IEC 61947-2:2001

INTERNATIONAL IEC
STANDARD
61947-2
First edition
2001-09
Electronic projection –
Measurement and documentation
of key performance criteria –
Part 2:
Variable resolution projectors
Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.
Consolidated editions
The IEC is now publishing consolidated versions of its publications. For example,
edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
amendments 1 and 2.
Further information on IEC publications
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology. Information relating to
this publication, including its validity, is available in the IEC Catalogue of
publications (see below) in addition to new editions, amendments and corrigenda.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is also available from the following:
• IEC Web Site (www.iec.ch)
• Catalogue of IEC publications
The on-line catalogue on the IEC web site (www.iec.ch/catlg-e.htm) enables
you to search by a variety of criteria including text searches, technical
committees and date of publication. On-line information is also available on
recently issued publications, withdrawn and replaced publications, as well as
corrigenda.
• IEC Just Published
This summary of recently issued publications (www.iec.ch/JP.htm) is also
available by email. Please contact the Customer Service Centre (see below) for
further information.
• Customer Service Centre
If you have any questions regarding this publication or need further assistance,
please contact the Customer Service Centre:
Email: custserv@iec.ch
Tel: +41 22 919 02 11
Fax: +41 22 919 03 00
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

– 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

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

– 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 publi
...