Bar code

Introduction

Barcode(barcode)isamethodofarrangingmultipleblackbarsandblanksofdifferentwidthsaccordingtocertaincodingrulestoexpressagroupofinformationGraphicidentifier.Acommonbarcodeisapatternofparallellinesarrangedbyblackbars(barsforshort)andwhitebars(emptyforshort)withverydifferentreflectivities.Barcodescanindicatethecountryofproduction,manufacturer,productname,productiondate,bookclassificationnumber,mailstartandendlocation,category,dateandmanyotherinformation,soitisusedinmanyfieldssuchascommoditycirculation,bookmanagement,postalmanagement,bankingsystem,etc.Hasbeenwidelyused.

Theautomaticbarcodeidentificationsystemconsistsofbarcodelabels,barcodegenerationequipment,barcodereadersandcomputers.

Barcodetechnology(BCT)isanautomaticidentificationtechnologyproducedanddevelopedintheapplicationofcomputers.Itisdesignedtorealizeautomaticscanningofinformation,anditisaneffectivemeanstorealizefast,accurateandreliabledatacollection.Theapplicationofbarcodetechnologysolvesthebottleneckproblemofdataentryanddatacollection,andprovidesfavorabletechnicalsupportforlogisticsmanagement.Abarcodeisasymbolcomposedofasetofregularbarsandcorrespondingcharacters,usedtorepresentcertaininformation.Thecorecontentofbarcodetechnologyistorealizetheautomaticrecognitionofthemachinebyusingphotoelectricscanningequipmenttoreadthesebarcodesymbols,andquicklyandaccuratelyinputthedataintothecomputerfordataprocessing,soastoachievethepurposeofautomaticmanagement.Theresearchobjectsofbarcodetechnologymainlyincludefiveparts:standardsymboltechnology,automaticidentificationtechnology,codingrules,printingtechnologyandapplicationsystemdesign.

Historyofdevelopment

In1948,BernardSelvowasagraduatestudentatthePhiladelphiaGasInstituteofTechnology.Once,heoverheardthepresidentofalocalsupermarketchainbeggingthedeantoinventawaytoautomaticallyrecordmerchandisesalesatthecheckoutcounter.Thedeanthinksthisiswhimsical.ButSelwoandhisfriendandgraduatestudentJosephWoodlandaredeterminedtogiveitatry,andbelieveitwillmakethemrich.

Firstofall,Selwothoughtthatitcouldbeachievedbyusingultravioletradiationtomaketheinkshapeglow.Theproblemisthatthepigmentsaretooexpensive,unstableandsmeareasily.Next,hetriedtocreateablindspotsystemformarking.However,itisdifficulttomarktheblindspotsystemintothecargo,anditoftendamagesthecargo.

Afterseveralmonthsofhardwork,SelwodecidedtouseMorsecode,asymbolsystemcomposedofdotsandlinesinventedbySamuelandMorse.Soon,SelwothoughtthatthedottedlinesinMorsecodecouldbesetintostripesofvaryingthickness.Thisidealaterbecamethemostbasicideaof​​variousbarcodes.

Woodlanddesignsmachinesthatcanreadandrecordbarcodes.HewantedtolearnfromtheearlysoundtrackingsysteminventedbyHollywoodLeeandDeForestforuseinmovies.DeForrespaintedapatternoflightanddarkontheedgeofthefilm.Duringtheprojection,theprojectoremitsalight,andthroughthesepatternsitshinesonaspecialreceiver,whichcanconvertthelightintoelectriccurrent.Canbeconvertedtosound.Thisisaverygoodidea.ButitturnsoutthatthisisnotpracticalforWoodland'sexperiment.Theirradiatedlightistooweak,andthelightpassingthroughthebarcodecannotactonthereceiver,anditcannotproducethesameeffectasthelightpassingthroughthetranslucentfilm.

In1951,thetwodecidedtoconductabarcodereaderoperationexperimentattheWoodlandhomeinBinghamton,NewYork.Theydesignedatable-sizedmachine,wrappedinblackclothtoblockthelightfromoutside,andinstalledalarge500-wattlightbulbinside.Becauseonlythelightisstrongenough,thelightemittedfromthebarcodecanbeperceivedbythefilmsoundreceiver.However,becausetheheatgeneratedbythe500-wattbulbwastoohotafterbeingconcentrated,thefirsttwopiecesofpapermarkedwithbarcodesforreadingburned.

Despitetheroarofnoiseandthebulkybody,withafantohelpcooldown,thewholesystemstartedtowork.Nowitisfinallypossibletocreateabarcodeandreadit.Butthesebarcodesdonotprovideanyusefulinformation.Theleveloftechnologicaldevelopmentatthattimecouldnotsolvethisproblem.

Twodevelopmentsinthe1960schangedthissituation.First,thelasercameout.AlaserbeamofonethousandthofawattcaneasilyproducethesameamountofconcentratedlightasWoodland's500-wattgiantbulb.Secondly,computertechnologyhasdevelopedtoacertainlevel.Thecomputercanalreadyread,accessandprocesstheinformationonthebarcodeveryeasily.

In1972,supermarketsbegantoadoptunifiedbarcoding.TheacronyminEnglishisUPC,andeachproductandeachmanufacturerhasitsowncode.Asof1974,mostmanufacturershadalreadyprintedbarcodesontheirproducts,eventhoughscannersandreadershadnotyetcomeout.

