История на развитието
Лазерната технология се появява през 60-те години на миналия век и нейното реално приложение започва в началото на 70-те години. Най-ранният лазерен предавател беше електронна лазерна тръба, пълна с хелий-неонов (He-Ne) газ, който беше много голям, така че имаше много ограничени практически приложения.
Inthelate1970s,semiconductortechnologytendedtomature.Semiconductorlaserswereborn,andhigh-sensitivityphotosensitivematerialswerecontinuouslydiscovered.Coupledwiththedevelopmentoflasercontroltechnology,lasertechnologymaturedrapidlyandenteredthefieldofpracticalapplications.
ScientificresearchersrepresentedbytheUnitedStatesandJapanhavecombinedlasertechnologyandcomputertechnologyonthebasisofelectrostaticcopiers,andhavesuccessivelydevelopedsemiconductorlaserprinters.Thistypeofprinterhasgoodprintingquality,fastspeedandnonoise,soithasbeenwidelyusedsoon.
Принцип
Съставът, конструкцията, методът на управление и компонентите на устройството за управление и частите, изисквани от работния процес на лазерния принтер, ще варират в зависимост от различните марки и модели., като:
①Thechargingpolarityofthephotosensitivedrumisdifferent.
②Thepartsusedtochargethephotosensitivedrumaredifferent.Somemodelsusethewiredischargemethodtochargethephotosensitivedrum,andsomemodelsuseachargingrubberroller(FCR)tochargethephotosensitivedrum.
③Частите, използвани при пренос на високо налягане, са различни.
④Theexposuremodeofthephotosensitivedrumisdifferent.Somemodelsuseascanningmirrortodirectlyscanandexposethephotosensitivedrum,andsomemodelsuseascannedreflectedlaserbeamtoexposethephotosensitivedrum.
However,theyworkbasicallythesame.Thelaserbeamemittedbythelaserisinjectedintotheacousto-opticdeflectionmodulatorthroughthemirror.Atthesametime,thebinaryimageandtextlatticeinformationsentbythecomputerissentfromtheinterfacetothefontgeneratortoformthebinarypulseofthedesiredfont.Information,thesignalgeneratedbythesynchronizercontrols9high-frequencyoscillators,whicharethenaddedtotheacousto-opticmodulatorviaafrequencysynthesizerandapoweramplifiertomodulatethelaserbeaminjectedbythemirror.Themodulatedlightbeamentersthepolygonmirror,andthenthelightbeamisfocusedbythewide-anglefocusinglensandshotontothesurfaceofthephotoconductordrum(tonerdrum),turningtheangularvelocityscanningintolinearvelocityscanning,completingtheentirescanningprocess.
Thesurfaceofthetonercartridgeisfirstchargedbyachargingelectrodetoobtainacertainpotential,andthenexposedtoalaserbeamcarryinggraphicimageinformationtoformanelectrostaticlatentimageonthesurfaceofthetonercartridge,whichpassesthroughamagneticbrushdeveloperAfterdeveloping,thelatentimageistransformedintoavisibletonerimage.Whenpassingthroughthetransferarea,thetoneristransferredtotheplainpaperundertheactionoftheelectricfieldofthetransferelectrode,andfinallyfixedbythepreheatingplateandhightemperatureheatroller.Thatis,textandimagesarefusedonthepaper.Afterprintingthegraphicinformation,thecleaningrollerremovesthetonerthathasnotbeentransferredaway,thedischargelampremovestheresidualchargeonthedrum,andthecleaningpapersystemisthoroughlycleanedtoenteranewroundofworkcycle.
Thelightsourcethatproduceslaserlightisobviouslydifferentfromordinarylightsources.Forexample,anordinaryincandescentlightsourceheatstheatomsofthetungstenfilamenttoanexcitedstatethroughelectriccurrent,andtheatomsintheexcitedstatecontinuouslyemitlightbyspontaneousemission.Thiskindofordinarylightsourcehasgreatscatteringanddiffusivity,andcannotbecontrolledtoformaconcentratedlightbeam,soitcannotbeusedinlaserprinters.Thelaserbeamrequiredbythelaserprintermusthavethefollowingcharacteristics:
①Highdirectivity.Theemittedlightbeamisnotscatteredanddiffusedwithinacertaindistance.
②Highmonochromaticity.Purewhitelightiscomposedofsevencolorsoflight.
③Highbrightness,whichisconducivetotheconcentrationofthebeamandhashighphysicalenergy.
④Highcoherence,easytostackandseparate.Thelaseristhelightsourceofthelaserscanningsystem,whichhasthecharacteristicsofgooddirectivity,strongmonochromaticity,highcoherence,concentratedenergy,andconvenientmodulationanddeflection.Theearlylaserprintersmostlyusedhelium-neon(He-Ne)gaslaserswithawavelengthof632.8nm,whichwerecharacterizedbyhighoutputpower,largevolume,andlonglife(generallygreaterthan10,000hours),reliableperformance,andnoiseLow,highoutputpower.Butbecauseofitslargesize,ithasbasicallybeeneliminated.Laserprintersusesemiconductorlasers,themostcommonisthegalliumarsenide-galliumaluminumarsenic(GaAs-GaAlAs)series.Thewavelengthoftheemittedlaserbeamisgenerallynear-infraredlight(λ=780nm),whichcanbecomparedwiththewavelengthsensitivitycharacteristicsofthephotosensitivedrumMatch.Thesemiconductorlaserissmallinsizeandlowincost,andcanbedirectlymodulatedinternally.Itisthelightsourceofaportabledesktoplaserprinter.
Laserscanningisusedtoproduceverysmallhigh-precisionlightspots,whichareusedforhigh-qualitytextandimageprinting.Theprincipleofcommonlyusedlasergenerationis:twopiecesaresetparalleltoeachotheratbothendsoftheworkingmaterialMirror(grid),aresonantcavityisformedbetweenthetwomirrors.Onereflectoroftheresonantcavityisatotalreflector,andtheotherisahalfreflector.Whentheworkingsubstanceisexcited,thephotonsemittedbytheatomspontaneouslyreflectbackandforthintheresonantcavity,andtheradiatedphotonscontinuetoincrease.Whenthesuperimposedphotonsintheresonantcavityincreasetoacertainamount,itwillpenetratethesemi-reflectivemirrorandemitaverystronglight,whichisthelaser.Thelightbeamsemittedinthiswayareveryconcentrated,andthereisalmostnoscattering.Aslongasweusecontroltechnologytocontrolthewavelengthofthelightwaveat700-900nm(nanometers),thelaserproducedcanmeettheexposureneedsofthephotosensitivedrumofthelaserprinter.
Modernsemiconductorlasersusuallyuselaserdiodes.Itsprincipleisverysimilartoordinarydiodes.Forexample,thereareapairofPNjunctions.Whenvoltageandcurrentareappliedtothelaserdiode,theP-typesemiconductormaterialTheholesintheN-typematerialandthefreeelectronsintheN-typematerialproducerelativemotion.ThecarrierdensityatthePNjunctionincreasesverygreatly.Thefreeelectronsandholesrecombine,therebygeneratingstimulatedradiationandreleasingphotonswithlasercharacteristics.Itisreflectedbythereflectorinthelaserresonantcavity,andemitsthelaserbeamthroughthelaserholeandthefocusingmirrorinthehole.
Itcanbeseenfromthegenerationoflaserthatalaserbeamonlyincludeslightofonemainwavelength,whichismonochromatic.Eachraytravelsinonedirectionandiscombinedinasuperimposedmanner,whichwecall"coherence".Thisfeatureallowsthelasertohitatargetinaverythinbeamwithalmostnoscattering.Eachlaserbeamislikeabulletshotoutofthebarrel,andeachbulletcanonlypunchoneholeinthetarget.Ifyouwanttotypea"one",youhavetoshootalotofbulletsandpunchalotofholesalongthedirectionofthe"one"toformahorizontalarrangementof"one"dots.Thisiswhatwecall"dotmatrixarrangement".Itisthetechnicalbasisforthe"dotmatriximage"tobediscussedlater.
Thegraphicinformationoflaserprinterisalsocomposedofdotmatrix.Thehighertheprintingqualityrequirements,themoredotsthatmakeupacharacter.Therearefourmethodsforlaserscanningdotmatrixformation.Single-linescanning:Sendthedotmatrixinformationofeachlineofalineofcharacterstothescannerforscanning,whichiscalledsingle-linescanning.Multi-linesequentialdeflectionscanning:Thehigh-frequencysignalgeneratorgenerates9differentfrequenciesinturn.AccordingtotheprincipleofBraggdiffraction,theywillgenerate9scanlineswithdifferentdeflectionanglesinthedeflectionmodulator,andthentherotatingmirrorrotatesasmallangle,Scanoutthedotmatrixinformationfromlefttoright.Becausethismethodonlyneedstorotatethemirrorthroughatinyangle,whichisequivalentto1/132ofthesingle-linescanningmethod,itcanform1character,soitisalsocalledsmallrasterscanning.Multi-linesimultaneousdeflectionscanning:referstothesimultaneousgenerationof9differentfrequenciesinthehigh-frequencydrivecircuit,whicharesynthesizedandsenttothedeflectionmodulator.Multi-linesimultaneousdeflectionscanning:Thismethodisofthesametypeasthemulti-linesimultaneousdeflectionscanning,exceptfortheformationofonecharacter.Thatis,whenscanninghighdotmatrixcharacters,acompletecharacterisdividedintomultiplescans.Thedotmatrixformationofgraphicinformationisbasicallysimilartothedotmatrixformationofcharacters.
Photosensitivedrum
Thephotosensitivedrumisthecorecomponentofalaserprinter.Itisaphotosensitivedevice,mainlymadeoflightguidematerial.Itsbasicworkingprincipleistheprocessof"photoelectricconversion".Itisusedasaconsumablematerialinlaserprinters,anditspriceisrelativelyexpensive.Photosensitivesemiconductorshavethecommonalitiesofsemiconductors,suchasbeingexcitedbyheatandchangingconductivityafterdoping.Inaddition,italsohas"photoconductivity"characteristicsthatothersemiconductorsdonothave.Afterthephotosensitivesemiconductorisirradiatedwithlight,itsconductivitycanrisebyseveralordersofmagnitude.Intermsofenergyband,theelectronsinitsvalencebandabsorbtheenergyoflightandthenjumpintotheconductionbandtoproduceelectron-holepairs.Thiselectron-holepairproducedbylightiscalled"photo-generatedcarrier".Asthe"photo-generatedcarriers"generatedinthephotosensitivesemiconductorincreases,itsconductivityrises.Thisincreasedconductivityafterexposuretolightiscalled"intrinsicphotoconductivity."Inpracticalapplications,photosensitivesemiconductormaterialsneedtobedopedbeforetheycanbemadeintosemiconductormaterialsusedinlasers.Therefore,inadditiontotheintrinsicphotoconductivity,thephotoconductivityoftheimpurityformedbylight-excitedelectronsorholesattheimpuritylevelmustalsobepossessed.Insomephotosensitivesemiconductors,"impurityphotoconductivity"playsamajorrole.
