Девелопментхистори
Lasertechnologyappearedinthe1960s,anditsactualapplicationbeganintheearly1970s.Theearliestlasertransmitterwasanelectroniclasertubefilledwithhelium-neon(He-Ne)gas,whichwasverylarge,soitwasverylimitedinpracticalapplications.
Inthelate1970s,semiconductortechnologytendedtomature.Semiconductorlaserswereborn,andhigh-sensitivityphotosensitivematerialswerecontinuouslydiscovered.Coupledwiththedevelopmentoflasercontroltechnology,lasertechnologymaturedrapidlyandenteredthefieldofpracticalapplications.
ScientificresearchersrepresentedbytheUnitedStatesandJapanhavecombinedlasertechnologyandcomputertechnologyonthebasisofelectrostaticcopiers,andhavesuccessivelydevelopedsemiconductorlaserprinters.Thistypeofprinterhasgoodprintingquality,fastspeedandnonoise,soithasbeenwidelyusedsoon.
Принцип
Thecomposition,designstructure,controlmethodandcomponentsofthecontroldeviceandpartsrequiredbythelaserprinterworkprocesswillvarywithdifferentbrandsandmodels.,Suchas:
①Поларитет пуњења фотоосетљивог бубња је различит.
②Thepartsusedtochargethephotosensitivedrumaredifferent.Somemodelsusethewiredischargemethodtochargethephotosensitivedrum,andsomemodelsuseachargingrubberroller(FCR)tochargethephotosensitivedrum.
③Thepartsusedinhigh-pressuretransferaredifferent.
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.
Пхотосенситиведрум
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.
Превод
(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.
Модулатор
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:
θи=θд=θБ
синθБ=λ/2А=λф/2в(в=фА)
where:θi:theanglebetweentheincidentlightandtheultrasonicsurface;λ:thewavelengthofthelightinthemedium;θd:theanglebetweenthediffractedlightandtheultrasonicsurface;A:theultrasonicwavelength;θB:Bregangle;f:ultrasonicfrequency.θBisverysmall,sinθB≈θd,thentheequationcanbesimplifiedas:θи=θд=θБ=λf/2v,whentheanglebetweenthediffractedlightandtheincidentlightisα,then:α=θi+θd=2θB=λf/v.Intheformula,αisthedeflectionangle,whichisproportionaltothefrequencyoftheultrasound.Changingtheultrasonicfrequencyfcanchangethedeflectionangleα,soastoachievethepurposeofcontrollingthedirectionofthelaserbeam.
AccordingtotheBraggdiffractiontheory,whenultrasonicwavesmaintainahigh-frequencysignalofonefrequency,theincidentlaserbeamproducesafirst-orderdiffractedlightinadditiontoazero-orderlight.The0-orderlightcontrolsthestartandstopofthesynchronizerandthehigh-frequencysignal,andthefirst-orderdiffractedlightexposesthephotosensitivedrumtoformpixels.
Сцаннер
Tomakethelaserbeamaftertheacousto-opticmodulatorproducetextorimagesonthephotosensitivedrum,thelaserbeamneedstocompletethemovementinboththehorizontalandverticaldirections.Itdependsonthemovementofthelaser,becausethevibrationcausedbythemovementoftheoptoelectronicdevicewillaffecttheaccuracyofthelaserbeam.Therefore,thelaserofthelaserprinteradoptsafixedstructure,andamulti-sidedrotatingmirrorcompletesthehorizontalscanningofthelaserbeam,andtheverticalscanningisrealizedbytherotationofthephotosensitivedrum.
Tomakethemodulatedlaserbeamproducetextandimagesonthephotosensitivedrum,thehorizontalmovement(inthedirectionoftheprintingpaperline)andverticalmovementshouldbecompleted.Thelongitudinalmovementiscompletedbytherotationofthetonercartridge,whilethelateralmovementofthebeamiscompletedbythescanner.Сцаннерsaredividedintoacousto-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.
Оптицалсистем
Inordertomakethelaserbeamreflectedbythescannergathertoformalightspotofaspecifiedsize,andeliminatethediffusionofthebeamduringthepropagationprocess,asetofopticallensesisneeded.Thebeamismodulatedtoimprovescanningaccuracy.Itincludes:curvedlens,sphericallens,reflector.Thisgroupoflensescanonlymeetthetechnicalrequirementsoflaserimagingifthedistortionofthelaserbeamiscorrectedto0.1‰.
