Electronic projection - Measurement and documentation of key performance criteria - Part 1: Fixed resolution projectors

Specifies requirements for measuring and documenting key performance parameters for electronic projection systems with fixed resolution projectors in which the light source and projection/magnification optics are an integral part of the system (i.e. individual pixel light sources or matrix displays such as liquid crystal, DMD, plasma, or electro-luminescent panels). Also applies to LCD panels or other fixed resolution imaging devices themselves that are used with overhead projectors.

Elektronische Projektion - Messung und Dokumentation wichtiger Leistungsmerkmale - Teil 1: Projektoren fester Auflösung

Projection électronique - Mesure et documentation des critères principaux de performance - Partie 1: Projecteurs à résolution fixe

Specifies requirements for measuring and documenting key performance parameters for electronic projection systems with fixed resolution projectors in which the light source and projection/magnification optics are an integral part of the system (i.e. individual pixel light sources or matrix displays such as liquid crystal, DMD, plasma, or electro-luminescent panels). Also applies to LCD panels or other fixed resolution imaging devices themselves that are used with overhead projectors.

Electronic projection - Measurement and documentation of key performance criteria - Part 1: Fixed resolution projectors (IEC 61947-1:2002)

General Information

Status
Published
Publication Date
06-Nov-2002
Current Stage
6060 - Document made available
Start Date
07-Nov-2002
Completion Date
07-Nov-2002

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SLOVENSKI SIST EN 61947-1:2003
STANDARD
oktober 2003
Electronic projection - Measurement and documentation of key performance
criteria - Part 1: Fixed resolution projectors (IEC 61947-1:2002)
ICS 33.160.99; 37.040.10 Referenčna številka
SIST EN 61947-1:2003(en)

© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD EN 61947-1
NORME EUROPÉENNE
EUROPÄISCHE NORM November 2002
ICS 37.020; 35.180; 33.160.60
English version
Electronic projection -
Measurement and documentation of key performance criteria
Part 1: Fixed resolution projectors
(IEC 61947-1:2002)
Projection électronique - Elektronische Projektion -
Mesure et documentation des critères Messung und Dokumentation wichtiger
principaux de performance Leistungsmerkmale
Partie 1: Projecteurs à résolution fixe Teil 1: Projektoren fester Auflösung
(CEI 61947-1:2002) (IEC 61947-1:2002)

This European Standard was approved by CENELEC on 2002-10-01. 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, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,

Netherlands, Norway, Portugal, Slovakia, 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 61947-1:2002 E
---------------------- Page: 2 ----------------------
EN 61947-1:2002 - 2 -
Foreword

The text of document 100/501/FDIS, future edition 1 of IEC 61947-1, prepared by 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 61947-1 on 2002-10-01.
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) 2003-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-10-01
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 and ZA are normative and annexes C, E, F, G, H and I are

informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 61947-1:2002 was approved by CENELEC as a European

Standard without any modification.
__________
---------------------- Page: 3 ----------------------
- 3 - EN 61947-1:2002
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
1) 2)
IEC 61947-2 - Electronic projection - Measurement EN 61947-2 2002
and documentation of key performance
criteria
Part 2: Variable resolution projectors
1) 2)
IEC 61966-4 - Multimedia systems and equipment - EN 61966-4 2000
Colour measurement and management
Part 4: Equipment using liquid crystal
display panels
1) 2)
IEC 61966-5 - Part 5: Equipment using plasma display EN 61966-5 2001
panels
1) 2)
ISO 3741 - Acoustics - Determination of sound EN ISO 3741 1999
power levels of noise sources using
sound pressure - Precision methods for
reverberation rooms
1) 2)
ISO 7779 - Acoustics EN ISO 7779 2001
Measurement of airborne noise emitted
by information technology and
telecommunications equipment
Undated reference.
Valid edition at date of issue.
---------------------- Page: 4 ----------------------
INTERNATIONAL IEC
STANDARD
61947-1
First edition
2002-08
Electronic projection –
Measurement and documentation
of key performance criteria –
Part 1:
Fixed resolution projectors
 IEC 2002  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, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue
---------------------- Page: 5 ----------------------
– 2 – 61947-1  IEC:2002(E)
CONTENTS

FOREWORD .......................................................................................................................... 3

INTRODUCTION ....................................................................................................................4

1 Scope .............................................................................................................................. 5

2 Normative references....................................................................................................... 5

3 Definitions........................................................................................................................ 6

4 General requirements......................................................................................................10

5 Light output measurement and specification ....................................................................11

5.1 Light output specifications......................................................................................12

5.2 Light output uniformity............................................................................................13

