Iec 62471 5 2015

I E C 62 471 -5 ® Edition 201 5-06 I N TE RN ATI ON AL S TAN D ARD colour in sid e Ph otobi ol og i cal s afety of l am ps an d l am p s ys tem s – IEC 62471 -5:201 5-06(en) Part 5: I m ag e proj ectors TH I S P U B L I C ATI O N I S C O P YRI G H T P RO TE C T E D C o p yri g h t © I E C , G e n e va , S w i tze rl a n d All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Abou t th e I E C The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i c a ti o n s The technical content of IEC publications is kept under constant review by the IEC Please make sure that you have the latest edition, a corrigenda or an amendment might have been published I E C C atal og u e - webs tore i ec ch /catal og u e E l ectroped i a - www el ectroped i a org The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad The world's leading online dictionary of electronic and electrical terms containing more than 30 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C pu bl i cati on s s earch - www i ec ch /s earch pu b I E C G l os s ary - s td i ec ch /g l os s ary The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications More than 60 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u st P u bl i s h ed - webs tore i ec ch /j u s u bl i s h ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email I E C C u s to m er S ervi ce C en tre - webs tore i ec ch /cs c If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C 62 471 -5 ® Edition 201 5-06 I N TE RN ATI ON AL S TAN D ARD colour in sid e Ph otobi ol og i cal s afety of l am ps an d l am p s ys te m s – Part 5: I m ag e proj ectors INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 29.1 40 ISBN 978-2-8322-2737-4 Warn i n g ! M ake s u re th at you obtai n ed th i s pu bl i cati on from an au th ori zed d i s tri bu tor ® Registered trademark of the International Electrotechnical Commission –2– I EC 62471 -5: 201 © I EC 201 CONTENTS FOREWORD I NTRODUCTI ON Scope Normative references Terms and definitions General Basis for risk groups Example applications 2.1 RG0 / RG1 projectors 2.2 RG2 projectors 2.3 RG3 projectors Projector lamps 4 Assessment criteria (background) Risk group determination Test conditions Measurement conditions for image projectors 2.1 Measurement throw ratio 2.2 Measurement distance The position and size of apparent source, the calculation of angular subtense Measurement of irradiance – specified apertures 5 Measurement of radiance Accessible emission limits 20 6.1 For CW emission 20 6.2 For pulsed emission 21 6.3 Spectral weighting functions 22 Applying information from the lamp manufacturers 23 7.1 General 23 7.2 Limits provided in irradiance/radiant exposure 24 7.3 Limits provided in radiance or radiance dose 24 Manufacturer’s requirements 24 General 24 Determination of HD (hazard distance) 25 Safety feature "soft start" 25 Optional safety features 25 4.1 Projection of warning message 25 4.2 Power reduction by sensor system 25 Labelling on products 25 5.1 General 25 5.2 RG0 projector 26 5.3 RG1 projector 26 5.4 RG2 projector 27 5.5 RG3 projector 28 6 User information 28 6.1 General 28 6.2 Assessment of user accessible area 29 I EC 62471 -5: 201 © I EC 201 –3– User information (user manual) 29 6 6.4 User information for maintenance 30 Labelling and user information for image projectors where the risk group will be changed by interchangeable lens 30 7.1 General 30 7.2 Labelling on the projector 30 7.3 Mark on the interchangeable lens 32 7.4 The user information in the user manual of the projector 32 7.5 The user information in the user manual of the interchangeable lens 32 I nformation for service 33 Annex A (normative) Test scheme for lamp types 34 Annex B (informative) Example of calculations 35 B Radiance calculations 35 B 1 General 35 B Calculation from measured irradiance 35 B Calculation from luminous output 36 B Calculation example of risk group (CW) 37 B 2.1 Example of a 000 lm projector 37 B 2.2 000 lm professional-use