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Kädessä pidettävä skannausase

Thehandheldscanninggunisaproductformedbytechnologylaunchedin1987.ItlooksverysimilarThesupermarketcashieristhesameasthebarcodescannerusedinhishand.ThemajorityofhandheldscannersuseCIStechnology,withanopticalresolutionof200dpi,andtherearemultipletypesofblackandwhite,grayscale,andcolor.Thecolortypeisgenerally18-bitcolor.Therearealsoafewhigh-endproductsthatuseCCDasaphotosensitivedevice,whichcanachievetruecolorwithbetterscanningeffect.

Pieni rumpuskanneri

Thisisanintermediateproductofhandheldscannersanddesktopscanners(newemergenceinrecentyears,becauseitisThebuilt-inpowersupplyandsmallsizearecallednotebookscanners.MostoftheseproductsuseCIStechnology,withanopticalresolutionof300dpi,andtwotypesofcolorandgrayscale.Thecolormodelisgenerally24-bitcolor.TherearealsoafewsmalldrumscanninggunsthatuseCCDtechnology,andthescanningeffectissignificantlybetterthanthatofCIStechnologyproducts,butduetostructurallimitations,thevolumeisgenerallysignificantlylargerthanthatofCIStechnologyproducts.

Thesmallrollerdesignistofixthelensofthescanninggun,andmovetheobjecttobescannedtoscanthroughthelens.Itoperateslikeaprinter.Theobjecttobescannedmustpassthroughthemachinebeforebeingsentout.,Thescannedobjectcannotbetoothick.Thebiggestadvantageofthisscanninggunisthatitisverysmall,butduetoitslimitations,forexample,itcanonlyscanthinpaper,andtherangecannotexceedthesizeofthescanninggun.

Platformscanner

Alsoknownasflatbedscanneranddesktopscanner,mostofthescannersonthemarketareflatbedscanners.Gunsarenowthemainstream.Theopticalresolutionofthistypeofscanninggunisbetween300dpi-8000dpi,thecolordigitsrangefrom24-bitto48-bit,andthescanningformatisgenerallyA4orA3.

Theadvantageoftheflatbedtypeisthatlikeusingacopier,aslongastheuppercoverofthescanninggunisopened,nomatterbooks,newspapers,magazines,photonegativescanbeputonandscanned,itisquiteconvenient,andthescannedeffectItisalsothebestamongallcommontypesofscanningguns.

muut

muutincludelarge-formatscanningguns,pen-typescanningguns,barcodescanningguns,filmscanningguns(noteItisnotaflatbedscanninggunplusapenetratingscan,theeffectismuchbetter,andthepriceisofcoursealsoexpensive),physicalscanningguns(notflatbedscanninggunswithphysicalscanningcapabilities,similartodigitalcameras),andmainlyusedinthefieldofprintingandtypesettingRollerscanninggunsandsoonaremany.

Käyttöliittymätyyppi

SCSI-käyttöliittymä

SCSI-käyttöliittymäisastandardinterfaceforsmallcomputers.

Themaximumnumberofconnecteddevicesforthisinterfaceis8.Usuallythemaximumtransmissionspeedis40M/S,whichisfaster,andgenerallyconnectstohigh-speeddevices.TheinstallationofSCSIdevicesismorecomplicated,andaSCSIcardisusuallyaddedtothePC,whichispronetohardwareconflicts,butithaspowerfulfunctions.

EPP-käyttöliittymä

EPP-käyttöliittymäisanenhancedparallelinterface.

Anenhancedtwo-wayparalleltransmissioninterfacewithamaximumtransmissionspeedof1.5Mbps.TheadvantageisthatthereisnoneedtouseothercardsinthePC,thenumberofconnectionsisunlimited(aslongasyouhaveenoughports),andthedeviceiseasytoinstallanduse.ThedisadvantageisthatthespeedisslowerthanSCSI.Thisinterfaceissimpleandconvenienttoinstallanduse,andreplacetheSCSI-käyttöliittymäinthelow-endandlow-endoccasionswhereperformanceisnothigh.

USB-liitäntä

USB-liitäntäistheuniversalserialbusinterface.

Upto127peripheralscanbeconnected.ThemaximumtransmissionspeedoftheUSB1.1standardis12Mbps,andthereisanauxiliarychanneltotransmitlow-speeddata.Inthefuture,ifthereisaUSB2.0standardscannerspeed,itmaybeexpandedto480M/s.Withhotplugfunction,plugandplay.ThescanninggunofthisinterfaceisgraduallypopularizedwiththeestablishmentandpromotionoftheUSBstandardunderthepushofIntel.