Afterthephotosensitivesemiconductorisirradiatedwithlight,itwillchangethe"carriermobility"intheobjecttovaryingdegrees(mobilityistheratioofthecarrier'smigrationspeedtotheexternalelectricfield).The"conductance"thatmarkstheconductivityofanobjectisequaltothecarrierdensitymultipliedbythemobility.Asthemobilityincreases,theconductivityincreases.Theconductivityisdeterminedbythevaluesofintrinsicphotoconductivity,impurityphotoconductivityandmobility,butundercertainconditions,oneofthesefactorsisthemainfactor.
Variouslightconductorsinpracticalapplicationshavedifferentsensitivitytolight.Theelectricalconductivityofthelightconductorisdirectlyproportionaltoitssensitivitytolight.Therefore,thelightperceptionhasagreatinfluenceontheconductivityofthephotoconductor.Thesensitivityoflightconductorstolightisdifferent.Acertaintypeoflightconductorhashighsensitivitytolightinacertainregionofthespectrum.Ifitleavesthisregion,itmayloseitssensitivity.
Thephotosensitivesemiconductorwillformanabsorptionpeakforlightinthewavelengthrangeoflightapplicabletoit.Thephotoconductivityeffectisbestinthispeakrange.Itisalsorelatedtotheilluminanceoflight.Thehighertheilluminance,themorecarriersaregenerated,andthehigherthephotoconductivity.However,thecharacteristicsofeachphotoconductoraredifferent,sounderthesameconditions,theilluminancerequiredtoachievethesamephotoconductivityindexisdifferent.
Thecommonlyusedphotoconductivematerialsforphotosensitivedrumsarecadmiumsulfide(CdS)andselenium-arsenic(Se-As).Organicphotoconductivematerials(opc)andotherseveral.Thelightguidematerialusedintheproductionofphotosensitivedrumsshouldhavethefollowingcharacteristics:
①Goodwearresistance.Thesurfaceofthephotoconductormusthaveacertaindegreeofhardness,anditmustbeabletowithstandthemechanicalabrasionduringthedevelopment,transferandcleaningprocess.Ifthephotosensitivedrum(photoconductor)iswornorscratched,itwillcausethedeteriorationoftheprintqualityordamagethephotosensitivedrum.Ifitisseverelyworn,itwillonlybescrapped.Inactualwork,mostofthephotosensitivedrumsarescrappedduetowearandscratches.Anewtypeoflong-lifeceramicphotosensitivedrum(a-Si)hasbeenapplied,whichcanprintmorethan300,000sheets.
②Goodtemperaturestability.Theperformanceofthephotoconductoriseasilyaffectedbytemperature.Therefore,intheperformanceofthelaserprinter,itisparticularlyemphasizedthattheoperatingenvironmentmusthaveasuitabletemperatureandhumidity,otherwiseitwillaffecttheprintquality.
③Goodphotoconductivity.Photoconductivityisanimportantindicatorofthephotosensitivedrum,whichdirectlyaffectsthequalityofprinting.Becausethephotosensitivedrumiscontinuouslyworkinginthecycleofcharginganddischarging,itisrequiredthatthepotentialrisesquicklyduringcharging,andthesurfacesaturationpotentialishigherthantheappliedpotential;otherwise,theinitialpotentialwillnotrise,whichwillalsoaffecttheprintquality.Thedarkattenuationofthephotosensitivedrumafterchargingshouldbesmall,otherwisethesurfacepotentialcannotbemaintainedandthenecessarypotentialdifferencelatentimagecannotbeformed.Thephotosensitivedrumdischargesquicklyafterexposure,thatis,thelightdecaysquickly.Themorethoroughthedischarge,thebetter.Becausetheamountofresidualpotentialnotonlyaffectsthecontrastofthelatentimage,butalsobringsaboutthe"graybottom"oftheprintedproduct.
④Resistanttofatigue.Intheprocessofusingthephotosensitivedrum,theprinterhastochargeitrepeatedly,soitmusthavegoodfatigueresistance.Duringthespecifiedlifetime,theprintqualitycannotbereducedduetocontinuoususe.Thephotosensitivedrumhasbetterstabilityoflightguidecharacteristicsandshouldmeettherequirementsofcontinuoususe.
Thephotosensitivedrumusedinlaserprintersgenerallyhasathree-layerstructure.Thefirstlayerisanaluminumalloycylinder(conductivelayer),thesecondlayerisavacuumevaporationmethodonthesurfaceofthecylinder,coatedwithalayeroflightconductormaterial(lightguidelayer),andthethirdlayerisontheoutsideofthelightguidematerialPlatingalayerofinsulatingmaterial(insulatinglayer).Inordertobetterdischargethecharge,somephotosensitivedrumsarecoatedwithalayerofsuperconductingmaterialbetweenthephotoconductivelayerandthealuminumalloyconductivelayertoreleasethechargemorequickly.
Theinsulatinglayeronthesurfaceofthephotosensitivedrumistoimprovethewearresistanceandincreasetheservicelife;theotheristoprovideprotectionforthephotoconductorlayer,preventtheabrasionofthephotoconductor,andmaintainthephotoconductivityofthephotoconductor.
Theconductivelayeraluminumalloycylinderisconnectedwiththegroundwireofthelaserprinter,sothatthepotentialafterexposureisquicklyreleased.Itisaveryhigh-precisioncylinderthatcanmaintainauniformspeedandmaintainauniformchargeduringoperation.
Asanimportantpartoflaserprinters,theratedlifeofphotosensitivedrumsisgenerallyabout6000to10000sheets.Whentheprintimageisfoundtobelight,light,uneven,andcausedbynon-transfercoronaelectrodeandtoner,itmeansthatthelifeofthephotosensitivedrumhasexpiredandshouldbereplaced.
ThefollowingtakesthecommonlyusedHP6Lprintertonercartridgeasanexampletointroducehowtoreplacethephotosensitivedrum:
Firstofall,cutoffthepowersupplyoftheprinterandtakethetonercartridgeoutoftheprinter.,Andthenusediagonalplierstoclampthemetalpinononeside,andcarefullypullitout(oruseanailtoputthemetalpinintothetonercartridge,andthemetalpincanbetakenoutafteropeningthetonercartridge).AfterpullingoutthesilvermetalpinsonbothsidesThetonercartridgecanbedividedintotwoparts.Thesidewithlightbluephotosensitiveseleniumisthewastetonercollectionpart,andthesidewiththemagneticrolleristhetonersupplypart.
Thenunscrewthescrewonthegearlesssideofthepartofthemagneticrollerthatsuppliesthepowder.Afterremovingtheplasticshell,youcanseeaplasticcover.Opentheplasticcoverandplacethetonercartridgeonthemagneticroller.Cleanupallthetoner,besuretocleanupalltheremainingtoner,itisbesttouseavacuumcleaner.Theninstallthemagneticrollerinthereverseorderofthepreviousone.Atthistime,applyforcetopressthemagneticrollertopreventthemagneticrollerfromleavingitsoriginalposition.Shakethetonerevenlyandslowlypouritintothetonersupplybin.Afterputtingontheplasticcoverandtheplasticshell,payattentiontoalignthesemicircleontheendofthemagneticroller'scentralshaftwiththesemicircularholeontheplasticshell.Gentlyturnthegearonthesideofthemagneticrollerseveraltimestomakethetonerevenly.
Nowwehavereachedthemostimportantstep-replacingthenewphotosensitivedrum.Usediagonalplierstopulloutthefixingpinofthewastetonercollectingpartthatfixesthephotosensitivedrum.Note:Donotusenailstodrivethefixingpinintothetonercartridge.Afterpullingoutthefixingpin,theoldphotosensitivedrumcanbetakenout,andthenthewastetonercollectingpartCleanupthewastepowder.Replacethenewphotosensitivedruminthereverseorderofdisassembly.Wheninstallingthephotosensitivedrum,payattentiontotheleftandrightpoints.Installthesidewiththegearbuttthegroove.Thenfixthephotosensitivedrumwiththefixingpins.Thenewlypurchasedphotoconductordrumhasablackanti-exposureseal.Donotremoveitbeforeinstallationtopreventexposure.Itcanberemovedonlyaftertheinstallationiscomplete.Finally,installandrestorethetonersupplypartandwastetonercollectionpartaccordingtothepositionswhentheyweredisassembled,insertthemetallatchesonbothsides,andthenstartprinting.
Translation
(1)Datatranslation:Toprintacompletetextandimage,inadditiontothefunctionsofthelaserprinteritself,thecontenttobeprinted,thatis,textorimage,mustalsobeprintedthroughthecomputerUsewordprocessingsoftwareorgraphicsprocessingsoftwaretoeditintoacomputerlanguagewithacertainformat.Thecontentofthedescriptionisdeterminedbythecomputereditingsoftwareandhasnothingtodowiththelaserprinter.WhenweselecttheprintercommandandpresstheOKandprintbutton,thecomputersendstheediteddatatotheprinterthroughtheprinterinterface,andtheprinterdriverinterpretstheprintedcontentandconvertsitintoalanguagethattheprintercanrecognize(alsoCalledprinterlanguage),theprinterwillprintouttheeditedtextorimageinitsownlanguage.
Differentmodelsoflaserprintershavedifferentprintinglanguagesanddifferentdrivers.Ofcoursetherearealsocompatibleprinterdrivers.ThelaserprintersproducedgenerallyusethestandardprintinglanguagePCL5orPCL6.
