I E C TS 62 5-5-2 ® Edition 201 6-04 TE C H N I C AL S P E C I F I C ATI ON colour i n sid e F l exi bl e d i s pl ay d e vi ces – P art 5-2 : M eas u ri n g m eth od s of opti cal ch aracteri s ti cs from th e van tag e poi n t IEC TS 6271 5-5-2:201 6-04(en) for cu rved d i s pl ays Copyright International Electrotechnical Commission TH I S P U B L I C ATI O N I S C O P YRI G H T P RO TE C T E D C o p yri g h t © I E C , G e n e va , S w i tze rl a n d All rights reserved Unless otherwise specified, 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 either IEC or IEC's member National Committee in the country of the requester If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information IEC Central Office 3, rue de Varembé CH-1 21 Geneva 20 Switzerland Tel.: +41 22 91 02 1 Fax: +41 22 91 03 00 info@iec.ch www.iec.ch Abo u t th e I E C The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies Ab o u t I E C p u b l i c a ti o n s The technical content of IEC publications is kept under constant review by the IEC Please make sure that you have the latest edition, a corrigenda or an amendment might have been published I E C C atal og u e - webs tore i ec ch /catal og u e E l ectroped i a - www el ectroped i a org The stand-alone application for consulting the entire bibliographical information on IEC International Standards, Technical Specifications, Technical Reports and other documents Available for PC, Mac OS, Android Tablets and iPad The world's leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and French, with equivalent terms in additional languages Also known as the International Electrotechnical Vocabulary (IEV) online I E C pu bl i cati on s search - www i ec ch /s earch pu b I E C G l o s sary - s td i ec ch /g l os s ary The advanced search enables to find IEC publications by a variety of criteria (reference number, text, technical committee,…) It also gives information on projects, replaced and withdrawn publications 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002 Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR I E C J u s t P u bl i s h ed - webstore i ec ch /j u s tpu bl i s h ed Stay up to date on all new IEC publications Just Published details all new publications released Available online and also once a month by email Copyright International Electrotechnical Commission I E C C u s tom er S ervi ce C en tre - webs tore i ec ch /cs c If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csc@iec.ch I E C TS 62 5-5-2 ® Edition 201 6-04 TE C H N I C AL S P E C I F I C ATI ON colour i n sid e F l exi bl e d i s pl ay d e vi ces – P art 5-2 : M eas u ri n g m eth od s of opti cal ch aracteri s ti cs from th e van tag e poi n t for cu rved d i s pl ays INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 31 20 ISBN 978-2-8322-3300-9 Warn i n g ! M ake s u re th at you obtai n ed th i s pu bl i cati on from an au th ori zed d i s tri bu tor ® Registered trademark of the International Electrotechnical Commission Copyright International Electrotechnical Commission –2– I EC TS 6271 5-5-2:201 © I EC 201 CONTENTS FOREWORD Scope Normative references Terms, definitions and abbreviations Terms and definitions Abbreviations Standard measuring equipment Video signal generator Non-contact LMD Standard measuring conditions Standard measuring environmental conditions Power supply Warm-up time Standard measuring dark room conditions 5 Adjustment of display modules Measuring geometry for vantage point 6.1 General 6.2 Measuring geometry in horizontal vantage point 6.3 Measuring geometry in vertical vantage point Measuring layout for viewing position 1 7.1 General 1 7.2 Measuring layout by moving LMD 1 7.3 Measuring layout by rotating the display module Minimum curvature radius for the measurement Screen visual angle 9.1 Screen visual angle of a flat display module 9.2 Screen visual angle of concave type display module Measuring methods of optical characteristics General 1 Measuring items Measuring point locations Test pattern 6 Measuring method 2.1 Measuring method at the screen centre position 2.2 Measuring method at viewing angle position Optical characteristics of white box by viewing angle 3.1 Luminance variation by viewing angle 3.2 Contrast ratio variation by viewing angle 3.3 Chromaticity variation by viewing angle 20 Optical characteristics of colour box by viewing angle 20 4.1 Colour gamut area variation by viewing angle 20 4.2 Chromaticity variation and Δ E by viewing angle 21 Uniformity and uniformity variation 22 5.1 General 22 5.2 Luminance uniformity and uniformity variation by viewing angle 23 5.3 Chromaticity uniformity and uniformity variation by viewing angle 23 Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 –3– Half-luminance and half-contrast viewing angle 23 6 6.1 Half-luminance viewing angle range 23 6.2 Half-contrast viewing angle range 24 Reporting 24 Requirements