Систем визуелизације
Laserprinterisasophisticatedmechanicalsystemthatusesthephysicalandchemicalprinciplesoflight,electricity,andheattooutputtextorimagesthroughinteraction.ThesecomplexprocessesareItisrealizedbyanelectroniccontrolsystem,calledanelectronicimagingsystem.Thetheoryof"electrostaticimaging"wasfirstproposedbyAmericanCarlson,soitisalsocalledCarlson'smethod.Orcalledtheelectricdischargeimagingmethod.Thebasicprocesscanbedividedinto7stepsofcharging,exposing,developing,transferring,fixing,cleaning,andde-energizing,ofwhich5stepsarecarriedoutaroundtheelectronicimagingsystem.
Класификација
Ласерски штампачи се могу поделити у три категорије према њиховој излазној брзини: ласерски штампачи мале брзине (излаз 10-30 страница у минути); средње брзи ласерски штампачи (излазне минуте 40-120 страница); ласерски штампачи велике брзине (излаз 130-300 страница).
Структура
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.
Превентивне мере
Becauselaserprintershavehigh-voltagecircuitsandhigh-temperaturecircuits,bothelectronicradiationandthermalradiationhaveacertainimpactonthehumanbody.Payattentiontotheprotectionorprotectionofpregnantwomenandyoungchildren.Stayawayfromthesedevices.Duringtheprintingprocess,hightemperatureheatingwillbringoutsomepowderandinkparticles,whichisnotgoodforbreathing,soyoushouldtrytoavoidworkingatthelaserprinterforalongtime.
Пуњење
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.
Сцаннингекпосуре
Justlikeweuseapentowriteonpaper,thescanningexposuretoolistousealaserbeamto"write"theexposureonthephotosensitivedrum.ThistextorimageItisinvisible.Thisiswhatwecallthe"electrostaticlatentimage."
Whenthesurfaceofthetonercartridgepassesthroughthetungstenwireelectrode,itssurfaceischargedwithpositiveelectricity,andnegativeelectricityisinducedattheinterfacebetweenthephotoconductivelayerandthesubstrate.Whenthelightpartofthelaserbeamhitsacertainareaonthedrumsurface,itiscalledexposure.Theresistivityoftheexposedareaissignificantlyreduced,andthepositivechargeonthesurfaceandthenegativechargeontheinterfaceareneutralizedanddisappeared.Duetothegoodinsulatingpropertiesbetweentheselenium-telluriumalloyparticles,thepositivechargeonthesurfaceoftheunexposedsurfaceremainsunchanged.Thatis,alayerofelectrostaticlatentimageisformed.
Сцаннингекпосуреistousethephotosensitivepropertiesofthephotoconductivematerialonthesurfaceofthephotosensitivedrum.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.
Развој
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.
Дисцхаргесистем
(1)Уређај за пренос
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) Пражњење уређаја
Whenthetonerimageistransferredtotheprintingpaper,theprintingpaperisalsocharged.Intheprocessofconveyingtheprintingpaper,electricfieldandfrictionmaydestroythestructureofthetonerimage,soafterthetonerimageistransferred,a"dischargedevice"(dischargerordischargingtooth)isadded,alsocalled"Separateteeth".Itsfunctionistoneutralizethechargeontheprintingpaperandtheadsorbedtoner,eliminatethepolaritytomakeitneutral,andphysicallyadheretotheprintingpaper,therebyensuringtheaccuracyofthetonerimagebeforefixing.Thede-energizationprocessusesACvoltagetoachievethebestde-energizationandneutralizationeffect.
Грејање и причвршћивање
Theprocessofprintingthetonerimageabsorbedonthepaper,usingthemethodofpressureheatfusion,sothatthemeltedtonerisimmersedintheprintingpapertoformafixedimage,Called"fixing".