(2)Datatransmission:Therearemanykindsofcommunicationtransmissionportsbetweentheprinterandthecomputer,themorecommononesare"serialport"or"parallelport".EPP/ECP(EnhancedParalleIPort/ExtendedCapabilitiesPort)iscalledanenhanced/extendedparallelport."Serialport"isgenerallyrarelyusedduetoitsslowerspeed.Others,suchastheSCSIinterface,aremostlyusedinhigher-endprintersduetotheirfastspeed.Someprinterscommunicatewiththecomputerusingthevideointerface(VDO)method.Thecommunicationmethodisdifferentfromotherinterfaces.Ittransmitsnotdata,butalaserbeam,whichisfaster.Itsdataiscompletedbyanother"videoconversioncard",butbecauseitsharesmemorywiththecomputer,itrequiresthecomputertohaveenoughbufferspace.Thegeneralprintingandtypesettingindustryusesmoreprintersofthistypeofinterface.Somehigh-endprintershavemultipleinterfacesandcanconnecttomultiplecomputersatthesametime.ManyprintersproducedareequippedwithfasterUSBports.
Whentheprintcontrollerreceivesdatafromthecomputer,theprintergenerallyadoptstwoworkingmethods:oneistosendthedatadirectlytotheinterpreterforprinting,whichiscalled"segmentworkingmode",whichworksTheprinterdoesnotneedalotofcacheandmemory,andmostordinaryprintersusethiswayofworking.Theotheristostorethetransmitteddataintheharddiskinsidetheprinterandprintitoutatanytimewhenitisreadytobeused.Itisalsocalled"poolmode",whichisusedbymanyhigh-endprinters.Itsadvantageisthatwhenmanyusersshareaprinter,theycanissueprintcommandsatthesametimewithoutwaiting,andcansavethewaitingtimeofdatacommunicationtransmission,butitspriceisalsomoreexpensive.[Alsocalleddotmatrixgraphics),similartoordinarydotmatrixprinting.Theformeristorealizethedotmatrixarrangementbycontrollingtheonandoffofthelaserbeam,whilethelatteristorealizethedotmatrixarrangementbystrikingtheprintingneedle.
Rasterimageisakindofvideodigitalimage.Therasterconverterintheprinterneedstorasterizethevideodataandconvertitintoadotmatriximageusedbytheprinterforprinting.Theso-calledrasterimageiscomposedofindependentdots.Compositionofimages.Forexample,imagesprintedonnewspapersordisplayedonTVscreensarerasterimages.
Thedotmatrixarrangementoflaserprintersiscontrolledbyasquarematrixcomposedofbinarydata.Eachdotcorrespondstoabinarydigit.Thearithmeticcontrollercontrolsthelasertoemitalaserbeamtothesurfaceofthephotosensitivedrum,whichiscalled"exposure",theexposed"dots"arecalled"pixels".Toprintatextoranimage,alotof"pixels"arerequired.Therefore,thegreaterthenumberofpixelsperunitarea,thehighertheresolutionofprinting.Ifalaserscanningdeviceshoots300dotsperinchalongthehorizontalsurfaceofthephotosensitivedrumaxis,andthephotosensitivedrumisdrivenbythemainmotortorotateataconstantspeedof1/300minutes,thenthelaserprintercanbe300×300DPIpersquareinchResolutionprintstextorimages.Theoutputaccuracyofhigh-endlaserprinterscanreach2400DPI.Thedotmatriximageisformedbythepixels,anditisalsocompletedbytheacousto-opticmodulator,high-frequencydriver,scannersynchronizerandopticalsystem.
Modulator
Asyouallknow,theimagesandsoundsreceivedbytheTVareemittedbytheTVstationbymodulatingthesoundandlightsignalsintoelectricalsignals.TheelectricalsignalreceivedbytheTVisdemodulatedandrestoredtoimageandsound.Thelightbeamemittedbythelaserofthelaserprinteralsocarriesdatainformation,andtheconversionprocessofthisinformationisalsosimilartotheinformationtransmissionprocessofaTV.Butthisprocessisconvertedbytheacousto-opticmodulator.
Themodulationfrequencyoftheacousto-opticmodulatorcanreachabout30MHz,andthecharacteristicsarestable.Therefore,mostlaserprintersusethismodulator.Theworkingprincipleoftheacousto-opticmodulatoristousethecharacteristicsofBraggdiffractionproducedbytheacousto-opticeffecttorealizethecontrolofthepropagationdirectionofthelaserbeam.Tocompletetheimagingtaskofthegraphicinformation,thelaserbeammustbemodulatedwiththegraphicinformation,justasthetelevisionstationmodulatestheimageandsoundsignalstotheradiowavetodemodulatetheimageandsoundsignalsintheTV.
Theworkingprincipleoftheacousto-opticmodulatoristousetheacousto-opticeffecttogenerateBraggdiffraction.Ifultrasonicwavesaregeneratedinultrasonicmediasuchasglassandcrystals,itwillcauseperiodicrefractiveindexchangestobecomephases.Thegratingconstantisequaltothewavelengthoftheultrasonicwave.Whenthelaserbeamhitstheultrasonicmedium,thelaserbeamwillbediffracted.Theintensityanddirectionofthediffractedlightwillchangewiththefrequencyandintensityoftheultrasonicwave,whichistheacousto-opticeffect.
Whentheultrasonicwaveisemittedtoglassorcrystalandreflected,thelightrefractedbytheincidentanglepropagatestoformadiffractiongratingwithaphasechange.Thegratingconstantisequaltothewavelengthλoftheultrasonicwave.Ifthelaserbeamisinjectedintotheultrasonicmedium,thelaserbeamwillbediffracted,andtheintensityanddirectionofthediffractedlightwillchangewiththefrequencyandintensityoftheultrasonicwave.Thisistheacousto-opticeffect.Accordingtothestrengtheningconditionsofwaveinterference,thedirectionsofincidentlightanddiffractedlightsatisfytheBraggequation:
θi=θd=θB
sinθB=λ/2A=λf/2v(v=fA)
където:θi: ъгълът между падащата светлина и ултразвуковата повърхност; λ: дължината на вълната на светлината в средата; θd: ъгълът между дифрагираната светлина и ултразвуковата повърхност; A: дължината на ултразвуковата вълна; θB: Bregangle; f: ултразвукова честота. /2v, когато ъгълът между дифрагираната светлина и падащата светлина е α, тогава :α=θi+θd=2θB=λf/v.Във формулата α е ъгълът на отклонение, който е пропорционален на честотата на ултразвука. Промяната на ултразвуковата честотаf може да промени ъгъла на отклонение α, така че да се постигне целта за контролиране на посоката на лазерния лъч.
AccordingtotheBraggdiffractiontheory,whenultrasonicwavesmaintainahigh-frequencysignalofonefrequency,theincidentlaserbeamproducesafirst-orderdiffractedlightinadditiontoazero-orderlight.The0-orderlightcontrolsthestartandstopofthesynchronizerandthehigh-frequencysignal,andthefirst-orderdiffractedlightexposesthephotosensitivedrumtoformpixels.
Scanner
Tomakethelaserbeamaftertheacousto-opticmodulatorproducetextorimagesonthephotosensitivedrum,thelaserbeamneedstocompletethemovementinboththehorizontalandverticaldirections.Itdependsonthemovementofthelaser,becausethevibrationcausedbythemovementoftheoptoelectronicdevicewillaffecttheaccuracyofthelaserbeam.Therefore,thelaserofthelaserprinteradoptsafixedstructure,andamulti-sidedrotatingmirrorcompletesthehorizontalscanningofthelaserbeam,andtheverticalscanningisrealizedbytherotationofthephotosensitivedrum.
Tomakethemodulatedlaserbeamproducetextandimagesonthephotosensitivedrum,thehorizontalmovement(inthedirectionoftheprintingpaperline)andverticalmovementshouldbecompleted.Thelongitudinalmovementiscompletedbytherotationofthetonercartridge,whilethelateralmovementofthebeamiscompletedbythescanner.Scannersaredividedintoacousto-optic,electro-optical,galvanometer,androtatingmirroraccordingtotheirworkingmethods.Inviewoftheadvantagesofrotatingmirrorscanners,suchaslargescanningangle,highresolution,lowlightenergyloss,andsimplestructure,theyarewidelyusedinlaserprinters.Inordertoreducethenonlinearerrorgeneratedwhenthepolygonmirrorrotates,thegeometricaccuracyerroroftherotatingmirrorandtheunstablerotatingspeedoftherotatingmirrordrivemotor,thelongitudinalspacingandtheuneventrajectoryofthecharacterscausedbytheshortcomingsaregenerallyinstalledinthescanner.Asyncsignalsensor.Thissensorusesthezero-orderlightgeneratedbyBraggdiffractionwithoutdeflection,soithasthecharacteristicoffixedirradiationpositionafterbeingreflectedbythepolygonmirror.Itisusedasasynchronizationsignaltocontrolthestartandstopofthehigh-frequencysignalgenerator.Ensurethatthescanningdistanceisconsistentandeliminatetheabove-mentionederrors.
Inordertointegratethescanningbeamgeneratedbythescannerintoaspecifiedsizeandperformauniformlinearmotiononthephotosensitivedrum,abetteropticalpathsystemshouldbeused.Theopticalpathsystemisdividedintotwotypes:frontandrearobjectivelensaccordingtothelens'sfrontandrearpositionofthescanner.Sincetherearobjectivelenshasseriousdistortionwhenscanninglargerimages,itisrarelyused.Thescanninglineinfrontoftheobjectivelensisrelativelystraight,butthereisdistortion.Sincethelaserprinterproducedlaterusesawide-anglefocusinglenscombinedwithmultiplelenses,thefocallengthis300mm,andtheobjectdistanceofthepolygonmirroris37mm.ThedistortionisItisonly0.0011%,whichcanfullymeettherequirementsoflaserimaging.