projector with an apparent source of small subtense angle (CW) 39 B 2.3 000 lm projector with small apparent source (CW) 40 B Calculation example of risk group (pulsed emission) 41 B 3.1 General 41 B 3.2 000 lm projector with one peak 41 B 3.3 000 lm projector with two peaks 44 Annex C (informative) Example of intra-beam of projector sources with millimetre scale 47 Annex D (informative) Measurement distance 48 Annex E (informative) Hazard distance as a function of modifying optics 50 Bibliography 51 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure – Exit pupil in projector – Examples of the application of the definition of pulse duration 3 – Definition of throw ratio – Diameter of the apparent source – RG1 label (optional) 26 – RG2 label 27 – RG2 caution symbol 27 – Sample design of RG2 caution pictogram 27 – RG3 label 28 – Optical radiation warning symbol 28 1 – "Not for household use" symbol 28 – RG2 label with the caution for RG3 31 – RG2 caution label with the caution for RG3 31 – RG2 pictogram with the caution for RG3 32 B.1 – I mage of the apparent source and measurement condition 37 –4– I EC 62471 -5: 201 © I EC 201 Figure B.2 – Picture of the apparent source of a projector at the exit pupil of the projection lenses with a scale 37 Figure B.3 – Example with one peak of pulsed emission 42 Figure B.4 – Example with two peaks of pulsed emission 44 Figure C – Examples of intra-beam images of projector sources with millimetre scale 47 Figure E.1 – Hazard distance as a function of modifying optics (example) 50 Table – Measurement criteria — field of view (angles of acceptance) for CW source Table – Measurement criteria — field of view (angles of acceptance) for pulsed source Table – AEL (accessible emission limits) for risk groups of lamps and lamp systems emitting CW optical radiation 20 Table – Time base values associated with the risk groups and hazards 20 Table – Basic retinal thermal emission limit 20 Table – The values of C and α for AEL calculation 21 Table – Pulse duration dependent values of α max 22 Table – Spectral weighting functions B ( λ ) and R( λ ) for assessing retinal hazards 23 Table – Labelling on products 26 Table – User information in user manual 29 Table A.1 –Required evaluations 34 I EC 62471 -5: 201 © I EC 201 –5– I NTERNATIONAL ELECTROTECHNI CAL COMMI SSI ON _ P H O T O B I O L O G I C AL S AF E T Y O F L AM P S AN D L AM P S YS T E M S – P a rt : I m a g e p ro j e c t o rs FOREWORD ) The I nternati onal El ectrotechnical Commi ssi on (I EC) is a worl d wi d e organizati on for standard izati on comprisi ng all nati onal electrotech nical committees (I EC N ational Comm ittees) Th e object of I EC i s to promote i nternati on al co-operati on on al l q u esti ons cernin g standard izati on i n the el ectrical and el ectronic fi el ds To this end an d in ad di ti on to other acti vi ti es, I EC pu blish es I nternati onal Stan d ards, Technical Speci fi cati ons, Technical Reports, Pu blicl y Avail abl e Specificati ons (PAS) and Gui d es (hereafter referred to as “I EC Pu blicati on(s)”) Their preparati on is entru sted to technical committees; any I EC N ati onal Committee i nterested i n the subject d eal t with may parti ci pate i n thi s preparatory work I ntern ati onal, g overn mental and non governm ental organizations l iaisi ng wi th the I EC al so participate i n this preparati on I EC coll aborates cl osel y wi th the I nternational Organizati on for Stand ard izati on (I SO) in accordan ce wi th cond i ti ons d etermin ed by agreement between th e two org anizati ons 2) Th e form al decision s or agreem ents of I EC on tech nical matters express, as nearl y as possibl e, an i nternati onal consensus of opi ni on on the rel evan t su bjects si nce each technical committee has representati on from all i nterested I EC N ati onal Commi ttees 3) I EC Pu blications have th e form of recommend ati ons for intern ati onal u se and are accepted by I EC N ati onal Comm ittees