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)Ваљак за грејање
Theheatingrollerismadeofseamlessaluminumalloytube,thewallthicknessofthetubeisbetween1to3mm,andthesurfaceiscoatedwithPTFE.Thispreventsthemeltedtonerfromstickingtotherollerduringfixing.ThePTFEcoatingonthesurfaceoftheheatingrollerwillsoftenslightlyathightemperatures.Whentheprintingpaperisstuckinthefixingdevice,donotusesharphardobjects(suchasscrewdrivers,cameras)toforceitout.Itwilldamagethesurfacecoatingoftheheatingrollerandaffecttheintegrityofthetonerimageafterfixing.
Постоји много ласерских штампача који користе напредније ископиваче керамике (ПЦТ), који се брзо загревају и штеде електричну енергију, као што су ХП4Л.4П, 5Л, 6Л, 6П, 2100, 4000, 5000 и Цанон460, 660, 800 и ЈКСами моделе за моделе.
(2) Лампа за грејање
Somelaserprintersusehalogenlampswithapowerof350～750W.Theyarefixedinthemiddleoftheheatingrolleranddonotrotatewiththeheatingroller.Aftertheprinterisenergized,theheatinglampisontopreheatthefixingroller.Afterabout1to2minutes,thetemperatureoftheheatingrollerreachesabout185degrees.Whenthesurfacetemperatureoftheheatingrollerreachesthefixingtemperature,thethermistorleaningonthesurfaceoftheheatingrollertodetectthetemperatureinformsthemainlogiccircuittostopheating,andthelampisreadytolightup.Theprintercanstartprinting.Whentheheatinglampisdamaged,thewholemachinewillnotwork,andthemodelwithadisplaypanelwilldisplayanerrorindicationoranerrorcodeof50Error.
(3)Прессурегуберроллер
Thepressurerubberrollerisalsocalledthelowerroller,anditsfunctionistocompletethehot-pressfixingandtransferofthetonerontheprintingpapertogetherwiththeheatingroller.Thepressureiscontrolledbythesupportspringsatbothends.Thepressurerollerisgenerallymadeofhigh-temperatureresistantsiliconrubber.Thepressurerollerinsomelaserprintersismadeofhoneycombheat-resistantsponge,andtheoutersurfaceisalayerofPTFEfilm.Itismoreconducivetotheseparationoftheprintingpaperandthepressurerubberrollertopreventpaperjams.
(4) Регулатор температуре (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) Термални заштитник (термопрекидач)
Inordertopreventthetemperatureinthelaserprinterfromrisingunrestrictedlyandburningtheheatinglampandheatingroller,theheatinglampcircuitAthermalprotector(thermalswitch)isconnectedinserieswiththeheatingroller.Insidethethermalswitchthereisasetoflongclosedcontacts,atitaniumsheetandastalk.Titaniumisakindofmemorymetalmaterialwithamemorytemperatureof210°Cduringmanufacture.Ifthetemperaturecontrolcircuitisoutofcontrol,whenthesurfacetemperatureoftheheatingrollerexceedsthesettemperatureof210℃,thetitaniummetalwillshrinkanddeformunderheat,pressingthestrikerbartodisconnectthenormallyclosedcontact,andcuttingoffthecircuitwillprotecttheheater.Whenthetemperatureislowerthan180°C,thetitaniummetalreturnstotheoriginalmemorystate,thenormallyclosedcontactisclosed,andthecircuitisturnedon.Someprintersusefuseprotectors,theprincipleissimilartocurrentfuse.
Систем за чишћење
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)Чишћење стругачем
Therubbercleaningbladeismadeofurearesinandhasaflatsurface.Thebladeisstraightandhasabrasionresistanceandflexibility.Thebladeformsashearanglewiththesurfaceofthephotosensitivedrumandhasacertainpressure.Whenthephotosensitivedrumrotateswiththetonerremainingonthesurface,theremainingtonerisscrapedintobythecleaningbladeInthewastetonercollectionbin.Thereisanon-returnsheetatthepositionoppositetothescrapertopreventthewastetonerfromflyingoutaftercleaning.Becausetherubberscraperisalwaysshearedwiththephotosensitivedrumandhasacertainpressure,itwillcausethesurfaceofthephotosensitivedrumIfthebladeofthecleaningbladeisdamaged,thetonerremainingonthesurfaceofthephotosensitivedrumcannotbecompletelyremoved,causingtheimagesinthenextprintingcycletooverlapandproducepoorprintingresults.