Thepolygonalscanner(mirror)usedinlaserprintersgenerallyhasthreekindsofmirrors,two-sidedmirror,four-sidedmirror,andsix-sidedmirror.Thescanningmotordrivestherotationtocompletethehorizontalscanningmovement.Itisakeycomponenttoensuretheprintingaccuracyoflaserprinters.Theprincipleofthescannertocompletethehorizontalscanningis:WesetMNasamirrorofthescanner.WhentheincidentlaserbeamhitspointAontheMNsurface,iftheincidentangleisθ?i,thereflectedbeamwillbereflectedatthereflectionangleθ?d,θ?i=θ?d,whenMNrotatesthroughanangleφ,Whilethedirectionoftheincidentbeamremainsunchanged,thereflectedbeamrotatesby2φ,thatis,thereflectedbeamrotatesattwicetheangleofMN.IfPisthereflectedlightspotatoneendofthephotosensitivedrum,andP1isthereflectedlightspot,thelateralscanningofthephotosensitivedrumiscompletedattheotherendofthephotosensitivedrum.Ofcourse,therotationspeedofthescannerisextremelyfast,soP～PAlotofreflectedlaserbeamspotsarealsoformedbetween?1.Whenthemainmotordrivesthephotoreceptordrumtorotate,italsocompletesthelongitudinalscanningofthereflectedlaserbeamspot,thusfinallycompletingthedotmatrixarrangementofthetextorimage.
Opticalsystem
Inordertomakethelaserbeamreflectedbythescannergathertoformalightspotofaspecifiedsize,andeliminatethediffusionofthebeamduringthepropagationprocess,asetofopticallensesisneeded.Thebeamismodulatedtoimprovescanningaccuracy.Itincludes:curvedlens,sphericallens,reflector.Thisgroupoflensescanonlymeetthetechnicalrequirementsoflaserimagingifthedistortionofthelaserbeamiscorrectedto0.1‰.
Visualizationsystem
Laserprinterisasophisticatedmechanicalsystemthatusesthephysicalandchemicalprinciplesoflight,electricity,andheattooutputtextorimagesthroughinteraction.ThesecomplexprocessesareItisrealizedbyanelectroniccontrolsystem,calledanelectronicimagingsystem.Thetheoryof"electrostaticimaging"wasfirstproposedbyAmericanCarlson,soitisalsocalledCarlson'smethod.Orcalledtheelectricdischargeimagingmethod.Thebasicprocesscanbedividedinto7stepsofcharging,exposing,developing,transferring,fixing,cleaning,andde-energizing,ofwhich5stepsarecarriedoutaroundtheelectronicimagingsystem.
Класификация
Лазерните принтери могат да се разделят на три категории според тяхната скорост на отпечатване: нискоскоростни лазерни принтери (производителност 10-30 страници в минута); средноскоростни лазерни принтери (производителност на минута 40-120 страници); високоскоростен лазерен принтер (производителност 130-300 страници в минута).
Structure
Laserprinteriscomposedoflaser,acousto-opticmodulator,high-frequencydrive,scanner,synchronizerandopticaldeflector.ItsfunctionistosendtheinterfacecircuitThebinarydotmatrixinformationismodulatedonthelaserbeam,andthenscannedontothephotoreceptor.Thephotoreceptorandthecameramechanismformanelectrophotographictransfersystem,whichtransferstheimageandtextshotonthephotoreceptordrumtotheprintingpaper.Theprincipleisthesameasthatofacopier.Thelaserprinterisanon-impactoutputdevicethatcombineslaserscanningtechnologyandelectronicimagingtechnology.Ithasdifferentmodelsanddifferentprintingfunctions,buttheworkingprincipleisbasicallythesame,andithastogothroughsevenprocesses:charging,exposure,developing,transfer,discharging,cleaning,andfixing,ofwhichfiveprocessesarecarriedoutaroundthephotosensitivedrum..Whenthetextorimagetobeprintedisinputintothecomputer,itispreprocessedbycomputersoftware.Thenitisconvertedbytheprinterdriverintoaprintcommand(printerlanguage)thattheprintercanrecognizeandsenttothehigh-frequencydrivecircuittocontroltheonandoffofthelaseremittertoformadotmatrixlaserbeam,andthentheelectronicimagingsystemthroughthescanningmirrorThephotosensitivedruminthephotoconductivedrumperformsaxialscanningexposure,andtheverticalscanningisrealizedbytherotationofthephotosensitivedrumitself.
Precautions
Becauselaserprintershavehigh-voltagecircuitsandhigh-temperaturecircuits,bothelectronicradiationandthermalradiationhaveacertainimpactonthehumanbody.Payattentiontotheprotectionorprotectionofpregnantwomenandyoungchildren.Stayawayfromthesedevices.Duringtheprintingprocess,hightemperatureheatingwillbringoutsomepowderandinkparticles,whichisnotgoodforbreathing,soyoushouldtrytoavoidworkingatthelaserprinterforalongtime.
Charging
Thephotoconductormaterialonthesurfaceofthephotosensitivedrumisaninsulatorwhenitisnotexposedtolight,anditisinaneutralstatewithoutanycharge.Torealizethe"electrostaticlatentimage"onthesurfaceofthephotoconductor,thesurfaceofthephotoconductormustbechargedtomakeitcharged.Onlyinthisway,whenthelaserbeamscansontothelightconductor,theexposedpointsofthelightconductorareturnedontoformabeamdotmatrix.Thedotmatrixchargeconductswiththesubstratetoforma"potentialdifferencelatentimage".Whenthephotosensitivedrumrotatestoapositiontangenttothedevelopingmagneticroller,thetoneronthemagneticrollerwiththeoppositechargepropertiesofthephotoconductorsurfaceisattractedtothesurfaceofthephotosensitivedrum.Asaresult,atonerimageappearsonthephotosensitivedrum.
Tomakethephotosensitivedrumabsorbthetoneraccordingtothegraphicinformation,thetonercartridgeshouldbechargedfirst.Thechargingelectrodeisatungstenwireparalleltothephotosensitivedrumshaftwitha5～7kVDChighvoltage,whenthesurfaceofthedrumisveryclosetothetungstenwire,thesurroundingairisionizedtoproducecoronadischarge,whichmakesthephotosensitivedrumcharged.Thepositiveornegativeofthevoltageisdeterminedbythevoltagecarriedbythetungstenwire.Ifthephotoconductivematerialisselenium-telluriumalloy,itwillbechargedpositively.Afterthephotosensitivedrumrotatesonce,theentiresurfacewillbecharged.
Themethodoflaserprinterchargingthephotosensitivedrumisdifferentdependingonthemodel,butthechargingprincipleisbasicallythesame,allusingDChighvoltagecoronadischargetochargethesurfaceofthephotosensitivedrum.
Earlylaserprintersusedelectrodewireandgridcompositestructuretochargemore,andmostnewlaserprintersusedchargingrubberroller(FCR)tochargethephotosensitivedrum.Whenthehighvoltagegeneratorsendsahighvoltagetotheelectrodewire,astrongelectricfieldisformedbetweentheelectrodewireandthegrid,andacoronaisreleased.Theairbetweentheelectrodewireandthephotosensitivedrumisionized,andtheairionsmigratetothesurfaceofthephotosensitivedrum,sothatthesurfaceofthephotoconductor(photosensitivedrum)isfullycharged.Thismethodcanmakethesurfaceofthephotoconductor(photosensitivedrum)evenlycharged,butatthesametimeitalsogeneratesalotofnegativeions(ozone).Whenozoneaccumulatestoacertainamount,itisharmfultothehumanbody.SuchasCanon'searlyproductsLBP-SXandSTmodels,HP'searlyproductsHP2and3,PanasonicKX6500producedinJapan,LenovoLJ6L,LJ6Pandothermodelsallusethismethodtocharge.
Mostofmodernlaserprintersarechargedbychargingrollers.Becauseofthecontactchargingmethod,thereisnoneedforhighchargingvoltageandnoozoneisproduced.However,duetotheaccumulationofionizeddust,theThewearofthephotosensitivedrumwillalsocauseunevencharging.
Сканиране на експозиция
Точно както използваме apentwrite на хартия, инструментът за сканиране на експозиция използва лазерен лъч, за да "напише" експозицията върху фоточувствителния барабан. Този текст или изображение е невидим. Това е, което наричаме "електростатично латентно изображение".
Whenthesurfaceofthetonercartridgepassesthroughthetungstenwireelectrode,itssurfaceischargedwithpositiveelectricity,andnegativeelectricityisinducedattheinterfacebetweenthephotoconductivelayerandthesubstrate.Whenthelightpartofthelaserbeamhitsacertainareaonthedrumsurface,itiscalledexposure.Theresistivityoftheexposedareaissignificantlyreduced,andthepositivechargeonthesurfaceandthenegativechargeontheinterfaceareneutralizedanddisappeared.Duetothegoodinsulatingpropertiesbetweentheselenium-telluriumalloyparticles,thepositivechargeonthesurfaceoftheunexposedsurfaceremainsunchanged.Thatis,alayerofelectrostaticlatentimageisformed.
Scanningexposureistousethephotosensitivepropertiesofthephotoconductivematerialonthesurfaceofthephotosensitivedrum.Whenthephotoconductorisscannedandirradiatedbythelaserbeam,theilluminatedpartisconnectedtotheconductivelayerofthephotosensitivedrumtomakethechargedisappear,andthepartnotilluminatedbythelightstillmaintainsthechargedcharge,thusformingapotentialdifferenceimage,whichcanalsobeunderstoodasThe"discharge"processofthephotosensitivedrum.Duringthede-chargeprocess,thepotentialonthesurfaceofthephotoconductorischanging,andthispotentialchangehasagreatinfluenceontheprintquality.
Whenthesurfaceofthephotosensitivedrumischarged,asthechargeaccumulatesonthesurfaceofthephotosensitivedrum,thepotentialcontinuestorise,andfinallyreachesthe"saturation"potential,whichisthehighestpotential.Thesurfacepotentialwilldecreasewiththepassageoftime.Generally,theworkingpotentialislowerthanthispotential.Thisprocessofnaturaldecreaseofthepotentialwithtimeiscalledthe"darkdecay"process.Whenthephotosensitivedrumisscannedandexposed,thedarkarea(referringtothesurfaceofthephotoconductornotirradiatedbylight)isstillinthedarkdecayprocess;thebrightarea(referringtothesurfaceofthephotoconductorunderthelightirradiation)rapidlyincreasesinthecarrierdensity.Theelectricalconductivityrisesrapidlytoformaphotoconductivevoltage,thechargequicklydisappears,andthesurfacepotentialofthephotoconductoralsodropsrapidly,whichiscalled"lightdecay",andfinallyslowsdown.
Intheory,thefasterandmorethoroughthelightdecayis,thebetter,butinpracticeitisdifficulttoachieve.Theleveloftheremainingresidualpotentialwillaffecttheprintquality.Iftheresidualpotentialistoohigh,thephenomenonofprinting"dust"willappear.Afteranelectrostaticlatentimageisformed,itmustundergoa"development"processasdescribedbelowbeforeitcanbeconvertedintoatonerimage.
