iso13406_检测标准英文版

ISO13406-2ISOtestingcertificateforLCDdisplaysQuality,notprice,isthemainpointEuropeans,andparticularlyGermans,aregenerallysaidtohaveastrongaffinityforstandards,guidelinesandregulations.Attimestheyevencomeinforsometeasingbecauseofthis.ButwerewouldtheITindustrybewithoutbindingguidelinessuchas,forexample,MPR,TCO,ISOTUVetc.,regulatingqualityandergonomicstandardsofCRTmonitorsforyears?Sofar,LCDwastheexceptiontothestandardizationtrend,sincetechnologywaspersuasiveduetotheirergonomic,environmentallyfriendlyqualities.InthiswaytheydistinguishedthemselvesfromCRTmonitors.Butnow,standardizationcommitteeshavebeguntorespondtothepressurefromindustry,whichhadrecognizedthatreliableparametersformakingqualitydistinctionswereintheinterestsofindustry,andbegandemandingthem.AsfromSpring2001,whentheISOstandard13406-2wasadaptedforLCD,LCDdisplaysareabletoobtainaspecialISOtestingcertificate.ViewingangleTheimagequalityofTFTmonitorsisnotconsistentlygoodfromeveryperspective.Ingeneral,onecansaythatthequalityisbetterthemoreoneapproachalineofsightthatisverticaltothemonitorsurface.YoucanevaluatethequalityofaTFTmonitor,interalias,fromtheevennessofitsbrightness,contrastorcolorwhenviewingthescreenfromarangeofvariousviewingangles.Thesequalitiescanvarywhenviewedfromvariousviewingangles,astheyrelatetothefocalpointofview.TheISO13406-2standardprovidesfromourclassesofviewinganglesthatrepresentreal-lifeusingsituations.ClassI-Thispermitsseveraluserstoviewtheentiredisplayareaatthesametime.Thisappliesbothforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)andforaviewinganglewithinan80conewithoutanyrestrictionofvisualefficiency.ClassII–Permitsasingleusertoviewtheentireareaofthedisplay.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromeverypositioninfrontofthescreen,insuchawaythatregularityofinformation(brightness,contrast,colors)ismaintained.ClassIII–Permitsasingleviewertoviewtheentireareaofthedisplay.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromonefixedposition,insuchawaythatregularityofinformation(brightness,contrast,colors)ismaintained.ClassIV–Permitsasingleusertoviewthecenterofthescreen.Thisappliesforintendedviewingdistance(between40and60cm,dependingonthesizeandresolutionofthemonitor)fromonefixedposition,insuchawaythatregularityofinformation(brightness,contrast,colors)ismaintained.PixelfaultsA15-inchLCDmonitorconsistsof1024x768pixels,eachofwhichcontainsthreesubpixels.Onetransistorregulatesthecolorofeachsubpixel(onetransistorpersubpixel!).Ifoneofthesetransistorsfails,thepixelcaneitherappearpermanentlyblackorwhiteordisplaythewrongcolor.Duetomanufacturingissues,errorscanariseonthepanels(theactualpictureelements)ofTFTmonitors,Dependingonwhatkindoffaultispresent,andtheimagecanbedistortedtoagreaterorlesserdegree.Ablinkingpixel,forexample,ismoreofanirritantthanaconstantlyilluminatedredone.Aclusterofdefectivepixelsinasmallareaismoreapparentthanifthefaultsaredistributedovertheentirepanel.Dependingonhowmanydefectssuchastheseoccurinapanel,onecancategorizeTFTmonitorsintofourpixelfaultclasses.Nopixelfaults–Thepixelmatrixisregular.Therearenogapsordefectivepixels.TypeImalfunction–Acompletepixelisconstantlyilluminated.Theresultisaconstantlywhitepoint.Toleranceper1millionpixels:ClassI:0ClassII:2ClassIII:5ClassIV:50TypeIImalfunction–Acompletepixelisnotilluminatedatall.Theresultisaconstantlydarkpoint.Toleranceper1millionpixels:ClassI:0ClassII:2ClassIII:15ClassIV:150TypeIIImalfunction–Oneortwosubpixels(red,greenorblue)arepermanentlyswitchedonoroff.Thisresultsinapixelinoneofthebasiccolors(red,green,blue,cyan,magenta,yellow)–herecyan.Ablinkingpixelcanalsooccur.Toleranceper1millionpixels:ClassI:0ClassII:5ClassIII:50ClassIV:500FaultclusterI–ThereareseveralTypeIorIImalfunctionsinafieldof5x5pixels.Toleranceper1millionpixels:ClassI:0ClassII:0ClassIII:0ClassIV:5FaultclusterII–ThereareseveralTypeIIImalfunctionsina5x5pixelarea.Toleranceper1millionpixels:ClassI:0ClassII:2ClassIII:5ClassIV:50Clusterdefinition1.ClusterisdefinedastwoormoreTypeIIIdefectswithin5*5pixelmatrix.2.Aimistominimizenumberofclusters,whencountingdefects.3.IndividualTypeIIIdefectscanbedoubleortriplecounted,whencountingclusters.LuminanceandbrightnessdistributionWithLCDmonitors,luminanceofthescreensurfaceisachievedbybacklighting.Athinfoilcoveringtheentiredisplaybackgrounddistributesthelightofanumberoflightelementssituatedattheedgesofthedisplayovertheentiredisplayarea.Luminanceisameasureforthelightemittedfromthemonitor.Becauseoftheirbacklighting,LCDmonitorsexhibitluminanceofover200cd/m2andthusagreaterdegreeofluminanceoverallascomparedwithCRTmonitors.Furthermore,theevennessofbrightnessdistributionisimportantforthequalityofimagegeneration.IrregularitiescanresultinparticularfromimproperorimpreciseoftheLCDmonitoralsofromlowerqualitylightingsystems.Sincethehumaneyeperceivescolorsinrelationtotheirbrightness,irregularitiesinthedistributionofbrightnesswillalsoleadtodeficienciesinth