SIST EN 61947-2:2003

SLOVENSKI SIST EN 61947-2:2003

STANDARD
oktober 2003
Electronic projection - Measurement and documentation of key performance
criteria - Part 2: Variable resolution projectors (IEC 61947-2:2001)
ICS 33.160.99; 37.040.10 Referenčna številka
SIST EN 61947-2:2003(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 61947-2
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2002
ICS 33.160.60;35.140;37.020
English version
Electronic projection –
Measurement and documentation of key
performance criteria
Part 2: Variable resolution projectors
(IEC 61947-2:2001)
Projection électronique – Elektronische Projektion –
Mesure et documentation des Messung und Dokumentation
critères principaux de performance wichtiger Leistungsmerkmale
Partie 2: Projecteurs à résolution Teil 2: Projektoren variabler Auflösung
variable (IEC 61947-2:2001)
(CEI 61947-2:2001)
This European Standard was approved by CENELEC on 2001-11-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61947-2:2002 E

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EN 61947-2:2002 - 2 -
Foreword
The text of document 100/268/FDIS, future edition 1 of IEC 61947-2, prepared by SC 100C, Audio,
video and multimedia subsystems and equipment, of IEC TC 100, Audio, video and multimedia
systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 61947-2 on 2001-11-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2002-08-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2004-11-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexes A, B, D, G and ZA are normative and annexes C, E, F, H, I and J
are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61947:2001 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
ISO 9241-8 NOTE Harmonized as EN ISO 9241-8:1997 (not modified).
IEC 60107-1 NOTE Harmonized as EN 60107-1:1997 (not modified).
__________

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- 3 - EN 61947-2:2002
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-845 1987 International Electrotechnical --
Vocabulary (IEV)
Chapter 845: Lighting
1)
IEC 61947-1 - Electronic projection --
Part 1: Fixed resolution projectors
ISO 3741 1999 Acoustics - Determination of sound EN ISO 3741 1999
power levels of noise sources using
sound pressure - Prescision methods
for reverbation rooms
ISO 7779 1999 Acoustics EN ISO 7779 2001
Measurement of airborne noise emitted
by information technology and
telecommunications equipment

1)
To be published.

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INTERNATIONAL IEC
STANDARD
61947-2
First edition
2001-09
Electronic projection –
Measurement and documentation
of key performance criteria –
Part 2:
Variable resolution projectors
 IEC 2001  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
X
International Electrotechnical Commission
For price, see current catalogue

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– 2 – 61947-2  IEC:2001(E)
CONTENTS
FOREWORD . 4
INTRODUCTION .6
1 Scope . 7
2 Normative references . 7
3 Definitions. 8
4 General requirements. 12
5 Light output measurement and specification . 13
5.1 Light output specifications . 14
5.1.1 Light output specification for projectors with a separate screen . 14
5.1.2 Full-black light level specification. 15
5.1.3 Luminance specification for devices with an integral screen . 15
5.2 Light output uniformity. 15
5.2.1 Example of a uniformity specification. 15
5.3 Contrast ratio . 15
5.4 Blanking measurement and specification . 15
5.5 Effective blanking time . 16
5.6 Blanking specification. 16
6 Variable resolution projector characteristics. 17
6.1 Visual resolution measurement and specification. 17
6.1.1 Description and general requirements. 17
6.1.2 Horizontal resolution. 17
6.1.3 Vertical resolution . 18
6.1.4 Procedure . 18
6.2 Video frequency response specifications . 20
6.2.1 Frequency response specifications . 20
6.3 Viewing angle (half/gain) specification for devices with an integral screen. 20
6.4 Input signal format compatibility . 20
6.5 Response time . 20
6.6 Colour measurements . 21
6.6.1 Colour chromaticity. 21
6.6.2 Colour uniformity. 21
6.7 Keystone correction . 22
7 Range of focus and image size. 22
8 Audio characteristics . 22
9 Light source specification . 22
10 Noise: maximum sound level . 23
11 Power consumption. 23
12 Weight . 23
13 Dimensions .23
14 Recommended practices . 23
14.1 Recommended practice 1 − Sync hierarchy . 23
14.2 Recommended practice 2 − DC restoration. 23
14.3 Recommended practice 3 − Sync . 24
14.4 Recommended practice 4 − Scan range labelling. 24