Development
The"electrostaticlatentimage"formedonthesurfaceofthephotoconductoris"developed"toshowthetonerimage.Thisprocessiscalled"electronicdevelopment".Thedevelopmentworkiscompletedbythedeveloper,anditsroleistoturntheelectrostaticlatentimageintoavisibleimage.Thedevelopmentisdonebyusingtheprincipleofthesame-sexrepulsionandtheopposite-sexattractionbetweenmaterials.
Thedeveloperisequippedwithironpowderandcarbonpowder.Afterfriction,theironpowderispositivelychargedandthecarbonpowderisnegativelycharged,sothattheironpowderissurroundedbythecarbonpowderandtheironpowderthathasadsorbedthecarbonpowderispermanentlyThemagnetisattractedtoformalayerofironpowderandcarbonpowdermixturesimilartoabrush.Whenthesurfaceofthetonercartridgepassesunderthislayerofmagneticbrush,thetonerisattractedtothepartofthetonercartridgethatisstillpositivelychargedduetothenegativecharge,formingavisibletonerimage.Thefunctionofthestirreristomaketheironpowderandthecarbonpowderfrictionallycharged.
The"electrostaticlatentimage"chargeonthesurfaceofthephotosensitivedrumisoppositetothechargecarriedbythedevelopertoner.Whenthephotosensitivedrumandthemagneticrollercarryingthetonerareclosetoacertaindistance,thetonerwillbeAttraction,orthetonerjumpstothesurfaceofthephotosensitivedrumtoforma"tonerimage",alsoknownasjerkydevelopment.Note:Afterthelaserprinterphotoconductordrumisexposed,thechargeofthe"electrostaticlatentimage"onthesurfaceisnegative,whilethechargeofthetonerispositive.Thetonertransferofthedevelopingunitiscompletedinthisway.
Whenthetonerisevenlystirredinthetonercartridgebytheagitator,thetoneriscarriedbythedopedcarrierandisadsorbedontheoutersurfaceofthemagneticrollerbythepermanentmagneticcoreinthemagneticroller.Nopolarity.Whenthemagneticrollercarriesthetonerandrotatesandtouchesandrubsagainstthetonerscraper,thetonerispositivelycharged.Undertheactionofthetonerscraperandthemagneticfield,thetonerformsathinanduniformtonermistonthesurfaceofthemagneticroller.Thetonerscraperalsoservestolimittheamountoftoner,sothatthetonerdoesnotabsorbtoomuch.
Asmentionedearlier,theresidualpotentialofthephotosensitivedrumisanimportantreasonforthe"bottomdust"inprinting.ThesolutionistoaddappropriateACandDC"bias"tothemagnetrollersleevetooffsetExcessivepowderdelivery.Thedevelopmentbiashastwofunctions.Adjustthedevelopmentbiasappropriately.Oneistoprevent"dust"andtheotheristoadjusttheprintingdensity.Inpracticalapplications,the"printdensity"adjustmentknobistoadjustthedevelopingbias.SomelaserprintermodelssuchasHP,Canon,Epson,andLenovohavethisknob.Buttheincreaseinprintdensityalsomeansthedecreaseinresolution,becausetoomuchtonerwillaffecttheresolutionafterfixing.
Newlyproducedlaserprintersgenerallyhave"resolutionenhancementmode"(RET).ThroughtheRETmethod,thedefectsofthediagonalorarc"dotmatrixholes"canbefilled.REThasnoeffectonthehorizontalandverticaldotmatrix.Ithasthreemodes:①Lighi;②Medium;③Dark.RETcanbecombinedwiththechoiceofprintingdensitytoprintbeautifultextorimages,alsoknownassmoothingtechnology.Withdifferentsettings,thelogoblockontheprintedsampleisdifferent.
Developingmagneticroller:Thedevelopingmagneticrollerisanimportantpartofcarryingtoner.Thepermanentmagneticcoredoesnotrotate.Itsfunctionistousemagnetismtoattracttonertothesurfaceofthemagneticroller.Thesurfaceofthemagneticrollerissprayedwitharoughgraphitelayertoformelectricalcavitieswiththetonerscrapertofacilitatetonertransfer.Whenthemagneticrollerloadedwithtonerrotatesoutofthepositionofthescraper,thetoneronthesurfaceofthemagneticrollerisnotonlycharged,butduetotheforceofthemagneticfield,itformsa"magneticspike",thatis,a"tonermist".Therollerjacketappliesabiasvoltagetoarrangethemagneticspikesinanorderlymanner.Thefunctionofthe"spacer"ofthemagneticrolleristocontroltheeffectiveattractiondistancebetweenthemagneticspikeonthesurfaceofthemagneticrollerandthephotosensitivedrum,whichisbeneficialtoimprovethe"bounceimaging"ofthetoner.
Toner:Thetonerusedinlaserprintersisasingle-componenttoner,andtheprincipleoftheprojectionmethodissimilartotheNPcopier,whichistheNPmethod."Single-componenttoner"isnotwithoutacarrier,becausewithoutabowl,thetonercannotbecarried.Itpowdersthe"carrier"intofineparticlesandmixeswiththetoner.Theparticlesofultrafinetonershouldbelessthan10nanometers.Differentmodelsoflaserprintersusedifferenttonersduetothedifferenceinexposureintensityanddevelopingbiasvoltage,sotheycannotbesubstitutedatwill.Differentmodelshavedifferenttoner"carrier"contentofthesamequality.Someprintersusenon-magnetictoner.
Разтоварваща система
(1)Трансферно устройство
Usehigh-voltagestaticelectricitytotransferthe"tonerimage"onthesurfaceofthephotosensitivedrumtoplainpaper,Thisprocessiscalled"transfer".Whenthepositivelychargedtonermovestothevicinityoftheprintingpaperalongwiththephotosensitivedrum,theelectrodeplacedbehindthepaperispositivelycharged.Becausethevoltageisashighas500～1000V,theelectrostaticattractionmakesthepaperclosetothelightguideplate.Thenegativelychargedtonerisadsorbedonthesurfaceofthepaper.Becausethistransfermethodisrelatedtothedegreeofinsulationofthepaper,whenthepaperisdampduetotheweather,thetonerwillnotbecompletelyandtightlyadsorbedonthepaperduetotheleakageofthepapersurface,resultinginpoorprintquality.
Therearetwotransfermethods,oneis"coronadischargetransfer"(wireelectrode),andtheotheris"dischargerubberroller"transfer.Theworkingprincipleofthetwoisthesame.Differentmodelshavedifferenttransfermethods.Theearlyproductionoflaserprintersmostlyusedthecoronadischargetransfermethod.Whenthephotosensitivedrumcarryingthetonerimagerotatestoapositiontangenttothetransferelectrodeortransferrubberroller,apieceofprintingpaperisalsofedbetweenthetwo,andthenthehighvoltageappliedtothetransferelectrodestartsDischarge,whilepushingtheprintingpapertothephotosensitivedrum,thetonerimageonthephotosensitivedrumisattractedtotheprintingpaperduetothetransferofthehigh-voltageelectricfieldonthebottomoftheprintingpapertocompletethesecondarytransferofthetonerimage.Thedischargepolarityofthetransferelectrodewireortransferrubberrolleristhesameandnegative,butthisnegativevoltageishigherthanthenegativevoltageintheexposedareaofthephotosensitivedrum,sothatwhilepushingtheprintingpapertothephotosensitivedrum,italsoreducesThetonerisattractedtotheprintingpaperasmuchaspossible.However,itshouldbenotedthatwhenthetoneristransferredtotheprintpaper,iftheprintpaperisdampandtheinsulationperformanceisnotgood,itwillaffectthetonertransferefficiency,sotherewillbeproblemsofimagedefectandpoorprintqualityofthecharacterhollowchip.
(2) Разредено устройство
Whenthetonerimageistransferredtotheprintingpaper,theprintingpaperisalsocharged.Intheprocessofconveyingtheprintingpaper,electricfieldandfrictionmaydestroythestructureofthetonerimage,soafterthetonerimageistransferred,a"dischargedevice"(dischargerordischargingtooth)isadded,alsocalled"Separateteeth".Itsfunctionistoneutralizethechargeontheprintingpaperandtheadsorbedtoner,eliminatethepolaritytomakeitneutral,andphysicallyadheretotheprintingpaper,therebyensuringtheaccuracyofthetonerimagebeforefixing.Thede-energizationprocessusesACvoltagetoachievethebestde-energizationandneutralizationeffect.
Нагряване и фиксиране
Процесът на отпечатване на тонерно изображение, абсорбирано върху хартията, като се използва методът на топлинно сливане под налягане, така че разтопеният тонер да се потопи в хартията за печат, за да образува фиксирано изображение, наречено „фиксиране“.
Thecarbonpowderadsorbedonthepaperisasmallparticlemadeofthermalresinandcarbonpowder.WhenthepaperwithcarbonpowderpassesthroughtwohighandsmallgapWhenthemetalrolleriscracked,theresininthetonermeltsandispressedtightlyonthepapertogetherwiththetoner,thusformingapermanentimage,andatthesametime,theentirelaserprintingprocessiscompleted.Themeltingtemperatureofthetonerisabout100°C,andthetemperatureoftheheatrollerisrelatedtothespeedofpaperpassing,generallybetween150and180°C.Aftercleaningtheresidualpowderandlight,thephotosensitivedrumentersthenextcycle.
Thelaserprinteradoptsthemethodofcompositehotpressing,andusesthe"fixingcomponent"tocompletethefixation.Theworkingprocessoftonerimagefixingisasfollows:
Whentheprintingpaperloadedwith"tonerimage"entersbetweentheheatingrollerandthepressurerubberrollerinthefixingdevicefromthepaperguide,theheatingrollerItisheatedbytheheatinglamp(185°C),andatthesametime,thetonerismeltedandimmersedintotheprintingpaperduetothepressureofthepressurerubberroller.ThesurfaceoftheheatingrolleriscoatedwithaPTFEcoating,whichmakesitdifficultfortonertoadhere.SomemodelsalsohavealayerofTeflonfilmonthesurfaceofthepressurerubberroller,whichishelpfulforthetoneronthebacksidetonotstickduringdouble-sidedprinting.Afterheatingandfixing,theprintingpaperisseparatedfromtheheatingrollerbytheseparatingclaw,andisledoutbythepaperdischargewheeltocompletethewholefixingprocess.
