1、BS EN ISO15254:2009ICS 11.040.70; 11.180.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDOpthalmic optics andinstruments Electro-optical devices forenhancing low visionThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCom
2、mittee on 31 July 2009 BSI 2009ISBN 978 0 580 65278 3Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 15254:2009National forewordThis British Standard is the UK implementation of EN ISO 15254:2009.It supersedes BS EN ISO 15254:2002 which is withdrawn.The UK participation in its p
3、reparation was entrusted to TechnicalCommittee CH/172/6, Ophthalmic instruments.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its corre
4、ct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 15254July 2009ICS 11.040.70; 11.180.30 Supersedes EN ISO 15254:2002 English VersionOphthalmic optics and instruments - Electro-optical devices forenhan
5、cing low vision (ISO 15254:2009)Optique et instruments ophtalmiques - Dispositifs lectro-optiques pour malvoyants (ISO 15254:2009)Augenoptik und ophthalmische Instrumente -Elektrooptische Sehhilfen fur Sehbehinderte (ISO15254:2009)This European Standard was approved by CEN on 27 June 2009.CEN member
6、s are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application t
7、o the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the sam
8、e status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Roman
9、ia, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldw
10、ide for CEN national Members.Ref. No. EN ISO 15254:2009: EBS EN ISO 15254:2009EN ISO 15254:2009 (E) 3 Foreword This document (EN ISO 15254:2009) has been prepared by Technical Committee ISO/TC 172 “Optics and optical instruments“ in collaboration with Technical Committee CEN/TC 170 “Ophthalmic optic
11、s” 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 January 2010, and conflicting national standards shall be withdrawn at the latest by January 2010. Atten
12、tion 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. This document supersedes EN ISO 15254:2002. According to the CEN/CENELEC Internal Regulatio
13、ns, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlan
14、ds, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 15254:2009 has been approved by CEN as a EN ISO 15254:2009 without any modification. BS EN ISO 15254:2009ISO 15254:2009(E) ISO 2009 All rights reserved iii
15、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 t
16、echnical 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
17、 of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulate
18、d to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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
19、for identifying any or all such patent rights. ISO 15254 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7, Ophthalmic optics and instruments. This second edition cancels and replaces the first edition (ISO 15254:2002), which has undergone minor revision to upda
20、te normative references. BS EN ISO 15254:2009BS EN ISO 15254:2009INTERNATIONAL STANDARD ISO 15254:2009(E) ISO 2009 All rights reserved 1Ophthalmic optics and instruments Electro-optical devices for enhancing low vision 1 Scope This International Standard applies to electro-optical devices specified
21、by the manufacturer for use by visually impaired persons, as low-vision aids. It specifies electro-optical and mechanical requirements and test methods. This International Standard does not cover optical devices for enhancing low vision which are specified in ISO 15253. 2 Normative references The fo
22、llowing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 12870, Ophthalmic optics Spectacle frames Requireme
23、nts and test methods ISO 15004-1, Ophthalmic instruments Fundamental requirements and test methods Part 1: General requirements applicable to all ophthalmic instruments IEC 60601-1-1, Medical electrical equipment Part 1-1: General requirements for safety Collateral standard: Safety requirements for
24、medical electrical systems IEC 61000-4-2, Electromagnetic compatibility (EMC) Part 4-2: Testing and measuring techniques Electrostatic discharge immunity test IEC 61000-4-3, Electromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic fi
25、eld immunity test EN 55022, Information technology equipment Radio disturbance characteristics Limits and methods of measurement (IEC/CISPR 22:2005, modified + A1:2005) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 electro-optical low-visio
26、n device system intended for low vision that produces an image by electronic means 3.2 display size horizontal and vertical dimensions of the display within which the image is visible BS EN ISO 15254:2009ISO 15254:2009(E) 2 ISO 2009 All rights reserved3.3 display magnification ratio between any line
27、ar dimension of the displayed image and the corresponding dimension of the object 3.4 spatial resolution smallest separation between two details in the object at which a pair of points may be recognized as being separate under a given set of conditions 3.5 object speed limit maximum object speed whi
28、ch produces no discernible reduction in resolution 3.6 luminance ratio ratio of the difference between the maximum and minimum luminance of the image to the minimum luminance (Lmax Lmin)/Lmin3.7 object table device used to support and position the object being viewed 3.8 free working distance electr
29、o-optical low-vision device accessible distance separating the camera or other image acquisition system and the object plane at a stated magnification 3.9 reverse polarity system system that is capable of changing the polarity of the image from positive to negative or vice-versa 3.10 portable system
30、 system that can be transported in its own package 4 Classification, designation and coding Electro-optical low-vision devices are classified according to the following usage: a) hand-held; b) tabletop; c) portable system; d) head-mounted. 5 Requirements 5.1 General Where a device is not designed as