of reporting 24 Recommendations of measurement results reporting 25 Bibliography 30 Figure – Measuring layout for non-contact measurement Figure – Measuring geometry in horizontal vantage point (top view) Figure – Measuring geometry in vertical vantage point (side view) 1 Figure – Measuring geometry by horizontal viewing angles (top view) Figure – Measuring geometry by horizontal display directions (top view) Figure – Minimum concave type curvature radius for the measurement (top view) Figure – Screen visual angle of concave type display device (top view) Figure – 9-point locations for vantage-point measurement Figure – Nine white boxes for vantage-point measurement Figure – N ine measuring points for vantage-point black measurement Figure 1 – N ine-colour boxes of R, G and B for vantage-point measurement Figure – Measuring directions of vantage points Figure – Measuring directions (right side) by viewing angle o , o , 30 o and 45 o Figure – Measuring directions (right side) by viewing angle 0°, 5°, 30° and 45° (front upper view) Figure – Measuring method for half-luminance viewing angle 23 Table – Example of measurement results for the optical characteristics 26 Table – Calculation results from the measurement data of Table 28 Copyright International Electrotechnical Commission –4– I EC TS 6271 5-5-2:201 © I EC 201 I NTERNATI ONAL ELECTROTECHNI CAL COMMISSI ON F L E XI B L E D I S P L AY D E VI C E S – P a rt -2 : M e a s u ri n g m e t h o d s o f o p t i c a l c h a c t e ri s t i c s fro m t h e v a n t a g e p o i n t fo r c u rv e d d i s p l a ys FOREWORD ) The I nternati onal Electrotechnical Com mi ssi on (I EC) is a worl d wi d e organizati on for standard izati on comprisi ng all nati onal electrotechnical com mi ttees (I EC N ati onal Com mittees) The object of I EC i s to promote i nternati onal co-operati on on al l q u esti ons concerni ng stand ard izati on i n the electrical and el ectronic fi el d s To th is end and in ad di ti on to oth er acti vi ti es, I EC pu blishes I n ternati onal Stan d ards, Technical Speci fi cati ons, Technical Reports, Pu bl icly Avail abl e Specificati ons (PAS) and Gui d es (hereafter referred to as “I EC Pu blicati on(s)”) Th ei r preparati on is entru sted to technical committees; an y I EC N ati onal Committee i nterested i n th e su bject d eal t wi th may parti ci pate i n thi s preparatory work I nternati on al , governmen tal and nongovernmental organ izati ons l iaisi ng wi th the I EC al so participate i n this preparati on I EC coll aborates cl osel y with the I n ternati onal Organizati on for Stand ard izati on (I SO) in accordance wi th cond i ti ons d etermined by ag reement between the two organizati ons 2) The formal decisions or ag reements of I EC on technical m atters express, as n earl y as possible, an i nternati on al consensus of opi ni on on the rel evant su bjects si nce each technical committee h as represen tati on from all i nterested I EC N ati onal Commi ttees 3) I EC Pu blicati ons h ave the form of recommend ati ons for internati onal u se and are accepted by I EC N ati onal Com mittees i n that sense Whi le all reasonabl e efforts are mad e to ensu re that the techn ical content of I EC Pu blicati ons is accu rate, I EC can not be hel d responsi bl e for the way in whi ch they are used or for any misinterpretati on by an y end u ser 4) I n ord er to promote i nternational u ni formi ty, I EC N ati onal Commi ttees und ertake to appl y I EC Publications transparentl y to the maximu m extent possi bl e i n thei r nati onal and regi onal pu blicati ons Any di vergence between any I EC Pu bl icati on and th e correspond i ng nati onal or regional publi cation shal l be cl earl y i n di cated in the l atter 5) I EC i tsel f d oes n ot provi d e an y attestation of conformity I nd epend ent certi ficati on bod ies provi d e conformity assessment services and , in some areas, access to I EC m arks of conform i ty I EC i s not responsi ble for any services carried ou t by i nd epend ent certification bodi es 6) All users should ensu re that they have the l atest edi ti on of this pu blicati on 7) N o li abili ty shal l attach to I EC or i ts di rectors, empl oyees, servants or ag ents incl u di ng i nd ivi du al experts and m embers of i ts tech ni cal comm ittees and I EC N ati onal Committees for any personal i nju ry, property d amag e or other d amage of any natu re whatsoever, whether di rect or ind i rect, or for costs (includ i ng l eg al fees) and expenses arising out of the pu blicati on, use of, or reliance u pon, thi s I EC Pu bl ication or an y other I EC Pu blicati ons 8) Attention is d rawn to the N ormative references ci ted in this pu bl icati on U se of the referenced pu blicati ons is i nd i spensabl e for th e correct appli cation of th is publicati on 9) Attention is d rawn to the possibili ty that some of the el