(1) Нагревателна ролка
Theheatingrollerismadeofseamlessaluminumalloytube,thewallthicknessofthetubeisbetween1to3mm,andthesurfaceiscoatedwithPTFE.Thispreventsthemeltedtonerfromstickingtotherollerduringfixing.ThePTFEcoatingonthesurfaceoftheheatingrollerwillsoftenslightlyathightemperatures.Whentheprintingpaperisstuckinthefixingdevice,donotusesharphardobjects(suchasscrewdrivers,cameras)toforceitout.Itwilldamagethesurfacecoatingoftheheatingrollerandaffecttheintegrityofthetonerimageafterfixing.
Има много лазерни принтери, които използват усъвършенствани керамични читери (PCT), които се загряват бързо и пестят електричество, като HP4L.4P, 5L, 6L, 6P, 2100, 4000, 5000 и Canon 460, 660, 800 и модели JX allus керамични читери за фиксиране.
(2) Нагревателна лампа
Somelaserprintersusehalogenlampswithapowerof350～750W.Theyarefixedinthemiddleoftheheatingrolleranddonotrotatewiththeheatingroller.Aftertheprinterisenergized,theheatinglampisontopreheatthefixingroller.Afterabout1to2minutes,thetemperatureoftheheatingrollerreachesabout185degrees.Whenthesurfacetemperatureoftheheatingrollerreachesthefixingtemperature,thethermistorleaningonthesurfaceoftheheatingrollertodetectthetemperatureinformsthemainlogiccircuittostopheating,andthelampisreadytolightup.Theprintercanstartprinting.Whentheheatinglampisdamaged,thewholemachinewillnotwork,andthemodelwithadisplaypanelwilldisplayanerrorindicationoranerrorcodeof50Error.
(3) Притискаща гумена ролка
Thepressurerubberrollerisalsocalledthelowerroller,anditsfunctionistocompletethehot-pressfixingandtransferofthetonerontheprintingpapertogetherwiththeheatingroller.Thepressureiscontrolledbythesupportspringsatbothends.Thepressurerollerisgenerallymadeofhigh-temperatureresistantsiliconrubber.Thepressurerollerinsomelaserprintersismadeofhoneycombheat-resistantsponge,andtheoutersurfaceisalayerofPTFEfilm.Itismoreconducivetotheseparationoftheprintingpaperandthepressurerubberrollertopreventpaperjams.
(4) Контролер на температурата (термистор)
Mostofthetemperaturecontrolmethodsforlaserprintersusethermalinduction,usingasmallthermistortocontacttheheatingrollertosenseheatingRolltemperature(165～200℃).Thenthelogiccircuitcontrolstheonandoffoftheheatinglamptorealizetheconstantfixingtemperatureofthelaserprinter.Theperformanceofthethermistoristhatthehighertheexternaltemperature,thelowertheresistanceofthethermistor.
Whentheheatingrollerisnotenergized,theresistanceofthethermistorisabout200K,thelogiccontrolcircuit0101isturnedon,thethyristorSSR101isturnedon,andtheheaterstartsheating.Whenthetemperatureoftheheatingrollergraduallyrises,theresistanceofthethermistordecreases.Whenthesurfacetemperatureoftheheaterreachesabout180°C,theresistanceofthethermistoralsoreachesthelowestvalue,about10K,andtheinputvoltageofthethermistortothelogiccontrolcircuitincreases.Afterreachingacertainvalue,0101willbecutoff,andtheheaterwillstopheating.Thisisrepeatedtocontrolthesurfacetemperatureoftheheatertokeepwithinthedesignedtemperaturerange.Thelaserprinterisequippedwithapowersavingfunction(sleepmode).Ifthereisnoprintingwithinasettime,themainlogiccircuitwillcontroltheheatertoenterapowersavingstatetokeeptheheatersurfacetemperatureatabout165°C.Ontheonehand,thiscontrolcansavepowerconsumption.Ontheotherhand,whentheprintjobisrestarted,itcanshortenthewarm-upwaitingtime(thetimetoenterthepower-savingstatecanbeset).
(5)Термичен протектор (термичен превключвател)
Inordertopreventthetemperatureinthelaserprinterfromrisingunrestrictedlyandburningtheheatinglampandheatingroller,theheatinglampcircuitAthermalprotector(thermalswitch)isconnectedinserieswiththeheatingroller.Insidethethermalswitchthereisasetoflongclosedcontacts,atitaniumsheetandastalk.Titaniumisakindofmemorymetalmaterialwithamemorytemperatureof210°Cduringmanufacture.Ifthetemperaturecontrolcircuitisoutofcontrol,whenthesurfacetemperatureoftheheatingrollerexceedsthesettemperatureof210℃,thetitaniummetalwillshrinkanddeformunderheat,pressingthestrikerbartodisconnectthenormallyclosedcontact,andcuttingoffthecircuitwillprotecttheheater.Whenthetemperatureislowerthan180°C,thetitaniummetalreturnstotheoriginalmemorystate,thenormallyclosedcontactisclosed,andthecircuitisturnedon.Someprintersusefuseprotectors,theprincipleissimilartocurrentfuse.
Cleaningsystem
Themainfunctionofthelaserprintercleaningsystemistoremovethe"residualtoner"thatisnotcompletelytransferredonthesurfaceofthephotosensitivedrum,sothatthenextprintingcyclewillhaveacleanphotosensitivedrum.Theoreticallyspeaking,the"tonerimage"shouldbecompletelytransferred,butitisdifficulttodoso.Duringtheprintingprocess,thelaserprintergoesthroughseveralprocessesofcharging,scanning,imaging,andtransfer.Duetopotentialmigration,tonertransfer,plustheinfluenceofthelightconductor"lightdecay"?Thetonerimage"cannotbecompletelytransferredtoOntheprintingpaper,theamountoftonerremainingonthesurfaceofthephotosensitivedrumdirectlyaffectsthequalityoftheprint.
Iftheresidualtoneronthesurfaceofthephotosensitivedrumcannotbecompletelyremoved,itwillbeInthenextprintingcycle,thenewlygenerated"tonerimage"willbedestroyed.Therefore,thesurfaceofthephotosensitivedrummustbethoroughlycleaned,whichrequiresaphotosensitivedrumcleaner.Therearetwocleaningmethodsforlaserprinters:rubberscrapercleaningandBrushcleaning.Theirroleistocleanthesurfaceofthephotosensitivedrum.
(1)Почистване на скрепер
Therubbercleaningbladeismadeofurearesinandhasaflatsurface.Thebladeisstraightandhasabrasionresistanceandflexibility.Thebladeformsashearanglewiththesurfaceofthephotosensitivedrumandhasacertainpressure.Whenthephotosensitivedrumrotateswiththetonerremainingonthesurface,theremainingtonerisscrapedintobythecleaningbladeInthewastetonercollectionbin.Thereisanon-returnsheetatthepositionoppositetothescrapertopreventthewastetonerfromflyingoutaftercleaning.Becausetherubberscraperisalwaysshearedwiththephotosensitivedrumandhasacertainpressure,itwillcausethesurfaceofthephotosensitivedrumIfthebladeofthecleaningbladeisdamaged,thetonerremainingonthesurfaceofthephotosensitivedrumcannotbecompletelyremoved,causingtheimagesinthenextprintingcycletooverlapandproducepoorprintingresults.
(2)Почистване на четки
Brushcleaningistousearotatingrollerbrushtocleantheresidualtoneronthesurfaceofthephotosensitivedrum,toremovetheresidualtonerandshakeFallingintothewastetonercollectionbin.Thebrushisgenerallymadeofman-madefibersandrubswiththephotosensitivedrumwhenrotatingtoremovetheresidualtoner.Atthesametime,thestaticelectricitygeneratedbythefrictionisusedtoabsorbtheresidualtoner,sothatthetonerwillnotflyandpolluteotherpartsoftheprinter.Themethodofusingabrushtocleanthesurfaceofthephotosensitivedrumcanprolongtheservicelifeofthephotosensitivedrum.
(3) Кошче за събиране на отпадъци
ThewastetonercollectionbinisRecyclingandcleaningtheresidualtonerdevice.Thecollectedtonerisgenerallynolongerused.Becausetherearemanyimpuritiesinthecollectedtoner,whichwillaffecttheprintingquality,someprintersuserecycledtoner.Thescrapedtonerissentbacktothetonersupplybinbyascrewfeedingdeviceforrecycling.However,afteraperiodofuse,thereplenishmentofnewtonerisinsufficientortheoldandnewtonercannotbefullymixed,andtheprintqualitywilldropalot.
Mechanicaltransmission
Theelectroniccontrolsystemcontrolsthemechanicaldevicetocompletethetransmissionofthepaperduringtheprintingprocess.Itincludesthetransmissiongear,thephotoelectricsensor'sblockingleverandthepickupwheel.Mechanical.Thetransmissionsystemhasdifferentstructureduetodifferentmodels,buttheworkingprincipleisbasicallythesame.Themechanicalstructureofhigh-endmodelsismorecomplicated.Forexample,thereisgenerallyno"printpaperalignment"deviceformid-rangeandlowermodels,andhigh-endmodelshavethisdevice.Therearealso"paper-inreel"and"paper-outreel".MultiplewindingdevicesSetting,canmakethetransferofprintingpapermorestable,andalsoreducethephenomenonof"paperjam".Themechanicaltransmissionsystemismainlygeartransmissionbetweenvariouscomponents,whichisrelativelyintuitive.Letmetalkabouthowthemechanicaltransmissionactionoftheelectromechanicaldeviceiscompleted.
(1)Смукателен електромагнитен съединител
ThepaperfeedingdeviceofHPseriesprintersadoptstheattractionelectromagneticclutchtocontrolthestopandrotationofthepaperfeedingcamtocompletepapertransportation.Whentheelectromagnetreceivesthesignalvoltageofthecontrolcircuit,currentflowsthroughtheelectromagnetcoil,generatinganelectromagneticfieldtoattractthearmature,thecamisreleased,andthetransmissiongeardrivesthepickuprollertorotatetogether.Thereisarubberlayeronthepickuprollersurface,whichfollowsthepickuproller.Rotate,thefrontedgeofthecamdrivesapieceofprintingpaperintotheprintingchannel.