i n th at sense While all reasonabl e efforts are mad e to ensu re that the technical content of I EC Pu blicati ons is accu rate, I EC cann ot be hel d responsi bl e for the way in wh i ch they are used or for an y misin terpretati on by any end u ser 4) I n ord er to promote i nternational u ni formi ty, I EC N ati onal Commi ttees u nd ertake to appl y I EC Publicati on s transparen tl y to the maximum exten t possi bl e i n thei r nati onal and reg i onal pu blicati ons An y di verg ence between an y I EC Pu bl icati on and the correspond i ng nati onal or region al publi cation shal l be cl earl y i ndi cated in the l atter 5) I EC i tsel f d oes not provi d e any attestation of conformity I nd epen d ent certi ficati on bodies provi d e conformity assessment services and , in some areas, access to I EC marks of conformi ty I EC i s not responsi bl e for any services carried ou t by i nd epend ent certi fication bodi es 6) All users should ensu re that they have the l atest edi ti on of this pu blicati on 7) N o li abili ty shal l attach to I EC or i ts di rectors, empl oyees, servants or agen ts incl u di ng i nd ivi d u al experts and m embers of i ts tech ni cal comm ittees and I EC N ati onal Committees for any personal i nju ry, property d amag e or other d amage of any natu re whatsoever, whether di rect or ind i rect, or for costs (includ i ng l eg al fees) and expenses arising out of the pu bli cati on, use of, or rel iance u pon, thi s I EC Pu bl ication or any other I EC Pu blicati ons 8) Attention is d rawn to the N ormative references ci ted i n this pu bl icati on U se of the referen ced pu blicati ons is i nd i spensabl e for th e correct appli cati on of this pu blicati on 9) Attention is d rawn to the possibili ty that some of the el ements of thi s I EC Pu bl icati on may be th e su bject of paten t ri ghts I EC shal l not be h eld responsi bl e for id enti fyi ng an y or all such patent ri gh ts I nternational Standard IEC 62471 -5 has been prepared by I EC technical committee 76: Optical radiation safety and laser equipment The text of this standard is based on the following documents: FDI S Report on voti ng 76/51 9/FDI S 76/521 /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/I EC Directives, Part –6– I EC 62471 -5: 201 © I EC 201 The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the I EC web site 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 I M P O R T AN T – T h e ' c o l o u r i n s i d e ' th at it c o n ta i n s u n d e rs t a n d i n g c o l o u r p ri n t e r of c o l o u rs i ts wh i ch co n te n ts l og o a re U s e rs on t h e c o ve r p a g e o f t h i s c o n s i d e re d sh ou l d to t h e re fo re be p u b l i ca ti o n u s e fu l p ri n t th i s fo r i n d i c a te s th e d o cu m e n t c o rre c t using a I EC 62471 -5: 201 © I EC 201 –7– I NTRODUCTION Most lamps and lamp systems are safe and not pose photobiological risks except under unusual exposure conditions This also is the case for optical image projectors where experience shows that even high power cinema projectors may be safe for accidental momentary viewing and can only under some conditions pose optical hazards at close distances or for intentional 'long-duration' staring into the source The rapid development of solid-state and other lamps or lamp systems has permitted new projector products, and generated the need for a photobiological safety standard for this group of lamp systems Optical radiation hazards from all types of lamps and lamp systems are currently assessed by the application of I EC 62471 : 2006 (CI E S 009: 2002), Photobiological safety of lamps and lamp systems I EC 62471 covers LEDs, incandescent, low- and high-pressure gas-discharge, arc and other lamps Following the concept of vertical standards, the risk group classification system in IEC 62471 for lamps is to be adapted for specific product groups such as image projectors This part of I EC 62471 provides a risk group