8.5 Image formation time (IFT).... 5.8.6 Spatial resolution... 5.8.7 Raster modulation or fill factor.. 5.8.8 Pixel density..... .20 6 Conformance.... AnnexA(informative)Overview oftheIsO9241series.. Annex B (informative)Attractivity, or subject visual quality...... Annex C (informative) Usability aspects of installation ... ....23 AnnexD (normative)Basic concepts ofvisual perception for contrastand luminance of electronic displays....... AnnexE (informative)Virtual display-Performanceobjectives... AnnexF (informative)Electronicvisual display accessibilitySelected bibliography.... Bibliography..... @ ISO 2011 All rights reserved tional Organization for Standardization ithout license from IHS Not for Resale ISO9241-303:2011(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies technicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeer non-governmental, in liaison with isO, also take part in the work. iso collaborates closely with the International Electrotechnical Commission (IEC) on all matte