SelvoandWoodlanddesignedthescannerwithanewlydevelopedlaserbeam.OnJune26,1974,thefirstbarcodescannerwasinstalledintheMarshSupermarketinTroy,Ohio.Theentirescanningsystemconsistsof4scanners,oneinstalledoneachofthe4cashregisters,andthenconnectedtoasimplecountingcomputerintheshopoffice.Thefirstproductscannedwas10packsofWrigley’sjuicyfruit-flavoredchewinggum.ThispackofchewinggumisstilldisplayedintheAmericanHistoryMuseumatSmithsonianCollegetoday.

Barcodereaders:

U.S.barcodesandscannerswerefirstusedinsupermarkets,andthenexpandedtowholesalersandsellers.Carmanufacturersfollowedclosely,puttingbarcodesoneachoftheautopartsontheassemblyline.

Today,scannershavebeenusedonthecheckoutcountersofvariousretailstores.Airbaggagecheckalsousesbarcodestotrackbaggage,andthebaggagelossratehasbeenreducedby95%.

Becauseoftheinventionofthebarcode,PresidentBushSr.awardedWoodlandtheNationalScienceandTechnologyAwardin1992.Evenso,WoodlandandSelvostilldidn'tmakemuchmoneyfromtheirinvention,eventhoughtheinventionofbarcodesmadeabillion-dollartrade.Inthesupermarketindustryalone,becauseoftheuseofbarcodes,morethan100millionU.S.dollarscanbesavedeveryyear.

Principleofoperation

Principleofrecognition

Barcodesymbolsarecomposedof"bars"and"spaces"withdifferentreflectivityinaccordancewithcertainAninformationsymbolcombinedbycodingrules.Becausethe"bar"and"space"inthebarcodesymbolhavedifferentreflectivitytothelight,thebarcodescannerreceivesthereflectedlightsignalofdifferentstrengthandcorrespondinglygenerateselectricpulseswithdifferentpotentials.Thewidthofthe"bar"and"empty"inthebarcodesymboldeterminesthelengthoftheelectricalpulsesignalswithdifferentpotentials.Theopticalsignalreceivedbythescannerneedstobephotoelectricallyconvertedintoanelectricalsignalandamplifiedbyanamplifiercircuit.Duetothecertainsizeofthescanninglightspot,theambiguityoftheedgesduringbarcodeprinting,andsomeotherreasons,theelectricalsignalofthebarcodeamplifiedbythecircuitisasmoothundulatingsignal,whichiscalledan"analogelectricalsignal."The"analogelectricalsignal"needstobereshapedintoanormal"digitalsignal".Accordingtothecodingrulescorrespondingtothecodesystem,thedecodercanreadandtranslate"digitalsignals"intonumbersandcharacterinformation.

Thebarcodescannerusesphotoelectricelementstoconvertthedetectedlightsignalsintoelectricalsignals,andthenconvertstheelectricalsignalsintodigitalsignalsthroughananalog-to-digitalconverterandtransmitsthemtothecomputerforprocessing.

Forone-dimensionalbarcodescanners,suchaslasertypeandimagetypescanners,thescannerreadsthebarcodeinformationbyemittingabeamoflightontothelabelfromacertainangleandreceivingthereflectedlight,soWhenreadingbarcodeinformation,thelightmustbeatanobliqueangletothebarcode,sothattheentirelightbeamwillbediffuselyreflected,whichcanconvertanalogwaveformsintodigitalwaveforms.Ifthelightisirradiatedperpendicularlytothebarcode,someoftheanalogwaveformswillbetoohighandcannotbeconvertedintodigitalwaveformsnormally,makingitimpossibletoreadtheinformation.

Fortwo-dimensionalbarcodescanners,suchascamerascanners,thescannerusesomnidirectionalandphotographicreadingmethods.Therefore,thelightisrequiredtobeperpendiculartothebarcodewhenreading,andthepositioningcrossandpositioningframearealignedwiththeposition.Scanthebarcodetomatch.

Barcodescannersaregenerallycomposedoflightsources,opticallenses,scanningmodules,analog-to-digitalconversioncircuits,andplasticormetalhousings.Eachbarcodescannerhascertainrequirementsfortheambientlightsource.Iftheambientlightsourceexceedsthemaximumfaulttolerancerequirement,thebarcodescannerwillnotbeabletoreadnormally.Whenbarcodesareprintedonmetal,silver-platedsurfaces,etc.,thelightbeamwillbereflectedbythehigh-brightnesssurface.Ifthelightreflectedbythemetalentersthelightreceivingelementofthebarcodescanner,itwillaffectthestabilityofthescanner'sreading.Coverorsmearthemetalsurfacewithblackpaint.

Classificationofsymbologies

ThecommonlyusedsymbologiesintheworldareEANbarcodes,UPCbarcodes,25barcodes,cross25barcodes,Koudbabarcodes,Code39barcodesandCode128barcodes,etc..

UPCbarcode(UniformProductCode):Itcanonlyrepresentnumbers.TherearefiveversionsofA,B,C,D,E,versionA-12digits,versionE-7digits,thelastdigitisthecheckdigit,thesizeis1.5in(inch)wide(lin-2.54cm),1inhigh,andthebackgroundshouldbeclear.ItismainlyusedintheUnitedStatesandCanadaforindustry,medicine,andstorage.Andotherdepartments.