classification system for image projectors, and measurement conditions for optical radiation emitted by image projectors I t includes manufacturing requirements that may be required as a result of an image projector system being assigned to a particular risk group Therefore, this part of I EC 62471 provides safety requirements for lamp systems that are intended to produce projected visible optical radiation, such as theatre projectors, data projectors and home-use projectors The assigned risk group of a projector product also may be used by projector manufacturers to assist with any risk assessments, e.g for occupational exposure in workplaces National requirements may exist for the assessment of products or occupational exposure The emission limits provided in this part of I EC 62471 are derived from the exposure limits specified by I CN IRP in their 201 Guidelines for incoherent visible and infrared radiation [1 ] These exposure limits are also the basis for the emission limits to be specified in the future I nternational Standard I EC 62471 -1 N u mbers in squ are brackets refer to the Bi bl iog raphy Revi si on of I EC 62471 : 2006 –8– I EC 62471 -5: 201 © I EC 201 P H O T O B I O L O G I C AL S AF E T Y O F L AM P S AN D L AM P S YS T E M S – P a rt : I m a g e p ro j e c t o rs Scope This part of I EC 62471 provides requirements regarding photobiological safety of the optical radiation emitted by image projectors This part of I EC 62471 does not deal with other hazards such as electrical, mechanical or fire hazards This part of IEC 62471 provides requirements regarding: • • • • optical radiation safety assessment of image projectors; projector risk groups; testing conditions and measurement conditions; manufacturer’s requirements including user information The scope of this part of I EC 62471 is photobiological safety of image projectors including the emissions from laser-illuminated projectors that fulfill the requirements as specified in I EC 60825-1 : 201 4, 4.4 and for which visible light emission has been excluded from classification in I EC 60825-1 This part of I EC 62471 does not address safety requirements for laser display products where collimated laser beams — generally scanned — are employed I t does address those laserilluminated projectors that employ a laser source to illuminate, for example, a micro-electromechanical system (MEMS) without scanned beams or crystal-based display projector system N OTE I mag e proj ectors contai ni ng l asers are subject to th ose provi sions of I EC 60825-1 applicabl e to the embed d ed l aser See I EC 60825-1 : 201 4, 4 for whi ch vi sibl e li ght emi ssi on h as been excl ud ed from th e l aser prod u ct cl assi ficati on This part of I EC 62471 includes projectors for only visible image projection and does not include ultraviolet (U V) projectors, infrared (I R) projectors, general lighting service (GLS) lamps (GLS; defined in IEC 62471 ) or projector lamp systems used for general lighting, which are treated in separate International Standards N o rm a t i v e re fe re n c e s 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 undated references, the latest edition of the referenced document (including any amendments) applies I EC 62471 , Photobiological safety of lamps and lamp systems I EC 60825-1 : 201 4, Safety of laser products – Part 1: Equipment classification and requirements I EC 60050 (all parts), International http: //www.electropedia.org) Electrotechnical Vocabulary (available I EC 60950-1 , Information technology equipment – Safety – Part 1: General requirements at – 40 ã I EC 62471 -5: 201 â I EC 201 Calculation of hazard distance (HD) L = E / Ω; E = P / S where S is projection area; S = ( l / NTR ) NAS ( l / NTR ); Ω = π α / Assume: the apparent source size of a projector dS is not changed at the position of HD, Ω = π dS / l L = P NTR / ( NAS π · dS ) L R for RG2 = 28 000/α = 28 000 lH D / dS where lH D is the distance between the source and the