(2)Чишћење четкица
Brushcleaningistousearotatingrollerbrushtocleantheresidualtoneronthesurfaceofthephotosensitivedrum,toremovetheresidualtonerandshakeFallingintothewastetonercollectionbin.Thebrushisgenerallymadeofman-madefibersandrubswiththephotosensitivedrumwhenrotatingtoremovetheresidualtoner.Atthesametime,thestaticelectricitygeneratedbythefrictionisusedtoabsorbtheresidualtoner,sothatthetonerwillnotflyandpolluteotherpartsoftheprinter.Themethodofusingabrushtocleanthesurfaceofthephotosensitivedrumcanprolongtheservicelifeofthephotosensitivedrum.
(3)Канта за сакупљање отпада
ThewastetonercollectionbinisRecyclingandcleaningtheresidualtonerdevice.Thecollectedtonerisgenerallynolongerused.Becausetherearemanyimpuritiesinthecollectedtoner,whichwillaffecttheprintingquality,someprintersuserecycledtoner.Thescrapedtonerissentbacktothetonersupplybinbyascrewfeedingdeviceforrecycling.However,afteraperiodofuse,thereplenishmentofnewtonerisinsufficientortheoldandnewtonercannotbefullymixed,andtheprintqualitywilldropalot.
Механички пренос
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)Усисно електромагнетно квачило
ThepaperfeedingdeviceofHPseriesprintersadoptstheattractionelectromagneticclutchtocontrolthestopandrotationofthepaperfeedingcamtocompletepapertransportation.Whentheelectromagnetreceivesthesignalvoltageofthecontrolcircuit,currentflowsthroughtheelectromagnetcoil,generatinganelectromagneticfieldtoattractthearmature,thecamisreleased,andthetransmissiongeardrivesthepickuprollertorotatetogether.Thereisarubberlayeronthepickuprollersurface,whichfollowsthepickuproller.Rotate,thefrontedgeofthecamdrivesapieceofprintingpaperintotheprintingchannel.
(2) Фрикционо електромагнетно квачило
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.
Елецтрониццонтрол
Theoperationofalldevicesofthelaserprinterisrealizedbyacontrolsystem,whichiscalledthe"electroniccontrolsystem".Thecontrolsystemofdifferentmodelsisdifferent,buttheworkingprincipleisbasicallythesame.Theelectroniccontrolsystemmainlyconsistsofthefollowingparts.
(1) Коло за напајање
Providecontrolvoltageforeachpartoftheprinter.Thepowersupplycircuitisrectified,filtered,andtransformedby220Valternatingcurrenttoprovide24V,5Vdirectcurrentworkingvoltageforthelaserprinter.
(2)Интерфејс коло
Establishcommunicationbetweenthecomputerandtheprinter.Receivecomputerdatainformationandconvertitintoprinterlanguagetoprovideprintingdatatothemaincontrolcircuitoftheprinter.Theinterfacecircuitincludesamicroprocessor(CPU).Memory(RAM/ROM).
(3) Главни контролни круг
Themaincontrolcircuitisthedatareceivedbytheinterfacecircuitandcontrolsthevariousdevicesoftheprintertoworktogetherinacommandmodetocompletetheprintingprocess.
(4)Сцаннингдриве Цирцуит
Thereceivedcomputerinformationisgeneratedbyahigh-frequencyoscillatortogeneratealaserbeam,andthescanningmotoriscontrolledtorotateatauniformspeedtodrivethescanningmirrortocompletethephotoreceptordrumScanandexposetoformanelectrostaticlatentimage.
(5) Круг главног мотора
Accordingtothecommandissuedbythemaincontrolcircuit,themainmotorisdriventorotate,andthroughthegeartransmissiondevice,poweristransmittedtoeachpartoftheoperation.
(6) Високонапонски преносни круг
Thiscircuitconvertsthelow-voltagepowerprovidedbythepowersupplycircuitintoahighvoltagethroughatransformertoprovidethephotosensitivedrumchargingandtransferrollertransferneeds.
