EN 62471-5:2015

SLOVENSKI STANDARD
01-december-2015
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Photobiological safety of lamps and lamp systems - Part 5: Image projectors
Ta slovenski standard je istoveten z: EN 62471-5:2015
ICS:
29.140.99 Drugi standardi v zvezi z Other standards related to
žarnicami lamps
37.040.10 Fotografska oprema. Photographic equipment.
Projektorji Projectors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 62471-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2015
ICS 29.140
English Version
Photobiological safety of lamps and lamp systems - Part 5:
Image projectors
(IEC 62471-5:2015)
Sécurité photobiologique des lampes et des appareils Photobiologische Sicherheit von Lampen und
utilisant des lampes - Partie 5: Projecteurs d'images Lampensystemen - Teil 5: Photobiologische Sicherheit von
(IEC 62471-5:2015) Lampensystemen für Bildprojektoren
(IEC 62471-5:2015)
This European Standard was approved by CENELEC on 2015-07-14. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62471-5:2015 E
European Foreword
The text of document 76/519/FDIS, future edition 1 of IEC 62471-5, prepared by IEC/TC 76 "Optical
radiation safety and laser equipment" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN 62471-5:2015.
The following dates are fixed:
– latest date by which the document has to be implemented at (dop) 2016-04-16
national level by publication of an identical national
standard or by endorsement
– latest date by which the national standards conflicting with (dow) 2018-07-14
the document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 62471-5:2015 was approved by CENELEC as a European
Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year

IEC 60050 series International Electrotechnical Vocabulary - - series
IEC 60065 -  Audio, video and similar electronic EN 60065 -
apparatus - Safety requirements
IEC 60825-1 2014 Safety of laser products -- Part 1: EN 60825-1 2014
Equipment classification and requirements
IEC 60950-1 -  Information technology equipment - Safety EN 60950-1 -
-- Part 1: General requirements
IEC 62471 -  Photobiological safety of lamps and lamp EN 62471 -
systems
IEC 62471-5 ®
Edition 1.0 2015-06
INTERNATIONAL
STANDARD
colour
inside
Photobiological safety of lamps and lamp systems –

Part 5: Image projectors
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.140 ISBN 978-2-8322-2737-4

– 2 – IEC 62471-5:2015 © IEC 2015
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references. 8
3 Terms and definitions . 9
4 General . 15
4.1 Basis for risk groups . 15
4.2 Example applications . 16
4.2.1 RG0 / RG1 projectors . 16
4.2.2 RG2 projectors . 16
4.2.3 RG3 projectors . 16
4.3 Projector lamps . 16
4.4 Assessment criteria (background) . 16
5 Risk group determination . 17
5.1 Test conditions . 17
5.2 Measurement conditions for image projectors . 18
5.2.1 Measurement throw ratio . 18
5.2.2 Measurement distance . 18
5.3 The position and size of apparent source, the calculation of angular
subtense . 18
5.4 Measurement of irradiance – specified apertures . 19
5.5 Measurement of radiance . 19
5.6 Accessible emission limits . 20
5.6.1 For CW emission. 20
5.6.2 For pulsed emission . 21
5.6.3 Spectral weighting functions . 22
5.7 Applying information from the lamp manufacturers . 23
5.7.1 General . 23
5.7.2 Limits provided in irradiance/radiant exposure . 24
5.7.3 Limits provided in radiance or radiance dose . 24
6 Manufacturer’s requirements . 24
6.1 General . 24
6.2 Determination of HD (hazard distance) . 25
6.3 Safety feature "soft start" . 25
6.4 Optional safety features . 25
6.4.1 Projection of warning message . 25
6.4.2 Power reduction by sensor system . 25
6.5 Labelling on products . 25
6.5.1 General . 25
6.5.2 RG0 projector . 26
6.5.3 RG1 projector . 26
6.5.4 RG2 projector . 27
6.5.5 RG3 projector . 28
6.6 User information . 28
6.6.1 General . 28
6.6.2 Assessment of user accessible area . 29

