1、BSI Standards Publication Electronic display devices Part 3-2: Evaluation of optical characteristics Mura PD IEC/TR 62977-3-2:2016National foreword This Published Document is the UK implementation of IEC/TR 62977-3-2:2016. The UK participation in its preparation was entrusted to Technical Committee
2、EPL/47, Semiconductors. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 201
3、6. Published by BSI Standards Limited 2016 ISBN 978 0 580 89485 5 ICS 31.120; 31.260 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 January 2016. Amendmen
4、ts/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TR 62977-3-2:2016 IEC TR 62977-3-2 Edition 1.0 2016-01 TECHNICAL REPORT Electronic display devices Part 3-2: Evaluation of optical characteristics Mura INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 31.120; 31.260 ISB
5、N 978-2-8322-3118-0 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside PD IEC/TR 62977-3-2:2016 2 IEC TR 62977-3-2:2016 IEC 2016 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 N
6、ormative references 7 3 Terms and definitions 7 4 Standard measuring conditions 8 4.1 Standard measuring conditions . 8 4.1.1 Standard measuring environmental conditions . 8 4.1.2 Standard measuring darkroom conditions 8 4.2 Light measuring device (LMD) . 8 4.3 Measuring setup . 9 4.4 Test signal 9
7、4.5 Measuring conditions 10 5 Standard evaluation method 10 5.1 Measurement data processing method 10 5.2 Measurement data processing flow . 10 5.2.1 General . 10 5.2.2 Median filter process . 11 5.2.3 Transformation to opponent colour space from CIE XYZ 12 5.2.4 Convolution with the contrast sensit
8、ivity function (CSF) of the human visual system . 12 5.2.5 Transformation to CIE XYZ from the opponent colour space 12 5.2.6 Transformation to CIELAB from CIE XYZ . 12 5.2.7 a* correction 13 5.3 Mura evaluation method 13 5.3.1 General . 13 5.3.2 Lightness mura evaluation . 13 5.3.3 Chroma mura evalu
9、ation 15 5.3.4 Mura evaluation . 16 5.3.5 Measurement report 16 6 Actual example 17 6.1 General . 17 6.2 Evaluation objects . 17 6.3 Subjective evaluation 17 6.4 Evaluation by the method indicated inthis document using apparatus 18 6.5 Correlation between subjective evaluation and mura evaluation va
10、lue 19 Annex A (informative) S-CIELAB model . 20 A.1 General . 20 A.2 S-CIELAB model . 20 A.3 Spatial sensitivity function model (two-dimensional CSF model) 20 Annex B (informative) Type of mura . 24 B.1 General . 24 B.2 Classification of mura . 24 Annex C (informative) Use case of a mura evaluation
11、 value . 26 C.1 General . 26 PD IEC/TR 62977-3-2:2016IEC TR 62977-3-2:2016 IEC 2016 3 C.2 Example of a use case of a mura evaluation value 26 Annex D (informative) Various mura measurement methods 27 D.1 General . 27 D.2 Comparison of mura evaluation standards 27 Bibliography 28 Figure 1 Measuring l
12、ayout 9 Figure 2 Example of input signal 10 Figure 3 Measurement data processing flow adopting the S-CIELAB model . 11 Figure 4 Concept diagram of real-space information integration . 14 Figure 5 3 3 neighbourhood domain 15 Figure 6 Evaluation objects in a dark room 17 Figure 7 CSF filter images in
13、opponent colour space . 18 Figure 8 Correlation of mura evaluation value and ITU-R subjective evaluation values . 19 Figure A.1 Flowchart of S-CIELAB calculation 20 Figure A.2 Two-dimensional CSF model 21 Figure A.3 Examples of the convolution of a two-dimensional CSF filter for illusion 23 Figure B
14、.1 Classification of mura by forms and/or causes 25 Table 1 Example of reported criteria of two-dimensional LMD 9 Table 2 Example of measurement results for a display screen uniformity . 16 Table 3 ITU-R quality and impairment scales . 17 Table 4 Subjective evaluation results . 18 Table 5 Evaluation
15、 results by apparatus . 19 Table A.1 Parameters for each axis of the opponent colour space . 21 Table C.1 Example of a use case of a mura evaluation value . 26 Table C.2 Example of subjects to evaluate . 26 Table D.1 Comparison chart of various mura measurement standards . 27 PD IEC/TR 62977-3-2:201
16、6 4 IEC TR 62977-3-2:2016 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRONIC DISPLAY DEVICES Part 3-2: Evaluation of optical characteristics Mura FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national elect
17、rotechnical 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 Specific
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21、ternational 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
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23、 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 certificat
24、ion 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,
25、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
26、 in this publication. Use of the referenced publications is indispensable for the correct application of this publication. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a technical report when it has col
27、lected data of a different kind from that which is normally published as an International Standard, for example “state of the art“. IEC TR 62977-3-2, which is a technical report, has been prepared by IEC technical committee 110: Electronic display devices. The text of this technical report is based
28、on the following documents: Enquiry draft Report on voting 110/674A/DTR 110/701A/RVC Full information on the voting for the approval of this technical report 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
29、, Part 2. PD IEC/TR 62977-3-2:2016IEC TR 62977-3-2:2016 IEC 2016 5 A list of all parts in the IEC 62977 series, published under the general title Electronic display devices, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until t