31、 a complete system, the manufacturer shall state which displays are suitable to meet the requirements of this International Standard. The manufacturer shall also state the recommended display size for which the range of magnification applies. BS EN ISO 15254:2009ISO 15254:2009(E) ISO 2009 All rights
32、 reserved 35.2 Image characteristics 5.2.1 Spatial resolution When tested in accordance with 7.2, using the level of illumination provided with the device or recommended by the manufacturer and with the device used as specified by the manufacturer, the system shall resolve a target consisting of lin
33、e pairs measuring not more than 0,233 mm per pair (0,116 mm per element) within the central 70 % of the display size as declared by the manufacturer. The manufacturer shall state the magnification for which this level of spatial resolution is achieved. 5.2.2 Display magnification When tested in acco
34、rdance with 7.3, the display magnification over the central 20 % of the display shall be within 10 % of the value declared by the manufacturer. 5.2.3 Lateral variation of magnification When tested in accordance with 7.4, the uniformity of the display magnification within the central 70 % of the line
35、ar dimensions of the display size as declared by the manufacturer shall be equal to the magnification at the centre of the display within 5 %. 5.2.4 Object speed limit The system shall meet the spatial resolution requirements at a relative speed, between camera and object, of not less than 20 mm/s,
36、and at the declared minimum magnification of the system. 5.2.5 Display luminance The maximum display luminance shall be declared by the manufacturer when the contrast is set to the maximum specified by the manufacturer. 5.2.6 Luminance ratio The luminance ratio shall be not less than 75 at the maxim
37、um display luminance. 5.3 Materials and construction 5.3.1 Object support Objects having the dimensions of 300 mm 220 mm, shall be accommodated by the display at its maximum magnification without changing the position of the object relative to its support. 5.3.2 Free working distance Where the syste
38、m is designed to have an accessible free working distance above the reading table, it shall, with the system set at maximum display magnification, be at least 100 mm. 5.3.3 Materials Materials used in the construction, when used as intended by the manufacturer, shall, when applicable, conform to ISO
39、 15004-1 and ISO 12870. BS EN ISO 15254:2009ISO 15254:2009(E) 4 ISO 2009 All rights reserved5.4 Electrical requirements 5.4.1 General The system shall meet the fundamental requirements and test methods specified in ISO 15004-1. 5.4.2 Radio frequency interference The electro-optical device shall comp
40、ly with EN 55022 relative to radio interference. 5.4.3 Electrostatic discharge The electro-optical device shall comply with IEC 61000-4-2 relative to electrostatic discharge. 5.4.4 Electromagnetic field The electro-optical device shall comply with IEC 61000-4-3 relative to electromagnetic fields. 6
41、Environmental conditions of use The electro-optical low-vision device shall, when in use, meet the fundamental environmental requirements and test conditions of ISO 15004-1. 7 Test methods 7.1 General All the methods described are type tests. Equivalent alternative methods are acceptable, but it is
42、the responsibility of the manufacturer/tester to demonstrate the equivalence of the methods used. 7.2 Spatial resolution test 7.2.1 Test principle The following test arrangement shall be used to test the resolving power of electro-optical low-vision devices. An appropriate optotype or a Ronchi rulin
43、g or equivalent, oriented in the directions 90, 180, 45 and 135, is used (see Figure 1 for an example). The criterion for assessing the resolution is the successful recognition of the optotype or the various directions of the ruling. The extent of the linear field of view in which the optotype can b
44、e resolved is measured. The observer shall have a visual acuity of at least 1,0. 7.2.2 Test procedure The observer shall wear any necessary corrective lenses for the viewing distance to the display. To perform the test, place the target at the object position. The illumination of the target shall be
45、 as recommended by the manufacturer for normal use. After alignment of the optotype, carry out the test at the maximum, mean and minimum values of the system magnification as declared by the manufacturer. BS EN ISO 15254:2009ISO 15254:2009(E) ISO 2009 All rights reserved 5Key b = 0,116 mm Figure 1 E
46、xample of optotype for the spatial resolution test 7.3 Display magnification test 7.3.1 Equipment Two identical measuring scales. 7.3.2 Procedure Place one scale on the reading table and set the system at the minimum magnification. Then measure a length on that scale of 100 mm or some suitable value
47、 on the display with the other scale. The length on the scale on the display shall be the highest available to obtain the greatest accuracy. Repeat the procedure with the system set at maximum magnification. 7.4 Lateral variation of magnification When the method of 7.3.2 is repeated anywhere within
48、the central 70 % of the display dimensions, the requirement of 5.2.3 shall be met. 8 Marking and instructions for use 8.1 Marking Each device shall be marked with at least the following: a) identity of device and manufacturer, with model and serial number; b) product classification according to Clau
49、se 4; c) additional markings as required by IEC 60601-1-1, if applicable; d) manufacturers stated range of magnification. 8.2 Documentation Each device shall be accompanied by an instruction manual, in large print, giving instructions for care and maintenance of the device. BS EN ISO 15254:2009ISO 15254:2009(E) 6 ISO 2009 All rights reservedAnnex A (informative) Mechanical design All controls, knobs, buttons or switches should be made easy to distinguish by the use of suitably contrasting colours, and of suffi