RG2 position: lH D = P NTR / (28 000 NAS π · dS ) ∙ ∙ P = 33, NTR = 5, NAS = 0, 75 dS = 0, 03 = ,68 (m) HD = , 68 - 0, = , (m) lH D B.2.3 000 lm projector with small apparent source (CW) The lenses are fixed The The The The maximum throw ratio is 0, aspect ratio (Horizontal: Vertical) is 4:3 apparent source size of a projector is 4, mm in diameter where TR = 0, distance lb between the outer surface of the lens and the exit pupil is lb = 3,0 cm Assumes: The spectral weighting functions are , for visible wavelength The luminous efficacy of radiation is 300 lm/W The optical emission is CW from a homogeneous source Angular subtense α of the source at a measurement distance of m is α = 0, 004 / (0, 03 + , )= 3, × -3 rad The angular subtense α is 3, mrad and the solid angle subtended by α is Ω I llumination area is , 29 m × = π (0, 003 9) / = ,2 × -5 sr 0, 966 m at , 03 m from the aperture of the projector (TR = 0, 8) The radiant power P (W) passing through the above illumination area is P = 000 / 300 = 6, 67 W The irradiance E at m distance from the outer surface of the lens is then I EC 62471 -5: 201 © I EC 201 E – 41 – = 6,67 / (1 , 29 × 0,966) = 5, 36 W∙m -2 Therefore, L • • = E/Ω = 5,36 / ,2 × -5 = 4, 53 × 05 W∙m -2 ∙sr-1 Retinal thermal hazard The emission limit of retinal thermal hazard L R is obtained from Table L R for RG2 = 28 000/ α = 28 000 / (3,88 × -3 ) = 7, 21 × W∙m -2 ∙sr -1 The angular subtense α is 3, mrad As a result, L is smaller than L R Blue-light hazard The emission limit of blue light hazard L B is obtained from Table L B for RG2 = 000 000 W∙m -2 ∙sr -1 ; L B for RG1 = 000 W∙m -2 ∙sr -1 L Average of retinal thermal hazard is lower than AEL of blue-light hazard for RG2 Therefore, the blue light hazard of the emission is RG2 or lower (see B.1 4) Therefore the projector is classified as RG2 if other hazard elements not exceed each emission limit for RG2 B.3 B.3.1 Calculation example of risk group (pulsed emission) General The pulsed emission is defined by 27 (pulse duration) and 28 (pulsed emission) I f the emission of the projector is categorized as pulsed emission, the AEL for retinal thermal is calculated and risk group is determined as follows (see 3) • • Compare the averaged irradiance or averaged radiance with the AEL values of Table The peak radiance shall be compared to the emission limit (AEL) in Table The AEL values shall be multiplied by the factor C5 in Table pulse duration, = D / L peak : D: radiance dose peak radiance L peak : α used in the calculation of AEL is defined in Table B.3.2 000 lm projector with one peak See Figure B – 42 – I EC 62471 -5: 201 © I EC 201 5, ms (= 80 H z) Peak level = 92 W colou r D Average power level 50 W 40 W 40 W 28 W colou r colour C B colour A Average power 7W 10 W 10 W colour A col ou r B t 23 W IEC Figure B.3 – Example with one peak of pulsed emission The lenses are fixed The The The The maximum throw ratio is 2, aspect ratio (Horizontal: Vertical) is 4:3 apparent source size of a projector is 20 mm in diameter where TR = 2, distance lb between the outer surface of the lens and the exit pupil is lb = 5, cm Assumes: The spectral weighting functions are , for visible wavelength The luminous efficacy of radiation is 280 lm/W The optical emission is pulsed emission from a homogeneous source Angular subtense α of the source at a measurement distance of m is = 0, 020 / (0, + , ) = , 74 α I llumination area is 0, 575 m × -2 rad × 0, 431 m at ,1 m from the aperture of the projector (TR = 2, 0) The average radiant power P (W) passing through the above illumination area is P = 000 / 280 = 50,0 W The average irradiance E at m distance from the outer surface of the lens is then E = 50, / (0, 575 × 0, 431 ) = 202 W∙m -2 The angular subtense α is 7,4 mrad and the solid angle is Ω = π (0, 01 74) / = 2, 38 × -4 sr I EC 62471 -5: 201 © I EC 201 – 43 – Therefore, average radiance is L Average • = E/Ω = 202 / (2,38 -4 ) = 8, 49 × × 05 W∙m -2 ∙sr-1 Evaluation of retinal thermal