ements of thi s I EC Pu bl icati on may be th e su bj ect of paten t ri ghts I EC shal l n ot be held responsi bl e for i d enti fyi ng any or all such paten t ri ghts The main task of I EC technical committees is to prepare International Standards I n exceptional circumstances, a technical committee may propose the publication of a technical specification when • • the required support cannot be obtained for the publication of an I nternational Standard, despite repeated efforts, or the subject is still under technical development or where, for any other reason, there is the future but no immediate possibility of an agreement on an International Standard Technical specifications are subject to review within three years of publication to decide whether they can be transformed into I nternational Standards I EC TS 6271 5-5-2, which is a technical specification, has been prepared by I EC technical committee 1 0: Electronic display devices Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 –5– The text of this standard is based on the following documents: Enq ui ry d raft Report on voti ng 1 0/71 5/DTS 1 0/739/RVC Full information on the voting for the approval of this technical specification can be found in the report on voting indicated in the above table This publication has been drafted in accordance with the ISO/I EC Directives, Part A list of all parts in the I EC 6271 series, published under the general title Flexible display devices , can be found on the IEC website The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the I EC website under "http: //webstore iec ch" in the data related to the specific publication At this date, the publication will be • • • • • transformed into an I nternational standard, reconfirmed, withdrawn, replaced by a revised edition, or amended I M P O R T AN T th at it – Th e co n ta i n s u n d e rs t a n d i n g c o l o u r p ri n t e r Copyright International Electrotechnical Commission of 'col ou r c o l o u rs i ts i n si d e' wh i ch co n te n ts l og o a re U s e rs on th e c o ve r p a g e c o n s i d e re d sh ou l d to t h e re fo re o f th i s be p ri n t p u b l i ca ti o n u s e fu l th i s fo r i n d i c a te s th e d ocu m en t c o rre c t using a –6– I EC TS 6271 5-5-2:201 © I EC 201 F L E XI B L E D I S P L AY D E VI C E S – P a rt -2 : M e a s u ri n g m e t h o d s o f o p t i c a l c h a c t e ri s t i c s fro m th e v a n t a g e p o i n t fo r c u rv e d d i s p l a ys S cope This part of I EC 6271 5, which is a technical specification, specifies the general rules and the details of optical measuring methods from a fixed point (the so-called vantage point) for curved emissive and transmissive type displays such as OLED and LCD in dark room conditions This document focuses on concave shape large screen displays (non-portable) around a horizontal and/or vertical axis with fixed or variable curvature radius The measuring method stipulated in this technical specification is applied to the curved display modules under the following states: • • • • • • • • • vantage-point luminance variation by viewing angles vantage-point contrast ratio variation by viewing angles vantage-point chromaticity variation of white colour by viewing angles vantage-point colour gamut area variation by viewing angles vantage-point chromaticity variation of primary colours by viewing angles luminance uniformity and its uniformity variation by viewing angles chromaticity uniformity and its uniformity variation by viewing angles viewing angle of half-luminance viewing angle of half-contrast N o rm a t i v e re fe re n c e s 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 I EC 6271 5-1 -1 , Flexible display devices – Part 1-1: Terminology and letter symbols T e rm s , 3.1 d e fi n i t i o n s a n d a b b re v i a t i o n s T e rm s a n d d e fi n i t i o n s For the purposes of this document, the terms and definitions given in I EC 6271 5-1 -1 as well as the following apply 3.1 c u rv e d d i s p l a y display that has a single curvature radius along the screen horizontally and/or vertically N ote to entry: The cu rvature radi us of each screen positi on i s fi xed by the manu facturer or u ser controll abl e cu rvatu re radi us N ote to entry: The d i recti on of cu rvatu re mi ght be concave or convex from the vi ewer’s posi ti on Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 –7– N ote to entry: Th e cu rved screen d ispl ay is also cal l ed curved display, as i n cu rved TV and cu rved mon i tor van tage-poin t m easu rem ent test configuration in which measurements are taken at various measuring points on the display screen through a common observation point in space in front of the screen N ote to entry: The observer (at the viewi ng di stance D ) is at a fi xed poi nt, the so-cal led vantag e poi nt or viewi n g poin t, an d th en from that fi xed vantag e poin t, the an gl