Historie vývoje
Laserová technologie se objevila v 60. letech 20. století a její aktuální použití začalo počátkem 70. let. Nejstarší laserový vysílač byl elektronická laserová trubice naplněná plynem helium-neon (He-Ne), což bylo velmi praktické použití v půdě.
Inthelate1970s,semiconductortechnologytendedtomature.Semiconductorlaserswereborn,andhigh-sensitivityphotosensitivematerialswerecontinuouslydiscovered.Coupledwiththedevelopmentoflasercontroltechnology,lasertechnologymaturedrapidlyandenteredthefieldofpracticalapplications.
ScientificresearchersrepresentedbytheUnitedStatesandJapanhavecombinedlasertechnologyandcomputertechnologyonthebasisofelectrostaticcopiers,andhavesuccessivelydevelopedsemiconductorlaserprinters.Thistypeofprinterhasgoodprintingquality,fastspeedandnonoise,soithasbeenwidelyusedsoon.
Princip
Složení, struktura návrhu, způsob ovládání a součásti ovládacího zařízení a součásti požadované pracovním procesem laserové tiskárny se budou lišit u různých značek a modelů.
①Thechargingpolarityofthephotosensitivedrumisdifferent.
②Thepartsusedtochargethephotosensitivedrumaredifferent.Somemodelsusethewiredischargemethodtochargethephotosensitivedrum,andsomemodelsuseachargingrubberroller(FCR)tochargethephotosensitivedrum.
③Součásti používané při vysokotlakém přenosu jsou odlišné.
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)
kde:θi:úhel mezi dopadajícím světlem a ultrazvukovým povrchem;λ:vlnová délka světla v médiu;θd:úhel mezi odraženým světlem aultrazvukovýmpovrchem;A:ultrazvuková vlnová délka;θB:Bregagon;f:B=lze θ,θ je θ,svšichny θ,imp. 2v, když je úhel mezi lomeným světlem a dopadajícím světlemα, pak :α=θi+θd=2θB=λf/v.Ve vzorci je αúhel vychýlení, který je úměrný frekvenci ultrazvuku. Změnou frekvence ultrazvuku lze změnit úhel vychýleníα, aby bylo dosaženo účelu řízení směru laserového paprsku.
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.
Klasifikace
Laserové tiskárny lze rozdělit do tří kategorií podle výstupní rychlosti tisku: nízkorychlostní laserové tiskárny (výstup 10-30 stran za minutu);středněrychlostní laserové tiskárny (výstup za minutu40-120 stran);vysokorychlostní laserová tiskárna-3 (0 stran za minutu130).
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.
Skenování expozice
Stejně jako my používáme apentopsaní na papír, tak i skenovací expoziční nástroj použije k "zapsání" expozice na fotocitlivý válec laserový paprsek. Tento text nebo obrázekJe neviditelný. Tomu říkáme"elektrostatický latentní obraz."
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.
Systém vybíjení
(1)Přenosové zařízení
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)Vybíjecí zařízení
Whenthetonerimageistransferredtotheprintingpaper,theprintingpaperisalsocharged.Intheprocessofconveyingtheprintingpaper,electricfieldandfrictionmaydestroythestructureofthetonerimage,soafterthetonerimageistransferred,a"dischargedevice"(dischargerordischargingtooth)isadded,alsocalled"Separateteeth".Itsfunctionistoneutralizethechargeontheprintingpaperandtheadsorbedtoner,eliminatethepolaritytomakeitneutral,andphysicallyadheretotheprintingpaper,therebyensuringtheaccuracyofthetonerimagebeforefixing.Thede-energizationprocessusesACvoltagetoachievethebestde-energizationandneutralizationeffect.
Zahřívání a fixace
Proces tisku obrazu tónu absorbovaného na papíře pomocí metody tlakové tepelné fúze, takže roztavený tón se ponoří do tiskového papíru a vytvoří pevný obraz, nazývaný "fixace".