5.3 Contrast ratio.........................................................................................................13

5.4 Light transmission for fixed resolution projection systems: liquid-crystal

imaging devices (LCD) used with an overhead projector (OHP) ..............................13

5.5 Small area contrast ratio for alternating black and white pixel lines .........................14

6 Fixed resolution projectors characteristics .......................................................................15

6.1 Displayable format (IEC resolution) ........................................................................15

6.2 Aspect ratio ...........................................................................................................15

6.3 Viewing angle (half/gain) specification for devices with an integral screen...............15

6.4 Input signal format compatibility .............................................................................16

6.5 Response time.......................................................................................................16

6.6 Colour measurements ............................................................................................16

6.7 Number of colours .................................................................................................17

6.8 Keystone correction ...............................................................................................17

7 Range of focus and image size........................................................................................17

8 Audio characteristics.......................................................................................................18

9 Light source specification................................................................................................18

10 Maximum acoustical noise level ......................................................................................18

11 Power consumption.........................................................................................................18

12 Weight ............................................................................................................................18

13 Dimensions.....................................................................................................................19

14 Sync hierarchy – Recommended practice ........................................................................19

Annex A (normative) Figures ................................................................................................20

Annex B (normative) Pattern generator specifications ...........................................................23

Annex C (informative) Considerations in formulating this standard ........................................24

Annex D (normative) Complete sample specification.............................................................26

Annex E (informative) Conversion equations.........................................................................27

Annex F (informative) Possible causes of photometric measurement errors ..........................28

Annex G (informative) Photometer precision and veiling glare ...............................................29

Annex H (informative) Light measuring devices.....................................................................31

Annex I (Informative) Figure of merit for projection display colour gamut ...............................32

Bibliography ..........................................................................................................................34

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61947-1  IEC:2002(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC PROJECTION –
MEASUREMENT AND DOCUMENTATION OF
KEY PERFORMANCE CRITERIA
Part 1: Fixed 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 61947-1 was prepared by 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
100/501/FDIS 100/537/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.

The committee has decided that the contents of this publication will remain unchanged until

2004. At that date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
---------------------- Page: 7 ----------------------
– 4 – 61947-1  IEC:2002(E)
INTRODUCTION

This standard was developed to ensure a common, meaningful description of key performance

parameters for fixed resolution 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 fixed 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 fixed resolution projectors and is not intended to provide design goals for manufacturers of

such equipment.
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61947-1  IEC:2002(E) – 5 –
ELECTRONIC PROJECTION –
MEASUREMENT AND DOCUMENTATION OF
KEY PERFORMANCE CRITERIA
Part 1: Fixed resolution projectors
1 Scope
This part of IEC 61947 specifies requirements for measuring and documenting key

performance parameters for electronic projection systems with fixed resolution projectors in

which the light source and projection/magnification optics are an integral part of the system

(i.e. individual pixel light sources or matrix displays such as liquid crystal, DMD, plasma, or

electroluminescent panels). It also applies to LCD panels or other fixed resolution imaging

devices themselves that are used with overhead projectors.

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 fixed resolution projectors that are primarily designed for use with

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 in ITU/R

publications, which are not within the scope of this standard. In this standard, all of these signals are referred to as

television video (TV video).

Projectors and projection systems with multiple variable resolutions, such as cathode-ray tubes

and laser projectors, are not fully addressed by this standard, and reference should be made to

IEC 61947-2.

A discussion of considerations taken into account in the development of this standard appears

in Annex C.
2 Normative references

The following referenced documents are indispensable for the application of this document. For

dated references, only the edition cited applies. For undated references, the latest edition of

the referenced document (including any amendments) applies.

IEC 61947-2, Electronic projection – Measurement and documentation of key performance

criteria – Part 2: Variable resolution projectors

IEC 61966-4, Multimedia systems and equipment – Colour measurement and management –

Part 4: Equipment using liquid crystal display panels

IEC 61966-5, Multimedia systems and equipment – Colour measurement and management –

Part 5: Equipment using plasma display panels

ISO 3741, Acoustics – Determination of sound power levels of noise sources using sound

pressure – Precision methods for reverberation rooms

ISO 7779, Acoustics – Measurement of airborne noise emitted by information technology and

telecommunication equipment
---------------------- Page: 9 ----------------------
– 6 – 61947-1  IEC:2002(E)
3 Definitions
For the purposes of this standard, 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

NOTE 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, the 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

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 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.