e of view from the screen centre to the corners is chan ged accord i ng to h u man viewi ng di recti ons toward the screen N ote to en try: I n thi s docum ent, the vantage point for the measu rement i s l ocated on the same horizontal pl ane as th e displ ay centre, and on a li n e between the d isplay centre an d th e d ispl ay’ s axis of rotati on 3 screen vi su al an gle maximum range of vantage-point viewing directions Ɵ VA measured from the vantage point towards the edges of the display N ote to entry: The h orizontal screen vi su al ang le is th e range of vantage-poi nt viewi n g d i recti ons between the l eft an d ri ght ed ges of the screen N ote to entry: The vertical screen visu al an gl e is the range of van tage-poi nt vi ewi ng di rections between the top and bottom ed ges of the screen vi ewing ang l e angle between the normal direction of the screen surface and the measurement or viewing direction N ote to entry: I f there is no i nd icati on abou t the screen posi ti on, the viewin g angl e is based on the screen centre N ote to entry: The h ori zon tal vi ewi n g ang le is the an gl e between the screen n ormal d i recti on and the van tage poi nt, both l yi ng on the same h orizontal plane N ote to entry: The vertical vi ewi ng angl e is the angl e between the screen normal d i recti on and the van tage poi nt, both l yi ng on the same verti cal plane l u mi nance vari ation by vi ewin g an gl e percent difference of display white luminance, between normal incidence (at 0° viewing angle) and a specific viewing angle at each screen measuring point or averaged over the screen measuring points contrast rati o vari ati on by vi ewin g an gl e percent difference of contrast ratio between normal incidence (at 0° viewing angle) and a specific viewing angle at each screen measuring point or averaged over the screen measuring points chromati ci ty vari ation by vi ewi ng ang l e chromaticity difference between normal incidence (at 0° viewing angle) and a specific viewing angle at each screen measuring point or averaged over the screen measuring points lu mi nance u n iform ity vari ation by vi ewi ng ang l e percent difference of display white luminance uniformity between normal incidence (at 0° viewing angle) and a specific viewing angle Copyright International Electrotechnical Commission –8– I EC TS 6271 5-5-2:201 © I EC 201 3.1 chromaticity uniformity variation by viewing angle difference of chromaticity uniformity at normal incidence (at 0° viewing angle) to the other viewing angle 3.1 half-luminance viewing angle horizontal viewing angle that has the half value of the luminance at the normal direction 3.1 1 half-contrast viewing angle horizontal viewing angle that has the half value of the contrast at the normal direction 3.2 Abbreviations For the purposes of this document, the following abbreviations apply APL CCT CI E CI ELAB DU T LMD 4.1 average picture level correlated colour temperature Commission I nternationale de I llumination) CI E 976 (L*a*b*) colour space device under test light measurement device l’Eclairage (I nternational Commission on Standard measuring equipment Video signal generator An analogue video signal generator or a digital video signal generator is used The signal characteristics shall match with the measured curved display module I nput signal, in this document, means pre-gamma signal and APL means post-gamma APL 4.2 Non-contact LMD For the purpose of vantage-point measurement, the non-contact LMD shall be used When using a non-contact LMD, a spectroradiometer or a non-contact colorimeter is installed, as shown in Figure The optical axis of the non-contact LMD should be normal in the case of measuring the centre of the display surface I n this document, for the purpose of vantagepoint measurement, the measuring distance lM from the LMD to the centre of the display screen shall be either the design viewing distance or V where V is the effective screen height of the display and H is the horizontally effective screen width of the display The design viewing distance might be recommended based on the display resolution and curvature radius The LMD colour measurements shall comply with the colour matching functions for the CI E 976 standard colorimetric observer Copyright International Electrotechnical Commission – 18 – 2.2 I EC TS 6271 5-5-2:201 © I EC 201 M easu rin g meth od at vi ewi ng an g le positi on At any measuring positions, the measuring points shall be the centre of rectangular white boxes According to the measuring positions, the viewing angles of the measurements shall be 0°, 5°, 30° and 45° from the perpendicular axis of the screen centre I n this case, the measuring distance is always the same, i.e V I n the viewing angle direction, the left-side or right-side direction of the perpendicular axis can be selected alternatively Figure shows the measuring directions