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)Ohřívací válec
Theheatingrollerismadeofseamlessaluminumalloytube,thewallthicknessofthetubeisbetween1to3mm,andthesurfaceiscoatedwithPTFE.Thispreventsthemeltedtonerfromstickingtotherollerduringfixing.ThePTFEcoatingonthesurfaceoftheheatingrollerwillsoftenslightlyathightemperatures.Whentheprintingpaperisstuckinthefixingdevice,donotusesharphardobjects(suchasscrewdrivers,cameras)toforceitout.Itwilldamagethesurfacecoatingoftheheatingrollerandaffecttheintegrityofthetonerimageafterfixing.
Existuje mnoho laserových tiskáren, které používají pokročilejší keramické ohřívače (PCT), které se rychle zahřívají a šetří elektřinu, jako jsou modely HP4L.4P, 5L, 6L, 6P, 2100, 4000, 5000 a opravy Canon460, 660 800 a JX.
(2)Tepelná žárovka
Somelaserprintersusehalogenlampswithapowerof350～750W.Theyarefixedinthemiddleoftheheatingrolleranddonotrotatewiththeheatingroller.Aftertheprinterisenergized,theheatinglampisontopreheatthefixingroller.Afterabout1to2minutes,thetemperatureoftheheatingrollerreachesabout185degrees.Whenthesurfacetemperatureoftheheatingrollerreachesthefixingtemperature,thethermistorleaningonthesurfaceoftheheatingrollertodetectthetemperatureinformsthemainlogiccircuittostopheating,andthelampisreadytolightup.Theprintercanstartprinting.Whentheheatinglampisdamaged,thewholemachinewillnotwork,andthemodelwithadisplaypanelwilldisplayanerrorindicationoranerrorcodeof50Error.
(3)Přítlačný pryžový válec
Thepressurerubberrollerisalsocalledthelowerroller,anditsfunctionistocompletethehot-pressfixingandtransferofthetonerontheprintingpapertogetherwiththeheatingroller.Thepressureiscontrolledbythesupportspringsatbothends.Thepressurerollerisgenerallymadeofhigh-temperatureresistantsiliconrubber.Thepressurerollerinsomelaserprintersismadeofhoneycombheat-resistantsponge,andtheoutersurfaceisalayerofPTFEfilm.Itismoreconducivetotheseparationoftheprintingpaperandthepressurerubberrollertopreventpaperjams.
(4) Regulátor teploty (termistor)
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)Tepelná ochrana (tepelný spínač)
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)Čištění škrabkou
Therubbercleaningbladeismadeofurearesinandhasaflatsurface.Thebladeisstraightandhasabrasionresistanceandflexibility.Thebladeformsashearanglewiththesurfaceofthephotosensitivedrumandhasacertainpressure.Whenthephotosensitivedrumrotateswiththetonerremainingonthesurface,theremainingtonerisscrapedintobythecleaningbladeInthewastetonercollectionbin.Thereisanon-returnsheetatthepositionoppositetothescrapertopreventthewastetonerfromflyingoutaftercleaning.Becausetherubberscraperisalwaysshearedwiththephotosensitivedrumandhasacertainpressure,itwillcausethesurfaceofthephotosensitivedrumIfthebladeofthecleaningbladeisdamaged,thetonerremainingonthesurfaceofthephotosensitivedrumcannotbecompletelyremoved,causingtheimagesinthenextprintingcycletooverlapandproducepoorprintingresults.
(2)Čištění štětcem
Brushcleaningistousearotatingrollerbrushtocleantheresidualtoneronthesurfaceofthephotosensitivedrum,toremovetheresidualtonerandshakeFallingintothewastetonercollectionbin.Thebrushisgenerallymadeofman-madefibersandrubswiththephotosensitivedrumwhenrotatingtoremovetheresidualtoner.Atthesametime,thestaticelectricitygeneratedbythefrictionisusedtoabsorbtheresidualtoner,sothatthetonerwillnotflyandpolluteotherpartsoftheprinter.Themethodofusingabrushtocleanthesurfaceofthephotosensitivedrumcanprolongtheservicelifeofthephotosensitivedrum.