EANbarcode:Itisaninternationalsymbolsystem,afixed-length,meaninglessbarcode.Theinformationexpressedisallnumbersandismainlyusedforproductidentification.

Code39barcodeandCode128barcode:Itisthecustomcodesystemwithinthecurrentdomesticenterprises.Thelengthandinformationofthebarcodecanbedeterminedaccordingtotheneeds,andtheinformationitencodescanbenumbers,Canalsocontainletters,mainlyusedinthefieldofindustrialproductionlines,bookmanagement,etc.,suchasindicatingproductserialnumbers,books,documentnumbers,etc.

Code93:ItisabarcodesimilartoCode39,withhigherdensity,whichisalsosuitableforindustrialmanufacturing.

Cross25barcode(alsocalledinterspersed25code):Itcanonlyrepresentnumbers0-9,thelengthisvariable,thebarcodeiscontinuous,andallbarsandspacesrepresentcodes.Thefirstnumberstartswithabar,andthesecondnumberconsistsofemptyspaces.Itisusedincommoditywholesale,warehouses,airports,production(packaging)identification,andcommerce.Thebarcodehasahighreadingrateandcanbeusedforreliablescanningbyfixedscanners.Ithasthehighestdensityamongallone-dimensionalbarcodes.

Codabarbarcode(Codabar):alsoknownas"codeforbloodbank",whichcanrepresentnumbers0-9,characters$,+,-,andcanonlybeusedasThefourcharactersa,b,c,dofthestartandstopcharacters,theblankareais10timeswiderthanthenarrowbar,non-continuousbarcode,eachcharacterisrepresentedas4barsand3spaces,thelengthofthebarcodeisvariable,andthereisnocheckdigitItismainlyusedforblooddonormanagementandbloodbankmanagementinbloodstations,andcanalsobeusedformaterialmanagement,library,andairportparceldelivery.

PDF417two-dimensionalbarcode(referredtoas417barcode):atypicaltwo-dimensionalbarcodecodesystem,doesnotneedtoconnecttoadatabase,itcanstorealargeamountofdata.The417barcodeismainlyusedinhospitals,driver'slicenses,materialmanagement,andcargotransportation;thefeatureisthatwhenthebarcodeisdamaged,theerrorcorrectioncanmakethebarcodecorrectlydecoded;thePDF417barcodeisatwo-dimensionalbarcodeproductdevelopedbySymbolTechnologyin1990.Itisamulti-line,continuous,variable-length,symbolicmarkcontainingalargeamountofdata.Eachbarcodehas3to90lines,andeachlinehasastartpart,datapart,andendpart.Itscharactersetincludesall128characters,andthemaximumdatacontentis1850characters.

Barcodeapplication

Barcodetechnologyhasbeenwidelyusedinmanyfields,andthetypicalapplicationsareinthefollowingfivefields:

First,theretailindustry.Theretailindustryisthemostmaturefieldofbarcodeapplications.EANcommoditybarcodeslaythefoundationfortheretailindustrytoapplybarcodesforsales.Atpresent,mostproductssoldinsupermarketsuseEANbarcodes.Whenselling,scanEANbarcodeswithascanner.ThePOSsystemfindsthecorrespondingname,priceandotherinformationfromthedatabase,andcountstheproductspurchasedbycustomers,Whichgreatlyspeedsupthespeedandaccuracyofcashregister,andvarioussalesdatacanalsobeusedasreferencedataforshoppingmallsandvirtualvendorstopurchaseandsupplygoods.Becausethesalesinformationcanbecountedintimeandaccurately,themerchantscanaccuratelygraspthecirculationinformationofvariouscommoditiesinthebusinessprocess,whichcangreatlyreducetheinventoryandmaximizetheuseoffunds.Therebyimprovingtheefficiencyandcompetitivenessofbusinesses.

Secondly,thelibrary.Barcodesarealsowidelyusedinthecirculationofbooksinlibraries.Barcodesareaffixedtobooksandlibrarycards.Whenborrowingbooks,youonlyneedtoscanthebarcodeonthelibrarycardandthenscanthebarcodeontheloanedbook.,Therelevantinformationisautomaticallyrecordedinthedatabase,andwhenreturningthebook,aslongasthebarcodeonthebookisscanned,thesystemwillcheckaccordingtothepreviouslyrecordedinformationandreturnthebooktothelibrarywhenitisdue.Comparedwithtraditionalmethods,thisgreatlyimprovesworkefficiency.

Third,warehousemanagementandlogisticstracking.FortheoccasionoftheflowofitemsinDaxie,thetraditionalmanualrecordingmethodisusedtorecordtheflowofitems.Itistime-consumingandlabor-intensive,andtheaccuracyislow.Insomespecialoccasions,manualrecordingisunrealistic.Moreover,theapplicationefficiencyofthesemanuallyrecordeddataintheprocessofdatacollectionandqueryisquitelow.Usingbarcodetechnology,itispossibletorecordeachitemquicklyandaccurately,andthevariousdatacollectedcanbeprocessedbythecomputersysteminrealtime.Thisenablesvariousstatisticaldatatoaccuratelyandtimelyreflectthestatusofitems.