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61947-2  IEC:2001(E) – 3 –
Annex A (normative) Figures . 25
Annex B (normative) Pattern generator specifications . 29
Annex C (informative) Considerations in formulating this standard . 30
C.1 General. 30
C.2 Light output measurement . 30
C.3 Visual resolution measurement. 31
C.4 Possible causes for measurement errors . 31
C.5 Input signal levels .31
Annex D (normative) Complete sample specification . 33
Annex E (informative) Other issues, outside the scope of this standard, that may affect
picture clarity. 35
Annex F (informative) Possible causes of photometric measurement errors. 36
F.1 Size of measured spot. 36
F.2 Colour measurement. 36
Annex G (normative) Alternative method for measuring resolution using the NIDL grille
contrast method. 37
Annex H (informative) Photometer precision and veiling glare . 39
H.1 Photometer precision . 39
H.2 Integration time . 39
H.3 Veiling glare . 39
Annex I (informative) Light measuring devices . 41
Annex J (informative) Figure of merit for projection display colour gamut. 42
Bibliography . 44
Figure A.1 – Test patterns/measurements set-up . 25
Figure A.2 – Thirteen-point measuring grid . 26
Figure A.3 – Contrast measurement. 26
Figure A.4 – Vertical alternating lines. 26
Figure A.5 – Horizontal alternating lines. 27
Figure A.6 – Resolution equipment set-up/depth of modulation measurement. 27
Figure A.7 – Sync and blanking timing . 28
Figure C.1 − Simulation of lowered resolution . 32

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– 4 – 61947-2  IEC:2001(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC PROJECTION –
MEASUREMENT AND DOCUMENTATION
OF KEY PERFORMANCE CRITERIA –
Part 2: Variable resolution projectors
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61947-2 has been prepared by subcommittee 100C: Audio, video
and multimedia subsystems and equipment, of IEC technical committee 100: Audio, video and
multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/268/FDIS 100/418/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.
Annexes A, B, D, and G form an integral part of this standard.
Annexes C, E, F, H, I and J are for information only.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.

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61947-2  IEC:2001(E) – 5 –
The committee has decided that the contents of this publication will remain unchanged until 2004.
At this date, the publication will be
reconfirmed;
withdrawn;
replaced by a revised edition, or
amended.

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– 6 – 61947-2  IEC:2001(E)
INTRODUCTION
This standard was developed to ensure a common, meaningful description of key performance
parameters for variable resolution projectors (for example, CRT or laser projectors).
The measurement methods and test signals correlate closely to typical uses involving
computer-generated text and graphics displays. These measurements evaluate the actual
viewable image that emanates from variable resolution projectors. The resulting performance
specifications are conservative in nature and allow any display device to be used beyond its
rated specifications with degraded performance. The point at which this degraded performance
is no longer useful is highly subjective and strongly affected by the environment and the
application.
This standard is designed to specify a means of measuring and quantifying the performance of
variable resolution projectors and is not intended to provide design goals for manufacturers
of such equipment.