(2) Фрикционен електромагнитен съединител
ThepaperfeedingdeviceofHP,Canon,Epsonandotherseriesofhigh-endprintersusesfrictionelectromagneticclutchtodirectlydrivethepickuproller,Thepaperisfedbythealignmentroller.Itsworkingprincipleis:whenthecurrentsignalflowsthroughtheinternalcoiloftheelectromagneticclutchtogenerateanelectricfield,thelinkageforkinthemiddleoftheclutchispushedtooneendofthecoupling,andthetwofrictionplatesproducefrictionstop,andthepick-upwheelisdrivenbytheshiftforktorotateandprintThepaperisfedintothefrontedgeofthe"paperregistrationroller"insidetheprinterandtheprintingpaperisslightlybowed,andtheprintingpaperisalignedwiththeregistrationroller.Atthistime,theregistrationrollerdoesnotrotate.Whentheregistrationrollerclutchreceivesacommandtorotate,itwillfeedtheprintingpaperintotheprintingpath(thepickuprollerofthefrictiontypeelectromagneticclutchiscircularratherthancam-shaped).
(3) Сензор
Thephotoelectricsensorconsistsofalight-emittingdiodeandaphotodioderespectivelyinstalledintwosmallsealedboxes.Intherelativepositionofthetwodiodes,eachhasasensingwindow.Usuallythereisalevershieldbetweenthetwowindowstoshieldthelightbeamofthelight-emittingdiode.Thephotodiodeisnotexposedtolight,soitcannotbeturnedon,andthelogiccircuitdoesnotwork.Whenthemovingprintingpaperknockstheshutterleverinthemiddleofthephotoelectricsensoropen,thelightbeamofthelight-emittingdiodeisdirectedtothephotodiode,andthephotodiodeisturnedonbythelight,andinformsthelogiccontrolcircuittoissueinstructionstocontroltheprinter'snextperiodofwork.Thepapersensor,paperfeedsensor,andpaperoutputsensoroflaserprintersallusephotoelectricsensors.Itisthelogiccontroldeviceofthemaincontrolcircuit,whichisusedtorealizethetimingcontroloftheprintingwork.Iftherequiredactionisnotsensedwithinthespecifiedperiodofprintingwork,thelogiccircuitwillimmediatelysenda"stop"messagetothemaincontrolcircuittostoptheprinter,andthedisplaypanelwillalsodisplayan"error"message.WaitCheckorrepair.
Electroniccontrol
Theoperationofalldevicesofthelaserprinterisrealizedbyacontrolsystem,whichiscalledthe"electroniccontrolsystem".Thecontrolsystemofdifferentmodelsisdifferent,buttheworkingprincipleisbasicallythesame.Theelectroniccontrolsystemmainlyconsistsofthefollowingparts.
(1) Захранваща верига
Providecontrolvoltageforeachpartoftheprinter.Thepowersupplycircuitisrectified,filtered,andtransformedby220Valternatingcurrenttoprovide24V,5Vdirectcurrentworkingvoltageforthelaserprinter.
(2) Интерфейсна верига
Establishcommunicationbetweenthecomputerandtheprinter.Receivecomputerdatainformationandconvertitintoprinterlanguagetoprovideprintingdatatothemaincontrolcircuitoftheprinter.Theinterfacecircuitincludesamicroprocessor(CPU).Memory(RAM/ROM).
(3)Основната контролна верига
Themaincontrolcircuitisthedatareceivedbytheinterfacecircuitandcontrolsthevariousdevicesoftheprintertoworktogetherinacommandmodetocompletetheprintingprocess.
(4) Сканираща задвижваща верига
Thereceivedcomputerinformationisgeneratedbyahigh-frequencyoscillatortogeneratealaserbeam,andthescanningmotoriscontrolledtorotateatauniformspeedtodrivethescanningmirrortocompletethephotoreceptordrumScanandexposetoformanelectrostaticlatentimage.
(5) Задвижваща верига на главния двигател
Accordingtothecommandissuedbythemaincontrolcircuit,themainmotorisdriventorotate,andthroughthegeartransmissiondevice,poweristransmittedtoeachpartoftheoperation.
(6)Преносна верига за високо напрежение
Thiscircuitconvertsthelow-voltagepowerprovidedbythepowersupplycircuitintoahighvoltagethroughatransformertoprovidethephotosensitivedrumchargingandtransferrollertransferneeds.
Отстраняване на неизправности
One.Outputafullsheetofblackpaper
Възможна причина за повреда:p>
(1)Ако лазерът е определено добър, зареждащият електрод може да е в късо съединение с мрежата;
(2) Логиката на веригата на сканиращото устройство е погрешна;
(3) Възелът на тонер касетата се разрежда лошо;
(4) Сигналната връзка не е свързана правилно.
Two.Outputfull-frameverticalblackbelt(line)
Възможна причина за повреда:
(1)Thephotosensitivedrumscraperisdamagedorthesharpobjectonthescraperscratchesthephotosensitivedrum;
(2) Частична повреда на стъргалото с магнитни ролки;
(3) Принтерът (Пътят на хартията с общо ръководство) е замърсен с тонер.
Three.Outputhorizontalirregularblackbelt(line)
Възможна причина за повреда:
(1)Фоторецепторът или елиминиращият електрод на барабана е в лош контакт;
(2)Фоторецепторът на срязващата сила на барабана е голям;
(3)Фоторецепторът на барабанното зъбно колело трепти, когато се върти;
(4)Фоточувствителният барабан е дефектен или неправилно инсталиран.
4.Изведете цял лист бяла хартия
Възможна причина за повреда:
(1)РозовоИма тонер в кутията;
(2)Механичният затвор на лазера не е отворен;
(3) Детекторът на лазерния лъч е замърсен или повреден;
(4) Лазерът е повреден.
5. Изходна вертикална редовна левкорея (лента)
Възможна причина за повреда:
(1)Тонерът е към изчерпване и няма тонер в частта от магнитната ролка (обикновено в средната част на пробата);
(2) Рефлекторът на лъча е замърсен от мръсотия като камък;
(3)Пътят на сканиращата светлина е блокиран от чужди обекти.
6. Изходни хоризонтални неправилни бели ленти (лента)
Възможна причина за повреда:
(1)Thechargingelectrodewireiscontaminatedorthecontactofthechargingrollerispoor;
(2)Фотопроводимият слой върху повърхността на фоточувствителния барабан е уморен;
(3)Фоточувствителният барабан е слабо разреден.
7.Изходното изображение и текст са бледи
Възможна причина за повреда:
(1) Влага на хартия за печат;
(2)Портът на тонера,компонентът на фоточувствителния барабан е дефектен;
(3)Фоточувствителният барабан се разрежда слабо след експониране и потенциалът на повърхността е нисък;
(4)Недоекспониране;
(5) Напрежението на магнитното въртене е ниско;
(6) Трансферното напрежение е ниско.
8.Изходното изображение е невярно
Възможна причина за повреда:
(1)Не използвайте стандартна хартия за печат;
(2)Моделът на тонера не съвпада с модела на машината или тонерът е влажен;
(3)Фоточувствителната барабанна влага;
(4)В модула за сканиране има разхлабени части;
(5) Сканиращият мотор не работи плавно и има трептене.
9. Изходният образец има сив фон
Възможна причина за повреда:
(1)Напрежение на отклонението на разработката е ниско;
(2)Магнитно въртящо се острие;
(3)Thedistancebetweenthedevelopingmagneticrollerandthephotosensitivedrumistooclose;
10. Лявата и дясната страна на изхода извеждат примерни картини с различни нюанси
Възможна причина за повреда:
(1) Тонерът ще изтече;
(2) Замърсяване на проводника на зареждащия електрод или ролката за зареждане;
(3) Замърсяване на прехвърлящия електроден проводник или трансферната ролка;
(4) Огледално покритие Частично изпадане.
11.Горната и долната дълбочина се появяват в изходното изображение и текст
Възможна причина за повреда:
(1)Трансферният електропроводник е замърсен;
(2)Моделът на тонера не отговаря.
12. Изходните примерни картини и текстове са с правилни различни нюанси отгоре до долу
Възможна причина за повреда:
(1) Частична умора на фоточувствителния барабан;
(2) Лош контакт между електродите на зареждащата и трансферната ролка.
13. Правилни бели петна се появяват в надлъжната посока на пробите
Възможна причина за повреда:
(1)Частично мазно петно върху фоточувствителния барабан;
(2) Частична повреда на зареждащата ролка;
(3) Частична повреда на повърхността на фиксиращата ролка.
14.Има правилни черни петна (точки) в надлъжната посока на пробите
Възможна причина за повреда:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Йонизационният филм на зареждащата ролка е повреден;
(3)На повърхността на фиксиращата ролка има нараняване от флуорен филм (дефектът е малко по-светъл на цвят).
15.Неправилни черни петна се появяват на доказателствата
Възможна причина за повреда:
(1)В тонера има примеси;
(2)Бялият лист за невръщане на отпадъчния тонер в комплекта на тонер касетата е деформиран или повреден;
(3)Течове на тонер.
Шестнадесет. Неправилни черни линии се появяват вертикално или хоризонтално на страницата
Възможна причина за повреда:
(1)Фотопроводимият слой върху повърхността на фоточувствителния тъпан е надраскан;
(2)Повърхността на фиксиращата ролка е надраскана;
(3)Фоточувствителният барабан трепти, когато работи.
Седемнадесет. Изведете примерни картини и текст с правилни различни нюанси отгоре до долу
Възможна причина за повреда:
(1) Частична умора на фоточувствителния барабан;
(2) Лош контакт между електродите на зареждащата и трансферната ролка.
18. Правилни бели петна се появяват в надлъжната посока на пробите
Възможна причина за повреда:
(1)Частично мазно петно върху фоточувствителния барабан;
(2) Частична повреда на зареждащата ролка;
(3) Частична повреда на повърхността на фиксиращата ролка.
19.Има правилни черни петна (точки) в надлъжната посока на пробите
Възможна причина за повреда:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Йонизационният филм на зареждащата ролка е повреден;
(3)На повърхността на фиксиращата ролка има нараняване от флуорен филм (дефектът е малко по-светъл на цвят).
20. Липсва информация за изображението на страницата
Възможна причина за повреда:
(1)Настройката на изображението е твърде висока и паметта не е достатъчна;
(2)Theprintmodesetbythedriveriincorrect;
(3)Размерът на изображенията и страницата за печат са зададени неправилно;
(4)Грешка при предаване на информация.
