1、BSI Standards Publication PD ISO/TR 20278:2015 Unwanted reflections from the active and inactive areas of display surfaces visible during usePD ISO/TR 20278:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 20278:2015. The UK participation in its pr
2、eparation was entrusted to Technical Committee PH/9, Applied ergonomics. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct a
3、pplication. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 91824 7 ICS 13.180; 35.180 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy an
4、d Strategy Committee on 31 December 2015. Amendments issued since publication Date Text affectedPD ISO/TR 20278:2015 ISO 2015 Unwanted reflections from the active and inactive areas of display surfaces visible during use Rflexions non dsires des zones actives et inactives des surfaces de lcran visib
5、les durant lutilisation TECHNICAL REPORT ISO/TR 20278 Reference number ISO/TR 20278:2015(E) First edition 2015-12-01PD ISO/TR 20278:2015ISO/TR 20278:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified,
6、 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 written permission. Permission can be requested from either ISO at the address below or ISOs me
7、mber body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgPD ISO/TR 20278:2015ISO/TR 20278:2015(E)Foreword v 1 Scope . 1 2 Terms and definitions . 1 3 Unwanted
8、 reflections within the context of the ISO 9241-3xx series .2 3.1 Glare and unwanted reflections . 2 3.2 Direct glare in the context of the ISO 9241-3xx standards series . 2 3.3 Glare by reflection 3 4 Visual discomfort and glare while using computer displays 3 4.1 Asthenopia 3 5 Unwanted reflection
9、s from displays 3 5.1 General . 3 5.2 Glare and unwanted reflections on screens in the ISO 9241-3xx series . 4 6 Pertinent regulations regarding glare and unwanted reflections 4 6.1 European Directive 90-270 On the minimum safety and health requirements for work with display screen equipment . 4 6.2
10、 The meaning of disturbing glare within the ISO 9241-3xx series 4 6.2.1 General 4 6.2.2 CIE definitions of discomfort glare and disability glare . 4 6.2.3 Unwanted reflections as currently specified and limited in ISO 9241-303, 9241-305 and 9241-307 for the active area of displays (screens) . 5 6.3
11、Interaction between specular, diffuse and haze reflection components . 6 6.3.1 General 6 6.3.2 Recognition of the interaction of unwanted reflection components in the ISO 9241-3xx series 6 7 Luminance balance 6 8 Glare and the ambient illumination in the office-working environment 6 8.1 Ambient illu
12、minance 6 8.2 Arrangement of the computer work area 7 8.3 Surface finishes (reflectivity) . 7 8.3.1 General 7 8.3.2 Conversion of specular gloss values to specular reflectance values . 8 9 Literature review of research regarding unwanted reflections from the bezel, screen housing, or other inactive
13、areas of the display visible during use 8 9.1 General . 8 9.2 Bezel gloss . 8 9.2.1 Howarth and Hodder, 2004 8 9.2.2 Bland and Andrn 8 9.2.3 Howarth and Hodder, 2013 8 9.3 Bezel reflectance 9 9.3.1 General 9 9.3.2 Hunter, et al. . 9 9.3.3 Soderston, et al. . 9 9.3.4 Bland and Andrn .10 9.3.5 Howarth
14、 and Hodder 11 9.3.6 Conclusions from the literature regarding bezel gloss and reflectance 11 10 A review of the literature regarding eyestrain due to vergence and accommodative demands of glare reflections 11 10.1 Accommodative stress .11 10.2 Vergence stress 12 11 Summary and conclusions .12 ISO 2
15、015 All rights reserved iii Contents PagePD ISO/TR 20278:2015ISO/TR 20278:2015(E)Bibliography .14 iv ISO 2015 All rights reservedPD ISO/TR 20278:2015ISO/TR 20278:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO memb
16、er 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, government
17、al 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
18、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 i
19、s 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/o
20、r 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 meaning of ISO specific terms and expressions related to conformity as
21、sessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information. The committee responsible for this document is ISO/TC 159, Ergonomics, Subcommittee SC 4, Ergonomics of human-system intera
22、ction. ISO 2015 All rights reserved vPD ISO/TR 20278:2015PD ISO/TR 20278:2015Unwanted reflections from the active and inactive areas of display surfaces visible during use 1 Scope This Technical Report provides users a summary of the existing knowledge about ergonomics requirements for unwanted refl
23、ections on electronic displays. The document furthermore provides some guidance on specification of unwanted reflections. NOTE ISO 9241 contains normative requirements related to unwanted reflections. It is possible that the information contained in this Technical Report will be used for a future up
24、date of ISO 9241. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 asthenopia weakness or tiring of the eyes accompanied by pain, headache, and dim vision Note 1 to entry: Symptoms include pain in or around the eyes; headache, usually aggravat
25、ed by using the eyes for close work; fatigue; vertigo; and reflex symptoms such as nausea, twitching of facial muscles, or migraine. SOURCE: Tabers Medical Dictionary 2.2 disability glare glare that impairs the vision of objects without necessarily causing discomfort 2.3 direct glare glare caused by
26、 self-luminous objects located in the visual field, especially near the line of sight 2.4 discomfort glare glare that causes discomfort without necessarily impairing the vision of objects 2.5 glare condition of vision in which there is discomfort or a reduction in the ability to see details or objec
27、ts, caused by an unsuitable distribution or range of luminance, or by extreme contrasts 2.6 glare by reflection glare produced by reflections, particularly when the reflected images appear in the same or nearly the same direction as the object viewed 2.7 gloss (of a surface) mode of appearance by wh
28、ich reflected highlights of light sources of objects are perceived as superimposed on the surface due to the directionally selective properties of that surface 2.8 glossmeter instrument for measuring the various photometric properties of a surface giving rise to gloss TECHNICAL REPORT ISO/TR 20278:2