(3)Sběrný koš na odpadky
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)Sací elektromagnetická spojka
ThepaperfeedingdeviceofHPseriesprintersadoptstheattractionelectromagneticclutchtocontrolthestopandrotationofthepaperfeedingcamtocompletepapertransportation.Whentheelectromagnetreceivesthesignalvoltageofthecontrolcircuit,currentflowsthroughtheelectromagnetcoil,generatinganelectromagneticfieldtoattractthearmature,thecamisreleased,andthetransmissiongeardrivesthepickuprollertorotatetogether.Thereisarubberlayeronthepickuprollersurface,whichfollowsthepickuproller.Rotate,thefrontedgeofthecamdrivesapieceofprintingpaperintotheprintingchannel.
(2)Třecí elektromagnetická spojka
ThepaperfeedingdeviceofHP,Canon,Epsonandotherseriesofhigh-endprintersusesfrictionelectromagneticclutchtodirectlydrivethepickuproller,Thepaperisfedbythealignmentroller.Itsworkingprincipleis:whenthecurrentsignalflowsthroughtheinternalcoiloftheelectromagneticclutchtogenerateanelectricfield,thelinkageforkinthemiddleoftheclutchispushedtooneendofthecoupling,andthetwofrictionplatesproducefrictionstop,andthepick-upwheelisdrivenbytheshiftforktorotateandprintThepaperisfedintothefrontedgeofthe"paperregistrationroller"insidetheprinterandtheprintingpaperisslightlybowed,andtheprintingpaperisalignedwiththeregistrationroller.Atthistime,theregistrationrollerdoesnotrotate.Whentheregistrationrollerclutchreceivesacommandtorotate,itwillfeedtheprintingpaperintotheprintingpath(thepickuprollerofthefrictiontypeelectromagneticclutchiscircularratherthancam-shaped).
(3) Senzor
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)Obvod napájení
Providecontrolvoltageforeachpartoftheprinter.Thepowersupplycircuitisrectified,filtered,andtransformedby220Valternatingcurrenttoprovide24V,5Vdirectcurrentworkingvoltageforthelaserprinter.
(2)Obvod rozhraní
Establishcommunicationbetweenthecomputerandtheprinter.Receivecomputerdatainformationandconvertitintoprinterlanguagetoprovideprintingdatatothemaincontrolcircuitoftheprinter.Theinterfacecircuitincludesamicroprocessor(CPU).Memory(RAM/ROM).
(3)Hlavní řídicí obvod
Themaincontrolcircuitisthedatareceivedbytheinterfacecircuitandcontrolsthevariousdevicesoftheprintertoworktogetherinacommandmodetocompletetheprintingprocess.
(4)Skenovací obvod pohonu
Thereceivedcomputerinformationisgeneratedbyahigh-frequencyoscillatortogeneratealaserbeam,andthescanningmotoriscontrolledtorotateatauniformspeedtodrivethescanningmirrortocompletethephotoreceptordrumScanandexposetoformanelectrostaticlatentimage.
(5)Obvod hlavního motoru
Accordingtothecommandissuedbythemaincontrolcircuit,themainmotorisdriventorotate,andthroughthegeartransmissiondevice,poweristransmittedtoeachpartoftheoperation.
(6)Vysokonapěťový přenosový obvod
Thiscircuitconvertsthelow-voltagepowerprovidedbythepowersupplycircuitintoahighvoltagethroughatransformertoprovidethephotosensitivedrumchargingandtransferrollertransferneeds.
Odstraňování problémů
Jeden.Výstup plný list černého papíru
Možná příčina selhání:p>
(1)Pokud je laser určitě dobrý, může být nabíjecí elektroda zkratovaná s mřížkou;
(2)Logikasnímacíhoobvoduješpatná;
(3)Sestava tonerové kazety se špatně vybíjí;
(4)Signálové připojení není správně připojeno.
Two.Outputfull-frameverticalblackbelt(line)
Možná příčina selhání:
(1)Thephotosensitivedrumscraperisdamagedorthesharpobjectonthescraperscratchesthephotosensitivedrum;
(2)Částečné poškození magnetického válečkového škrabáku;
(3) Tiskárna (Obecná vodicí dráha papíru) je znečištěná tonerem.