from the 0° to the 45° viewing angle The directions for 5° and 30° are not drawn fully and omitted except the direction of the centre box The total number of measurements is 36 (= × 9) 45 ° 0° 5° 30° 45° IEC Fi gu re – M easu rin g d i rections (ri gh t side) by vi ewing ang l e o , o , 30 o an d 45 o Figure shows the front upper view of Figure 45 ° 45° 0° 5° 30° IEC Fi gu re – M easu ri ng di rection s (ri gh t sid e) by vi ewing an gl e 0°, 5°, 30° an d 45° (fron t u pper view) 6 3.1 Optical ch aracteri stics of wh ite box by vi ewing an g le Lu m in an ce vari ati on by vi ewi ng ang l e L Ɵ , which is the luminance at Ɵ° of the horizontal viewing angle, shall vary by viewing angle The luminance variation of the measuring point p by the viewing angle is as follows: Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 LVΘ_p where L Ɵ_p : – 19 – L0_p − LΘ_p x1 00 (%), where Θ = 5, 30, 45 (degree) L0_p = (4) luminance of white in cd/m of point p at viewing angle Ɵ The average (mean) and standard deviations of the luminance variation of points at viewing angle Ɵ are as follows: LVΘ = ∑ LVΘ_p (%), where Θ = 5, 30, 45 (degree) p =0 (5) SLVΘ = ∑ ( LVΘ_p − LVΘ ) p =0 (%), where Θ = 5, 30, 45 (degree) (6) Attention is drawn to the fact that Equation (5) is not a variation of the average luminance of points by the viewing angle because the changes in luminance of each point might compensate each other I t is just the 9-point average of Equation (4) at each viewing angle 6.3.2 Contrast ratio variation by viewing angle CR Ɵ , which is the contrast ratio at Ɵ ° of the horizontal viewing angle, shall vary by the viewing angle The contrast ratio variation of the measuring point p by the viewing angle is as follows: CRVΘ_p = where CR Ɵ_p : L Ɵ_p ( k): CR0_p − CRΘ_p x1 00 = CR0_p L0_p (W ) LΘ_p (W ) − L0_p ( k ) LΘ_p ( k ) x1 00 (%), where Θ = 5, 30, 45 (degree) (7) L0_p (W ) L0_p ( k ) contrast ratio of point p at viewing angle Ɵ luminance of black in cd/ m of point p at viewing angle Ɵ The average (mean) and standard deviations of the contrast ratio variations of points at viewing angle Ɵ are as follows: CRVΘ = ∑ CRVΘ_p (%), p =0 where Θ = 5, 30, 45 (degree) (8) SCRVΘ = ∑ (CRVΘ_p − CRVΘ ) p =0 (%), where Θ = 5, 30, 45 (degree) (9) Attention is drawn to the fact that Equation (8) is not a variation of the average contrast ratio of points by viewing angle because the changes in contrast ratio of each point might compensate each other I t is simply the 9-point average of Equation (7) at each viewing angle Copyright International Electrotechnical Commission – 20 – 6.3.3 I EC TS 6271 5-5-2:201 © I EC 201 Chromaticity variation by viewing angle The chromaticity of the white boxes is also calculated in the u’v’ colour space by averaging the colour coordinates of the points u’ Ɵ and v’Ɵ are the u’ and v’ colour coordinates of CI E 976 at Ɵ ° of the horizontal viewing angle The chromaticity of the white boxes shall vary by viewing angle The chromaticity variation of the measuring point p by the viewing angle in the u’v’ colour coordinate is as follows: ∆C w_Θ_p = (u ' w_Θ_p − u ' w_0_p ) + (v ' w_Θ_p − v ' w_0_p ) , where Θ = 5, 30, 45 (degree) (1 0) where u’ w_ Θ _p : u’ of the point p white box at viewing angle Ɵ v’ of the point p white box at viewing angle Ɵ v’ w_ Θ _p : The average (mean) and standard deviations of the chromaticity variation of the white box at viewing angle Ɵ are as follows: ∆C w_Θ = ∑ ∆Cw_Θ_p , p =0 where Θ = 5, 30, 45 (degree) (1 ) S ∆C w_Θ = 6.4 ∑ (ΔCw_Θ_p − ΔCw_Θ ) p =0 , where Θ = 5, 30, 45 (degree) (1 2) Optical characteristics of colour box by viewing angle 6.4.1 Colour gamut area variation by viewing angle The chromaticity of the display shall be measured at points described in Figure 1 from each viewing direction From the primary colour coordinates of measuring point p, the colour gamut area SΘ _p at viewing angle Ɵ is as follows: SΘ_p = [(u'r_Θ_p - u'b_Θ_p )(v'g_Θ_p - v'b_Θ_p )-(u'g_Θ_p where Θ = 0, 5, 30, 45 (degree) - u'b_Θ_p )(v'r_Θ_p - v'b_Θ_p )], (1 3) where u’ r_ Θ _p : u ’ v’ r_ Θ _p : u’ g_ Θ _p : v’ g_ Θ _p : u’ b_ Θ _p : v’ b_ Θ _p : of the point p red box at viewing angle Ɵ v’ of the point p red box at viewing angle Ɵ u’ of the point p green box at viewing angle Ɵ v’ of the point p green box at viewing angle Ɵ u’ of the point p blue box at viewing angle Ɵ v ’ of the point p blue box at viewing angle Ɵ The colour gamut area shall vary by viewing angle The colour gamut area variation by the viewing angle of the measuring point p can be calculated as follows: Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 SVΘ_p = – 21 – S0_p − SΘ_p , S0_p where Ɵ = 5, 30, 45 (degree) (1 4) The average (mean) and standard deviations of the colour gamut area variation at viewing angle Ɵ are as follows: SVΘ = ∑ SVΘ_p × 00 (%), p =0 where Θ = 5, 30, 45 (degree) (1 5) SSVΘ 6.4.2 ∑ (SVΘ_p − SVΘ ) p =0 = Chromaticity