Решавање проблема
Оне. Оутпутафулл схеетоф блацкпапер
Могући узрок неуспеха:p>
(1) Ако је ласер дефинитивно добар, електродема за пуњење може бити у кратком споју са мрежом;
(2)Тхелогицоофтхесцандривецирцуитисвронг;
(3)Склоп кертриџа са тонером се слабо празни;
(4)Сигнална веза није правилно повезана.
Тво.Оутпутфулл-фрамевертицалблацкбелт(линија)
Могући узрок неуспеха:
(1)Thephotosensitivedrumscraperisdamagedorthesharpobjectonthescraperscratchesthephotosensitivedrum;
(2) Делимично оштећење магнетних ваљака стругача;
(3) Штампач (општи водич за папир) је контаминиран тонером.
Тхрее.Оутпутхоризонталиррегуларблацкбелт(линија)
Могући узрок неуспеха:
(1)Thephotoreceptordrumeliminationelectrodeisinpoorcontact;
(2)Thephotoreceptordrumscrapershearingforceistoolarge;
(3)Thephotoreceptordrummaingearjitterswhenitrotates;
(4)Thephotosensitivedrumisdefectiveorincorrectlyinstalled.
4.Оутпутафуллсхеетофвхитепапер
Могући узрок неуспеха:
(1)ПинкТхереиснотонеринтхебок;
(2) Механички затварач ласера није отворен;
(3)Детектор ласерског зрака је контаминиран или оштећен;
(4)Тхеласерисдамагед.
5. Излаз вертикалне нормалне леукореје (бар)
Могући узрок неуспеха:
(1)Thetonerisabouttorunout,andthereisnotonerinthepartofthemagneticroller(usuallyinthemiddlepartofthesample);
(2)Thebeamreflectoriscontaminatedbydirtsuchastoner;
(3)Путања светлости скенирања блокирана страним објектима.
6.Оутпутхоризонталиррегуларвхитебарс(банд)
Possiblecauseoffailure:
(1)Thechargingelectrodewireiscontaminatedorthecontactofthechargingrollerispoor;
(2)Thephotoconductivelayeronthesurfaceofthephotosensitivedrumisfatigued;
(3)Фотоосетљиви бубањ је слабо испражњен.
7.Тхеоутпутимагеандтектарепале
Могући узрок неуспеха:
(1)Влажност папира за штампање;
(2)Thetonerisdamporthephotosensitivedrumcomponentisdefective;
(3)Thephotosensitivedrumispoorlydischargedafterexposure,andthesurfacepotentialislow;
(4) Недовољна експозиција;
(5)Магнетиццроллербиасволтагеислов;
(6)Преносни напон је спор.
8.Тхеоутпутимагеисфалсе
Могући узрок неуспеха:
(1)ДонотусеСтандардпринтингпапер;
(2)Thetonermodeldoesnotmatchthemodelofthemachineorthetonerisdamp;
(3)Тхепхотосенситиведрумисдамп;
(4) Има лабавих делова у склопу за скенирање;
(5)Thescanningmotorisnotrunningsmoothlyandthereisjitter.
9.Тхеоутпутсамплехасаграибацкгроунд
Могући узрок неуспеха:
(1) ДевелопментБиасволтагеистоолов;
(2)Тхемагнетицроллербладеисагинг;
(3)Thedistancebetweenthedevelopingmagneticrollerandthephotosensitivedrumistooclose;
10.Theleftandrightsidesoftheoutputsamplepictureshavedifferentshades
Могући узрок неуспеха:
(1)Тонервиллруноут;
(2)Contaminationofthechargingelectrodewireorchargingroller;
(3)Contaminationofthetransferelectrodewireortransferroller;
(4)МиррорцоатингПартиаллифаллофф.
11.Theupperandlowerdepthsappearintheoutputsampleimageandtext
Могући узрок неуспеха:
(1)Тхетрансферелецтродевиреиспрљав;
(2)Модел тонера не одговара.
12.Theoutputsamplepicturesandtextshaveregulardifferentshadesfromtoptobottom
Могући узрок неуспеха:
(1) Делимични замор фотосензитивног бубња;
(2)Poorcontactbetweenthechargingandtransferrollerelectrodes.
13.Regularwhitespotsappearinthelongitudinaldirectionoftheproofs
Могући узрок неуспеха:
(1) Делимично обојење на фотоосетљиви бубањ;
(2) Делимично оштећење ваљка за пуњење;
(3) Делимично оштећење површине ваљка за причвршћивање.
