Star Micronics 4 manual ThePrint engine

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1.2.5 ThePrint engine

It’s the print engine that-formsthe actual charactersand graphics.The enginedirectsitslaser,apinpointstreamof lightpulses,throughmirrorsand lensesonto the surfaceof a positively-chargedrotatingdrum.

Mirror

Lens

Laser beam

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~%a~nirr~mirror

nductor laser diode

Photosensitive drum

Asthelaserscans,it “draws”thepage-mapstoredin yourprinter’smemory. Wherevera lightpulsestrikes,that tiny part of the drumdropsto a neutral electricalcharge. That spot then attracts fine toner powder as the drum rotatespast the powdercompartment.

As the drumrotatesfurtherit meetsthepaper.The paperitselfis negatively chargedbypassingby a finecoronawire.Sinceoppositechargesattract,the negativepaper clingsto the positivedrum.Then heat and pressurefrom a rollermeltor~usethedotsof tonerontothepaper,preciselyreproducingthe image.

Finallythepaperslidesintotheoutputbin.Thepaperusuallycomesoutface down so it stacksin the correctsequence.

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