Tři.Outputhorizontalirregularblackbelt(line)
Možná příčina selhání:
(1)Elektroda eliminace fotoreceptoru nebo bubnu je ve špatném kontaktu;
(2)Fotoreceptorbubny škrabkysmyková sílajevelká;
(3)Fotoreceptor nebo buben způsobující jittery při dusičnanech;
(4) Fotocitlivý válec je vadný nebo je nesprávně nainstalován.
4. Výstup celého listu bílého papíru
Možná příčina selhání:
(1)RůžováV rámečku není žádný tón;
(2)Mechanický uzávěr laseru není otevřen;
(3)Laserový detektor je kontaminovaný nebo poškozený;
(4)Laser je poškozen.
5.Outputverticalregularleucorrhea(bar)
Možná příčina selhání:
(1)Tón se vypíná a v části magnetického válečku není tón (obvykle ve střední části vzorku);
(2)Reflektor paprsku je kontaminován nečistotami;
(3) Dráha skenovacího světla je blokována cizími objekty.
6.Outputhorizontalirregularwhite bars(band)
Možná příčina selhání:
(1)Thechargingelectrodewireiscontaminatedorthecontactofthechargingrollerispoor;
(2)Fotovodivá vrstva na povrchu fotocitlivého bubnu je unavená;
(3)Fotocitlivý válec se špatně vybíjí.
7.Výstupní obraz a text jsou bledé
Možná příčina selhání:
(1)Vlhkost tiskového papíru;
(2)Toner je poškozen, fotocitlivá komponenta bubnu je vadná;
(3)Fotocitlivý buben se po expozici špatně vybíjí a povrchový potenciál je nízký;
(4)Podexponování;
(5)Napětí magnetického válce je nízké;
(6)Přenosové napětí je pomalé.
8.Výstupní obraz je nepravdivý
Možná příčina selhání:
(1)Nepoužívejte standardní tiskařský papír;
(2)Model toneru neodpovídá modelu stroje ani toneru je vlhký;
(3)Fotosenzitivní bubnová vlhkost;
(4)V sestavě skenování jsou volné části;
(5)Snímací motor neběží hladce a dochází k chvění.
9.Ukázka výstupu má šedé pozadí
Možná příčina selhání:
(1)Vývoj Biasvoltageistoolow;
(2)Deaktivace magnetického kotouče;
(3)Thedistancebetweenthedevelopingmagneticrollerandthephotosensitivedrumistooclose;
10. Levá a pravá strana výstupních vzorových obrázků měla různé odstíny
Možná příčina selhání:
(1)Dojde toner;
(2)Znečištění nabíjecího elektrodového drátu nebo nabíjecího válce;
(3)Kontaminace drátu přenosového elektrodového drátu nebo přenosového válečku;
(4)Zrcadlový povlak Částečně odpadá.
11.Ve výstupním ukázkovém obrázku a textu se objeví horní a spodní hloubka
Možná příčina selhání:
(1)Přenosový elektrodový drát je špinavý;
(2)Model toneru neodpovídá.
12.Výstupní vzorové obrázky a texty mají pravidelné různé odstíny odshora dolů
Možná příčina selhání:
(1)Částečná únava fotosenzitivního bubnu;
(2)Špatný kontakt mezi elektrodami nabíjecího a přenosového válce.
13. V podélném směru nátisků se objevují pravidelné bílé skvrny
Možná příčina selhání:
(1)Parciální olejová skvrna na fotocitlivém bubnu;
(2)Částečné poškození nabíjecího válečku;
(3)Částečné poškození povrchu upevňovacího válečku.
14.V podélném směru důkazů jsou pravidelné černé skvrny (tečky)
Možná příčina selhání:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Je poškozen ionizační film nabíjecího válce;
(3)Na povrchu fixačního válečku je fluor, jako měsíc, zranění (defekt má lehce světlejší barvu).