29、015(E) ISO 2015 All rights reserved 1PD ISO/TR 20278:2015ISO/TR 20278:2015(E) 2.9 reflectometer instrument for measuring quantities pertaining to reflection 2.10 specular gloss ratio of the luminous flux reflected from an object in the specular direction for a specified source and receptor angle to
30、the luminous flux reflected from glass with a refractive index of 1,567 in the specular direction 2.11 veiling glare (imaging) light, reflected from an imaging medium, that has not been modulated by the means used to produce the image 3 Unwanted reflections within the context of the ISO 9241-3xx ser
31、ies 3.1 Glare and unwanted reflections At various places in the ISO 9241-3xx series, we specifically adopt the CIE definition of glare, which includes both discomfort glare and disability glare. We note that the CIE defines discomfort glare verbally as: “glare which causes discomfort without necessa
32、rily impairing the vision of objects”, 11 and disability glare as “glare that impairs vision”. 13 Glare is commonly classed as direct glare, in which the eye is directly illuminated by some object, such as a display, a luminaire or the sun, and indirect glare, in which the eye is illuminated by ligh
33、t reflected from a surface such as that of a display screen. 3.2 Direct glare in the context of the ISO 9241-3xx standards series ISO 9241-6 discusses two types of glare in the context of office working environments. Direct glare is described thusly: “Direct glare from daylight can typically be caus
34、ed by a direct view of the sun or clouds and by their reflections on adjacent buildings.”, 2 and “Direct glare from artificial lighting can be caused by luminaires or illuminated room surfaces with high luminance”. Clearly, direct glare is seen to be associated with reflections as well as luminance
35、sources directly in the users line of sight. In general, room lighting as a source of direct glare has been studied extensively and appropriate designs are well specified. However it is important to note that the recent introduction of new technologies such as luminaires composed of Light Emitting D
36、iodes (LED) has stimulated reconsideration of both the concept of comfortable lighting, 14and questions about the applicability of existing standards to environments illuminated by LEDs. 1415Although we will not discuss direct glare in detail in this paper, the specification of limits for the ambien
37、t illuminance for office computer workplaces in standards such as EN 12464-1 overlaps with the discussion of unwanted reflections from the inactive and active areas of displays that are visible during use. Moreover, there is at least one specification within the ISO 9241-3xx series that deals specif
38、ically with the issue of direct glare as defined and discussed by CIE and ISO 9241-6:1999, 3.9, 5.4, Clause 10 and Annex A.2 ISO 2015 All rights reservedPD ISO/TR 20278:2015ISO/TR 20278:2015(E) ISO 9241-303:2011, D.5 states a requirement regarding the upper limit for LH, display screen luminance: “G
39、lare (disability glare or discomfort glare) shall not be produced by the display”. Clearly this refers to a limit on direct glare resulting from an excessively high luminance of a self-luminous object (the display) located in the visual field, especially near the line of sight, exactly satisfying th
40、e definition of direct glare. 3.3 Glare by reflection The second type of glare discussed in ISO 9241-6 is glare by reflection: “Glare by reflection can occur in vertical, horizontal and intermediate planes. It can impair visual perception and/or cause discomfort. Disturbing glare caused by reflectio
41、n on working surfaces and work equipment (for example, visual displays, printed documents, keyboards) should be prevented by suitable design and positioning of the work equipment and the lighting.” The majority of the discussion on glare within the context of the ISO 9241-3xx series pertains to indi
42、rect glare resulting from reflections from display surfaces. The context of use for the great majority of the current standards content in the ISO 9241-3xx series is in regard to displays in the office computer workplace, however, this may be expanded in the future to include the home and other envi
43、ronments. It will be critical to maintain distinctions between specifications developed for different environments or contexts of use. It is also important to determine what is meant by the term “disturbing glare”, as this term is not defined by the CIE and does not appear to be used outside of Euro
44、pe. 4 Visual discomfort and glare while using computer displays 4.1 Asthenopia Visual discomfort while viewing displays is commonly referred to as computer vision syndrome or asthenopia while viewing computer displays. Asthenopia complaints from computer users are common, with estimates of current s
45、ymptom prevalence ranging as high as 90 % of all computer users. 16It is an issue well known and documented since the introduction of personal computers. 17 Sheedy, et al. list potential causes for asthenopia: 18 “Direct glare from lighting, anomalies of binocular vision, accommodative dysfunction,
46、uncorrected refractive error, compromised quality of the viewed image, less than optimal viewing angles, flickering visual stimuli such as CRT computer displays, and dry eye”. Sheedy further classifies asthenopic symptoms into two groups, internal and external, based on a principle components analys
47、is of the responses made by subjects during a study of asthenopia. The external symptom factor included eye symptoms such as burning, irritation, and dryness. These symptoms were associated with inducing conditions such as glare, upward gaze angle, flicker, font size, and reduced blink rate. The int
48、ernal symptom factor included symptoms such as eyestrain, headache and eye ache, they were associated with inducing conditions such as astigmatism and close viewing distance. Consequently, while glare is an important causal factor for asthenopia occurring in the office computer workplace, it is impo
49、rtant to note that it is one of many causal factors. 5 Unwanted reflections from displays 5.1 General The question currently before ISO TC 159/SC4 technical committee is that of glare from the inactive areas of the display, such as housings, that are visible during use. It has been proposed that a limit should be set on the reflectivity (specular gloss) of equipment housings visible during use. In order ISO 2015 All rights reserved 3PD ISO/TR 20278:2015ISO/TR 20278:2015(E) to more fully understand the issue of glare, thi