variation and ΔE (%), where Θ = 5, 30, 45 (degree) (1 6) by viewing angle As with the case of the white box, the chromaticity of the colour box also varies by viewing angle In the red colour box, the chromaticity variation of the measuring point p by viewing angle in the u’v’ colour coordinate is as follows: ∆Cr_Θ_p = (u ' r_Θ_p − u ' r_0_p ) + (v ' r_Θ_p − v ' r_0_p ) , where Θ = 5, 30, 45 (degree) (1 7) I n the same way, the chromaticity variation Δ Cg_ Θ _p for green and Δ Cb_Θ _p for blue is calculated at each 9-point by the viewing angle I n the red colour boxes, the average (mean) and standard deviations of the chromaticity variation at viewing angle Ɵ are as follows: ΔCr_Θ = ∑ ΔCr_Θ_p , where Θ = 5, 30, 45 (degree) p =0 (1 8) SΔCr_Θ = ∑ (ΔCr_Θ_p − ΔCr_Θ ) p =0 , where Θ = 5, 30, 45 (degree) (1 9) I n the same way, for the green and blue colour boxes, the average and standard variation of Δ Cg_ Θ _p and Δ Cb_ Θ _p ( Δ Cg_ Θ , SΔ Cg_Θ and Δ Cb_ Θ , SΔ Cb_ Θ ) can be calculated For the evaluation of Δ E, the CIELAB colour coordinates are used L* , a* and b* are defined as follows: Copyright International Electrotechnical Commission – 22 – I EC TS 6271 5-5-2:201 © I EC 201 Y L* r = 1 f r − 6, Y w X Y a * r = 500 f r − f r Yw X w , Y Z b * r = 200 f r − f r , Z Yw w f( s ) = s / f ( s ) = 7, 787 s + / 1 s > 0, 008856 s ≤ 0, 008856 (20) (21 ) (22) where Xr, Yr, Zr : CI E X, Y, Z tri-stimulus value in red colour box Xw , Yw , Zw : CI E X, Y, Z tri-stimulus value in white box For an example of the red colour, Δ E of measuring point p at viewing angle Θ is defined based on the o viewing angle asfollows: ∆ Er_ Θ_p = ( L* r_0_p − L* r_Θ_p ) + ( a * r_0_p − a * r_Θ_p ) + ( b * r_0_p − b * r_Θ_p ) , where Θ = 5, 30, 45 (degree) (23) where L* r_0_p , a* r_0_p , b* r_0_p : L* , a* and b* * of the measuring point p at viewing angle 0° L* r_ Θ _p , a* r_ Θ _p , b* r_ Θ _p : L* , a* and b* of the measuring point p at viewing angle Ɵ I n the same way, Δ Eg_Θ _p for green and Δ Eb_Θ _p for blue are calculated at each 9-point by viewing angle I n the red colour boxes, the average (mean) and standard deviations of Δ Er_Θ _p at viewing angle Ɵ are as follows: ∆ Er_Θ = ∑ ∆ Er_Θ_p , p =0 where Θ = 5, 30, 45 (degree) (24) S ∆ Er_Θ = ∑ ( ∆ Er_Θ_p − ∆ Er_Θ ) p =0 , where Θ = 5, 30, 45 (degree) (25) I n the same way, for the green and blue colour boxes, the average and standard variation of Δ Eg_ Θ _p and Δ Eb_ Θ _p ( Δ Eg_ Θ , SΔ Eg _Θ and Δ Eb_ Θ , SΔ Eb_ Θ ) can be measured 6 5.1 U n i form i ty and u n iform i ty vari ation Gen eral Uniformity and uniformity variation for luminance and chromaticity shall be evaluated using the white box Copyright International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 6.5.2 – 23 – Luminance uniformity and uniformity variation by viewing angle Ɵ is the luminance uniformity at Ɵ ° of viewing angle Luminance uniformity variation at Ɵ ° of viewing angle is obtained as follows: LU LUΘ = min( LΘ _ 0, LΘ _ 1, LΘ _ 2, , LΘ _ ) × 00 (%) where Θ = 5,30, 45( degree ) max (LΘ _ 0, LΘ _ 1, LΘ _ 2, , LΘ _ ) LUVΘ 6.5.3 LU = − LU LUΘ (26) × 00 where Θ = 5,30, 45( degree ) (27) Chromaticity uniformity and uniformity variation by viewing angle Chromaticity uniformity at viewing angle Ɵ can be calculated with the maximum Δ u’v’ based on the colour coordinate of the centre white box The chromaticity uniformity variation Δ CUƟ at viewing angle Ɵ is obtained as follows: CUΘ ( ) = max ( uΘ' _ − uΘ' _ ) + vΘ' _ − vΘ' _ ~ ( Θ' _ − u ' uΘ _0 )2 + ( Θ' _ − v ' vΘ where Θ = 5,30, 45( degree ) ∆CUΘ = 6.6 6.6.1 CU0 − CUΘ , where Θ = 5, 30, 45 (degree) _0 )2 (28) (29) Half-luminance and half-contrast viewing angle Half-luminance viewing angle range Each luminance at the front, and left side and right side is calculated by averaging only luminances of white boxes number 0, 6, in a horizontal centre line, as in Figure Measuring boxes Left half-luminance viewing angle range Ɵ H L-R Ɵ H L-L l M = 3V Ri gh t h al f-l u minance viewi n g angl e rang e IEC Figure – Measuring method for half-luminance viewing angle LΘ where L Θ H L-L : Copyright International Electrotechnical Commission HL −L = ( L0_0 + L0_6 + L0 luminance at viewing angle Θ H L-L _8 ) = LΘ HL −L _0 + LΘ HL−L _6 + LΘ HL −L _8 (30) – 24 – I EC TS 6271 5-5-2:201 © I EC 201 LΘ HL R = ( L0_0 + L0_6 + L0_8 ) = LΘ HL R _0 + LΘ HL R _6 + LΘ HL R _8 − where − − − (31 ) luminance at viewing angle Θ H L-R L Θ H L-R: Ɵ H L-LR is the viewing angle range of the half-luminance compared to the front luminance I t is calculated by adding the left-side and right-side half-luminance viewing angles ΘHL −LR = ΘHL −L + ΘHL −R where Ɵ H L-L : Ɵ H L-R : (32) left-side half-luminance viewing angle right-side half-luminance viewing angle 6.2 H al f-contrast vi ewin g an gl e rang e I n the same way as for the half-luminance viewing angle range, Ɵ H CR-LR is the viewing angle