hazard ) Comparison of the average radiance with the CW AEL L Average = E/Ω = 8,49 W∙m -2 ∙sr-1 05 × The exposure duration time t is t = 0, 25 s From Table and Table 7, the maximum angular subtense α max is = 0, α max t0, = 0,1 rad α < α max Therefore, α is selected for the calculation of AEL AEL = 2, × 04 × 0, 25 -0, 25 × (1 , 74 × -2 ) -1 = ,63 × 06 W∙m -2 ∙sr-1 Therefore, averaged radiance < AEL 2) Comparison of the pulse energy and AEL of multiple pulse emissions Calculate for the total radiance dose D of one cycle: D = L Average /1 80 = (8,49 × ) / 80 = 4, 72 × 03 J∙m -2 ∙sr-1 Calculate for the combination of peak radiance: L peak • = L Averag e 92 / 50 = , 56 × 06 W∙m -2 ∙sr-1 The calculation of AEL The pulse duration is = D /L peak = (4, 72 × ) / (1 , 56 × ) = 3,02 × -3 s From Table and Table 7, the maximum angular subtense α max is α max = 0, t0, rad = 0, × (3, 01 × -3 ) 0, =1 α max < α • Therefore, α max is selected for the calculation of AEL The calculation of C5 N (the number of pulses that occurs within the time base) is N = 80 × 0,25 = 45 × -3 rad – 44 – For α max < α < I EC 62471 -5: 201 © I EC 201 00 mrad, for N ≤ 625, C5 = N-0, 25 = 0, 39 The emission limit of retinal thermal hazard (AEL) is obtained from Table AEL = 2, ã ì 04 ì (3,02 ì -3 ) -0, 25 × 0, 39 × (1 ,0 × -3 ) -1 = 3, × W∙m -2 ∙sr-1 Peak radiance ( L peak ) of [colour D] is less than AEL of multiple pulse emissions Evaluation of blue-light hazard The emission limit of blue-light hazard L B is obtained from Table L B for RG2 = 000 000 W∙m -2 ∙sr -1 ; L B for RG1 = 000 W∙m -2 ∙sr -1 ; L averag e is smaller than L B for RG2, larger than L B for RG1 Therefore the projector is classified as RG2 if other hazard elements not exceed each emission limit for RG2 B.3.3 000 lm projector with two peaks See Figure B 80 H z 00 W colour B colour B 87 W Average power l evel 50W 40 W 25 W colour D colour C colou r A col ou r A Average power 10 W 15 W 12 W 13 W t IEC Figure B.4 – Example with two peaks of pulsed emission The lenses are fixed The The The The maximum throw ratio is 2, aspect ratio (Horizontal: Vertical) is 4:3 apparent source size of a projector is 20 mm in diameter where TR = 2, distance lb between the outer surface of the lens and the exit pupil is lb = 5, cm Assumes: The spectral weighting functions are , for visible wavelength The luminous efficacy of radiation is 280 lm/W I EC 62471 -5: 201 © I EC 201 – 45 – The optical emission is pulsed emission from a homogeneous source Angular subtense α of the source at a measurement distance of m is α = 0, 02 / (0, + , ) = , 74 × -2 rad The angular subtense α is mrad and the solid angle is Ω I llumination area is (0, 575m × = π (0, 01 74) /4 = 2,38 × -4 sr 0, 431 m) at , m from the aperture of the projector (TR = 2, 0) The average radiant power P (W) passing through the above illumination area is P = 000 / 280 = 50, W The average irradiance E at m distance from the outer surface of the lens is then E = 50, / (0, 575 × 0, 431 ) = 202 W∙m -2 Therefore, average radiance is L average = E/Ω = 202 / 2,38 × -4 = 8, 49 × W∙m -2 ∙sr-1 • Evaluation of retinal thermal hazard ) Comparison of the average radiance with the CW AEL: L Average = 8,49 × W∙m -2 ∙sr-1 The time base is t = 0, 25 s From Table and Table 7, the maximum angular subtense α max is α max Therefore, since α AEL = 2, ã ì < max , 04 × = 0, t0, rad = 0,1 rad is selected for the calculation of AEL 0, 25 -0, 25 × (1 , 74 × -2 ) -1 = ,63 × 06 W∙m -2 ∙sr-1 Averaged radiance < AEL 2) Comparison of the pulse energy and AEL of single pulse multiplied by C5 Calculate for the total radiance dose of one cycle I n the case of multiple peaks, the maximum peak value is selected for the calculation of L peak : D = L Averag e /1 80 = (8,49 × ) / 80 = 4,72 × J∙m -2 ∙sr-1 ; L peak = L Average 00/50 = , 70 × W∙m -2 ∙sr-1 The calculation of AEL The pulse duration is = D /L peak = (4, 72 × ) / (1 , 70 × ) =2.78 × -3 s – 46 – I EC 62471 -5: 201 © I EC 201 From Table