15.Na důkazech se objevují nepravidelné černé skvrny
Možná příčina selhání:
(1)V toneru jsou nečistoty;
(2)Bílý nevratný list odpadního tonu v sestavě kazety s tonerem je deformovaný nebo poškozený;
(3)Úniky toneru.
Šestnáct.Na stránce se svisle nebo vodorovně objevují nepravidelné černé čáry
Možná příčina selhání:
(1)Fotovodivá vrstva na povrchu fotocitlivého bubnu poškrábaná;
(2)Povrch upevňovacího válce je poškrábaný;
(3) Fotosenzitivní buben se při běhu chvěje.
Sedmnáct.Výstup vzorových obrázků a textů má pravidelné různé odstíny odshora dolů
Možná příčina selhání:
(1)Částečná únava fotosenzitivního bubnu;
(2)Špatný kontakt mezi elektrodami nabíjecího a přenosového válce.
18. V podélném směru nátisků se objevují pravidelné bílé skvrny
Možná příčina selhání:
(1)Parciální olejová skvrna na fotocitlivém bubnu;
(2)Částečné poškození nabíjecího válečku;
(3)Částečné poškození povrchu upevňovacího válečku.
19.V podélném směru důkazů jsou pravidelné černé skvrny (tečky)
Možná příčina selhání:
(1)Thephotoconductoronthesurfaceofthephotosensitivedrumisbrokendownortherearespots;
(2)Je poškozen ionizační film nabíjecího válce;
(3)Na povrchu fixačního válečku je fluor, jako měsíc, zranění (defekt má lehce světlejší barvu).
20. Chybí informace o obrázku stránky
Možná příčina selhání:
(1)Nastavení rozlišení obrazu je vysoké a paměť nestačí;
(2)Režim tisku nastavený ovladačem je nesprávný;
(3)Velikost obrázků a tisková stránka jsou nastaveny správně;
(4)Chyba přenosu informací.
Dvacet jedna.Pageverticalcharactercompression
Možná příčina selhání:
(1)Přenosové zařízení na fotosenzitivním bubnu uvolnění;
(2)Poměr převodového kola není správný;
(3)Ovládání otáček hlavního motoru se nezdaří.
Dvacet dva.Vodorovné nesprávné zarovnání obrázku stránky
Možná příčina selhání:
(1)Obsah tisku stránky je komplikovaný a paměť tiskárny nestačí;
(2)Velikost stránky překračuje velikost nastavenou tiskárnou.
Dvacet tři.Znaky stránky jsou zkreslené a zkreslené
Možná příčina selhání:
(1)Fotocitlivý bubensestava kazety se pohybuje axiálně;
(2)Čočka ve snímací sestavě je uvolněná;
(3)Špatný elektrický výboj před upevněním;
(4)Krystaloscilátor ve snímači je poškozen.
Dvacet čtyři. Kontaminace na zadní straně tiskového papíru
Možná příčina selhání:
(1)Papír tiskárny je znečištěn tonerem;
(2)Přítlačný pryžový válec v upevňovací sestavě je znečištěný.
Dvacet pět. Vytištěné znaky jsou duté
Možná příčina selhání:
(1)Použitý tiskový materiál nesplňuje požadavky;
(2)Model toneru je špatný
(3)Teplota upevňovacího válečku je vysoká.
26. Znaky na stránce nejsou pevně zafixovány a povrch je drsný
Možná příčina selhání:
(1)Teplota fixace je nízká;
(2)Přítlak upevňovacího pryžového válce je nedostatečný;
(3)Použitý toner neodpovídá modelu.
27.Chybí znak na levé nebo pravé straně svislé stránky
Možná příčina selhání:
(1)Světelná cesta je blokována;
(2)Ceramiccheating model, upevňovací kryt je poškozen a posunut.
Dvacet osm.Ve svislém směru stránky se zobrazí dva dvojité obrázky
Možná příčina selhání:
(1)Fotocitlivé čištění nožů;
(2)Thesurfacetemperatureoftheheatrolleristooloworthepressureoftherubberrollerisinsufficient;
(3)ThefluorinefilmonthesurfaceoftheheatrolleriswornandthesurfaceTonermeltthatadheresalot.