30、he stability date indicated on the IEC website 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
31、. 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. PD IEC/TR 62977-3-2:2016 6 IEC TR 62977-3-2:
32、2016 IEC 2016 INTRODUCTION Electronic displays, for example liquid crystal displays (LCDs), plasma display panels (PDPs), organic light emission displays (OLEDs), and so on, have grown popular as displays for high- quality images. It is therefore increasingly important to measure the image quality o
33、f electronic displays. One factor degrading the image quality is non-uniformity, known as mura. The mura is classified into three types. The first is luminance mura, the second is colour mura. The third is called merely “mura” and includes luminance mura and colour mura simultaneously. It is impossi
34、ble to recognize luminance mura and colour mura as completely separate objects. Various measurement methods about luminance mura and colour mura have been reported in various academic conferences. There are also some standards for these mura. For example, uniformity of luminance and chromaticity are
35、 specified in IEC IEC 61747-30-1, SEMU (SEMI mura) is specified in SEMI D31-0213 and uniformity measurement is specified in IDMS ver.1.03 sec. 8. However there is no report which clearly provides the quantitative method for the mura that is called merely “mura” (see Annex D). Therefore the majority
36、of electronic display manufacturers are still using the limit sample for visual inspection. This Technical Report, which intends to verify one mura measurement method, shows the detailed mura measurement method and its inspection experiment results. The International Electrotechnical Commission (IEC
37、) draws attention to the fact that it is claimed that compliance with this document may involve the use of a patent. IEC takes no position concerning the evidence, validity and scope of this patent right. The holder of this patent right has assured the IEC that he/she is willing to negotiate licence
38、s either free of charge or under reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of the holder of this patent right is registered with IEC. Information may be obtained from: Sony Corporation 1-7-1 Konan, Minato-ku, Tokyo, 10
39、8-0075 Japan Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. IEC shall not be held responsible for identifying any or all such patent rights. ISO (www.iso.org/patents) and IEC (http:/patents.iec.c
40、h) maintain on-line database of patents relevant to their standards. Users are encouraged to consult the databases for the most up to date information concerning patents. PD IEC/TR 62977-3-2:2016IEC TR 62977-3-2:2016 IEC 2016 7 ELECTRONIC DISPLAY DEVICES Part 3-2: Evaluation of optical characteristi
41、cs Mura 1 Scope This part of IEC 62977, which is a Technical Report, provides an optical measuring method of mura for electronic displays. It defines general measuring procedures for mura measurement and an evaluation method of electronic displays. 2 Normative references The following documents, in
42、whole or in part, are 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. Void. 3 Terms and definitions For the purposes
43、of this document, the following terms and definitions apply. 3.1 lightness mura luminance unevenness whose lightness differs partially from the background lightness of a display screen with the exception of pixel defects 3.2 chroma mura colour unevenness whose chroma differs partially from the backg
44、round of a display screen with the exception of pixel defects 3.3 mura both luminance and colour unevenness whose lightness and chroma differ partially from the background of a display screen with the exception of pixel defects Note 1 to entry: In general, lightness mura and chroma mura exist simult
45、aneously. Mura evaluation shows the degree of screen uniformity considering how both lightness mura and chroma mura affect human perception. 3.4 lightness edge area ratio of lightness gradient area that is rapidly changed lightness to whole screen area 3.5 lightness mura area area of uneven lightnes
46、s that is bright or dark regions against the background of a display screen 3.6 maximum lightness difference maximum lightness difference from the average L *of a whole display screen PD IEC/TR 62977-3-2:2016 8 IEC TR 62977-3-2:2016 IEC 2016 3.7 chroma edge area ratio of the chroma gradient area tha
47、t is rapidly changed from the chroma to the whole screen area 3.8 chroma mura area area of uneven chroma that is coloured regions against the background of a display screen 3.9 maximum chroma maximum C *value in a whole display screen 3.10 opponent colour space three dimensions that are described as
48、 w/k, r/g, and b/y channels Note 1 to entry: The w/k channel is a luminance component. The r/g and b/y channels are a chromaticity component of red to green, blue to yellow, respectively. 4 Standard measuring conditions 4.1 Standard measuring conditions 4.1.1 Standard measuring environmental conditi
49、ons The standard measuring environmental conditions specified in IEC 62341-6-1:2009, 5.1, should be applied. 1 14.1.2 Standard measuring darkroom conditions The standard measuring darkroom conditions specified in IEC 62341-6-1:2009, 5.2, should be applied. 1 4.2 Light measuring device (LMD) The LMD used for measurements of the displays should be checked for the following criteria and specified accordingly: sensitivity of the measured quantity; errors