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61947-2  IEC:2001(E) – 7 –
ELECTRONIC PROJECTION –
MEASUREMENT AND DOCUMENTATION
OF KEY PERFORMANCE CRITERIA –
Part 2: Variable resolution projectors
1 Scope
This part of IEC 61947 specifies requirements for measuring and documenting key
performance parameters for CRT and laser-based projectors and other variable resolution
projectors that are capable of multiple variable resolutions and in which the image is raster-
scanned.
The provisions of this standard are designed to codify the measurement of the performance of
variable resolution projectors and are not intended to provide design goals for manufacturers of
such equipment.
This standard is intended for variable resolution projectors (including projection displays that
are capable of multiple variable resolutions) that are designed for use with primarily discrete
colour (RGB) raster-scanned video, text, and graphics signals generated by computer
equipment.
NOTE These devices may also accept composite or component television video signals encoded to
NTSC/RS170A, PAL, SECAM, or future HDTV, or ATV standards, which are fully described in their respective
documentation and are not within the scope of this part of IEC 61947. In this part of IEC 61947, all of these signals
are referred to as television video (TV video) (see IEC 60107-1 [27]).
Displays with fixed resolutions (i.e. individual pixel light sources or matrix displays such as
liquid crystal, DMD, plasma, or electroluminescent panels), are not fully addressed by this
standard, and reference should be made to IEC 61947-1.
Factors outside the scope of this standard that may have a bearing on projector performance
are listed in annex E. A discussion of considerations informing the development of standard
appears in annex C.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61947. For dated references, subsequent amendments
to, or revisions of, any of these publications do not apply. However, parties to agreements
based on this part of IEC 61947 are encouraged to investigate the possibility of applying the
most recent editions of the normative documents indicated below. For undated references, the
latest edition of the normative document referred to applies. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60050(845):1987, International Electrotechnical Vocabulary (IEV) – Chapter 845: Lighting
IEC 61947-1, Electronic projection – Measurement and documentation of key performance
1)
criteria – Part 1: Fixed resolution projectors
________
1)
To be published.

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– 8 – 61947-2  IEC:2001(E)
ISO 3741:1999, Acoustics – Determination of sound power levels of noise sources using sound
pressure – Precision methods for reverberation rooms
ISO 7779:1999, Acoustics – Measurement of airborne noise emitted by information technology
and telecommunications equipment
3 Definitions
For the purposes of this part of IEC 61947, the following definitions apply.
3.1
active matrix display
display that uses switches at each pixel to select those pixels to which a voltage will be applied
3.2
active viewing area
horizontal and vertical dimensions in millimetres (inches) of the boundary of the array of pixels.
It may also be expressed in square millimetres or square inches
3.3
aperture ratio (fill factor)
light transmitting/reflecting area of a pixel times the number of pixels divided by the active
viewing area (light transmitting area and light blocking area)
3.4
aspect ratio
proportions of a projected picture area, for example, the width compared to the height. It is
usually expressed in standard ratios such as 4:3, 16:9, or others
3.5
blanking
process of the beam turning off (blanking) which occurs during horizontal and vertical retrace
(flyback)
3.6
CIE
Commission Internationale de l’Eclairage (International Commission on Illumination)
NOTE The CIE is an organization devoted to international cooperation and exchange of information among its
member countries on all matters relating to the art and science of lighting.
3.7
CIE chromaticity values
Cartesian coordinates used to define a colour in CIE colour space
NOTE The 1931 chromaticity values are designated x and y. In 1976, the CIE defined a more uniform colour
space. The 1976 CIE chromaticity values are u′ and v′.
3.8
colour mapping
means for accurately displaying colour signals or altering sets of colour signals in a controlled
manner
3.9
contrast ratio
luminance or illuminance ratio of a light area of the image to the dark area of the same image