Fourth,qualitytrackingmanagement.TheISO9000qualityassurancesystememphasizesthetraceabilityofqualitymanagement,thatistosay,forproductswithqualityproblems,itshouldbepossibletotracebackinformationsuchasitsproductiontimeandoperators.Inthepast,itwasdifficulttorecordthisinformation.Evenifsomefactories(suchassomehouseholdappliancemanufacturers)usedtheformofprocessingorderstorecord,withtheaccumulationoftime,thereweremoreandmoreprocessingorders,andsomefactoriesevenrequiredUseseveralhousestostorethesedocuments.Youcanimaginehowdifficultitistofindareceiptfromsomanyreceipts!Forexample,barcodetechnologyisused,inthemainlinkoftheproductionprocess,thedataoftheproducerandtheproductisrecordedbyscanningthebarcode,andthecomputersystemisusedforprocessingandstorage.Suchasproductqualityproblems.Thecomputersystemcanbeusedtoquicklyfindthedataduringtheproductionoftheproducttoprovideabasisforthefactorytofindthecauseoftheaccidentandimprovethequalityofwork.

Fifth,automaticdataentry(two-dimensionalbarcode).Theproblemofinputtingalargenumberofformatteddocumentsisaverytedioustask,nottomentionwastingalotofmanpower,anditisdifficulttoguaranteethecorrectrate.Withtwo-dimensionalbarcodetechnology,thousandsoflettersorChinesecharacterscanbeputintoatwo-dimensionalbarcodethesizeofabusinesscard,andthesecontentscanbeenteredcorrectlywithinafewsecondswithadedicatedscanner.Atpresent,computersandprinters,asakindofessentialofficesupplies,havebecomequitepopular.Somesoftwarecanbedevelopedtoprintthecontentsofformattedreportsinatwo-dimensionalbarcodeatthesametime.Scanthetwo-dimensionalbarcodewhereyouneedtoenterthecontentsofthesereports,andthecontentsofthereportsareautomaticallyentered.Atthesametime,thedatacanbeencryptedtoensuretheauthenticityofthereportdata.

Barcodetechnologyhasbeenwidelyusedinmycountry’spostandtelecommunicationssystems,libraryinformation,productionprocesscontrol,medicalandhealth,transportationandotherfields.Especiallywiththecontinuousimprovementofcommercialinformation,barcodetechnologyisgraduallyPopularization,andinturnpromotedthedevelopmentofcommercialpossystems.

Developmentprospects

Withtherapidexpansionanddevelopmentoftheretailandconsumermarkets,ithasalsopromotedthegrowthofChina'sbarcodelabelbusiness.Becausemoreandmoreplacesneedtouselabelsandbarcodes.Infact,asearlyasthe1970s,barcodeshavebeenusedinasmallrangeintheglobalretailindustry.Nowadays,barcodesandautomaticidentificationsystemsanddatacollectiontechnologiesstillplayavitalroleglobally.

Infact,onaglobalscale,thenumberofbarcodescanningneedstobeusedeverydayhasexceededhundredsofmillions,anditsapplicationscopealsoinvolvesvariousfieldsandindustries,includinglogistics,warehousing,libraries,banks,POScashregistersystems,medicalandhealth,retailgoods,clothing,foodservices,andhigh-techelectronicproducts,etc.,andcurrentlycontinuetousebarcodeapplicationsinsomenewlyaddeditemseveryday.Withthecontinuousdevelopmentofthemarket,wehaveenoughconfidencetobelievethatbarcodeswilldefinitelypromoteustoexperienceabetterlifeandsaveourprecioustime.

Forexample,inthelogisticsindustry,theclassificationofgoodsinlogistics,theallocationofwarehouselocations,theinquiryofwarehouselocations,theinformationofinandoutofthewarehouse,theinventoryofinandoutofthewarehouse,andtheproductinquiry,etc.,ifyouusehumanresourcestodothesethings,Notonlywastingtime,manpower,materialresourcesandfinancialresources,butalsooftenaccompaniedbyaverylargeerrorrate,whichbroughtalotoftroubletothedevelopmentofmostbusinessesandeventheentirelogisticsindustry.Therefore,itcanbesaidthatthelogisticsprocesswithoutbarcodeswillHowmessyitwillbe,andtheconsequencesareoftenunimaginable.Theadvantagesofbarcodetechnologytothelogisticsindustryarealsoobvious,bothaccuratemanagementandpracticalfunctions.Itcanmeetmostoftheneedsofmodernwarehousemanagement.Theoperationisconvenientandsimple,andmaintenanceisnotnecessary.Thewarehouseadministratorcanquicklygetondutyaftersimpletraining.Anditcangreatlyreducethehighhumanerrorrate.Itturnstedioustasksintoeasytasksinaninstant.Itisespeciallyconvenienttocheckthegoods.Itdoesnotneedtospendalotofmanpowertocheckthevariousreceiptsandreceiptsofgoods.Youonlyneedtoscanonthecomputertofindthetypeofgoodsyouneed.,Dealers,dateofpurchaseanddelivery,andthepersoninchargecanallbedisplayedandprintedout.Andthispartofthedatacanalsobebackedup,sothereisnofearofdatalossduetocrashesorvirusesinthecomputer.Itisahumanizedmanagementsystem.

