电视(Television)
详细内容
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television-----themostpervasiveandpersuasiveofmoderntechnologies,markedbyrapidchangeandgrowth-ismovingintoanewera,aneraofextraordinarysophisticationandversatility,whichpromisestoreshapeourlivesandourworld.itisanelectronicrevolutionofsorts,madepossiblebythemarriageoftelevisionandputertechnologies.
theword"television",derivedfromitsgreek(tele:distant)andlatin(visio:sight)roots,canliterallybeinterpretedassightfromadistance.verysimplyput,itworksinthisway:throughasophisticatedsystemofelectronics,televisionprovidesthecapabilityofconvertinganimage(focusedonaspecialphotoconductiveplatewithinacamera)intoelectronicimpulses,whichcanbesentthroughawireorcable.theseimpulses,whenfedintoareceiver(televisionset),canthenbeelectronicallyreconstitutedintothatsameimage.
televisionismorethanjustanelectronicsystem,however.itisameansofexpression,aswellasavehicleformunication,andassuchbeesapowerfultoolforreachingotherhumanbeings.
thefieldoftelevisioncanbedividedintotwocategoriesdeterminedbyitsmeansoftransmission.first,thereisbroadcasttelevision,whichreachesthemassesthroughbroad-basedairwavetransmissionoftelevisionsignals.second,thereisnonbroadcasttelevision,whichprovidesfortheneedsofindividualsorspecificinterestgroupsthroughcontrolledtransmissiontechniques.
traditionally,televisionhasbeenamediumofthemasses.wearemostfamiliarwithbroadcasttelevisionbecauseithasbeenwithusforaboutthirty-sevenyearsinaformsimilartowhatexiststoday.duringthoseyears,ithasbeencontrolled,forthemostpart,bythebroadcastworks,abc,nbc,andcbs,whohavebeenthemajorpurveyorsofnews,information,andentertainment.thesegiantsofbroadcastinghaveactuallyshapednotonlytelevisionbutourperceptionofitaswell.wehaveetolookuponthepicturetubeasasourceofentertainment,placingourroleinthisdynamicmediumasthepassiveviewer.