iso13406-检测标准英文版

1、iso13406_一Quality,notprice,isthemainpointEuropeans,andparticularlyGermans,aregenerallysaidtohaveastrongaffinityforstandards,guidelinesandregulations.Attimestheyevencomeinforsometeasingbecauseofthis.ButwerewouldtheITindustrybewithoutbindingguidelinessuchas,forexample,MPR,TCO,ISOTUVetc.,regulatingqual

2、ityandergonomicstandardsofCRTmonitorsforyears?Sofar,LCDwastheexceptiontothestandardizationtrend,sincetechnologywaspersuasiveduetotheirergonomic,environmentallyfriendlyqualities.InthiswaytheydistinguishedthemselvesfromCRTmonitors.Butnow,standardizationcommitteeshavebeguntorespondtothepressurefromindu

3、stry,whichhadrecognizedthatreliableparametersformakingqualitydistinctionswereintheinterestsofindustry,andbegandemandingthem.AsfromSpring2001,whentheISOstandard13406-2wasadaptedforLCD,LCDdisplaysareabletoobtainaspecialISOtestingcertificate.ViewingangleTheimagequalityofTFTmonitorsisnotconsistentlygood

4、fromeveryperspective.Ingeneral,onecansaythatthequalityisbetterthemoreoneapproachalineofsightthatisverticaltothemonitorsurface.YoucanevaluatethequalityofaTFTmonitor,interalias,fromtheevennessofitsbrightness,contrastorcolorwhenviewingthescreenfromarangeofvariousviewingangles.Thesequalitiescanvarywhenv

5、iewedfromvariousviewingangles,astheyrelatetothefocalpointofview.TheISO13406-2standardprovidesfromourclassesofviewinganglesthatrepresentreal-lifeusingsituations.ClassI-Thispermitsseveraluserstoviewtheentiredisplayareaatthesametime.Thisappliesbothforintendedviewingdistance(between40and60cm,dependingon

6、thesizeandresolutionofthemonitor)andforaviewinganglewithinan80conewithoutanyrestrictionofvisualefficiency.ClassII-Permitsasingleusertoviewtheentireareaofthedisplay.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromeverypositioninfrontofthescreen,i

7、nsuchawaythatregularityofinformation(brightness,contrast,colors)ismaintained.ClassIII-Permitsasingleviewertoviewtheentireareaofthedisplay.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromonefixedposition,insuchawaythatregularityofinformation(brig

8、htness,contrast,colors)ismaintained.ClassIV-Permitsasingleusertoviewthecenterofthescreen.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromonefixedposition,insuchawaythatregularityofinformation(brightness,contrast,colors)ismaintained.PixelfaultsA1

9、5-inchLCDmonitorconsistsof1024x768pixels,eachofwhichcontainsthreesubpixels.Onetransistorregulatesthecolorofeachsubpixel(onetransistorpersubpixel!).Ifoneofthesetransistorsfails,thepixelcaneitherappearpermanentlyblackorwhiteordisplaythewrongcolor.Duetomanufacturingissues,errorscanariseonthepanels(thea

10、ctualpictureelements)ofTFTmonitors,Dependingonwhatkindoffaultispresent,andtheimagecanbedistortedtoagreaterorlesserdegree.Ablinkingpixel,forexample,ismoreofanirritantthanaconstantlyilluminatedredone.Aclusterofdefectivepixelsinasmallareaismoreapparentthanifthefaultsaredistributedovertheentirepanel.Dep

11、endingonhowmanydefectssuchastheseoccurinapanel,onecancategorizeTFTmonitorsintofourpixelfaultclasses.Nopixelfaults-Thepixelmatrixisregular.Therearenogapsordefectivepixels.TypeImalfunction-Acompletepixelisconstantlyilluminated.Theresultisaconstantlywhitepoint.Toleranceper1millionpixels:ClassI:0ClassII

12、:2ClassIII:5ClassIV:50TypeIImalfunction-Acompletepixelisnotilluminatedatall.Theresultisaconstantlydarkpoint.Toleranceper1millionpixels:ClassI:0ClassII:2ClassIII:15ClassIV:150TypeIIImalfunction-Oneortwosubpixels(red,greenorblue)arepermanentlyswitchedonoroff.Thisresultsinapixelinoneofthebasiccolors(re

13、d,green,blue,cyan,magenta,yellow)-herecyan.Ablinkingpixelcanalsooccur.Toleranceper1millionpixels:ClassI:0ClassII:5ClassIII:50ClassIV:500FaultclusterI-ThereareseveralTypeIorIImalfunctionsinafieldof5x5pixels.Toleranceper1millionpixels:ClassI:0ClassII:0ClassIII:0ClassIV:5FaultclusterII-ThereareseveralT

14、ypeIIImalfunctionsina5x5pixelarea.Toleranceper1millionpixels:ClassI:0ClassII:2ClassIII:5ClassIV:50ClusterdefinitionClusterisdefinedastwoormoreTypeIIIdefectswithin5*5pixelmatrix.Aimistominimizenumberofclusters,whencountingdefects.IndividualTypeIIIdefectscanbedoubleortriplecounted,whencountingclusters

15、.LuminanceandbrightnessdistributionWithLCDmonitors,luminanceofthescreensurfaceisachievedbybacklighting.Athinfoilcoveringtheentiredisplaybackgrounddistributesthelightofanumberoflightelementssituatedattheedgesofthedisplayovertheentiredisplayarea.Luminanceisameasureforthelightemittedfromthemonitor.Beca