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61947-2  IEC:2001(E) – 9 –
3.10
correlated colour temperature (CCT) of the white-point
temperature, in kelvins, of the black-body radiator, the chromaticity of which is closest to the
chromaticity of a particular light, for example from a display screen, as measured in the 1960
CIE (u, v) uniform chromaticity space
NOTE An algorithm for computing the CCT of the white-point, either from 1931 CIE (x, y) coordinates or from 1960
(u, v) coordinates, appears in Wyszecki and Stiles [1]. A graphical nomogram also appears in this work.
Alternatively, a successful numerical approximation has been derived by C. S. McCamy [2]. Given CIE 1931
coordinates (x, y), McCamy's approximation is CCT = 437 n3 + 3 601 n2 + 6 831 n + 5 517, where
n = (x - 0,3320)/(0,1858 – y). This approximation, the second of three proposed, is close enough for any practical
use between 2 000 K and 10 000 K. In units of 1960 u ,v chromaticity, it is agreed that the concept of CCT of the
white-point has little meaning beyond the distance of 0,01 from the Planckian locus (see Robinson et al [3]), where
the distance is specified by
2 2
Δuv = (u - u ) + (v - v )
1 2 1 2
Most commercial colourimeters will report the CCT of the white-point from 0,0175 u, v units above the Planckian
locus to 0,014 u, v units below this locus.
3.11
digital micromirror device (DMD)
semiconductor light micromirror array. The DMD can switch incident light on or off in discrete
pixels within microseconds to produce projection display systems
3.12
optical distortion
situation in which an image is not a true-to-scale reproduction of an object due to the optics of
the system
NOTE There are many types of distortion, such as anamorphic, barrel, curvilinear, geometric, keystone,
panoramic, perspective, radial, stereoscopic, tangential, and wide-angle.
3.13
f/number
focal length of a projection lens divided by the diameter of the lens aperture
3.14
fall time
time, in milliseconds, for the image brightness to change from 90 % of its maximum value to
10 % of its maximum value
3.15
focal length
distance between the centre of the focusing lens or mirror and the focal spot. Shorter focal
length projection lenses produce larger screen images for a given distance from the screen
3.16
focus
adjustment of an optical system to achieve the greatest possible sharpness
3.17
four corners
centres of the four corner points (see figure A.2), located at 10 % of the distance from the
corners to the centre of point 5
3.18
front screen projection
image projected on the audience side of a light-reflecting screen

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– 10 – 61947-2  IEC:2001(E)
3.19
illuminance
quotient of a luminous flux incident on an element of the surface containing the point by the
area of that element.
Unit: lux (lx)
3.20
light source life expectancy
time that the light source can keep its projected light output as measured in this standard,
higher than 50 % of the initial value when tested with a duty cycle of 2 h on and 15 min off
3.21
liquid-crystal display (LCD)
display made of material, the reflectance or transmittance of which changes when an electric
field is applied
3.22
luminance
luminance (L) in a given direction is the luminous intensity per unit of projected area of any
surface, as viewed for that direction
2
Unit: candela per square metre (cd/m )
3.23
luminous flux
quantity derived from radiant flux by evaluating the radiation according to its action upon a
selective receptor, the spectral sensitivity of which is defined by the standard 1931 CIE spectral
luminance efficiency function for the photopic V(λ) function
NOTE Quantity of light expressed in lumens and directed in a given direction.
3.24
luminous intensity
luminous flux per unit solid angle emitted or reflected from a point source
Unit: candela
3.25
object
slide or transmissive/reflective image forming panel, such as an LCD, that is illuminated and
imaged by the optics onto a viewing screen
3.26
peak angle
angle at which maximum luminance is observed
3.27
photometric units
units of light measurement based on the response of the average human observer.
The response of the average human observer is defined by the 1931 CIE spectral luminance
efficiency function for the photopic V(λ) function
3.28
pixel
smallest element of a display space that can be independently assigned a colour or intensity

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61947-2  IEC:2001(E) – 11 –
3.29
projection distance
distance between the projector and the screen measured in linear units (i.e., metres, feet, or
inches). This distance is considered to be the distance from the image displayed on the screen
to the outermost element of the projection lens
3.30
rear screen projection
image projected through a light transmitting screen to the audience side of the screen
3.31
response time
sum of the rise and fall times divided by 2. It is measured at (23 ± 5) °C ambient temperature
after 15 min in operation:
t + t
r f
t =
res
2
3.32
rise time
time, in milliseconds, for the image brightness to change from 10 % of its maximum value to
90 % of its maximum value
3.33
scan rate
3.33.1
vertical scanning
rate (hertz) at which one complete image (frame) is drawn
3.33.2
horizontal scanning
rate (kilohertz) at which each line of the display is scanned
3.34
screen gain
measure of the projector screen luminance as compared to the luminance of a block of
magnesium carbonate illuminated with the same projection source, which serves as the
standard for a gain of 1,0
NOTE Gains are typically measured perpendicular to the centre of the screen.
3.35
standard viewing position
for display devices the screen of which is an integral part of the projection device, the standard
...