range of the half-contrast ratio compared to the front contrast ratio I t is obtained by measuring the black and white luminance at measuring points 0, and CRΘHCR L = − where (CR0 _ + CR0 _ + CR0 _ ) = CRΘHCR−L _0 + CRΘHCR−L _6 + CRΘHCR−L _8 contrast ratio at viewing angle Θ H CR-L CR Θ H CR-L : CRΘHCR R = − where CR Θ H CR-R : Ɵ H CR-LR (CR0 _ + CR0 _ + CR0 _ ) = CRΘHCR−R _0 + CRΘHCR−R _6 + CRΘHCR−R _8 where Ɵ H CR-L : Ɵ H CR-R : left-side half-contrast viewing angle right-side half-contrast viewing angle Reporti n g Requ i remen ts of reporti n g The report shall include the following items: a) date and time of the visual inspection b) identification of display module – product name, type and lot number – date of production – company name of production Copyright International Electrotechnical Commission (34) contrast ratio at viewing angle Θ H CR-R is calculated by adding the left-side and right-side half-contrast viewing angles ΘHCR−LR = ΘHCR−L + ΘHCR−R (33) (35) I EC TS 6271 5-5-2:201 © I EC 201 – 25 – – curvature type (concave or convex) – curvature radius or curvature radii for variable curvature – measuring viewing angle direction (right or left) – measuring distance lM ( if not specified, V is assumed) c) optical setting conditions of the display module such as contrast, brightness, etc d) measurement results of optical characteristics Recom men d ation s of measu remen t resu lts reportin g The measurement results should include the following items: a) luminance of white, black and colour boxes b) chromaticity of white box c) luminance of white box at the half-luminance viewing angle Table is an example of measurement results for the optical characteristics Copyright International Electrotechnical Commission Ta b l e – E x a m p l e o f m e a s u re m e n t re s u l t s fo r t h e o p t i c a l c h a c t e ri s t i c s poi n t n u m ber D i ffe r e n c e (max – mi n ) 0° 387 371 366 365 362 366 369 360 359 28 5° 380 372 361 367 357 360 359 361 370 23 30° 345 342 341 330 337 338 337 341 346 16 45° 300 302 299 301 305 308 305 301 293 15 0° 0, 97 0, 97 0, 96 0, 97 0, 96 0, 97 0, 97 0, 96 0, 96 0, 001 5° 0, 96 0, 96 0, 97 0, 97 0, 97 0, 97 0, 97 0, 97 0, 97 0, 001 30° 0, 99 0, 96 0, 96 0, 98 0, 98 0, 98 0, 99 0, 97 0, 98 0, 0030 45° 0, 99 0, 98 0, 98 0, 99 0, 98 0, 99 0, 98 0, 99 0, 99 0, 001 0° 0, 467 0, 464 0, 467 0, 464 0, 466 0, 466 0, 467 0, 467 0, 466 0, 003 5° 0, 469 0, 469 0, 468 0, 468 0, 465 0, 464 0, 465 0, 464 0, 468 0, 005 30° 0, 478 0, 477 0, 468 0, 470 0, 470 0, 470 0, 470 0, 478 0, 478 0, 009 45° 0, 483 0, 478 0, 487 0, 480 0, 480 0, 480 0, 483 0, 482 0, 483 0, 008 0° 0, 001 0, 002 0, 002 0, 002 0, 002 0, 002 0, 002 0, 001 0, 002 0, 001 5° 0, 001 0, 002 0, 001 0, 001 0, 001 0, 002 0, 002 0, 001 0, 002 0, 001 30° 0, 002 0, 002 0, 002 0, 002 0, 002 0, 002 0, 002 0, 002 0, 003 0, 001 45° 0, 002 0, 002 0, 002 0, 002 0, 002 0, 003 0, 002 0, 003 0, 003 0, 001 0° 0, 454 0, 455 0, 455 0, 454 0, 455 0, 455 0, 454 0, 454 0, 455 0, 001 5° 0, 454 0, 455 0, 455 0, 454 0, 454 0, 454 0, 454 0, 454 0, 454 0, 001 30° 0, 453 0, 453 0, 453 0, 453 0, 453 0, 453 0, 453 0, 453 0, 454 0, 001 45° 0, 452 0, 452 0, 452 0, 452 0, 453 0, 452 0, 453 0, 452 0, 453 0, 001 0° 0, 537 0, 539 0, 538 0, 540 0, 538 0, 538 0, 537 0, 537 0, 538 0, 003 5° 0, 535 0, 534 0, 535 0, 535 0, 539 0, 540 0, 538 0, 539 0, 536 0, 005 30° 0, 52 60 0, 526 0, 535 0, 533 0, 534 0, 533 0, 534 0, 526 0, 525 0, 009 I te m s vi e w i n g angl e Wh ite ( L Ɵ _p (W)) (cd /m ) u’ of wh ite ( u’ w_ Θ _p ) u’ of red ( u’ r_ Θ _p ) v’ of red ( v’ r_ Θ _p ) right International Electrotechnical Commission I EC TS 6271 5-5-2:201 © I EC 201 Black ( L Ɵ _p (k)) (cd /m ) – 26 – v’ of whi te ( v’ w_ Θ _p ) D i ffe r e n c e (max – mi n ) 45° 0, 521 0, 525 0, 529 0, 528 0, 524 0, 524 0, 522 0, 522 0, 530 0, 008 0° 0, 24 0, 24 0, 24 0, 25 0, 24 0, 24 0, 24 0, 24 0, 24 0, 001 5° 0, 24 0, 24 0, 24 0, 25 0, 25 0, 25 0, 25 0, 25 0, 25 0, 001 30° 0, 26 0, 23 0, 24 0, 26 0, 25 0, 26 0, 26 0, 25 0, 26 0, 003 I te m s vi e w i n g angl e of green ( u’ g _ Θ _p ) u’ of green ( v’ g_ Θ _p ) v’ v’ of bl u e ( v’ b_ Θ _p ) H al fl u ance (l eft, cd /m ) H al fl u mi nance (ri gh t, cd/m ) 0, 26 0, 26 0, 25 0, 25 0, 26 0, 26 0, 26 0, 27 0, 26 0, 001 0° 0, 552 0, 555 0, 552 0, 555 0, 553 0, 553 0, 552 0, 552 0, 553 0, 003 5° 0, 550 0, 554 0, 551 0, 551 0, 554 0, 554 0, 554 0, 543 0, 551 0, 01 30° 0, 541 0, 542 0, 550 0, 548 0, 549 0, 549 0, 549 0, 541 0, 541 0, 009 45° 0, 54 60 0, 541 0, 543 0, 539 0, 539 0, 539 0, 543 0, 546 0, 546 0, 007 0° 0, 77 0, 77 0, 76 0, 78 0, 77 0, 77 0, 77 0, 76 0, 77 0, 001 5° 0, 77 0, 77 0, 77 0, 78 0, 78 0, 77 0, 77 0, 78 0, 78 0, 001 30° 0, 78 0, 76 0, 77 0, 79 0, 78 0, 77 0, 77 0, 82 0, 77 0, 002 45° 0, 78 0, 77 0, 78 0, 79 0, 77 0, 77 0, 77 0, 78 0, 77 0, 002 0° 0, 54 0, 52 0, 55 0, 52 0, 53 0, 54 0, 54 0, 55 0, 53 0, 003 5° 0, 57 0, 56 0, 56 0, 55 