16、useoftheirbacklighting,LCDmonitorsexhibitluminanceofover200cd/m2andthusagreaterdegreeofluminanceoverallascomparedwithCRTmonitors.Furthermore,theevennessofbrightnessdistributionisimportantforthequalityofimagegeneration.IrregularitiescanresultinparticularfromimproperorimpreciseoftheLCDmonitoralsofroml

17、owerqualitylightingsystems.Sincethehumaneyeperceivescolorsinrelationtotheirbrightness,irregularitiesinthedistributionofbrightnesswillalsoleadtodeficienciesinthedisplayofcolor.FlickerFontanalysisThecharactersmustbeclearandsharp.Theremustnotbeanydistractingirregularitiesasregardsthecharactersandsurfac

18、esofequalluminance.ReflectionsThereflectioncharacteristicsofanLCDscreenareofparticularimportanceinverybrightambientconditionsorinthevicinityofmultiplelightsources,asacceptabledisplayqualityisrequiredhereaswell.Thestandardprovidesforthreequalityclasses:Appropriateforgeneralofficeconditionswithoutspec

19、ialrequirementsastoworkplacelighting.Appropriateformostofficeconditions,withfewexceptions.Appropriateforofficeconditionswithcontrolledluminance,i.e.theworkstationissubjecttospeciallightingrequirements.ContrastContrastistheratiobetweentheindividualtonesofbrightnessinthepicture.Picturecontrastisofcruc

20、ialimportanceforthequalityofaTFTmonitor.Thismeansthat-dependingonthequalityofthemonitorandambientlightconditions,theperceptualdifferencebetweenpictureareaswhichareverydark-evenblackinthemostextremecases-andverybrightones-evenwhiteinthemostextremecases-canbeverygreatorveryslight.ISOstandard13406-2mea

21、suresthecontrastofamonitorunderthreedifferentambientconditions:inabsolutedarkness,underofficeconditionsandunderconditionsofdaylight.Darkroom(5000lx)Inbrightdaylightoutside,displaycontrastisstronglyreduced.Thecontrastratioisonlyafractionofthatobservedinthedarkroom.Thismeasurementislargelyirrelevantto

22、workinsidebuildings.ISO13406Part2TheNewStandardforLCDbringsTransparencytotheDisplayMarketISO13406Part2,introducedatthebeginningofthisyear,aspartoftheTUVergonomictesting,istheansweroftheInternationalOrganizationofStandardization(ISO)totheincreaseddemandforliquidcrystaldisplays.Thenewstandarddealswith

23、ergonomicrequirementsspecifictoLCDtechnology.Sofar,onlyISO9241Parts3,7,and8havesetstandardsforvisualdisplayterminals,buttheywereinitiallydevelopedforCathodeRayTube(CRT)monitorsanddidnottakealloftheLCDcharacteristicsintoaccount.ThekeyqualityissuescoveredbythenewstandardISO13406Part2aretherefore:Displ

24、ayluminanceContrastColorreproductionLuminanceandcoloruniformityFontanalysisFlickerReflectionPixeldefectsTheabove-mentionedpropertiesareevaluatedandtheresultstranslatedintothethreecategoriesexplainedbelow.ThesecategoriesareexplicitlystatedontheISOcertificateissuedforthemonitorinquestion.ViewingAngles

25、OneofthecharacteristicsspecifictoLCDisthefactthatthequalityofthedisplayedimagedependsontheviewingangle.Apartfromthedisplayquality,luminance,colorreproduction,andcontrasthavetobetakenintoconsideration.TheISO13406Part2standardspecifiesmeasurementvaluesforergonomicdesignandqualityrequirementsinordertoe

26、valuatetheperformanceofanLCDmonitorfromdifferentviewingangles.ClassesfromItoIVdescribethemainuseforwhichamonitorhasbeendesigned.Forexample,aclassIVmonitoristobeusedbyasinglepersonsittingrightinfrontofthescreen.ClassImonitorsaredesignedforanumberofpeopleviewingfromdifferentanglesatthesametime.Viewing

27、angleclassificationprovidesperformanceassessmenttypeofapplicationClassI:ForparallelviewingbyseveralusersClassII:Adequatefor1user(suitableforgeneralofficeuse)ClassIII:LimitedviewingangleClassIV:UnacceptableforgeneraluseReflectionContrastratiomeasurements:DarkroomIEC5lxISO5000lxQuotesfromTUEVRheinland

28、:“Contrastratiosof300:1,350:1,400:1arelies”LCDMonitormanufacturersmustspecifycontrastratio:“Xxx:1indarkroom(5lx),yyy:1instandardofficeenvironment(293lx)”PixelDefectsPixeldefectsarecharacteristicsofLCDmonitors,whichareduetotechnologyandproductionengineeringreasons.A15“displaywiththestandardresolution

29、of1024x768dpi,forexample,consistsof2.4millioncells.Withsuchanenormousnumberitisvirtuallyimpossibleforeachandeverycelltofunctionperfectly.Thereisahighpossibilitythatindividualcellsarefaulty,thatistheyareconstantlyturnedonoroff.Theresultisconstantlybrightordarkpixels.Byclearlydefiningpixeldefectcatego

30、ries,ISO13406Part2providestransparency,sinceitenablescustomerstocomparetheproductpropertiesguaranteedbythemanufacturers.Onceamonitorisassignedtoacertainpixeldefectcategory,themanufacturerhastomakesurethatallmonitorsofthesametypemeetthecorrespondingcompliancecriteriainmassproduction.Whichdefectbelongstowhichpixeldefectcategoryisdeterminedaccordingtothenumberofpixeldefectsandthequalityofthedefect(defecttype).Thefollowingtableprovidesanoverviewofthedifferentclassesandtypesofpixeldefects.Thenumberofpixeldefectsisdefinedper1millionpixels.Pixe