Langaton käyttöliittymä

TheBluetoothbarcodescannerdoesnotneedtobechargedwithinacertainrange!

Toimintaperiaate

Commonflatbedscanninggunsaregenerallycomposedoflightsource,opticallens,scanningmodule,analog-digitalconversioncircuitandplasticshell.Itusesphotoelectricelementstoconvertthedetectedlightsignalintoanelectricalsignal,andthenconvertstheelectricalsignalintoadigitalsignalthroughananalog-digitalconverterandtransmitsittothecomputerforprocessing.Whenscanninganimage,thelightsourceshinesontheimageandthereflectedlightpassesthroughthelenstoconvergeonthescanningmodule.Thescanningmoduleconvertsthelightsignalintoananalogdigitalsignal(ievoltage,whichisrelatedtotheintensityofthereceivedlight).Related),andatthesametimepointoutthedegreeofdarknessoftheimagenumber.

Atthistime,theanalog-digitalconversioncircuitconvertstheanalogvoltageintoadigitalsignalandsendsittothecomputer.Thecolorisquantizedwith8,10,and12bitsoftheRGBthreecolors,andthesignalisprocessedintotheimageoutputoftheabove-mentionednumberofbits.Ifthereisahighernumberofquantizationbits,itmeansthattheimagecanhavericherlevelsanddepth,butthecolorrangehasexceededtherecognitionabilityofthehumaneye,soforus,ahighernumberofscanninggunsarewithinthedistinguishablerange.Theeffectofscanningisthatthecolorsaresmoothlyconnected,andmoredetailsofthepicturecanbeseen.

Resoluutio

Theresolutionofthescanninggunshouldbedeterminedfromthreeaspects:theopticalpart,thehardwarepartandthesoftwarepart.Inotherwords,theresolutionofthescanninggunisequaltotheresolutionofitsopticalcomponentsplusitsownresolutionobtainedbyprocessingandanalyzinghardwareandsoftware.

Opticalresolutionistheactualnumberoflightpointsthatcanbecapturedbytheopticalcomponentsofthescanninggunpersquareinch.ItreferstothephysicalresolutionofthescanninggunCCD(orotheroptoelectronicdevices),whichisalsothescanningTherealresolutionofthegun,itsvalueisthevalueobtainedbydividingthepixelpointsthatthephotoelectricelementcancapturebythemaximumscannablesizeofthescanninggun.Forexample,ascanninggunwitharesolutionof1200DPIoftenonlyaccountsfor400-600DPIintheresolutionoftheopticalpart.Theresolutionoftheextendedpartisjointlygeneratedbyhardwareandsoftware.Thisprocessisgeneratedbyanalyzingtheimagethroughacomputerandmathematicallyfillingtheblankpart(thisprocessisalsocalledinterpolationprocessing).

Opticalscanningandoutputareone-to-one,andwhatisscannediswhattheoutputis.Afterthecomputersoftwareandhardwareareprocessed,theoutputimagewillbecomemorerealisticandtheresolutionwillbehigher.Mostofthescannerssoldonthemarkettodayhavetheabilitytoexpandtheresolutionofsoftwareandhardware.Somescanninggunadvertisementswrite9600×9600DPI,whichisonlythemaximumresolutionobtainedthroughsoftwareinterpolation,nottherealopticalresolutionofthescanninggun.Soforthescanninggun,itsresolutionhasopticalresolution(oropticalresolution)andmaximumresolution.Ofcourse,whatwecareaboutisopticalresolution,whichishardwork.Wesaythattheresolutionofascanninggunisashighas4800DPI(this4800DPIisthesumoftheopticalresolutionandsoftwaredifferenceprocessing),whichmeansthatwhenthescanninggunisusedtoinputtheimage,itcancollect4800×onthescanningareaof​​1squareinch.4800pixels(Pixel).Thescanningareaof​​1inchsquare,theimagesizegeneratedafterscanningwiththeresolutionof4800DPIis4800Pixel×4800Pixel.Whenscanninganimage,thehigherthescanningresolutionisset,thefinertheeffectofthegeneratedimageandthelargerthegeneratedimagefile,butthemoreinterpolatedcomponents.