and Table 7, the maximum angular subtense α max is α max • = 0, t0, rad = 0,2 (2, 78× -3 ) 0, =1 0,5 × -3 rad Therefore, α max < α ≥ α max is selected for the calculation of AEL The calculation of C5 N (the number of pulses that occurs within the time base) is N For α max < α < = 80 × 0,25 = 45 00 mrad, for N 625, C5 ã ì = N-0, 25 = 0, 39 The emission limit of retinal thermal hazard (AEL) is obtained from Table AEL = 2, × × (2,78 × -3 ) -0, 25 × 0, 39 × (1 0, × -3 ) -1 = 3, × W∙m -2 ∙sr-1 Peak radiance ( L peak ) is less than AEL of multiple pulse emissions Blue-light hazard The emission limit of blue-light hazard L B is obtained from Table L B for RG2 = 000 000; L B for RG1 = 000; L Average is smaller than L B for RG2, larger than L B for RG1 Therefore the projector is classified as RG2 if other hazard elements not exceed each emission limit for RG2 I EC 62471 -5: 201 © I EC 201 – 47 – Annex C (informative) Example of intra-beam of projector sources with millimetre scale See Figure C.1 Tu ngsten projector l amp IEC IEC IEC Digital M EMS devi ce LCD proj ector source Figure C.1 – Examples of intra-beam images of projector sources with millimetre scale – 48 – I EC 62471 -5: 201 © I EC 201 Annex D (informative) Measurement distance The reference distance of , m for the determination of image projector risk group is based upon a number of considerations The worst-case default condition of 20 cm provided in I EC 62471 : 2006 was provided for applications and use conditions totally unknown; however, the use conditions, operation and potential exposure conditions of an image projector are very well known and understood The apparent source is well within the projection optics and can vary in exact position relative to the closest plane of human access, the external surface of the projection lens system Furthermore, the apparent source and beam irradiance will vary little in the immediate nearfield of the projection optics in front of the lens Since the measurement distance from the external surface of the lens system is straightforward to measure, there will be no variation from measurement to measurement I n the immediate near field in front of the projection optics, the irradiance can be substantial, but the eye cannot focus on a bright source H igh-power xenon-short-arc cinema projectors have been in use for more than 50 years, and there has never been a reported public retinal injury, despite the fact that the beams of these projectors exceed current exposure limits to distances on the order of m An analysis of accidental viewing conditions shows that direct viewing of the projector’s bright light beam is not reasonably foreseeable at such close distances Unintentional viewing is certainly not onaxis nor does it occur with a large, 7-mm pupil Pupil size greatly affects the amount of light entering the eye Blue-light photochemical hazard, from staring into the projector for a long enough duration to pose a blue-light hazard, is not reasonably foreseeable because of the aversion response limit exposure of 0,25 s The potential hazard of concern for very bright projectors is the potential risk for retinal thermal injury from viewing the projector source at very close distances The current exposure limits for retinal thermal injury are created under the assumption of a 7-mm dark-adapted pupil; however, a smaller pupil will exist for reasonably foreseeable, direct-beam viewing conditions Unintentional viewing would rarely, if ever, involve the macular (central retinal) area, but, rather, the peripheral retina, which further reduces the pupil size before direct macular exposure Data projectors are normally used in a room with ambient illumination, and reflected light from the screen adds to the ambient light level A more realistic pupil size of about mm is typical of these settings Smaller pupil sizes are also required for good acuity (i.e vision is very poor and acuity low for a 6-mm to 7-mm pupil) A smaller pupil also results