14.Thereareregularblackspots(dots)inthelongitudinaldirectionoftheproofs
Могући узрок неуспеха:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Тхеионизатионфилмофтхецхаргингроллерис оштећен;
(3)ThereisafluorinefilmonthesurfaceofthefixingrollerInjury(thedefectisslightlylighterincolor).
15.Иррегуларблацкспотсаппеаронтхепроофс
Могући узрок неуспеха:
(1)У тонеру постоје нечистоће;
(2)Thewhitenon-returnsheetofthewastetonerinthetonercartridgeassemblyisdeformedordamaged;
(3)Тхетонерлеакс.
Sixteen.Irregularblacklinesappearverticallyorhorizontallyonthepage
Могући узрок неуспеха:
(1)Thephotoconductivelayeronthesurfaceofthephotosensitivedrumisscratched;
(2)Површина ваљка за причвршћивање је изгребана;
(3)Тхепхотосенситиведрумјиттерсвхенитисруннинг.
Seventeen.Outputsamplepicturesandtextshaveregulardifferentshadesfromtoptobottom
Могући узрок неуспеха:
(1) Делимични замор фотосензитивног бубња;
(2)Poorcontactbetweenthechargingandtransferrollerelectrodes.
18.Regularwhitespotsappearinthelongitudinaldirectionoftheproofs
Могући узрок неуспеха:
(1) Делимично обојење на фотоосетљиви бубањ;
(2) Делимично оштећење ваљка за пуњење;
(3) Делимично оштећење површине ваљка за причвршћивање.
19.Thereareregularblackspots(dots)inthelongitudinaldirectionoftheproofs
Могући узрок неуспеха:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Тхеионизатионфилмофтхецхаргингроллерис оштећен;
(3)ThereisafluorinefilmonthesurfaceofthefixingrollerInjury(thedefectisslightlylighterincolor).
20.Пагеимагеинформатионисмиссинг
Могући узрок неуспеха:
(1)ImageTheresolutionsettingistoohighandthememoryisnotenough;
(2)Тхепринтмодесетбитхедривериинцоррецт;
(3)Величина слике и страница за штампање нису исправно подешени;
(4) Грешка у преносу информација.
Двадесет један.Пагевертицалцхарацтерцомпрессион
Могући узрок неуспеха:
(1)Thetransmissiongearonthephotosensitivedrumisloose;
(2)Однос мењача није тачан;
(3)Тхемаинмоторспеедцонтролфс.
Двадесет два.Хоризонтално неусклађеност слике странице
Могући узрок неуспеха:
(1)Thepageprintcontentistoocomplicatedandtheprintermemoryisnotenough;
(2)Величина странице премашује величину коју је поставио штампач.
Twenty-three.Pagecharactersaredistortedanddistorted
Могући узрок неуспеха:
(1)Thephotosensitivedruminthetonercartridgeassemblymovesaxially;
(2)Олабављено сочиво у склопу за скенирање;
(3) Лоше електрично пражњење пре фиксирања;
(4)Thecrystaloscillatorinthescancontrolcircuitisdamaged.
Twenty-four.Contaminationonthebackoftheprintingpaper
Могући узрок неуспеха:
(1)Папирна стаза штампача је контаминирана тонером;
(2)Thepressurerubberrollerinthefixingassemblyiscontaminated.
Двадесет пет. Одштампани знакови су шупљи
Могући узрок неуспеха:
(1)Theprintingmaterialuseddoesnotmeettherequirements;
(2)Тхетонермоделисвронг
(3) Температура ваљка за причвршћивање је висока.
26.Thecharactersonthepagearenotfixedfirmly,andthesurfaceisrough
Могући узрок неуспеха:
(1)Тхефикингтемпературеислов;
(2)Thepressureofthefixingrubberrollerisinsufficient;
(3)Употребљени тон не одговара моделу.
27.Thecharactersontheleftorrightsideoftheverticalpagearemissing
Могући узрок неуспеха:
(1)Тхелигхтпатхисблоцкед;
(2)Модел керамичке обраде, фиксирање је оштећено и померено.