IEC 62471-5:2015 © IEC 2015 – 3 –
6.6.3 User information (user manual) . 29
6.6.4 User information for maintenance . 30
6.7 Labelling and user information for image projectors where the risk group will
be changed by interchangeable lens . 30
6.7.1 General . 30
6.7.2 Labelling on the projector . 30
6.7.3 Mark on the interchangeable lens . 32
6.7.4 The user information in the user manual of the projector . 32
6.7.5 The user information in the user manual of the interchangeable lens . 32
7 Information for service . 33
Annex A (normative) Test scheme for lamp types . 34
Annex B (informative) Example of calculations . 35
B.1 Radiance calculations . 35
B.1.1 General . 35
B.1.2 Calculation from measured irradiance . 35
B.1.3 Calculation from luminous output . 36
B.2 Calculation example of risk group (CW) . 37
B.2.1 Example of a 5 000 lm projector . 37
B.2.2 10 000 lm professional-use projector with an apparent source of small
subtense angle (CW) . 39
B.2.3 2 000 lm projector with small apparent source (CW) . 40
B.3 Calculation example of risk group (pulsed emission) . 41
B.3.1 General . 41
B.3.2 14 000 lm projector with one peak . 41
B.3.3 14 000 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 1 – Exit pupil in projector . 10
Figure 2 – Examples of the application of the definition of pulse duration . 13
Figure 3 – Definition of throw ratio. 15
Figure 4 – Diameter of the apparent source . 18
Figure 5 – RG1 label (optional) . 26
Figure 6 – RG2 label . 27
Figure 7 – RG2 caution symbol . 27
Figure 8 – Sample design of RG2 caution pictogram . 27
Figure 9 – RG3 label . 28
Figure 10 – Optical radiation warning symbol . 28
Figure 11 – "Not for household use" symbol . 28
Figure 12 – RG2 label with the caution for RG3 . 31
Figure 13 – RG2 caution label with the caution for RG3 . 31
Figure 14 – RG2 pictogram with the caution for RG3 . 32
Figure B.1 – Image of the apparent source and measurement condition . 37

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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.1 – 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 1 – Measurement criteria — field of view (angles of acceptance) for CW source . 19
Table 2 – Measurement criteria — field of view (angles of acceptance) for pulsed
source . 19
Table 3 – AEL (accessible emission limits) for risk groups of lamps and lamp systems
emitting CW optical radiation . 20
Table 4 – Time base values associated with the risk groups and hazards . 20
Table 5 – Basic retinal thermal emission limit . 20
Table 6 – The values of C and α for AEL calculation . 21
Table 7 – Pulse duration dependent values of α . 22
max
Table 8 – Spectral weighting functions B(λ) and R(λ) for assessing retinal hazards . 23
Table 9 – Labelling on products . 26
Table 10 – User information in user manual . 29
Table A.1 –Required evaluations . 34

IEC 62471-5:2015 © IEC 2015 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
PHOTOBIOLOGICAL SAFETY OF LAMPS AND LAMP SYSTEMS –

Part 5: Image projectors
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62471-5 has been prepared by IEC technical committee 76:
Optical radiation safety and laser equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
76/519/FDIS 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/IEC Directives, Part 2.

– 6 – IEC 62471-5:2015 © IEC 2015
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
IEC 62471-5:2015 © IEC 2015 – 7 –
INTRODUCTION
Most lamps and lamp systems are safe and do 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 IEC 62471:2006 (CIE S 009:2002), Photobiological safety of lamps and
lamp systems. IEC 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 IEC 62471 provides a risk group classification system for image projectors, and
measurement conditions for optical radiation emitted by image projectors. It 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 IEC 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 IEC 62471 are derived from the exposure limits
specified by ICNIRP in their 2013 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
International Standard IEC 62471-1 .

______________
Numbers in square brackets refer to the Bibliography.
Revision of IEC 62471:2006.
– 8 – IEC 62471-5:2015 © IEC 2015
PHOTOBIOLOGICAL SAFETY OF LAMPS AND LAMP SYSTEMS –

Part 5: Image projectors
1 Scope
This part of IEC 62471 provides requirements regarding photobiological safety of the optical
radiation emitted by image projectors. This part of IEC 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 IEC 62471 is photobiological safety of image projectors including the
emissions from laser-illuminated projectors that fulfill the requirements as specified in
IEC 60825-1:2014, 4.4 and for which visible light emission has been excluded from
classification in IEC 60825-1.
This part of IEC 62471 does not address safety requirements for laser display products where
collimated laser beams — generally scanned — are employed. It does address those laser-
illuminated projectors that employ a laser source to illuminate, for example, a micro-electro-
mechanical system (MEMS) without scanned beams or crystal-based display projector system.
NOTE Image projectors containing lasers are subject to those provisions of IEC 60825-1 applicable to the
embedded laser. See IEC 60825-1:2014, 4.4 for which visible light emission has been excluded from the laser
product classification.
This part of IEC 62471 includes projectors for only visible image projection and does not
include ultraviolet (UV) projectors, infrared (IR) 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.
2 Normative references
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.
IEC 62471, Photobiological safety of lamps and lamp systems
IEC 60825-1:2014, Safety of laser products – Part 1: Equipment classification and
requirements
IEC 60050 (all parts), International Electrotechnical Vocabulary (available at
http://www.electropedia.org)
IEC 60950-1, Information technology equipment – Safety – Part 1: General requirements