Commonlyusedbarcodereadingequipment

ThecommonlyusedbarcodereadingequipmentmainlyincludesCCDscanner,laserscannerandlightpenscanner.

1.CCDscanner

TheCCDscannermainlyusesafixedlightbeam(usuallyafloodlightsourceoflight-emittingdiodes)toilluminatetheentirebarcode,andreflectsthebarcodesymbolsontothephotosensitiveelementarray.Afterphotoelectricconversion,itisrecognizedBarcodesymbol.ThenewCCDscannercanrecognizenotonlyone-dimensionalbarcodesandrow-typetwo-dimensionalbarcodes,butalsomatrix-typetwo-dimensionalbarcodes.

2.Laserscanner

Thelaserscannerisascannerwithlaserasthelightsource.Duetothestrongscanninglight,itcanbescannedatalongdistanceandthescanningaccuracyishigh,soitiswidelyused.Laserscannerscanbedividedintohandheldscannersandhorizontalscanners.

3.Lightpenscanner

Thelightpenisthefirsthand-heldtouchbarcodereadertoappear,anditisalsothemosteconomicalbarcodereader.Wheninuse,theoperatorneedstotouchthelightpentothesurfaceofthebarcode.Whenthelightpointfromthelightpenslidesacrossthebarcodefromlefttoright,thelightinthe"empty"partwillbereflected,andpartofthelightinthe"bar"willbeabsorbed.Afterphotoelectricconversion,theelectricalsignalisamplifiedandreshapedforuseinthedecoder.Theadvantagesoflightpenscannersarelowcost,lowpowerconsumption,durability,suitablefordatacollection,andlongreadablebarcodesymbols;thedisadvantageisthatlightpensaredestructivetobarcodes.

Advantagesofbarcodetechnology

Barcodeisbyfarthemosteconomicalandpracticalautomaticidentificationtechnology.Barcodetechnologyhasthefollowingadvantages.

(1)Fastinformationcollection.Comparedwithkeyboardinput,thespeedofbarcodeinputis5timesfasterthankeyboardinput,anditcanrealizereal-timedatainput.

(2)Highreliability.Theerrorrateofkeyboardinputdatais1%,theerrorrateofusingopticalcharacterrecognitiontechnologyis1in10,000,andtheerrorrateofusingbarcodetechnologyislessthan1inamillion.

(3)Theamountofinformationcollectedislarge.Thetraditionalone-dimensionalbarcodecancollectdozensofcharactersofinformationatatime,andthetwo-dimensionalbarcodecancarrythousandsofcharactersofinformation,andhascertainautomaticerrorcorrectioncapabilities.

(4)Flexibleandpractical.Barcodeidentificationcanbeusedaloneasameansofidentification,oritcanbecombinedwithrelatedidentificationequipmenttoformasystemtoachieveautomaticidentification,anditcanalsobeconnectedwithothercontrolequipmenttoachieveautomaticmanagement.Inaddition,barcodelabelsareeasytomake,therearenospecialrequirementsforequipmentandmaterials,identificationequipmentiseasytooperate,nospecialtrainingisrequired,andtheequipmentisrelativelycheap.

(5)Largedegreesoffreedom.ThedegreeoffreedomoftherelativepositionoftherecognitiondeviceandthebarcodelabelismuchgreaterthanthatofOCR(OpticalCharacterRecognition).Barcodesusuallyonlyexpressinformationinaone-dimensionaldirection,andtheinformationexpressedonthesamebarcodeisexactlythesameandcontinuous,sothatevenifpartofthelabelismissing,youcanstillenterthecorrectinformationfromthenormalpart.

(6)Theequipmentissimple.Thebarcodesymbolrecognitionequipmenthasasimplestructureandeasyoperationwithoutspecialtraining.

(7)Easytomake.Printable,called"printablecomputerlanguage".Barcodelabelsareeasytomake,andtherearenospecialrequirementsforprintingtechnology,equipmentandmaterials.

Barcodecomposition

Barcode,alsoknownasbarcodesymbol,isaparallellinegraphiccomposedofasetofregularlyarrangedbars,spaces,andcharacterstoindicateacertaininformationcode.Commonbarcodesarecomposedofblackbars(barsforshort)andwhitebars(emptyforshort)withverydifferentreflectivities.

1.Quietzone

Thequietzonereferstothelimitedareawiththesamereflectivityontheleftandrightendsofthebarcode.Itisawhiteareawithoutanysymbols,andisonlyusedtopromptthebarcodereadertostartscanning.

2.Startcharacter

Thestartcharacterreferstothefirstcharacterofthebarcodesymbol,whichmarksthebeginningofabarcodesymbol.Thereaderstartstoprocessthescanpulseafterconfirmingtheexistenceofthischaracter.

3.Datacharacter

Datacharacterreferstothecharacterafterthestartcharacter,whichisusedtorecordthedatavalueofabarcode.Itsstructureisdifferentfromthestartcharacterandallowsbidirectionalscanning.

4.Terminator

Theterminatorreferstothelastcharacterofthebarcodesymbol,markingtheendofabarcode,andthereaderstopsworkingafterconfirmingthecharacter.