Двадесет и едно. Вертикална компресия на знаци на страници
Възможна причина за повреда:
(1)Предавката на фоточувствителния барабан е разхлабена;
(2)Отношението на трансмисионната предавка е неправилно;
(3) Контролът на скоростта на основния мотор е неуспешен.
Двадесет и две. Хоризонтално неподравняване на изображението на страницата
Възможна причина за повреда:
(1)Съдържанието за печат на страницата е твърде сложно и паметта на принтера не е достатъчна;
(2)Размерът на страницата надвишава размера, зададен от принтера.
Двадесет и три. Знаците на страницата са изкривени и изкривени
Възможна причина за повреда:
(1) Възелът на фоточувствителния барабан на тонер касетата се движи аксиално;
(2) Лещата в модула за сканиране е разхлабена;
(3) Слабо електрическо разреждане преди фиксиране;
(4)Кристалосцилаторът във веригата за управление на сканера е повреден.
Двадесет и четири. Замърсяване на гърба на хартията за печат
Възможна причина за повреда:
(1)Пътят на хартията на принтера е замърсен от тонер;
(2)Гумената ролка под налягане в фиксиращия възел е замърсена.
Двадесет и пет. Отпечатаните знаци са кухи
Възможна причина за повреда:
(1)Използваният печатен материал не отговаря на изискванията;
(2)Thetonermodeli е грешен
(3)Температурата на фиксиращата ролка е твърде висока.
26.Знаците на страницата не са фиксирани стабилно и повърхността е грапава
Възможна причина за повреда:
(1)Температурата на фиксиране е ниска;
(2)Налягането на фиксиращата гумена ролка е недостатъчно;
(3)Използваният тонер не отговаря намодела.
27. Липсват знаците от лявата до дясната страна на вертикалната страница
Възможна причина за повреда:
(1)Пътят на светлината е блокиран;
(2)Модел на керамично изкривяване, фиксиращият капак е повреден и изместен.
Двадесет и осем. Две двойни изображения се появяват във вертикалната посока на страницата
Възможна причина за повреда:
(1)Острието за почистване на фоточувствителен барабан;
(2)Thesurfacetemperatureoftheheatrolleristooloworthepressureoftherubberrollerisinsufficient;
(3)ThefluorinefilmonthesurfaceoftheheatrolleriswornandthesurfaceTonermeltthatadheresalot.
29. Неправилни черни линии се появяват вертикално или хоризонтално на страницата
Възможна причина за повредата:
(1)Фотопроводимият слой върху повърхността на фоточувствителния тъпан е надраскан;
(2)Повърхността на фиксиращата ролка е надраскана;
(3)Фоточувствителният барабан трепти, когато работи.
30.Неправилни черни петна се появяват на доказателствата
Възможна причина за повреда:
(1)В тонера има примеси;
(2)Белият лист за невръщане на отпадъчния тонер вътре в барабана е деформиран или повреден;
(3)Течове на тонер.
Developmentprospects
ThelaserprinterwasinventedbyXeroxinthelate1960s,usingelectro-photo-graphytechnology.Thistechnologyusesalaserbeamtoscantheopticaldrum,andbycontrollingtheonandoffofthelaserbeamtomakethesensordrumabsorbornotabsorbthetoner,theopticaldrumtransferstheabsorbedtonertothepapertoformaprintingresult.Theentireprintingprocessofalaserprintercanbedividedintothecontrollerprocessingstage,inkshadowandtransferstage.Thelaserprinterwasinventedveryearly,buttherealpopularizationandpromotionbeganintheearly1980s,andthedevelopmenttrendhasbeenacceleratedinthepasttwoyears.Thedevelopmentoflaserprintersincludesthefollowingaspects.
(1)Цената е спаднала значително
Theoriginallaserprinterwasaluxuryproduct,andmostpeoplecouldnotreachit.Intheearly1980s,Canoncommercializeddesktoplaserprintersandformedtheminbatches.Thepricedroppedsharply.Asaresult,laserprintersgraduallybegantobepromoted.Theirpopularityandpromotioninturnpromotedthedeclineinprices,andtheirdevelopmentspeedwasrapid.,Israreincomputersandperipheralproducts.Inearly1997,Hewlett-Packardtooktheleadinfurtherreducingthepricesofmostofitslaserprinters,andothercompaniesalsoloweredtheirprices,bringingthepriceofordinarylaserprinterstonearly3,000yuanperunit.In2003,abatchofthousand-yuanlaserprintersledbyHPappeared.
(2) Ефективността на движението е значително подобрена
Asakeycomponentofthelaserprinter,themovementincludestheintegrationofmachinery,optoelectronicsandothertechnologies.Technologicalprogresshaspromotedtheimprovementofmovementperformance.Twoyearsago,thepopularlaserprintercoresweregenerally600dpi,andthecoresweregenerally240,000dpiorevenhigher;thespeedalsodevelopedfrom4ppm,8ppmto16ppm,24ppm;theformatisnotonlyA4,butalsoB4,A3format..
(3) Технологията за управление става все по-съвършена
Thecontrolleristhesoulofthelaserprinter,itdirectlyaffectstheperformanceoftheprinter,andtheprocessingusedbythecontrollerisnowTheprocessor(CPU)hasevolvedfromasingleMotorola68000toaRISCchip,suchasIntel’si960andAMD’s29000,anditsprocessingcapabilitieshavebeengreatlyenhanced;secondly,thelaserprinterpagedescriptionlanguage(PDL)hasbecomeanindustrystandard,andPostScripthasbecomeahigh-endlaserprinterThestandardlanguageofHPPCL;HPPCLlanguagehasbecomethedefactostandardformiddleandlow-endlaserprinters.Laserprinterseitherhaveemulationsinoneoftheselanguagesorboth;again,newtechnologiessuchasresolutionenhancementtechnology(RET,alsoknownassmoothingtechnology)andmemoryenhancementtechnology(MET,alsoknownasmemorycompressiontechnology)continueAppeared,andismasteredbymoreandmoremanufacturers.
Theindustryhasbeenarguingwhetherthefuturedevelopmentprospectsarelaserstoreplaceinkjets,orwhetherthetwowillleadtheway.Butitissuchatopicthatisnolongernew,afterthefirstquarterof2006,itonceagainbecamethecenterofpeople'sdiscussion.Thepurelytheoreticaldiscussionand"teaching"maybetooemptyandabstract.Therefore,wemightaswellcomparethetwofromtheseveralelementsthatmustemergefromtheprintingrequirements,intermsofcostinvestment,printingqualityandspeed,printingloadandstabilityInthesethreeaspectsthatconsumersaremostconcernedabout,acomprehensivecomparisonismadebetweenLaserandPenta.
Features
Thetechnicalstructureoflaserprintingismuchmorecomplicatedthanthatofinkjet,whichinvisiblyincreasesthecostoftheproduct.Therefore,inkjetoccupiesaclearadvantageintheinitialinvestment,entry-levelInkjetprintingonlycostsafewhundredyuan,andsomeproductsareevenlower,whileblackandwhitelaserprintingishoveringatthethresholdofonethousandyuan.Therefore,thereisalsoaviewthatthelaserhittingthatrequiresrelativelyhighupfrontinvestmentcannotbecomparedtothecheapandhigh-qualityjethitting.Infact,thisviewignoresaverykeyhiddenfactor,thatis,sprayingisnotalwayssuchalowprice,anditsproductshavegonethroughalongprocesslikebeingpopularizedandapplied.Ontheotherhand,thepriceofLaserisdroppingstepbystep.WhetheritcanbereducedtothesamepriceasPentaisunknown,butitwillbeamatteroftimebeforeitbreaksthroughthepsychologicalpriceofconsumers.Thepriceofabout1,000yuanisactuallynothighforbusinessapplications.Therearemanyexamplesofsuccessfulproductsonthemarket,suchastheSamsungML-1610,whichisknownasthe"KingofShortShots",andthesmallestandlightestblackandwhitelaserall-in-onemachine.SamsungSCX-4200,thehotsalesofthesetwoproductsfullyshowthatthepricethresholdoflaserhittingisnotasinsurmountableasimagined.
Anotheraspectthatdeterminesthecostisthelaterstageinvestmentoftheproduct,especiallythelaterstageconsumablesinvestment.Behindthecommonpricecutsandfiresales,themeaningoftheproductitselfhasbeenweakenedtoacertainextent,andtheinputofconsumableshasbecomethemostcriticalfactoraffectingTCO.Generallyspeaking,theoriginalinkcartridgesusedininkjetprintersarepricedataboutoneortwohundredyuan,andcanprintfourtofivehundredordinaryA4textfiles,ignoringthecostofpaper,andtheaverageprintingcostperpageisabout0.2to0.5yuan.Thepriceofatonercartridgeforlaserprintersisabout500yuan(blackandwhite).Regardlessofthelossofthetonercartridge(thelifeofthetonercartridgeisusuallyverylonganditisnotallowedtobeincludedintheconsumablesundertheconditionofnotverystrict),itsconvertedprintingcostisnotTo0.1yuan.Inthisway,ifyouprintalargenumberofdocuments,youcansavemoneyforafewprintersinamonth,andtheadvantageoflaserprintersintheoverallcostinvestmentisimmediatelyapparent.
В сравнение сматрични и струйни принтери, лазерните принтери имат много очевидни предимства.
(1) Висока плътност. Минималната разделителна способност на печат на лазерния принтер е 300 dpi, а има и високи разделителни способности като 400 dpi, 600 dpi, 800 dpi, 1200 dpi, 2400 dpi и 4800 dpi.
(2) Висока скорост. Минималната скорост на печат на лазерния принтер е 4 стр./мин, обикновено 12 стр./мин, 16 стр./мин, а скоростта на печат на някои лазерни принтери може да достигне повече от 24 стр./мин.
(3) Нисък шум. Обикновено под 53 dB е много подходящ за използване в тихи офиси.
(4)Strongprocessingcapability.Thelaserprinter'scontrollerhasaCPUandmemory.Thecontrollerisequivalenttothecomputer'smotherboard,soitcanperformcomplexwordprocessing,imageprocessing,andgraphicsprocessing,whichcannotbedonebydotmatrixprintersandinkjetprinters.Thedifferencebetweenapageprinterandalineprinter.