Twenty-eight.Twodoubleimagesappearintheverticaldirectionofthepage
Могући узрок неуспеха:
(1)Тхепхотосенситиверумцлеанингбладеисагинг;
(2)Thesurfacetemperatureoftheheatrolleristooloworthepressureoftherubberrollerisinsufficient;
(3)ThefluorinefilmonthesurfaceoftheheatrolleriswornandthesurfaceTonermeltthatadheresalot.
29.Irregularblacklinesappearverticallyorhorizontallyonthepage
Могући узрок неуспеха:
(1)Thephotoconductivelayeronthesurfaceofthephotosensitivedrumisscratched;
(2)Површина ваљка за причвршћивање је изгребана;
(3)Тхепхотосенситиведрумјиттерсвхенитисруннинг.
30.Иррегуларблацкспотсаппеаронтхепроофс
Могући узрок неуспеха:
(1)У тонеру постоје нечистоће;
(2)Thewhitenon-returnsheetofthewastetonerinsidethedrumassemblyisdeformedordamaged;
(3)Тхетонерлеакс.
Перспективе развоја
ThelaserprinterwasinventedbyXeroxinthelate1960s,usingelectro-photo-graphytechnology.Thistechnologyusesalaserbeamtoscantheopticaldrum,andbycontrollingtheonandoffofthelaserbeamtomakethesensordrumabsorbornotabsorbthetoner,theopticaldrumtransferstheabsorbedtonertothepapertoformaprintingresult.Theentireprintingprocessofalaserprintercanbedividedintothecontrollerprocessingstage,inkshadowandtransferstage.Thelaserprinterwasinventedveryearly,buttherealpopularizationandpromotionbeganintheearly1980s,andthedevelopmenttrendhasbeenacceleratedinthepasttwoyears.Thedevelopmentoflaserprintersincludesthefollowingaspects.
(1)Цена је значајно пала
Theoriginallaserprinterwasaluxuryproduct,andmostpeoplecouldnotreachit.Intheearly1980s,Canoncommercializeddesktoplaserprintersandformedtheminbatches.Thepricedroppedsharply.Asaresult,laserprintersgraduallybegantobepromoted.Theirpopularityandpromotioninturnpromotedthedeclineinprices,andtheirdevelopmentspeedwasrapid.,Israreincomputersandperipheralproducts.Inearly1997,Hewlett-Packardtooktheleadinfurtherreducingthepricesofmostofitslaserprinters,andothercompaniesalsoloweredtheirprices,bringingthepriceofordinarylaserprinterstonearly3,000yuanperunit.In2003,abatchofthousand-yuanlaserprintersledbyHPappeared.
(2)Перформансе кретања су знатно побољшане
Asakeycomponentofthelaserprinter,themovementincludestheintegrationofmachinery,optoelectronicsandothertechnologies.Technologicalprogresshaspromotedtheimprovementofmovementperformance.Twoyearsago,thepopularlaserprintercoresweregenerally600dpi,andthecoresweregenerally240,000dpiorevenhigher;thespeedalsodevelopedfrom4ppm,8ppmto16ppm,24ppm;theformatisnotonlyA4,butalsoB4,A3format..
(3)Thecontroltechnologyisbecomingmoreandmoreperfect
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.
Карактеристике
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.
Comparedwithdotmatrixprintersandinkjetprinters,laserprintershaveveryobviousadvantages.
(1)Хигхденсити. Минимална резолуција штампања ласерског штампача је 300 дпи, а постоје високе резолуције као што су 400 дпи, 600 дпи, 800 дпи, 1200 дпи, 2400 дпи и 4800 дпи.
(2)Highspeed.Theminimumprintingspeedoflaserprintersis4ppm,generally12ppm,16ppm,andtheprintingspeedofsomelaserprinterscanreachmorethan24ppm.
(3) Ловноисе. Генерално испод 53дБ, веома је погодан за употребу у тихим канцеларијама.
(4)Strongprocessingcapability.Thelaserprinter'scontrollerhasaCPUandmemory.Thecontrollerisequivalenttothecomputer'smotherboard,soitcanperformcomplexwordprocessing,imageprocessing,andgraphicsprocessing,whichcannotbedonebydotmatrixprintersandinkjetprinters.Thedifferencebetweenapageprinterandalineprinter.