29.Na stránce se svisle nebo vodorovně objevují nepravidelné černé čáry
Možná příčina selhání:
(1)Fotovodivá vrstva na povrchu fotocitlivého bubnu poškrábaná;
(2)Povrch upevňovacího válce je poškrábaný;
(3) Fotosenzitivní buben se při běhu chvěje.
30. Na důkazech se objevují nepravidelné černé skvrny
Možná příčina selhání:
(1)V toneru jsou nečistoty;
(2)Bílý nevratný list odpadního tonu uvnitř sestavy bubnu je deformován nebo poškozen;
(3)Úniky toneru.
Developmentprospects
ThelaserprinterwasinventedbyXeroxinthelate1960s,usingelectro-photo-graphytechnology.Thistechnologyusesalaserbeamtoscantheopticaldrum,andbycontrollingtheonandoffofthelaserbeamtomakethesensordrumabsorbornotabsorbthetoner,theopticaldrumtransferstheabsorbedtonertothepapertoformaprintingresult.Theentireprintingprocessofalaserprintercanbedividedintothecontrollerprocessingstage,inkshadowandtransferstage.Thelaserprinterwasinventedveryearly,buttherealpopularizationandpromotionbeganintheearly1980s,andthedevelopmenttrendhasbeenacceleratedinthepasttwoyears.Thedevelopmentoflaserprintersincludesthefollowingaspects.
(1)Cena výrazně klesla
Theoriginallaserprinterwasaluxuryproduct,andmostpeoplecouldnotreachit.Intheearly1980s,Canoncommercializeddesktoplaserprintersandformedtheminbatches.Thepricedroppedsharply.Asaresult,laserprintersgraduallybegantobepromoted.Theirpopularityandpromotioninturnpromotedthedeclineinprices,andtheirdevelopmentspeedwasrapid.,Israreincomputersandperipheralproducts.Inearly1997,Hewlett-Packardtooktheleadinfurtherreducingthepricesofmostofitslaserprinters,andothercompaniesalsoloweredtheirprices,bringingthepriceofordinarylaserprinterstonearly3,000yuanperunit.In2003,abatchofthousand-yuanlaserprintersledbyHPappeared.
(2)Výkon tohoto pohybu je výrazně vylepšen
Asakeycomponentofthelaserprinter,themovementincludestheintegrationofmachinery,optoelectronicsandothertechnologies.Technologicalprogresshaspromotedtheimprovementofmovementperformance.Twoyearsago,thepopularlaserprintercoresweregenerally600dpi,andthecoresweregenerally240,000dpiorevenhigher;thespeedalsodevelopedfrom4ppm,8ppmto16ppm,24ppm;theformatisnotonlyA4,butalsoB4,A3format..
(3)Technologie ovládání je stále dokonalejší
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.
Ve srovnání sjehličkovými tiskárnami a inkoustovými tiskárnami mají laserové tiskárny všechny zřejmé výhody.
(1) Vysoká hustota. Minimální rozlišení tisku na tiskárnách s tiskárnou je 300 dpi a vysoké rozlišení je například 400 dpi, 600 dpi, 800 dpi, 1200 dpi, 2400 dpi a 4800 dpi.
(2) Vysoká rychlost. Minimální rychlost tisku na tiskárnách s tiskárnou je 4 strany za minutu, obvykle 12 stran za minutu, 16 stran za minutu a rychlost tisku některých laserových tiskáren může dosáhnout více než 24 stran za minutu.
(3) Nízký hluk. Obecně pod 53 dB je velmi vhodný pro použití v tichých kancelářích.
(4)Strongprocessingcapability.Thelaserprinter'scontrollerhasaCPUandmemory.Thecontrollerisequivalenttothecomputer'smotherboard,soitcanperformcomplexwordprocessing,imageprocessing,andgraphicsprocessing,whichcannotbedonebydotmatrixprintersandinkjetprinters.Thedifferencebetweenapageprinterandalineprinter.