Optoelektroniset laitteet

CCD

ThemainstreamistwokindsofCCD,theprincipleissimply:integratedonasiliconsinglecrystalTherearethousandstotensofthousandsofphototransistors,thesephototransistorsaredividedintothreerows,respectivelycoveredwithred,greenandbluecolorfilters,soastoachievecolorscanning.ComparingthetwoCCDs,thesiliconoxideisolationCCDisbetterthanthesemiconductorisolationCCD.Friendswhoarefamiliarwithphysicsnaturallyknowthereason.Simplyput,theleakagephenomenonbetweenthesemiconductorCCDtransistorswillaffectthescanningaccuracy.Theisolationwithsiliconoxidewillgreatlyreducetheleakagephenomenon(thisisaninsulator).Ofcourse,itisbesttoaddtemperaturecontrol,becausewhetheritisasemiconductororaconductor.Theyarealltemperature-sensitive,andtheconductivitywillgenerallyincreasewhenthetemperaturerises(thecostwillincreasealot,theprice,letaloneeveryoneknowswhatwillhappen).Nowadays,mostofthemainstreammarketisforsemiconductor-isolatedCCD,whilethesilicon-oxide-isolatedCCDisrelativelysmall,obviouslybecauseofthehighercost.Ifyouwanttounderstandtheeffectofascanninggun,itisveryimportanttounderstandwhatqualityphotoelectriccomponentsthescanninggunuses.Haha,eventhesamesemiconductorisolationqualityisdifferent.

Kosketusvaloherkkä laite

Thephotosensitivematerialusedinthecontactphotosensitivedeviceisgenerallycadmiumsulfide,whichisusedtomakephotosensitiveresistors.TheproductioncostshouldbeItismuchlowerthanCCD(thesameprecisionCISscanneronthemarketisalwayscheaperthanCCDscannerforthisreason).Thescanningdistanceisshort,thescanningresolutionislow,orsometimesitcannotreachthenominalvalue,andthetemperaturechangeiseasiertoaffectthescanningaccuracy.Thesearethefatalproblemsofthisscanninggun.Friendswhoarefamiliarwithphysicsshouldknowthattheleakageofcadmiumsulfidebetweenresistorsislargerthanthatofsemiconductorbarriers,whichwillreducetheaccuracy(hehe,letalone,CISseemstobeterriblybad,themanufacturerofthescanninggunwillcomeandkillMe).

Valomonistinputki

Valomonistinputki,thephotosensitivematerialismainlytheoxideofmetalcesium.Hisscanningaccuracy,eventhedegreeofinfluencebytemperatureandnoisearethebest,butthepriceisalsothemostexpensive.Generaluserslikemearejustdreamingofit.Thepriceistooexpensiveandwewillignoreitsspecifictechnicalfeatureshere.

Muut

Theoptoelectronicdeviceofascanninggunisanimportantfactorindeterminingitsperformance,andotherthingssuchascontrolcircuitsandsoftwarearealsoveryimportant.Itmaybedifficulttounderstandthesematerialsdirectly.Wecanoftenonlyunderstandlimitedcontent(tradesecrets).Whenwedetecttheperformanceofascanner,wecanonlyunderstanditbymeansofactualoperationandevaluationsoftware.

Hintaero

One-dimensionalbarcodescanninggunsaremainlydividedintoredlightCCDscanning(redstripsduringscanning)andlaserscanning(redlightscanning),

Thetwo-dimensionalcodescannermainlyusestheimage-baseddecodingmethod(thegeneralscanningheadcanseethecrystalsimilartothecamera),

Sohowtodistinguishthepricefactorofeachtypeofscanner,themostThemainreasonliesinthescanningaccuracyofthescanner.Forexample,thesmallerthebarcodethatcanbescannedbyaone-dimensionalscanner,thefasterthescanningspeed,andthehighertheprice;thesameistruefortwo-dimensionalscanners.Thismethodofjudgment.

muutpecialfunctionswillalsoincreasethepriceofthescanner,suchasscanningDPMcodes(laserengravingcodes),orscanningfarawaybarcodes.

Moreover,thepriceofscannersisgenerallydeclining,andtherearealsofreemobilephonesintheworldtoscanbarcodesandsendthemtocomputers,sothatthemobilephonescanbeusedasbarcodescanners,soifthebarcodescannerdoesnotrequirespecialscanningcapabilities,Thepricehasdroppedalot.