laserová tiskárna

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.Theconductivityisdeterminedbythevalues​​ofintrinsicphotoconductivity,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.

Differentmodelsoflaserprintershavedifferentprintinglanguages​​anddifferentdrivers.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,butthisnegativevoltageishigherthanthenegativevoltageintheexposedareaof​​thephotosensitivedrum,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.Laserprinterseitherhaveemulationsinoneoftheselanguages​​orboth;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.

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