Barcodedesignandprinting

Thequalityofbarcodedesignandprintingisdirectlyrelatedtothesuccessorfailureofbarcodeapplications.Ifthedesigndoesnotmeetthespecifications,itmaycausetheentireprintedproducttobescrappedandevenaffectSalesofgoods.Thefollowingaresomespecificationsandrequirementsforbarcodedesign,productionandprinting.

1.Thechoiceofstandardbarcodesize

Theencodingoftheproductbarcodefollowstheprincipleofuniquenesstoensurethattheproductbarcodeisnotrepeatedworldwide,thatis,aproductitemcanonlyhaveonecode,oroneThecodecanonlyidentifyoneproductitem.Productsofdifferentspecifications,differentpackaging,differentvarieties,differentprices,anddifferentcolorscanonlyusedifferentproductcodes.Thestandardsizeofcommoditybarcodeis37.29mmx26.26mm.Inspecialcircumstances,itcanbezoomedappropriately.Thezoommagnificationisspecifiedas:0.8,0.85,0.90,0.95,1.00,1.05,1.10,1.15,1.20,1.25,1.30,1.35,1.40,1.50,1.60,1.70,1.80,1.90,2.00.Whentheprintingareaisallowed,abarcodewithamagnificationof1.0ormoreshouldbeselectedtomeetthereadingrequirements.Thesmallerthesizeofthebarcode,thehighertheprintingaccuracyisrequired.Whentheprintingaccuracycannotmeettherequirements,itiseasytocausedifficultyinreadingthebarcode.Inaddition,thebarcodecanbereducedbyreducingtheheightofthebarcode.Theheightofthebarcodemustbecarefullyintercepted.Thereductionintheheightofthegeneralproductbarcodeshouldnotexceedone-thirdoftheoriginalstandardheight,otherwiseitwillaffectthescanningeffectofthebarcodescanner.

2.Thecolordesignofthebarcode

Thebarcodescannerrecognizesthebarcodesymbolsaccordingtothedifferenceincolorbrightnessbetweenthestripesandblanksofthebarcode.Therefore,asufficientcontrastcoefficientshouldbemaintainedbetweenthebarcolorandthebackgroundcolorofthebarcode.ThecoefficientisrepresentedbythePCSvalueinthebarcodetechnology.Themeasurementofthisvalueiscarriedoutbyspecializedtechniques,andthedesigneronlyneedstomasterthegeneralrules.Thecolormatchingofthebarcodereferstotheproblemthatthebarsandspacesofthebarcodeareusedtoformacompletebarcodeindifferentcolors.Barcodereadingequipmentmostlyusesredlightasthescanninglightsource.Therefore,notanycolorcombinationissuitableforbarcodescanningandreadingequipment.Generally,theprincipleof"darkbarsforbarsandlightcolorsforemptyspaces"isfollowed.Becarefulnottouseredasthebarcolor.Thesafestcontrastcolorsforbarcodesareblackbarsandwhitespaces.

Whentheproductpackagingcolorconflictswiththechoiceofbarcodecolor,inordertoensurethereading,thebarcodeareashouldbetreatedasablankbottom,andthebarcodeshouldbespeciallyprinted;incaseoftransparentpackagingpaper,theblankareaof​​thebarcodeAwhitebackgroundoralightbackgroundshouldbeprintedinsidetoenhancethegamma..

3.Thepositionarrangementofthebarcode

Thepositionarrangementofthebarcodegenerallyfollowsthefollowingprinciples:

①Thepositionisrelativelyuniformandeasytoscan;

②TheprintingofthebarcodeThelocationmustbedesignedinaplacethatcanbereadbyvariousscanners;

③Choosethepositionoftheproductbarcodeaccordingtodifferentpackagingforms.Generallyspeaking,thepositionofbarcodeprintingshouldbedesignedatthebottomofthearticleorthenaturalbottomofthepackage.Ifitisabottleorcancontainer,itshouldbeplacedatthelowerrightcornerofthebottlestickeroratthebottomofthecanbody;packagingboxes,squareobjectsorwrappingpaperwithanaturalflatbottomshouldbeplacedatthebottom;

④Thebarcodeonthebookshouldusuallybearrangedonthesideoftheorderingopening,andthepreferredpositionforprintingisthebottomrightcornerofthebackcover(orthecorrespondingpositionoftheprotectiveseal).

⑤Thebarcodemustbeatleast5mmawayfromthepackagingedge,overlaps,wrinklesorcornersof5mm,topreventthebarcodefrombeingworn,covered,ordeformedwiththepackaging,causingproblemswhenscanningandreading.

Thepositionwherethebarcodeshouldbeavoided:

①Placewherethebarcodesymbolwillbedeformedorotherwisedamaged;

②YesPerforations,punchingcuts,openings,staples,seams,folds,folds,overlaps,bulges,wrinklesandotherplaceswithroughgraphicsandtextures;

③ThecornersorsurfacecurvaturesaretoolargePlace;

④Placethatmaybecoveredbythefoldededgesoroverhangsofthepackage.

4.Theleftandrightblankareasofthebarcode

Whenthescannerscansthebarcode,theremustbealow-levelresetsignalwithacertainwidthtodeterminethebeginningandendofscanningthebarcode.Therefore,theleftandrightblankareasshouldbeinaccordancewiththefourLeaveenoughsizeasshowninthecornermark,otherwisethebarcodewillbedifficultorevenimpossibletoread.