0, 53 0, 52 0, 53 0, 52 0, 55 0, 005 30° 0, 58 0, 58 0, 56 0, 58 0, 58 0, 58 0, 57 0, 58 0, 60 0, 003 45° 0, 59 0, 62 0, 59 0, 59 0, 60 0, 59 0, 58 0, 64 0, 58 0, 006 79° 90, – – – – – 84, – 85, – 80° 88, – – – – – 79, – 81 , – 80° 88, – – – – – 81 , – 81 , – 81 ° 87, – – – – – 86, – 82, – From the white luminance average value of Table at viewing angle 0°, the half-luminance becomes 83,6 cd/m By selecting the nearest value to the half-luminance, the half–luminance viewing angles are known to be 80° for the left side and 80° as well for the right side right International Electrotechnical Commission – 27 – u’ of bl u e ( u’ b_ Θ _p ) 45° I EC TS 6271 5-5-2:201 © I EC 201 poi n t n u m ber From the measurement data of Table , the calculation results shall include the following items: a) luminance characteristics b) chromaticity characteristics c) half-luminance viewing angle Table shows the calculation results from the data of Table In Table 2, the colour gamut variation and uniformity related results are left out because they are not necessary for typical formats T a b l e – C a l c u l a t i o n re s u l t s fro m t h e m e a s u re m e n t d a t a o f T a b l e poi n t n u mber S t a n d a rd I te m s A v e g e d e vi a t i o n vi e w i n g an g l e CRVƟ_p (%) right International Electrotechnical Commission 0, 27 , 37 0, 55 , 38 , 64 2, 71 0, 28 3, 06 ,5 ( LV1 ) 0, 996 30 ° 0, 85 7, 82 6, 83 9, 59 6, 91 7, 65 8, 67 5, 28 3, 62 7, ( LV30 ) 2, 75 45 ° 22, 48 8, 60 8, 31 7, 53 5, 75 5, 85 7, 34 6, 39 8, 38 7, ( LV45 ) 2, 044 0° 387 86 83 83 81 83 85 360 80 225, ( CR ) 84, 41 5° 380 86 361 367 357 80 80 361 85 284, ( CR ) 96, 458 30 ° 73 71 71 65 69 69 69 71 115 63, ( CR 30 ) 8, 58 45 ° 50 51 50 51 53 03 53 00 98 34, ( CR 45 ) 25, 439 5° ,8 0, 97, 01 , 97, ,6 2, 0, 3, 33, ( CRV1 ) 48, 474 30 ° 55, 7, 6, 9, 6, 7, 8, 52, 35, 21 , ( CRV30 ) 20, 726 45 ° 61 , 8, 8, 7, 5, 43, 7, 72, 45, 34, ( CRV45 ) 21 , 769 I EC TS 6271 5-5-2:201 © I EC 201 CR Ɵ_p (x1 000: ) , 81 – 28 – LVƟ_p (%) 5° S t a n d a rd I te m s A v e g e d e vi a t i o n vi e w i n g an g l e Δ CW_ Θ _p Δ Cr_ Θ _p Δ Cb_ Θ _p 0, 002 0, 005 0, 001 0, 004 0, 001 0, 002 0, 001 0, 002 0, 002 0, 0026 ( Δ Cw_1 ) 0, 001 30 ° 0, 01 0, 01 3 0, 001 0, 006 0, 004 0, 004 0, 003 0, 01 0, 01 0, 007 ( Δ Cw_30 ) 0, 004 45 ° 0, 01 0, 01 0, 01 96 0, 01 0, 01 0, 01 0, 01 0, 01 0, 01 0, 01 ( Δ Cw_45 ) 0, 001 5° 0, 002 0, 005 0, 0035 0, 004 0, 001 0, 002 0, 001 0, 002 0, 002 0, 002 ( Δ Cr_1 ) 0, 001 30 ° 0, 01 0, 01 0, 0040 0, 006 0, 004 0, 004 0, 003 0, 01 0, 01 0, 008 ( Δ Cr_30 ) 0, 004 45 ° 0, 01 0, 01 0, 01 06 0, 01 0, 01 0, 01 0, 01 4 0, 01 0, 008 0, 01 ( Δ Cr_45 ) 0, 002 5° 0, 002 0, 001 0, 001 0, 003 0, 001 0, 000 0, 001 0, 009 0, 002 0, 002 ( Δ Cg _1 ) 0, 002 30 ° 0, 01 0, 01 3 0, 001 0, 006 0, 004 0, 004 0, 003 0, 01 0, 01 0, 007 ( Δ Cg _30 ) 0, 004 45 ° 0, 007 0, 01 0, 0087 0, 01 0, 01 0, 01 0, 009 0, 007 0, 007 0, 01 ( Δ Cg _45 ) 0, 00 36 5° 0, 002 0, 004 0, 001 0, 003 0, 001 0, 002 0, 001 0, 002 0, 002 0, 002 ( Δ Cb_1 ) 0, 001 30 ° 0, 004 0, 006 0, 001 0, 006 0, 004 0, 004 0, 003 0, 004 0, 006 0, 004 ( Δ Cb_30 ) 0, 001 45 ° 0, 004 0, 01 0 0, 0048 0, 007 0, 006 0, 005 0, 004 0, 009 0, 004 0, 006 ( Δ Cb_45 ) 0, 002 H al f-l u mi nance angl e Left 80 ° Ri ght 80 ° Su m 60 ° H al f-contrast an gl e Left 70 ° Ri ght 70 ° Su m 40 ° right International Electrotechnical Commission – – 29 – Δ Cg_ Θ _p 5° I EC TS 6271 5-5-2:201 © I EC 201 poi n t n u mber – 30 – I EC TS 6271 5-5-2:201 © I EC 201 Bibliography [1 ] I DMS ver.1 03b:201 2, In forma tio n D isp la y Me a sure me n t Sta n da rd – Ch a p te r : Va n ta ge -p o in t suite o f me a sure me n ts [2] I DMS ver.1 03b:201 2, In forma tion Disp la y Me a sure me n t Sta n da rd – Ch a p te r 8: Disp la y Me a sure me n t Sta n da rd – Ch a p te r 9: D isp la y Me a sure me n t Sta n da rd – Un ifo rm ity me a sure me n ts [3] I DMS ver.1 03b:201 2, In forma tion Vie win g-a n gle m e a sure me n ts [4] I DMS ver 03b:201 2, In fo rm a tio n A 4: Sp a tia l in va ria n ce a n d in te gra tion tim e s [5] CI E 01 5:2004, [6] I SO 1 664-5 / CI E S 01 4-5/E, Co lo rime try, 3rd Editio n Co lo rim e try – Pa rt 5: CIE 976 L *u*v* Co lo ur sp a ce a n d u’, v’ un ifo rm ch ro m a ticity sca le dia gra m [7] I EC 62341 -6-1 : 2008, Orga n ic ligh t e mittin g diode (OL ED) disp la ys – Pa rt 6-1 : disp la ys – Pa rt 6-3: Me a surin g me th o ds o f o p tica l a n d e le ctro-o p tica l p a me te rs [8] I EC 62341 -6-3: 201 2, Orga n ic ligh t e mittin g Me a surin g m e th o ds o f im a ge qua lity Copyright International Electrotechnical Commission dio de (OL ED) Copyright International Electrotechnical Commission I NTERNATIONAL ELECTROTECHNI CAL COMMISSION 3, rue de Varembé PO Box 31 CH-1 21 Geneva 20 Switzerland Tel: + 41 22 91 02 1 Fax: + 41 22 91 03 00 info@iec.ch www.iec.ch Copyright International Electrotechnical Commission