from viewing the glare from the projector lens from outside the beam, and as a person approaches the beam For typical high luminance projectors, the apparent source (the exit pupil) is at least cm to 20 cm behind the front lens surface and the near-field (collimated) part of the beam is contained within the projector lens or a few centimetres in front of it Assuming a typical diameter of the exit pupil of mm and the exit pupil being cm behind the front lens surface, the angular subtense of the apparent source at m from the lens equals mm/(1 50 mm + 000 mm) = 0, 01 rad Considering that in the far-field condition, radiance is constant with distance and the exposure limit scales with the inverse ratio of the angular subtense of the apparent source, the ratio of exposure (constant radiance) and exposure limit increases linearly with distance relative to the exit pupil On the other hand, the exposure limit expressed as radiance, for a given pupil size, can be scaled with the square of the ratio of the pupil diameter to mm (see also [1 ]) For instance, a pupil with a diameter of 3,5 mm would result in an increase of the exposure limit by a factor of From these dependencies it follows that a reference distance of m for the determination of the risk group, where the emission limit is based on the assumption of a mm pupil is equivalent to a reference distance of 20 cm from the lens for the assumption of a pupil diameter of 3, mm, when the exit pupil is I EC 62471 -5: 201 © I EC 201 – 49 – cm behind the lens surface In other words, if the exposure level at m distance is just below the exposure limit for 0, 25 s exposure duration for a mm pupil, it will also be below the exposure limit for exposure at a distance of 20 cm when the pupil diameter is 3, mm or less Thus, for a pupil diameter of 3, mm, the classification reference distance of m is equivalent to the conservative reference distance of 20 cm Additionally, for a complete risk analysis, the safety margin of the exposure limits compared to injury thresholds, particularly for large apparent sources, was taken into consideration Thus the choice of a m measurement/assessment distance for all projectors can be considered as a conservative value based upon detailed analysis of pupil size and constriction for unintentional viewing, projection optical design and macular exposure – 50 – I EC 62471 -5: 201 © I EC 201 Annex E (informative) Hazard distance as a function of modifying optics This part of I EC 62471 requires in that the manufacturer provides HD information if the product's HD exceeds m due to the possible use of modifying optics This is to assist the end user in estimating the HD of their image projectors The given example is derived from a theoretical system with the following characteristics: • Lumen output: I mager chip: F number: Lens: • Hazard distance: • • • 000 lumens (luminous efficiency 251 lm/W) 25,4 mm in diagonal 2, variable throw SXGA resolution, 30 mm outer diameter, 20 % off axis capabilities based on 28 000/α W∙m -2 ∙sr-1 Figure E.1 displays the radiance of a 000 lm projector and its related HD determined from the nearest point of human access At the point where the AEL crosses the radiance of the system, the hazard distance approaches m This is at a throw ratio of 4, IEC Figure E.1 – Hazard distance as a function of modifying optics (example) I EC 62471 -5: 201 © I EC 201 – 51 – Bibliography [1 ] I CN IRP Guidelines on limits of exposure to incoherent visible and infrared radiation, Health Physics 05(1 ):74-91 ; 201 [2] I EC 60050-845, International Electrotechnical Vocabulary – Chapter 845: Lighting [3] I EC TR 60825-1 4, Safety of laser products – Part 14: A user's guide [4] I EC 6041 7, Graphical symbols for use http: //www.graphical-symbols info/equipment) _ on equipment (available at: INTERNATIONAL ELECTROTECHNICAL COMMISSI ON 3, rue de Varembé PO Box 31 CH-1 21 Geneva 20 Switzerland Tel: + 41 22 91 02 1 Fax: + 41 22 91 03 00 info@iec.ch www.iec.ch