5.Barcodeprintingmaterialsselection

Barcodesaremostlyprintedonpackagingmaterials,andcommonlyusedpackagingmaterialscanbeusedasmaterialsforprintingbarcodes.Intheselectionofmaterials,weshouldfirstconsiderthereflectivepropertiesofthematerials.Trytoavoidchoosingreflectiveormirror-likematerials;whenprintingbarcodesymbolsontransparentmaterials(suchasplastic,glass,etc.),youshouldnotonlyprintthecolorofthebarwithoutprintingthebackgroundcolor(emptycolor).Otherwise,thescannercannotcollectemptyreflectionsignalsandcannotberead.Therefore,theseprintingmaterialsshouldbeusedwithcaution,ifitisunavoidable,whiteorlight-coloredbackgroundshouldbeprinted.Inaddition,whenchoosingthematerial,itshouldbeconsideredfromtheaspectofensuringtheprintingdimensionalaccuracy.Afterbeingaffectedbyforceortemperature,thematerialhasstrongdimensionalstability,highcolorfastness,moderateinkdiffusion,andgoodsmoothness.Iftheprintingmaterialcannotmeetthebarcoderequirements,theformoftag,self-adhesivesticker,etc.shouldbeconsidered.

Theuseofbarcodes

(1)Standardsfortheuseofbarcodes.Thestandardfortheuseofbarcodesincludestwoaspects:oneisthechoiceofbarcodesymbology;theotheristheprintingpositionandrepresentationmethodofbarcodesymbols.Theformulationofbarcodestandardsisgenerallyrelatedtothespecifichabitsandcharacteristicsofacertainindustry.

1)Choiceofcodesystem.Thechoiceofbarcodesymbologyandthedatastructurerepresentedbythebarcodesymbolarerelatedtothetypeofdatathatcanbeencoded.Thedatatypeoftheselectedbarcodeshouldincludeallthedatainformationrequiredbytheindustry.

2)Printingposition.Duetodifferentindustryhabitsanddifferentshapesofobjects,theprintingpositionsofbarcodesymbolsarealsodifferent.Inthefieldofindustrialproduction,itisgenerallyprintedonthelowerrightcornerofthesidewherethearticleislocated,andinthefieldofcommoditycirculation,itisprintedonthelowerleftcornerofthesidewherethearticleislocated.Thegeneralprintingpositionofthebarcodeisdefinedas:firstselectthefrontoftheitem,secondlyselectthebackoftheitem,andthenselectthesideoftheitemagain.Ifnoneoftheabove-mentionedsidescanbeused,usehangingtagstohangonthearticles.Allitemswithhandlesareprintedonthelowerleftcornerofthesideofthehandle,andcannotbeprintedoncurved,partitioned,orcorneredpositions.

3)Thewayofexpression.Therearethreewaystoexpressthebarcodesymbol:thebarcodesymbolisdirectlyprintedonthesurfaceoftheproductorthepackagingcontainer;thebarcodesymbolismadeintoalabeltobepastedorhungontheproduct;thebarcodesymbolisdirectlyprintedontheouterpackagingortransportationpackageoftheproduct.

(2)Usemanagementofbarcode.Theuseofbarcodesmustcomplywithcertainmanagementprocedurestoensurethatbarcodescomplywithcorrespondingregulations.Theuseandmanagementofbarcodesgenerallyneedtogothroughthefollowingprocedures.

1)Themanufacturerappliesforthemanufacturercode.Manufacturersthatusebarcodes,especiallythosethatproducegoods,applytothebarcodeencodingcenterandlocalbranchesforthemanufacturer'scode.

2)Thecodingcenterissuesthemanufacturercode.Afterreviewingtheapplicant'sapplicationformanddocuments,thebarcodeencodingcenterwillissuearegistrationcertificateandmanufacturercodetotheapplicant,aswellastherelevanttechnicalmaterialsforprintingthebarcode.

3)Settheproductcode.Theapplicantmanufacturercanfreelysettheproductcodeaccordingtotheprincipleofproductcodesetting,andobtainthecheckcodethroughcalculation.Theproductcodeandthecheckcodeformtheserialnumberoftheproductbarcode.

4)Printbarcodes.Accordingtorelevantregulationsonbarcodeprintingorprinting,themanufacturernegotiateswiththeprinterorprintsthebarcodesymbolsonthepackagingmaterialswithaprinter.

5)Distributealistofbasicinformation.Themanufacturerdistributesthelistofbasiccommodityinformationcontainingbarcodenumberstoretailers,wholesalers,andothertransactionparticipants.

Barcodeclassification

One-dimensionalbarcode

One-dimensionalbarcodecanidentifytheproductioncountry,manufacturer,productname,productiondate,categoryandotherinformationoftheitem.Ithasawiderangeofapplicationsinmanyfieldssuchascommoditycirculation,bookmanagement,postalmanagement,andbankingsystems.Currently,themostfrequentlyusedcodesystemsareEAN(EuropeanArticleNumber)code,UPC(UniversalProductCode)code,39code,interleaved(ITF)25codeandEAN128code.UPCbarcodesaremainlyusedinNorthAmerica.EANbarcodeisaninternationalsymbolsystem,itisafixed-length,meaninglessbarcode,mainlyusedforproductidentification.EAN128barcodeisaspecificbarcodesymboljointlydevelopedandadoptedbytheInternationalArticleNumberingAssociation(EANInternational)andtheUnitedStatesUniformCodeCouncil(UCC).Itisacontinuous,non-fixed-lengthandmeaningfulhigh-densitycodetoindicateproductiondate,batchnumber,quantity,specification,shelflife,receivingplaceandmorecommodityinformation.Othercodesystemsaremainlyusedforapplicationswithspecialneeds.Forexample,theCoudbarcodeisusedforthetrackingmanagementofbloodbanks,libraries,parcels,etc.,andtheITF25codeisusedforpackaging,transportationandinternationalaviationsystemsforsequentialnumberingoftickets.Therearecode93similartocode39,whichhasahigherdensityandcanreplacecode39.