---------------------- Page: 10 ----------------------
61947-1  IEC:2002(E) – 7 –

Alternatively, a successful numerical approximation has been derived by C. S. McCamy [2]. Given CIE 1931

3 2

coordinates (x, y), McCamy's approximation is CCT = 437 n + 3601 n + 6831 n + 5517 where

n = (x - 0,3320)/(0,1858 - y). This approximation, the second of three proposed, is close enough for any practical

use between 2000 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 colorimeters will report 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
stop number
the reciprocal value of the relative aperture

NOTE Relative aperture of a photographic lens: twice the numerical aperture where the numerical aperture is the

sine of the semi-angle subtended by the exit pupil at the focal plane. For photographic applications, the aperture is

equivalent (within a 1/3 stop) to the ratio of the diameter of the entrance pupil to the focal length. (See ISO 517:

1996(E) Photography – Apertures and related properties pertaining to photographic lenses – Designations and

measurements.)
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.

NOTE 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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– 8 – 61947-1  IEC:2002(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 in a given direction is the luminous intensity per unit of projected area of any

surface, as viewed for that direction
Unit: candela per square metre (cd/m²).
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

---------------------- Page: 12 ----------------------
61947-1  IEC:2002(E) – 9 –
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
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 a

perfect reflecting diffuser, (preferably a calibrated tablet of pressed barium sulfate, as specified

in CIE 38: 1977, Section 12.2.5 or pressed polytetrafluoroethylene (PTFE) powder, see CIE

135/6: 1999) 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

viewing position is the reference position for measurements, and is specified by the standard

viewing distance measured from the horizontal plane on which the display under test is placed

3.36
steradian

Sl unit of solid angle: solid angle that, having its vertex at the centre of a sphere, cuts off an

area of the surface of the sphere equal to that of a square with sides of length equal to the

radius of the sphere
[IEV 845-01-20 (ISO 31/1-2.1,1978)]
---------------------- Page: 13 ----------------------
– 10 – 61947-1  IEC:2002(E)
3.37
transmission

measure of the amount of light that is transmitted by an optical medium relative to the total

amount of incident light
3.38
vertical lines
number of active lines in a picture
3.39
viewing angle/half gain

angle between the direction of maximal reflection and the direction where the luminance drops

to 50 % of its value
NOTE This quantity should be measured in the centre of the viewing screen.
3.40
visible light

electromagnetic radiation to which the human observer is sensitive through the visual

sensations that arise from the stimulation of the retina of the eye

NOTE The spectral range is typically considered to have a range of 380 nm to 780 nm (3 800 Å to 7 800 Å).

3.41
zoom lens
focusing lens that has a second, primary adjustment for focal length

NOTE This capability allows smaller or larger image sizes from a fixed projection distance. The zoom ratio is

typically stated in a range of screen width/projection distance ratios, for example a 1:2 to 1:4 zoom lens could focus

a 10 m or a 5 m wide image from a 20 m throw distance.
4 General requirements

This part of IEC 61947 is intended to specify a complete description of the product. In

accordance with these intentions, a complete specification (see example in Annex D) shall be

used in product descriptions. If a particular specified measurement was not performed, the

complete specification shall include the text “not measured” or “data not available” under that

measurement section.

NOTE The use of partial specifications in product descriptions is not recommended since many of the specified

measurements are interrelated (e.g. resolution and light output).
All measurements and specifications shall conform to the following:

• the measurements of light output, visual resolution, and blanking found in this standard are

interrelated and shall be measured and specified as a set;

• the parameters and measurement criteria specified in this document allow for a wide variety

of equipment performance. Secondary, non-conforming specifications are permitted to

allow flexibility for special features of various products and technologies, but shall be

displayed in the same type face font and density at least 25 % smaller in size;

• a sample from normal production runs shall be used to establish the specifications. Results

from measurements of pre-production and prototype units shall be identified as preliminary

specifications;

• the sample units shall not be adjusted or enhanced beyond normal production parameters,

especially in a way that would reduce the normal operating life of any component or of the

entire display;

• all optical, electrical focus, and convergence controls shall be adjusted for the sharpest

display over the largest possible percentage of the illuminated area, using appropriate

patterns from an internal or external test generator as needed;
---------------------- Page: 14 ----------------------
61947-1  IEC:2002(E) – 11 –

• the equipment shall be allowed to stabilize without further adjustment for a minimum

of 15 min, at a nominal ambient room temperature of (23 ± 5) °C, before taking
measurements;

NOTE Measurement could also be taken after 1 h of operation with all covers in place, white raster, as

intended for normal use.

• measurements shall take place in a lightproof room where the only source of illumination is

the projector. Less than 1 % of the light on the screen shall be from any source other than

the projector. The projector should be operated with all covers in place as in
...

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