IEC 62471-5:2015 © IEC 2015 – 9 –
IEC 60065, Audio, video and similar electronic apparatus – Safety requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62471,
IEC 60050-845 [2] and the following apply.
3.1
accessible emission
AE
level of radiation determined at a certain distance from the product and with measurement
conditions described in Clause 5
Note 1 to entry: The accessible emission is compared with the AEL (see 3.2) to determine the risk group of the
product.
3.2
accessible emission limit
AEL
maximum accessible emission permitted within a particular risk group
3.3
angle of acceptance
γ
plane angle within which a detector will respond to optical radiation
Note 1 to entry: The angle of acceptance is usually measured in radians (SI unit).
Note 2 to entry: This angle of acceptance may be controlled by apertures or optical elements in front of the
detector. The angle of acceptance is also sometimes referred to as the field of view (see 3.12).
Note 3 to entry: The angle of acceptance should not be confused with the angular subtense of the source
(see 3.4) or the beam divergence.
3.4
angular subtense
α
visual angle subtended by the apparent source at the eye of an observer or at the point of
measurement
Note 1 to entry: In this part of IEC 62471, subtended angles are denoted by the full included angle, not the half
angle.
Note 2 to entry: SI unit: radian.
Note 3 to entry: The angular subtense α may be modified by incorporation of lenses and mirrors as projector
optics, i.e. the angular subtense of the apparent source may differ from the angular subtense of the physical
source.
Note 4 to entry: The limitations of α in this part of IEC 62471 are:

For continuous wave: α = 0,1 rad, α = 0,001 5 rad.
max min
For pulsed emission: α is described in Table 7, α = 0,001 5 rad.
max min
3.5
cinema-use projector
image projector used for projection in theatrical environment
3.6
consumer product
item intended for consumers or likely to be used by consumers, even if not intended for them

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Note 1 to entry: Products provided in the framework of a service to consumers are also considered to
be consumer products.
Note 2 to entry: RG3 products are intended for professional use only, and are not intended for consumer use.
3.7
continuous wave emission
CW emission
emission of a projector which can be considered continuous when the output is continuous for
times greater than 0,25 s and the peak radiated power is not higher than 1,5 times the
average radiated power
3.8
data projector
image projector system using digital imager(s) routinely employed in offices, meetings and
sales presentations
Note 1 to entry: Examples of data imager are MEMS and liquid crystal based display.
3.9
exit pupil
image of the aperture stop which also functions as a virtual aperture of the projection lens
Note 1 to entry: The position of the apparent source is located at the apparent position of the exit pupil
(see Figure 1).
Lens front
Exit pupil
Imager
Aperture stop
Screen
Origin of measurement
distance (see 5.2.2)
Distance used for “Throw Ratio”
Projection lens
Projector
IEC
Figure 1 – Exit pupil in projector
3.10
exposure limit
EL
maximum level of exposure of optical radiation to the eye or skin that is not expected to result
in adverse biological effects
Note 1 to entry: These ELs are used to determine hazard distances with respect to photobiological effects.
3.11
exposure to limit ratio
ELR
ratio of the exposure level and the exposure limit

IEC 62471-5:2015 © IEC 2015 – 11 –
Note 1 to entry: Since both values can be functions of distance and exposure duration, the ELR can depend on
exposure distance and exposure duration.
3.12
field of view
γ
solid angle as "seen" by the detector (acceptance angle), for example of a radiometer or
spectroradiometer, out of which the detector receives radiation
Note 1 to entry: SI unit: steradian (sr).
Note 2 to entry: The field of view should not be confused with the angular subtense of the apparent source, α.
Note 3 to entry: A plane angle is sometimes used to describe a circular symmetric solid angle field of view.
Note 4 to entry: The field of view is sometimes referred to as angle of acceptance (see 3.3).
3.13
fixed projector installation
projector installed permanently or semi-permanently in a fixed location
EXAMPLE A cinema-use projector mounted in an operating booth.
3.14
hazard distance
HD
distance from the projector's nearest point of human access, where the beam radiance or
irradiance exceeds the applicable exposure limit (EL: see 3.10)
Note 1 to entry: The hazard distance for a projector is determined by the EL for a 0,25 s exposure. This also is
the time base of the accessible emission limit of RG2.
3.15
home-use projector
image projector used for audio-visual presentations in the domestic environment under non-
controlled conditions and non-professional use
3.16
image projector product
member of the family of products that includes all types of image projectors such as data
projectors (see 3.8), home-use projectors (see 3.15) and cinema-use projectors (see 3.5)
3.17
intended use
usage of a product, process or application in accordance with specifications, instructions and
information provided by the manufacturer or supplier
3.18
lamp
electrically powered device emitting optical radiation in the wavelength range between 200 nm
and 3 000 nm, with the exception of direct, non-diffuse laser radiation
3.19
lamp system
electrically operated product incorporating lamp(s), including fixtures, projection optics and
incorporated electrical or electronic components as intended by the manufacturer
Note 1 to entry: A lamp system can include diffusers, enclosures and/or beam modifying optics. An image
projector (see 3.16) is a type of lamp system.

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3.20
laser illuminated projecting system
LIP system
projection lamp system emitting visible diffused light as a result of laser light source(s) in
order to replace traditional projector lamps
3.21
light emitting diode
LED
solid-state lamp device embodying a p-n junction, emitting incoherent optical radiation when
excited by an electric current
3.22
liquid-crystal display projector
LCD projector
projector employing an LCD digitized image panel that is projected by the system
3.23
micro-electro-mechanical system based imager
MEMS based imager
micro-electro-mechanical system with electro-optical arrays of micro-mirrors
3.24
modifying optics
optical components that process the light, such as filters, lenses and reflectors, which change
the characteristics of the optical radiation from the initial light source when incorporated into
an image projector (see 3.16)
3.25
projector
optical system using reflection and/or refraction to increase the luminous intensity within a
limited solid angle
Note 1 to entry: The light emitted into a limited solid-angle is generally referred to as the “beam”.
Note 2 to entry: The emitted beam is intended to be incident on a screen or some other diffuse surface such as a
house or room wall.
3.26
projector lamp
lamp in which the luminous element is mounted in such a way that the lamp may be used with
an optical system to project the light in chosen directions
3.27
pulse duration
t
p
time increment calculated by D/L where D is the total radiance dose of the pulse and
peak
L is the peak radiance of that pulse (see Figure 2)
peak
IEC 62471-5:2015 © IEC 2015 – 13 –
D (total radiance dose of the pulse) D (total radiance dose of the pulse)
t = D / L
t = D / L
p peak
p peak
L
L peak
peak
1 cycle
1 cycle
IEC
Figure 2 – Examples of the application of the definition of pulse duration
Note 1 to entry: Unit: second (s).
Note 2 to entry: For a pulse that has a triangular or rectangular temporal emission shape, this definition of pulse
duration is identical to the full-width-half-maximum (FWHM) definition.
Note 3 to entry: A rectangular pulse, shown with dashed borders in Figure 2, with the pulse duration t has the
p
same radiance dose and peak radiance as the actual pulse.
3.28
pulsed emission
emission in the form of a single pulse or a train of pulses where each pulse is assumed to have
a duration of less than 0,25 s
Note 1 to entry: Pulsed emission refers to a product with a continuous train of pulses or modulated radiant energy
where the peak radiated power is at least 1,5 times higher than the average radiated power.
3.29
radiance
L
quantity defined by the formula
L = dΦ/(dA⋅cosθ⋅dΩ)
in a given direction at a given point of a real or imaginary surface,
where
dΦ is the radiant power (flux) transmitted by an elementary beam passing through the given
point and propagating in the solid angle (dΩ) containing the given direction;
dA is the area of a section of that beam containing the given point;
θ is the angle between the normal to that section and the direction of the beam
-2 -1
Note 1 to entry: SI unit: watt per square metre per steradian (W·m ·sr ).
3.30
radiance dose
D
time integrated radiance quantity defined by the equation
D = dQ /(dA⋅cosθ⋅dΩ)
e
where
dQ is the radiant energy transmitted by an elementary beam passing through the given
e
point and propagating in the solid angle (dΩ) containing the given direction;
dA is the area of a section of that beam containing the given point;

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θ is the angle between the normal to that section and the direction of the beam
-2 -1
Note 1 to entry: SI unit: joule per square metre per steradian (J·m ·sr ).
Note 2 to entry: Equivalent term: “(time) integrated radiance”.
3.31
restricted area
area where an engineering and/or administrative control measure is established to restrict
access except to authorized personnel with appropriate safety training
Note 1 to entry: Access is only possible through the use of a tool, lock, key or other means of security.
3.32
spatially averaged radiance
L
sa
quantity defined by the equation
L = dΦ/(dA⋅cosθ⋅dΩ)
sa γ
radiance spatially averaged over a given angle of acceptance to account for physiological
factors such as eye-movements (sometimes referred to as “physiological radiance”)
where
dΦ is the radiant power (flux);
dA is limited by area of field of view (see 3.12);
γ
θ is the angle between the normal to that section and the direction of the beam;
dΩ is the solid angle
-2 -1
Note 1 to entry: SI unit: watt per square metre per steradian (W·m ·sr ).
Note 2 to entry: The spatially averaged radiance may be lower than the true source radiance (see 3.34).
3.33
throw ratio
TR
ratio between the distance from the exit pupil to the screen and the width of the image on the
screen
Note 1 to entry: It is thus approximated by the inverse of the tangent of the full angle of the light beam in the
horizontal direction (see Figure 3).

IEC 62471-5:2015 © IEC 2015 – 15 –
l : Lens front - Apparent source
b
l : Projection distance
a
Lens front
Apparent source
(Exit pupil)
W: Projection width
IEC
Figure 3 – Definition of throw ratio
Note 2 to entry: TR = (l + l )/W.
a b
3.34
true source radiance
L
radiance of the emitting element of the source, physically measured
Note 1 to entry: The applicable averaging angle of acceptance for the determination of radiance shall not be
larger than 1,5 mrad.
-2 -1
Note 2 to entry: SI unit: watt per square metre per steradian (W·m ·sr ).
Note 3 to entry: This definition differs from spatially averaged radiance (see 3.32). This is a quantity that is useful
as information regarding the projector light source (see 5.7.3). For the spatially averaged radiance, the given angle
of acceptance should have a value as defined in Table 1 or Table 2. This value is defined based on physiological
factors. While the true source radiance should be averaged over a small angle in order to be more accurate, the
maximum allowed averaging angle is defined to 1,5 mrad.
3.35
unintentional viewing
condition when ocular exposure to optical radiation is not intended
4 General
4.1 Basis for risk groups
IEC 62471 provides the default method to determine the risk group of any lamp or any product
incorporating a lamp, unless a vertical (application-specific) standard exists. The risk groups
in IEC 62471 indicate the degree of risk from potential optical radiation hazards and minimize
the need for further measurements. The risk groups were developed based upon decades of
lamp use experience and the analysis of accidental injuries related to optical radiation
emission (where injuries were generally quite rare except from, for example, ultraviolet-
emitting lamps or arc lamps).
The risk groups are described as follows:
• Exempt Group (RG0) where no optical hazard is considered reasonably foreseeable, even
for continuous, unrestricted use.
• Risk Group 1 (RG1) products are safe for most applications, except for very prolonged
direct ocular exposures (staring into the source for very long times, greater than 100 s).

– 16 – IEC 62471-5:2015 © IEC 2015
• Risk Group 2 (RG2) products do not pose an optical hazard because of aversion
responses to bright light which make long exposures (staring into the source) not
reasonably foreseeable. RG2 projectors can be safely used in all situations, except if
intrabeam (direct) viewing is intended.
• Risk Group 3 (RG3) products pose a potential hazard even for momentary exposures at
close distance and product safety requirements are generally essential. RG3 projectors
pose a risk resulting from direct, intra-beam viewing at close distance. User information on
protective measures shall be provided. The RG3 projector products require controlled use
or special installation (for example, theatre projectors), and user instructions should
clearly state the HD and the requirement for supervised use or special installation. From
the labelling and information for the user, the user should recognize the risk and take
protective measures.
RG3 products are intended for professional use only, and are not intended for consumer
use.
4.2 Example applications
4.2.1 RG0 / RG1 projectors
Typical examples are conventional tungsten halogen slide or film projectors for home use or
pico-projectors.
4.2.2 RG2 projectors
For example, home-use projectors or mobile projectors may be RG2 projectors.
4.2.3 RG3 projectors
For example, high luminance projection systems used in cinemas or theatres may be RG3
projectors. Rental projectors for professional staging applications, seminars and other big
events may also be RG3 projectors.
4.3 Projector lamps
It should be noted that the risk group classification system of IEC 62471 in its current version
is primarily applied to lamps. However, manufacturers of image projectors have the
responsibility for assessing the final product. They may have limited capabilities for tests and
measurements and may need to rely on the lamp data provided by the lamp manufacturer.
Therefore, guidance is provided in 5.7 on how and when projector system manufacturers may
rely on data provided by the lamp manufacturer.
4.4 Assessment criteria (background)
The standard measurement conditions consider the emission spectrum and, depending on the
hazard, either irradiance or spatially averaged radiance to determine risk to the eye and/or
the skin. The measurement conditions are rel
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