Two-dimensionalbarcodes

One-dimensionalbarcodescarryalimitedamountofinformation.Forexample,theEAN-13codecanonlyhold13Arabicnumerals,andmoreinformationcanonlyrelyontheproductdatabase.Support,leavingthepre-establisheddatabase,thiskindofbarcodeismeaningless,therefore,toacertainextentalsolimitsthescopeofapplicationofthebarcode.Forthisreason,two-dimensionalbarcodesappearedinthe1990s.Atpresent,two-dimensionalbarcodesmainlyincludePDF417codes,Code49codes,Code16Kcodes,DataMatrixcodes,Maxioclecodesandsoon.Itismainlydividedintotwocategories:stackedorlayered,chessboardormatrix.

Asanewinformationstorageandtransmissiontechnology,two-dimensionalbarcodeshavereceivedextensiveattentionfromtheinternationalcommunitysinceitsbirth.Afterseveralyearsofhardwork,ithasnowbeenusedinmanyfieldssuchasnationaldefense,publicsafety,transportation,healthcare,industry,commerce,finance,customs,andgovernmentmanagement.

Relyingonitshugeinformationcarryingcapacity,two-dimensionalbarcodescanincludetheinformationstoredintheback-enddatabasewhenone-dimensionalbarcodeswereusedinthepastinthebarcode,andthecorrespondinginformationcanbeobtaineddirectlybyreadingthebarcode.Weibarcodealsohaserrorcorrectiontechnologyandanti-counterfeitingfunctions,whichincreasethesecurityofdata.

Two-dimensionalbarcodecancompilephotosandfingerprintsinit,whichcaneffectivelysolvetheproblemofmachinereadableandanti-counterfeitingofdocuments.Therefore,itcanbewidelyusedinpassports,IDcards,drivingpermits,militarycertificates,andhealthcertificates.,Insurancecard,etc.

Thedriver'slicense,U.S.militarycertificate,militarymedicalcertificate,etc.ofmorethantenstatessuchasArizonahaveadoptedPDF417technologyafewyearsago.Encodingthepersonalinformationandphotosonthecertificateintoatwo-dimensionalbarcodecannotonlyrealizetheautomaticreadingoftheIDcard,butalsoeffectivelypreventtheoccurrenceofcounterfeitcertificateincidents.ManycountriessuchasthePhilippines,Egypt,andBahrainhavealsoadoptedtwo-dimensionalbarcodesontheirIDcardsordriver'slicenses,andthepassportsofmycountry’sHongKongSpecialAdministrativeRegionhavealsoadoptedtwo-dimensionalbarcodetechnology.Inaddition,therearealsoexamplesofusingtwo-dimensionalbarcodetechnologytosolvedatainputandpreventforgeryandalterationofformsoncustomsdeclarationforms,long-distancefreightbills,taxreports,andinsuranceregistrationforms.Two-dimensionalbarcodeshavealsobeeninitiallyappliedinareassuchascertifiedpublicaccountantcertificatesandautomobilesalesandafter-salesservicesinsomeregionsofmycountry.

2DimensionalBarCode(2DimensionalBarCode)isabarcodewithinformationinboththehorizontalandverticaldirections.Inadditiontotheadvantagesofone-dimensionalbarcodes,two-dimensionalbarcodesalsohavetheadvantagesoflargeamountofstoredinformation,strongdamageresistance,highreliability,confidentiality,andstronganti-counterfeiting.

Problemssolvedbyusingtwo-dimensionalbarcodes

(1)ItcanrepresentsmalldatafilesincludingChinesecharacters.

(2)Alargeamountofinformationcanbeexpressedonalimitedarea(suchasonanelectronicchip).

(3)Itispossibletoaccuratelydescribethe"items".

(4)Itcanpreventtheimitationofvariousdata,certificates,cardsanddocuments.

(5)Datacollectioncanberealizedinplacesfarawayfromdatabasesandinconvenientnetworking.

TwoUsingscenariosofone-dimensionalbarcodes

(1)Whentheamountofinformationrepresentedbyone-dimensionalbarcodesisnotenough.

(2)Whenthedataneedstofollowtheproductcirculation.

(3)Whenthefileinformationneedstobekeptconfidential.

(4)Whentherearealargenumberofdocumentstobefaxedandthefaxfeeneedstobereduced.

(5)Wherethereisnonetworkcommunication.

(6)Whenthedataneedstobeloggedinrepeatedly.

(7)Whendataneedstobebackedup.

(8)Whentheformflowneedstobesynchronizedwiththecargoflow.

Localcodetable

Localcodetable: