electrical fields light devices made semiconductors used amplification switching energy conversion conductivity silicon increased adding small amount order sup sup pentavalent antimony phosphorus arsenic trivalent boron gallium indium atoms process known doping resulting semiconductors known doped extrinsic semiconductors apart doping conductivity semiconductor improved increasing temperature contrary behavior metal conductivity decreases increase temperature modern understanding


properties semiconductor relies quantum physics explain movement charge carriers crystal lattice ref name feynman ref doping greatly increases number charge carriers within crystal doped semiconductor contains free holes called p type contains free electrons known n type semiconductor materials used electronic devices doped precise conditions control concentration regions p n type dopants single semiconductor device crystal many p n type regions p n junctions regions responsible

Applied science
Engineering and technology
Electrical Engineering
Semiconductors


useful electronic behavior using hot point probe one determine quickly whether semiconductor sample p n type properties semiconductor materials observed throughout mid th first decades th century first practical application semiconductors electronics development cat 's whisker detector primitive semiconductor diode used early radio receivers developments quantum physics led turn invention transistor integrated circuit mosfet metal oxide semiconductor field effect transistor properties variable electrical conductivity semiconductors natural state


poor conductors current requires flow electrons semiconductors valence bands filled preventing entire flow new electrons several developed techniques allow semiconducting materials behave like conducting materials doping gating modifications two outcomes '''n type''' '''p type''' refer excess shortage electrons respectively balanced number electrons would cause current flow throughout material ref name neamen ref heterojunctions '''heterojunctions''' occur two differently doped semiconducting materials joined example configuration could consist p doped n doped germanium results


exchange electrons holes differently doped semiconducting materials n doped germanium would excess electrons p doped germanium would excess holes transfer occurs equilibrium reached process called recombination causes migrating electrons n type come contact migrating holes p type result process narrow strip immobile ions causes electric field across junction ref name feynman ref name neamen excited electrons difference electric potential semiconducting material would cause


used construction light emitting diodes fluorescent quantum dots high thermal conductivity semiconductors high thermal conductivity used heat dissipation improving thermal management electronics thermal energy conversion semiconductors large thermoelectric power factors making useful thermoelectric generators well high thermoelectric figures merit making useful thermoelectric coolers materials silicon crystals common semiconducting materials used microelectronics photovoltaics large number elements compounds semiconducting properties including ref name yacobi b g yacobi ''semiconductor materials introduction basic principles'' springer pp ref


certain pure elements found group nbsp periodic table commercially important elements silicon germanium silicon germanium used effectively valence electrons outermost shell gives ability gain lose electrons equally time binary compounds particularly elements groups nbsp gallium arsenide groups nbsp groups nbsp different group elements eg silicon carbide certain ternary compounds oxides alloys organic semiconductors made organic compounds semiconducting metal organic frameworks common semiconducting


materials crystalline solids amorphous liquid semiconductors also known include hydrogenated amorphous silicon mixtures arsenic selenium tellurium variety proportions compounds share better known semiconductors properties intermediate conductivity rapid variation conductivity temperature well occasional negative resistance disordered materials lack rigid crystalline structure conventional semiconductors silicon generally used thin film structures require material higher electronic quality relatively insensitive impurities radiation damage preparation semiconductor materials almost


today 's electronic technology involves use semiconductors important aspect integrated circuit ic found desktops laptops scanners cell phones electronic devices semiconductors ics mass produced create ideal semiconducting material chemical purity paramount small imperfection drastic effect semiconducting material behaves due scale materials used ref name neamen high degree crystalline perfection also required since faults crystal structure dislocations twins stacking faults interfere semiconducting properties


material crystalline faults major cause defective semiconductor devices larger crystal difficult achieve necessary perfection current mass production processes use crystal ingots diameter grown cylinders sliced wafers combination processes used prepare semiconducting materials ics one process called thermal oxidation forms silicon dioxide surface silicon used gate insulator field oxide processes called photomasks photolithography process creates patterns


circuit integrated circuit ultraviolet light used along photoresist layer create chemical change generates patterns circuit ref name neamen etching next process required part silicon covered photoresist layer previous step etched main process typically used today called plasma etching plasma etching usually involves etch gas pumped low pressure chamber create plasma common etch gas chlorofluorocarbon commonly known freon high radio frequency voltage


cathode anode creates plasma chamber silicon wafer located cathode causes hit positively charged ions released plasma result silicon etched anisotropically ref name feynman ref name neamen last process called diffusion process gives semiconducting material desired semiconducting properties also known doping process introduces impure atom system creates p n junction get impure atoms embedded silicon wafer wafer


first put degree celsius chamber atoms injected eventually diffuse silicon process completed silicon reached room temperature doping process done semiconducting material ready used integrated circuit ref name feynman ref name neamen physics semiconductors energy bands electrical conduction semiconductors defined unique electric conductive behavior somewhere conductor insulator differences materials understood terms quantum states electrons may contain


zero one electron pauli exclusion principle states associated electronic band structure material electrical conductivity arises due presence electrons states delocalized extending material however order transport electrons state must ''partially filled'' containing electron part time state always occupied electron inert blocking passage electrons via state energies quantum states critical since state partially filled energy


near fermi level see fermi dirac statistics high conductivity material comes many partially filled states much state delocalization metals good electrical conductors many partially filled states energies near fermi level insulators contrast partially filled states fermi levels sit within band gaps energy states occupy importantly insulator made conduct increasing temperature heating provides energy promote electrons across bandgap inducing partially filled states band states beneath band gap valence band


band states bandgap conduction band intrinsic semiconductor bandgap smaller insulator room temperature significant numbers electrons excited cross band gap ref name kittel charles kittel ''introduction solid state physics'' th ed wiley ref pure semiconductor however useful neither good insulator good conductor however one important feature semiconductors insulators known ' 'semi insulators'' conductivity increased controlled doping impurities gating


electric fields doping gating move either conduction valence band much closer fermi level greatly increase number partially filled states wider bandgap semiconductor materials sometimes referred '' 'semi insulators''' undoped electrical conductivity nearer electrical insulators however doped making useful semiconductors semi insulators find niche applications micro electronics substrates hemt example common semi insulator gallium arsenide materials titanium dioxide even used insulating materials applications treated


wide gap semiconductors applications charge carriers electrons holes partial filling states bottom conduction band understood adding electrons band electrons stay indefinitely due natural thermal recombination move around time actual concentration electrons typically dilute unlike metals possible think electrons conduction band semiconductor sort classical ideal gas electrons fly around freely without subject pauli


exclusion principle semiconductors conduction bands parabolic dispersion relation electrons respond forces electric field magnetic field etc much would vacuum though different effective mass ref name kittel electrons behave like ideal gas one may also think conduction simplistic terms drude model introduce concepts electron mobility partial filling top valence band helpful introduce concept electron hole although electrons valence band always moving


around completely full valence band inert conducting current electron taken valence band trajectory electron would normally taken missing charge purposes electric current combination full valence band minus electron converted picture completely empty band containing positively charged particle moves way electron combined ''negative'' effective mass electrons top valence band arrive picture


positively charged particle responds electric magnetic fields normal positively charged particle would vacuum positive effective mass ref name kittel particle called hole collection holes valence band understood simple classical terms electrons conduction band carrier generation recombination ionizing radiation strikes semiconductor may excite electron energy level consequently leave hole process known ''electron hole pair generation'' electron hole pairs constantly generated


approximately exp ''e'' sub g sub ''kt'' ''k'' boltzmann 's constant ''t'' absolute temperature ''e'' sub g sub bandgap probability meeting increased carrier traps nbsp impurities dislocations trap electron hole hold pair completed carrier traps sometimes purposely added reduce time needed reach steady state doping conductivity semiconductors may easily modified introducing impurities crystal lattice process adding controlled impurities semiconductor known '' 'doping''' amount impurity dopant added ''intrinsic'' pure semiconductor


varies level conductivity doped semiconductors referred ''extrinsic'' adding impurity pure semiconductors electrical conductivity may varied factors thousands millions nbsp cm sup sup specimen metal semiconductor order sup sup atoms metal every atom donates least one free electron conduction thus nbsp cm sup sup metal contains order sup sup free electrons whereas nbsp cm sup sup sample pure germanium c contains atoms free electrons holes addition arsenic impurity donates


extra '' sup sup '' free electrons volume electrical conductivity increased factor '' '' materials chosen suitable dopants depend atomic properties dopant material doped general dopants produce desired controlled changes classified either electron acceptors donors semiconductors doped ' 'donor'' impurities called ''n type'' doped ''acceptor'' impurities known ''p type'' n p type designations indicate charge carrier acts material 's majority carrier opposite carrier called minority carrier


exists due thermal excitation much lower concentration compared majority carrier example pure semiconductor silicon four valence electrons bond silicon atom neighbors silicon common dopants ''group iii'' ''group v'' elements group iii elements contain three valence electrons causing function acceptors used dope silicon acceptor atom replaces silicon atom crystal vacant state electron hole created move around lattice function charge carrier group v elements


five valence electrons allows act donor substitution atoms silicon creates extra free electron therefore silicon crystal doped boron creates p type semiconductor whereas one doped phosphorus results n type material manufacture dopants diffused semiconductor body contact gaseous compounds desired element ion implantation used accurately position doped regions amorphous semiconductors materials rapidly cooled glassy amorphous state semiconducting properties include b si ge se te


multiple theories explain early history semiconductors history understanding semiconductors begins experiments electrical properties materials properties time temperature coefficient resistance rectification light sensitivity observed starting early th century karl ferdinand braun developed crystal detector first semiconductor device thomas johann seebeck first notice effect due semiconductors michael faraday reported resistance specimens silver sulfide decreases heated contrary behavior metallic substances


cleaned william grylls adams richard evans day observed photovoltaic effect selenium ref name jtit ref unified explanation phenomena required theory solid state physics developed greatly first half th century edwin herbert hall demonstrated deflection flowing charge carriers applied magnetic field hall effect discovery electron jj thomson prompted theories electron based conduction solids karl baedeker observing hall effect reverse sign metals theorized copper iodide positive charge carriers


barrier characteristics metal semiconductor junction boris davydov developed theory copper oxide rectifier identifying effect p n junction importance minority carriers surface states ref name agreement theoretical predictions based developing quantum mechanics experimental results sometimes poor later explained john bardeen due extreme structure sensitive behavior semiconductors whose properties change dramatically based tiny amounts impurities ref name commercially pure materials containing varying proportions trace contaminants produced differing experimental results


spurred development improved material refining techniques culminating modern semiconductor refineries producing materials parts per trillion purity devices using semiconductors first constructed based empirical knowledge semiconductor theory provided guide construction capable reliable devices alexander graham bell used light sensitive property selenium transmit sound beam light working solar cell low efficiency constructed charles fritts using metal plate coated selenium thin layer gold device became commercially useful photographic light meters


ref name point contact microwave detector rectifiers made lead sulfide used jagadish chandra bose cat 's whisker detector using natural galena materials became common device development radio however somewhat unpredictable operation required manual adjustment best performance hj round observed light emission electric current passed silicon carbide crystals principle behind light emitting diode oleg losev observed similar light emission time effect practical use power rectifiers using copper oxide selenium developed


detectors nbsp mhz advanced radar systems relied fast response crystal detectors considerable research development silicon materials occurred war develop detectors consistent quality ref name early transistors john bardeen william shockley walter brattain developed bipolar point contact transistor detector power rectifiers could amplify signal many efforts made develop solid state amplifier successful developing device called point contact transistor could amplify db ref name morris peter robin morris ''a history world semiconductor industry'' iet pp


ref oleg losev developed two terminal negative resistance amplifiers radio perished siege leningrad successful completion julius edgar lilienfeld patented device resembling field effect transistor practical r hilsch r w pohl demonstrated solid state amplifier using structure resembling control grid vacuum tube although device displayed power gain cut frequency one cycle per second low practical applications effective application available theory ref name bell labs william shockley


holden started investigating solid state amplifiers first p n junction silicon observed russell ohl specimen found light sensitive sharp boundary p type impurity one end n type slice cut specimen p n boundary developed voltage exposed light first working transistor point contact transistor invented john bardeen walter houser brattain william shockley bell labs shockley earlier theorized field effect amplifier made germanium silicon failed


build working device eventually using germanium invent point contact transistor france war herbert matar observed amplification adjacent point contacts germanium base war matar 's group announced transistron amplifier shortly bell labs announced transistor physical chemist morris tanenbaum fabricated first silicon junction transistor bell labs however early junction transistors relatively bulky devices difficult manufacture mass production basis limited number specialised applications ref name moskowitz ref germanium silicon semiconductors mohamed atalla developed


surface passivation process mos transistor first silicon semiconductor device silicon radio crystal detector developed american engineer greenleaf whittier pickard ref name computerhistory russell ohl discovered p n junction photovoltaic effects silicon techniques producing high purity germanium silicon crystals developed radar microwave detectors world war ii ref name computerhistory timeline carl frosch lincoln derick bell labs accidentally discovered silicon dioxide sio sub sub could grown silicon ref name bassett ref later proposed could mask silicon surfaces diffusion processes


ref name saxena ref early years semiconductor industry late germanium dominant semiconductor material transistors semiconductor devices rather silicon germanium initially considered effective semiconductor material able demonstrate better performance due higher carrier mobility ref name dabrowski ref ref name heywang ref relative lack performance early silicon semiconductors due electrical conductivity limited unstable quantum surface states ref name feldman ref electrons trapped surface due dangling bonds occur unsaturated bonds present surface ref name kooi ref


demonstrated ref name lojek ref name bassett ref first demonstration show high quality silicon dioxide insulator films could grown thermally silicon surface protect underlying silicon p n junction diodes transistors ref name saxena atalla 's surface passivation process enabled silicon surpass conductivity performance germanium led silicon replacing germanium dominant semiconductor material ref name heywang ref name feldman atalla 's surface passivation process considered important advance silicon semiconductor technology paving way mass production silicon semiconductor devices ref name sah considered successful effort bell labs group led


atalla stabilize silicon surface important significant technology advance blazed trail led silicon integrated circuit technology developments second phase volume production third phase bibcode ieeep ref mid atalla 's process oxidized silicon surfaces used fabricate virtually integrated circuits silicon devices mosfet mos transistor mosfet mos transistor invented mohamed atalla dawon kahng x px late mohamed atalla utilized surface passivation thermal oxidation methods develop metal oxide semiconductor mos process proposed could used


gordon breach science pub external links https electronicshowstuffworkscom diodehtm semiconductors work howstuffworks http hyperphysicsphy astrgsuedu hbase solids semcnhtml semiconductor concepts hyperphysics calculator http wwwstevesquecom calculators intrinsic carrier concentration intrinsic carrier concentration silicon semiconductor onesource http wwwsemi sourcecom shof semiconductor hall fame http wwwsemiconductorglossarycom semiconductor glossary http ece wwwcoloradoedu bart book book principles semiconductor devices bart van zeghbroeck university colorado online textbook http wwwtpubcom content neets indexhtm us navy electrical engineering training series http wwwiofferssiru sva nsm semicond indexhtml nsm archive physical properties semiconductors https webarchiveorg web http wwwsemiconductor scoutcom manufacturer semiconductor manufacturerhtml semiconductor manufacturer list https nanohuborg topics edusemiconductor abacus introduction semiconductor devices nbsp gerhard klimeck dragica vasileska online learning resource simulation tools nanohub http wwworganicsemiconductorscom organic semiconductors page https wwwdoitpomsacuk tlplib semiconductors indexphp doitpoms teaching learning package introduction


semiconductors https wwwchiphistoryorg organizations virtual museum semiconductors organizations semiconductors


'''strategy''' greek ' 'strat gia'' art troop leader office general command generalship general plan achieve one long term overall goals conditions uncertainty sense art general included several subsets skills including military tactics siegecraft logistics etc term came use th century ce eastern roman terminology translated western vernacular languages th century th century word strategy came denote comprehensive way try pursue political ends

Applied science
Military sciences
Strategy


including threat actual use force dialectic wills military conflict adversaries interact ref name lfreedman ref strategy important resources available achieve goals usually limited strategy generally involves setting goals priorities determining actions achieve goals mobilizing resources execute actions ref name lfreedman strategy describes ends goals achieved means resources strategy intended emerge pattern activity organization adapts environment competes ref name lfreedman involves activities strategic planning


human attempt get desirable ends available means dr vladimir kvint defines strategy system finding formulating developing doctrine ensure long term success followed faithfully complexity theorists define strategy unfolding internal external aspects organization results actions socio economic context components professor richard p rumelt described strategy type problem solving wrote good strategy underlying structure called ''kernel'' kernel three parts ' 'diagnosis'' defines explains


nature challenge ''guiding policy'' dealing challenge coherent ''actions'' designed carry guiding policy ref name rumelt ref president kennedy illustrated three elements strategy cuban missile crisis address nation october diagnosis government promised maintained closest surveillance soviet military buildup island cuba within past week unmistakable evidence established fact series offensive missile sites preparation imprisoned island purpose bases


none provide nuclear strike capability western hemisphere guiding policy unswerving objective therefore must prevent use missiles country secure withdrawal elimination western hemisphere action plans first among seven numbered steps following halt offensive buildup strict quarantine offensive military equipment shipment cuba initiated ships kind bound cuba whatever nation port found contain cargoes offensive weapons


turned back rumelt wrote three important aspects strategy include premeditation anticipation others' behavior purposeful design coordinated actions described strategy solving design problem trade offs among various elements must arranged adjusted coordinated rather plan choice ref name rumelt formulation implementation strategy typically involves two major processes ''formulation'' ''implementation'' ''formulation'' involves analyzing environment situation making diagnosis developing guiding policies includes activities strategic planning strategic thinking ''implementation'' refers action plans taken achieve goals


established guiding policy ref name mintzberg quinn ref name rumelt bruce henderson wrote strategy depends upon ability foresee future consequences present initiatives wrote basic requirements strategy development include among factors extensive knowledge environment market competitors ability examine knowledge interactive dynamic system imagination logic choose specific alternatives henderson wrote strategy valuable finite resources uncertainty adversary 's capability intentions irreversible commitment resources necessity coordinating action time


distance uncertainty control initiative nature adversaries' mutual perceptions military theory military theory strategy utilization peace war nation 's forces large scale long range planning development ensure security victory ''random house dictionary'' ref name charlesw father western modern strategic study carl von clausewitz defined military strategy employment battles gain end war b h liddell hart 's definition put less emphasis battles defining strategy art distributing applying military means


fulfill ends policy hence gave pre eminence political aims military goals us naval war college instructor andrew wilson defined strategy process political purpose translated military action ref name wilson ref lawrence freedman defined strategy art creating power eastern military philosophy dates back much examples ''the art war'' sun tzu dated around bc ref name lionel giles ''the art war sun tzu'' special edition books ref management theory ref modern business strategy emerged field study practice


prior time words strategy competition rarely appeared prominent management literature ref name los ref ref name ghemawat ref alfred chandler wrote strategy determination basic long term goals enterprise adoption courses action allocation resources necessary carrying goals michael porter defined strategy broad formula business going compete goals policies needed carry goals combination ''ends'' goals


firm striving ''means'' policies seeking get ref name porter henry mintzberg described five definitions strategy strategy plan directed course action achieve ''intended'' set goals similar strategic planning concept strategy pattern consistent pattern past behavior strategy ' 'realized'' time rather planned ''intended'' realized pattern different intent referred strategy ''emergent'' strategy position locating brands products companies within market based


strategy may recursively look ahead consider actions happen contingent state game eg player takes action presents opponent certain situation might good bad whereas player takes action opponents presented different situation case choices make determine future situation strategies game theory may random mixed deterministic pure pure strategies thought special case mixed strategies probabilities


assigned actions strategy based games generally require player think sequence solutions determine best way defeat opponent counterterrorism strategy counterterrorism involves synchronized efforts numerous competing bureaucratic entities national governments frequently create overarching counterterrorism strategies national level ref name ref national counterterrorism strategy government 's plan use instruments national power neutralize terrorists organizations networks order render incapable using violence instill fear coerce government citizens react


accordance terrorists' goals ref name united states several strategies past including ''united states national strategy counterterrorism'' obama era ''national strategy counterterrorism'' ''national strategy combatting terrorism'' also number ancillary supporting plans ''strategy counter islamic state iraq levant'' ''strategic implementation plan empowering local partners prevent violent extremism united states'' ref name similarly united kingdom 's counterterrorism strategy contest seeks reduce


risk uk citizens interests overseas terrorism people go lives freely confidence see also concept driven strategy consultant odds algorithm odds strategy strategy game strategy pattern strategic planning strategic management strategist strategy markup language time management us army strategist reading burgelman james ''strategy destiny '' https wwwamazoncom strategy destiny strategy making companys dp strategy destiny strategy making shapes company 's future freedman lawrence ''strategy history'' https wwwamazoncom strategy history lawrence freedman dp strategy history st edition heuser beatrice ''the evolution strategy'' https wwwamazoncom evolution strategy thinking antiquity present dp x ref sr books ie utf qid sr keywords beatrice heuser evolution strategy reader x evolution strategy thinking war antiquity


present kvint vladimir ''strategy global market theory practical applications'' https booksgooglecom booksid mb n yic printsec frontcover dq vladimir kvint hl en sa x ei hnpaupnzkpossqsinydgdq ved cdoq aewaa v onepage q vladimir kvint f false excerpt google books references external links planning


flat screen televisions sale consumer electronics store '''television''' sometimes shortened '''tv''' '''telly''' telecommunication medium used transmitting moving images black white color two three dimensions sound term refer television set television show medium television transmission television mass medium advertising entertainment news sports television became available crude experimental forms late would still several years new technology would marketed consumers world war ii


improved form black white television broadcasting became popular united kingdom united states television sets became commonplace homes businesses institutions television primary medium influencing public opinion ref name diggs brown p diggs brown barbara https booksgooglecom booksid c ycysng yc pg pa lpg pa ''strategic public relations audience focused practice'' p ref mid color broadcasting introduced us developed countries availability various types archival storage media betamax vhs tapes high capacity hard disk drives dvds flash drives high definition blu ray discs cloud digital video recorders enabled viewers watch pre recorded


material movies home time schedule many reasons especially convenience remote retrieval storage television video programming also occurs cloud video demand service netflix end first decade digital television transmissions greatly increased popularity another development move standard definition television sdtv interlaced lines resolution high definition television hdtv provides resolution substantially higher hdtv may transmitted different formats p p since


invention smart television internet television increased availability television programs movies via internet streaming video services netflix amazon video iplayer hulu world 's households owned television set replacement earlier bulky high voltage cathode ray tube crt screen displays compact energy efficient flat panel alternative technologies lcds fluorescent backlit led oled displays plasma displays hardware revolution began computer monitors late television sets sold flat panel mainly leds major manufacturers announced


discontinuation crt dlp plasma even fluorescent backlit lcds mid ref name ceprocom ref ref name tomsguidecom ref near future leds expected gradually replaced oleds ref name oled infocom ref also major manufacturers announced increasingly produce smart tvs mid ref name thevergecom ref ref name techtimescom ref ref name cnetcom ref smart tvs integrated internet web functions became dominant form television late ref name techcrunchcom ref television signals initially distributed terrestrial television using high powered radio frequency television transmitters broadcast signal individual television receivers alternatively television signals distributed coaxial cable optical fiber


satellite systems since via internet early transmitted analog signals transition digital television expected completed worldwide late standard television set consists multiple internal electronic circuits including tuner receiving decoding broadcast signals visual display device lacks tuner correctly called video monitor rather television etymology word ''television'' comes first documented usage term dates back russian scientist constantin perskyi used paper


presented french st international congress electricity ran august international world fair paris anglicised version term first attested still theoretical system transmit moving images telegraph telephone wires ref name etymonline ref formed english borrowed french l vision ref name etymonline th century early th century proposals name hypothetical technology sending pictures distance telephote televista ref name etymonline abbreviation ''tv''


use term mean television set dates ref name etymonline use term mean television medium dates ref name etymonline slang term ''telly'' common uk slang term ''the tube'' ''boob tube'' derives bulky cathode ray tube used tvs advent flat screen tvs another slang term tv idiot box also throughout early rapid growth television programming television set ownership united states another slang


term became widely used period continues used today distinguish productions originally created broadcast television films developed presentation movie theaters ref name smallscreen johnson richard https pagesixcom big movie stars making cut small screen big movie stars making cut small screen p ''the new york post'' october retrieved november ref small screen compound adjective noun became specific references television big screen used identify productions made theatrical release ref name smallscreen history mechanical nipkow disk schematic shows circular paths traced


hole scanned line image although never built working model system variations nipkow 's spinning disk image rasterizer became exceedingly common constantin perskyi coined word ''television'' paper read international electricity congress international world fair paris august perskyi 's paper reviewed existing electromechanical technologies mentioning work nipkow others however developments amplification tube technology lee de forest arthur korn among others made design practical ref name sending photographs telegraph https querynytimescom gst abstracthtmlres e da e c c cf


sending photographs telegraph ''the new york times'' sunday magazine september p ref first demonstration live transmission images georges rignoux fournier paris matrix selenium cells individually wired mechanical commutator served electronic retina receiver type kerr cell modulated light series differently angled mirrors attached edge rotating disc scanned modulated beam onto display screen separate circuit regulated synchronization x pixel resolution proof concept demonstration


radio widely regarded world 's first public television demonstration baird 's system used nipkow disk scanning image displaying brightly illuminated subject placed front spinning nipkow disk set lenses swept images across static photocell thallium sulphide thalofide cell developed theodore case us detected light reflected subject converted proportional electrical signal transmitted radio waves receiver unit video signal applied neon light behind


second nipkow disk rotating synchronized first brightness neon lamp varied proportion brightness spot image hole disk passed one scan line image reproduced baird 's disk holes producing image scan lines enough recognize human face baird transmitted signal telephone line london glasgow baird 's company baird television development company cinema television broadcast first transatlantic television signal london new york


first shore ship transmission became involved first experimental mechanical television service germany november year baird bernard natan path established france 's first television company l vision baird natan made first outdoor remote broadcast derby demonstrated ultra short wave television baird 's mechanical system reached peak lines resolution bbc telecasts though mechanical system scan televised scene directly instead mm film shot rapidly developed scanned film still wet us inventor


charles francis jenkins also pioneered television published article motion pictures wireless december transmitted moving silhouette images witnesses june publicly demonstrated synchronized transmission silhouette pictures jenkins used nipkow disk transmitted silhouette image toy windmill motion distance miles nbsp km naval radio station maryland laboratory washington dc using lensed disk scanner line resolution ref name glinsky ref granted


us patent transmitting pictures wireless june filed march herbert e ives frank gray bell telephone laboratories gave dramatic demonstration mechanical television april reflected light television system included small large viewing screens small receiver inch wide inch high screen nbsp cm large receiver screen nbsp inches wide nbsp inches high nbsp cm sets capable reproducing reasonably accurate monochromatic moving images along pictures sets received synchronized sound system transmitted images two


paths first copper wire link washington new york city radio link whippany new jersey comparing two transmission methods viewers noted difference quality subjects telecast included secretary commerce herbert hoover flying spot scanner beam illuminated subjects scanner produced beam aperture disk disc revolved rate frames per second capturing one frame every milliseconds today 's systems typically transmit frames per second one frame every milliseconds respectively television historian albert abramson underscored


significance bell labs demonstration fact best demonstration mechanical television system ever made time would several years system could even begin compare picture quality wrgb w xb started world 's first television station broadcast general electric facility schenectady ny popularly known wgy television meanwhile soviet union l theremin developing mirror drum based television starting lines resolution lines eventually


using interlacing part thesis may electrically transmitted projected near simultaneous moving images screen ref name glinsky theremin achieved image lines resolution surpassed may rca lines december kenjiro takayanagi demonstrated television system line resolution employed nipkow disk scanner crt display hamamatsu industrial high school japan prototype still display takayanagi memorial museum shizuoka university hamamatsu campus research


creating production model halted scap world war ii ref name nhkorjp http wwwnhkorjp strl aboutstrl evolution tv en p ''kenjiro takayanagi father japanese television'' nhk japan broadcasting corporation retrieved may ref limited number holes could made disks disks beyond certain diameter became impractical image resolution mechanical television broadcasts relatively low ranging lines nevertheless image quality line transmissions steadily improved technical advances uk broadcasts using baird system remarkably clear systems ranging


line region also went air two line system compagnie des compteurs cdc installed paris line system peck television corp started station ak montreal advancement electronic television including image dissectors camera tubes cathode ray tubes reproducer marked start end mechanical systems dominant form television mechanical television despite inferior image quality generally smaller picture would remain primary television technology last mechanical telecasts


crt russian scientist boris rosing used crt receiving end experimental video signal form picture managed display simple geometric shapes onto screen ref name crthistory ref alan archibald campbell swinton fellow royal society uk published letter scientific journal ''nature'' described distant electric vision could achieved using cathode ray tube braun tube transmitting receiving device ref name swinton dev ref ref name swinton dev ref expanded vision speech given london


conducted march minchin died ref name minchin ref later repeated two different teams h miller j w strange emi ref name miller strange ref h iams rose rca ref name iams rose ref teams succeeded transmitting faint images original campbell swinton 's selenium coated plate although others experimented using cathode ray tube receiver concept using one transmitter novel first cathode ray tube use hot cathode developed john b johnson gave name


term johnson noise harry weiner weinhart western electric became commercial product hungarian engineer k lm n tihanyi designed television system utilizing fully electronic scanning display elements employing principle charge storage within scanning camera tube ref name us united states patent office patent october ref ref name us united states patent office patent may ref problem low sensitivity light resulting low electrical output transmitting camera tubes would solved introduction charge storage technology k lm n tihanyi beginning ref


name iec tihanyi http wwwiecch history techline swf tempxml k lm n tihanyi ''iec techline'' international electrotechnical commission iec july ref solution camera tube accumulated stored electrical charges photoelectrons within tube throughout scanning cycle device first described patent application filed hungary march television system called radioskop ref name radioskop http wwwunescoorg new en communication information flagship project activities memory world register full list registered heritage registered heritage page kalman tihanyis patent application radioskop k lm n tihanyi 's patent application 'radioskop' ''memory world'' united nations educational scientific cultural organization unesco retrieved january ref refinements included patent application ref name iec tihanyi tihanyi 's patent declared void great britain ref


name abstract http v espacenetcom publicationdetails bibliodb epodoc adjacent true locale en v ft date cc gb nr kc tihanyi koloman ''improvements television apparatus'' european patent office patent gb convention date uk application declared void published november retrieved april ref applied patents united states although breakthrough would incorporated design rca 's iconoscope us patent tihanyi 's transmitting tube would granted may patent receiving tube granted previous october patents purchased rca prior approval ref name autogenerated ref ref name autogenerated ref charge storage remains basic principle design


imaging devices television present day ref name radioskop december hamamatsu industrial high school japan japanese inventor kenjiro takayanagi demonstrated tv system line resolution employed crt display ref name nhkorjp first working example fully electronic television receiver takayanagi apply patent allen b dumont made first crts last hours use one factors led widespread adoption television september us inventor philo farnsworth 's image dissector camera tube


transmitted first image simple straight line laboratory green street san francisco ref name postman https webarchiveorg web http wwwtimecom time time scientist profile farnsworthhtml postman neil philo farnsworth ''the time scientists thinkers'' ''time'' march retrieved july ref ref name sfmuseum http wwwsfmuseumorg hist philohtml philo taylor farnsworth ''the virtual museum city san francisco'' retrieved july ref september farnsworth developed system sufficiently hold demonstration press widely regarded first electronic television demonstration ref name sfmuseum system improved elimination motor generator


color transmission version patent application ref name us https wwwgooglecom patents aboutid mz kaaaaebaj zworykin vladimir k television system patent us patent office filed issued november retrieved july ref also divided original application ref name us https wwwgooglecom patentsid tqt aaaaebaj zworykin vladimir k television system patent us patent office filed issued november retrieved may ref zworykin unable unwilling introduce evidence working model tube based patent application september losing appeal courts determined go forward


showed great promise fields electronics unfortunately issue multipactor wore unsatisfactory rate ref name everson everson george ''the story television life philo farnsworth'' new york ww norton co p ref berlin radio show august manfred von ardenne gave public demonstration television system using crt transmission reception however ardenne developed camera tube using crt instead flying spot scanner scan slides film philo farnsworth gave world 's first


history technology series london iee p ref original us iconoscope noisy high ratio interference signal ultimately gave disappointing results especially compared high definition mechanical scanning systems becoming available ref name winstor media ref ref name winstor history ref emi team supervision isaac shoenberg analyzed iconoscope emitron produces electronic signal concluded real efficiency theoretical maximum ref name alexander ref ref name burns blumlein ref solved problem developing patenting two new camera tubes dubbed super emitron cps emitron ref


name gb ref ref name gb ref ref name gb ref super emitron ten fifteen times sensitive original emitron iconoscope tubes cases ratio considerably greater ref name alexander used outside broadcasting bbc first time armistice day general public could watch television set king laid wreath cenotaph ref name alexander ref first time anyone broadcast live street scene cameras installed roof neighboring buildings neither farnsworth rca would


new york world 's fair ad beginning experimental television broadcasting new york city rca indian head test pattern used black white era displayed television station first signed every day hand zworykin shared patent rights german licensee company telefunken ref name inglis ref image iconoscope superikonoskop germany produced result collaboration tube essentially identical super emitron production commercialization super emitron image iconoscope europe


competing american tradition represented image orthicon ref name vries ref ref name multicon ref german company heimann produced superikonoskop berlin olympic games ref name heimann ref ref name etm ref later heimann also produced commercialized ref name heimann ref finally dutch company philips produced commercialized image iconoscope multicon ref name multicon ref name philips ref us television broadcasting time consisted variety markets wide range sizes competing programming dominance separate technology deals made standards agreed upon ref


name everson everson george ''the story television life philo farnsworth'' new york ww norton co p ref rca example used iconoscopes new york area farnsworth image dissectors philadelphia san francisco ref name thehistoryoftv abramson albert ''the history television '' jefferson nc albert abramson p ref september rca agreed pay farnsworth television radio corporation royalties next ten years access farnsworth 's patents ref name schatzkin schatzkin paul ''the boy invented television'' silver spring maryland teamcom books pp ref


historic agreement place rca integrated much best farnsworth technology systems ref name thehistoryoftv united states implemented line television electrical engineer benjamin adler played prominent role development television world 's first line television standard designed soviet union became national standard ref name th anniversary http netru files h fb bb beginning broadcast lines years ago '' '' magazine russian ref first broadcast line standard occurred moscow concept lines per frame subsequently implemented


european ccir standard k lm n tihanyi described principle plasma display first flat panel display system early electronic television sets large bulky analog circuits made vacuum tubes following invention first working transistor bell labs sony founder masaru ibuka predicted transition electronic circuits made transistors would lead smaller portable television sets first fully transistorized portable solid state television set inch sony tv developed released began transformation television viewership


communal viewing experience solitary viewing experience sony sold million portable television sets worldwide color samsung led tv basic idea using three monochrome images produce color image experimented almost soon black white televisions first built although gave practical details among earliest published proposals television one maurice le blanc color system including first mentions television literature line frame scanning polish inventor jan szczepanik patented color television system using


patent ref name tvmuseumru http wwwtvmuseumru attachaspa rokhlin tak rozhdalos' dal'novidenie russian ref scottish inventor john logie baird demonstrated world 's first color transmission july using scanning discs transmitting receiving ends three spirals apertures spiral filters different primary color three light sources receiving end commutator alternate illumination baird also made world 's first color broadcast february sending mechanically scanned line image baird 's crystal palace studios projection screen london 's dominion theatre mechanically scanned color television


also demonstrated bell laboratories june using three complete systems photoelectric cells amplifiers glow tubes color filters series mirrors superimpose red green blue images one full color image first practical hybrid system pioneered john logie baird publicly demonstrated color television combining traditional black white display rotating colored disk device deep later improved mirror folding light path entirely practical device resembling large conventional console however baird unhappy


design early commented british government committee fully electronic device would better hungarian engineer peter carl goldmark introduced electro mechanical system cbs contained iconoscope sensor cbs field sequential color system partly mechanical disc made red blue green filters spinning inside television camera rpm similar disc spinning synchronization front cathode ray tube inside receiver set system first demonstrated federal communications commission fcc august


shown press september ref name colortvsuccess color television success test ''the new york times'' august p ref cbs began experimental color field tests using film early august live cameras november ref name colortvsuccess nbc owned rca made first field test color television february cbs began daily color field tests june color systems compatible existing black white television sets color television sets available public time viewing color field


tests restricted rca cbs engineers invited press war production board halted manufacture television radio equipment civilian use april august limiting opportunity introduce color television general public early baird started work fully electronic system called telechrome early telechrome devices used two electron guns aimed either side phosphor plate phosphor patterned electrons guns fell one side patterning using cyan


magenta phosphors reasonable limited color image could obtained also demonstrated system using monochrome signals produce image called stereoscopic time demonstration august first example practical color television system work telechrome continued plans made introduce three gun version full color however baird 's untimely death ended development telechrome system similar concepts common differing primarily way combined colors generated three guns geer tube


similar baird 's concept used small pyramids phosphors deposited outside faces instead baird 's patterning flat surface penetron used three layers phosphor top increased power beam reach upper layers drawing colors chromatron used set focusing wires select colored phosphors arranged vertical stripes tube one great technical challenges introducing color broadcast television desire conserve bandwidth potentially three times existing black white standards


use excessive amount radio spectrum united states considerable research national television systems committee ref name name national television system committee report reports panel supplementary references cited reports petition adoption transmission standards color television federal communications commission np v illus diagrams tables cm lc control http cataloglocgov cgi bin pwebreconcgidb local page first library congress online catalog ref approved electronic system developed rca encoded color information separately brightness information greatly reduced resolution


color information order conserve bandwidth black white televisions could receive transmission display black white color system adopted backwards compatible compatible color featured rca advertisements period mentioned song america west side story brightness image remained compatible existing black white television sets slightly reduced resolution color televisions could decode extra information signal produce limited resolution color display higher resolution black white lower resolution color images combine brain produce seemingly high resolution color image


ntsc standard represented major technical achievement color bars used test pattern sometimes used program material available first color broadcast first episode live program ''the marriage'' occurred july following ten years network broadcasts nearly local programming continued black white mid color sets started selling large numbers due part color transition announced half network prime time programming would broadcast color


fall first color prime time season came one year later last holdout among daytime network programs converted color resulting first completely color network season early color sets either floor standing console models tabletop versions nearly bulky heavy practice remained firmly anchored one place ge 's relatively compact lightweight porta color set introduced spring used transistor based uhf tuner first fully transistorized color television united states quasar television introduced developments made watching color


black white sets color broadcasting europe standardized pal format broadcasts start point many technical issues early sets worked spread color sets europe fairly rapid mid stations broadcasting black white high numbered uhf stations small markets handful low power repeater stations even smaller markets vacation spots even last converted color early b w


sets pushed niche markets notably low power uses small portable sets use video monitor screens lower cost consumer equipment late even areas switched color sets digital digital television dtv transmission audio video digitally processed multiplexed signals contrast totally analog channel separated signals used analog television due data compression digital television support one program channel bandwidth innovative service represents significant evolution television broadcast technology since color


first proposed image compression nasir ahmed ref name ahmed ref later adapted motion compensated dct video coding algorithm video coding standards h x formats onwards mpeg formats onwards ref name ghanbari ref ref name li ref motion compensated dct video compression significantly reduced amount bandwidth required digital television signal ref name lea ref name barbero dct coding compressed bandwidth requirements digital television signals nbsp mbit sdtv around nbsp mbit hdtv maintaining near studio quality transmission making digital television practical reality ref name barbero digital


television service proposed nippon telegraph telephone ntt ministry posts telecommunication mpt japan plans develop integrated network system service however possible practically implement digital television service adoption dct video compression technology made possible early ref name lea mid japanese consumer electronics firms forged ahead development hdtv technology muse analog format proposed nhk japanese company seen pacesetter threatened eclipse us electronics companies'


technologies june japanese muse standard based analog system front runner among technical concepts consideration us company general instrument demonstrated possibility digital television signal breakthrough significance fcc persuaded delay decision atv standard digitally based standard could developed march became clear digital standard possible fcc made number critical decisions first commission declared new atv standard must


enhanced analog signal able provide genuine hdtv signal least twice resolution existing television images ensure viewers wish buy new digital television set could continue receive conventional television broadcasts dictated new atv standard must capable simulcast different channels new atv standard also allowed new dtv signal based entirely new design principles although incompatible existing ntsc standard new dtv standard would able incorporate many improvements last standards


adopted fcc require single standard scanning formats aspect ratios lines resolution compromise resulted dispute consumer electronics industry joined broadcasters computer industry joined film industry public interest groups two scanning processes interlaced progressive would best suited newer digital hdtv compatible display devices ref name bambooavcom ref interlaced scanning specifically designed older analogue crt display technologies scans even numbered lines first odd numbered ones fact interlaced scanning looked first


video compression model partly designed double image resolution exceed limitations television broadcast bandwidth another reason adoption limit flickering early crt screens whose phosphor coated screens could retain image electron scanning gun relatively short duration however interlaced scanning work efficiently newer display devices liquid crystal lcd example better suited frequent progressive refresh rate ref name bambooavcom progressive scanning format computer industry long adopted


computer display monitors scans every line sequence top bottom progressive scanning effect doubles amount data generated every full screen displayed comparison interlaced scanning painting screen one pass second instead two passes second computer industry argued progressive scanning superior flicker new standard display devices manner interlaced scanning also argued progressive scanning enables easier connections internet cheaply converted interlaced formats vice versa film industry


also supported progressive scanning offered efficient means converting filmed programming digital formats part consumer electronics industry broadcasters argued interlaced scanning technology could transmit highest quality pictures currently feasible ie lines per picture pixels per line broadcasters also favored interlaced scanning vast archive interlaced programming readily compatible progressive format william f schreiber director advanced television research program massachusetts institute technology retirement


thought continued advocacy interlaced equipment originated consumer electronics companies trying get back substantial investments made interlaced technology digital television transition started late governments across world set deadline analog shutdown initially adoption rate low first digital tuner equipped television sets costly soon price digital capable television sets dropped households converting digital television sets transition expected completed worldwide mid late smart television


smart tv confused internet tv internet protocol television iptv web tv internet television refers receiving television content internet instead traditional systems terrestrial cable satellite although internet received methods iptv one emerging internet television technology standards use television networks web television webtv term used programs created wide variety companies individuals broadcast internet tv first patent filed extended following year intelligent television


system linked data processing systems means digital analog network apart linked data networks one key point ability automatically download necessary software routines according user 's demand process needs major tv manufacturers announced production smart tvs middle end high end tvs ref name thevergecom ref name techtimescom ref name cnetcom smart tvs gotten affordable compared first introduced million us households least one television conveys depth perception viewer employing techniques


stereoscopic display multi view display plus depth form display modern television sets use active shutter system polarized system autostereoscopic without need glasses stereoscopic television demonstrated first time august john logie baird company 's premises long acre london baird pioneered variety television systems using electromechanical cathode ray tube techniques first television produced advent digital television greatly improved television sets


although television sets quite popular watching home media blu ray discs programming largely failed make inroads public many television channels started early shut mid according displaysearch televisions shipments totaled nbsp million units compared late number tv viewers started decline broadcast systems terrestrial television modern high gain uhf yagi television antenna directors one reflector made rods


adoption cable across united states terrestrial television broadcasts decline estimated us households used antenna slight increase use began around due switchover digital terrestrial television broadcasts offered pristine image quality large areas offered alternate cable television catv cord cutters countries around world also process either shutting analog terrestrial television switching digital terrestrial television cable television coaxial cable used


united states originally stood community access television community antenna television cable television 's origins areas air reception limited distance transmitters mountainous terrain large community antennas constructed cable run individual homes satellite television dbs satellite dishes installed apartment complex satellite television system supplying television programming using broadcast signals relayed communication satellites signals received via outdoor parabolic reflector antenna usually referred satellite dish low noise block downconverter lnb satellite


receiver decodes desired television program viewing television set receivers external set top boxes built television tuner satellite television provides wide range channels services especially geographic areas without terrestrial television cable television common method reception direct broadcast satellite television dbstv also known direct home dth ref name tr ref dbstv systems signals relayed direct broadcast satellite k sub u sub wavelength completely digital ref name ref satellite tv systems formerly used systems known television receive systems received analog signals transmitted


c band spectrum fss type satellites required use large dishes consequently systems nicknamed big dish systems expensive less popular ref name fcc ref direct broadcast satellite television signals earlier analog signals later digital signals require compatible receiver digital signals may include high definition television hdtv transmissions channels free air free view many channels pay television requiring subscription british science fiction writer arthur c clarke proposed worldwide communications system would function means three satellites equally spaced apart


earth orbit published october issue ''wireless world'' magazine franklin institute 's stuart ballantine medal first satellite television signals europe north america relayed via telstar satellite atlantic ocean july ref name histchannel ref signals received broadcast north american european countries watched million ref name histchannel launched ''relay '' satellite first satellite transmit television signals us japan ref name relay ref first geosynchronous communication satellite syncom


received existing uhf television technology rather microwave technology ref name ekran ref internet television internet television internet tv online television digital distribution television content via internet opposed traditional systems like terrestrial cable satellite although internet received terrestrial cable satellite methods internet television general term covers delivery television series video content internet video streaming technology typically major traditional television broadcasters internet television confused smart tv iptv web tv smart television refers


television set built operating system internet protocol television iptv one emerging internet television technology standards use television networks web television term used programs created wide variety companies individuals broadcast internet television sets rca ts first mass produced television set sold television set also called television receiver television tv set tv telly device combines tuner display amplifier speakers purpose viewing television hearing audio components introduced


late mechanical form television sets became popular consumer product world war ii electronic form using cathode ray tubes addition color broadcast television increased popularity television sets outdoor antenna became common feature suburban homes ubiquitous television set became display device recorded media betamax vhs enabled viewers record tv shows watch prerecorded movies subsequent decades television sets used watch dvds blu ray discs movies


content major tv manufacturers announced discontinuation crt dlp plasma fluorescent backlit lcds mid televisions since mostly use leds ref name ceprocom ref name tomsguidecom ref name displaysearchcom ref ref name referencea ref leds expected gradually replaced oleds near future ref name oled infocom display technologies disk earliest systems employed spinning disk create reproduce images usually low resolution screen size never became popular public crt inch cathode ray tube showing deflection coils electron guns cathode ray tube crt vacuum tube containing one electron guns


particularly crt used consumer product television sets computer monitors entire front area tube scanned repetitively systematically fixed pattern called raster image produced controlling intensity three electron beams one additive primary color red green blue video signal reference ref name 'workings' ref modern crt monitors televisions beams bent ''magnetic deflection'' varying magnetic field generated coils driven electronic circuits around neck tube


although electrostatic deflection commonly used oscilloscopes type diagnostic instrument ref name 'workings' dlp christie mirage dlp projector digital light processing dlp type video projector technology uses digital micromirror device dlps tv tuner makes type tv display originally developed dr larry hornbeck texas instruments dlp imaging device invented texas instruments first dlp based projector introduced digital projection ltd digital projection texas instruments awarded emmy


awards invention dlp projector technology dlp used variety display applications traditional static displays interactive displays also non traditional embedded applications including medical security industrial uses dlp technology used dlp front projectors standalone projection units classrooms business primarily also private homes cases image projected onto projection screen dlp also used dlp rear projection television sets digital signs also used digital cinema projection plasma plasma display panel pdp


type flat panel display common large television displays larger called plasma displays technology utilizes small cells containing electrically charged ionized gases essence chambers commonly known fluorescent lamps lcd generic lcd tv speakers either side screen liquid crystal display televisions lcd tv television sets use lcd display technology produce images lcd televisions much thinner lighter cathode ray tube crts similar display size available much larger sizes eg inch diagonal manufacturing costs fell


combination features made lcds practical television receivers lcds come two types using cold cathode fluorescent lamps simply called lcds using led backlight called leds lcd television sets surpassed sales crt based television sets worldwide first time sales figures relative technologies accelerated lcd television sets quickly displaced major competitors large screen market plasma display panel rear projection television mid lcds especially leds became far widely produced sold television display type ref name displaysearchcom ref name referencea


lcds also disadvantages technologies address weaknesses including oleds fed sed none entered widespread production oled oled tv oled organic light emitting diode light emitting diode led emissive electroluminescent layer film organic compound emits light response electric current layer organic semiconductor situated two electrodes generally least one electrodes transparent oleds used create digital displays devices television screens also used computer monitors portable systems


mobile phones handheld game consoles pdas two main groups oled based small molecules employing polymers adding mobile ions oled creates light emitting electrochemical cell lec slightly different mode operation oled displays use either passive matrix pmoled active matrix amoled addressing schemes active matrix oleds require thin film transistor backplane switch individual pixel allow higher resolution larger display sizes oled display works without backlight thus display deep black levels thinner lighter


liquid crystal display lcd low ambient light conditions dark room oled screen achieve higher contrast ratio lcd whether lcd uses cold cathode fluorescent lamps led backlight oleds expected replace forms display near future ref name oled infocom display resolution uhdtv k uhdtv hdtv sdtv resolution ld low definition television ldtv refers television systems lower screen resolution standard definition television systems p used handheld television common source ldtv programming internet


sdtv due resolution approximately sd standard definition television sdtv refers two different resolutions interlaced lines resolution derived european developed pal secam systems based american national television system committee ntsc system sdtv television system uses resolution considered either high definition television p p p k uhdtv k uhd enhanced definition television edtv p north america digital sdtv broadcast aspect ratio ntsc signals widescreen content center cut


however parts world used pal secam color systems standard definition television usually shown aspect ratio transition occurring mid mid older programs aspect ratio shown united states non atsc countries preferring reduce horizontal resolution anamorphically scaling pillarboxed image hd high definition television hdtv provides resolution substantially higher standard definition television hdtv may transmitted various formats p p pixels megapixels per frame pixels


mp per field pixels mp per frame non standard cea resolution exists countries pixels mp per field pixels mp per frame p p pixels mp per frame uhd ultra high definition television also known super hi vision ultra hd television ultrahd uhdtv uhd includes k uhd p k uhd p two digital video formats proposed nhk science technology research laboratories defined approved international telecommunication union itu consumer electronics association announced october


ultra high definition ultra hd would used displays aspect ratio least least one digital input capable carrying presenting natural video minimum resolution pixels market share north american consumers purchase new television set average every seven years average household owns televisions million sold year average price size ref name martin ref class wikitable style width colspan worldwide lcd tv manufacturers market share manufacturer statista ref name market share ref samsung electronics


tcl lg electronics hisense skyworth sony sharp others content programming getting tv programming shown public happen many ways production next step market deliver product whichever markets open using typically happens two levels original run first run producer creates program one multiple episodes shows


station network either paid production license granted television producers broadcast syndication terminology rather broadly used describe secondary programming usages beyond original run includes secondary runs country first issue also international usage may managed originating producer many cases companies television stations individuals engaged syndication work words sell product markets allowed sell


contract copyright holders cases producers first run programming increasing subscription services outside united states domestically produced programs syndicated domestic free air fta elsewhere practice increasing however generally digital fta channels subscriber first run material appearing fta unlike united states repeat fta screenings fta network program usually occur network also affiliates rarely buy produce non network programming focused local programming genres television genres include broad range programming types entertain inform


educate viewers expensive entertainment genres produce usually dramas dramatic miniseries however genres historical western genres may also high production costs pop culture entertainment genres include action oriented shows police crime detective dramas horror thriller shows well also variants drama genre medical dramas daytime soap operas sci fi series fall either drama action category depending whether emphasize philosophical questions high adventure comedy popular genre includes situation comedy sitcom animated series


adult demographic comedy central 's ''south park'' least expensive forms entertainment programming genres game shows talk shows variety shows reality television game shows feature contestants answering questions solving puzzles win prizes talk shows contain interviews film television music sports celebrities public figures variety shows feature range musical performers entertainers comedians magicians introduced host master ceremonies crossover talk shows variety shows leading talk shows often feature performances bands singers comedians


air fta global tv market represented nbsp million tv households least one tv total revenues nbsp billion eur declining compared north america biggest tv revenue market share followed europe asia pacific latin america africa middle east globally different tv revenue sources divide tv advertising revenues subscription fees public funding advertising television 's broad reach makes powerful attractive medium advertisers many television networks stations sell blocks broadcast time advertisers


sponsors fund programming ref name hornick http wwwamericanheritagecom articles magazine ah shtml karen hornick year ''american heritage'' oct ref television advertisements variously called television commercial commercial ad american english known british english advert span television programming produced paid organization conveys message typically market product service advertising revenue provides significant portion funding privately owned television networks vast majority television advertisements today consist brief advertising spots ranging length seconds several


minutes well program length infomercials advertisements sort used promote wide variety goods services ideas since beginning television television still experimental phase medium 's potential sell goods already predicted effects television advertising upon viewing public effects mass media general subject discourse philosophers including marshall mcluhan viewership television programming measured companies nielsen media research often used metric television advertisement placement


watches company paid anywhere reports vary displayed wnbt test pattern modified look like clock hands showing time bulova logo phrase bulova watch time shown lower right hand quadrant test pattern second hand swept around dial one minute first tv ad broadcast uk itv september advertising gibbs sr toothpaste first tv ad broadcast asia nippon television tokyo august advertising seikosha


ratings time day popularity channel determine much tv commercial cost example cost approximately second block commercial time highly popular singing competition american idol amount time super bowl cost several million dollars conversely lesser viewed time slots early mornings weekday afternoons often sold bulk producers infomercials far lower rates recent years paid program infomercial become common usually lengths minutes one hour


drug companies businesses even created news items broadcast known industry video news releases paying program directors use television programs also deliberately place products shows advertisements practice started feature films known product placement example character could drinking certain kind soda going particular chain restaurant driving certain make car sometimes subtle shows vehicles provided manufacturers low cost exchange product placement sometimes specific brand


trade mark music certain artist group used excludes guest appearances artists perform show united kingdom tv regulator oversees tv advertising united kingdom restrictions applied since early days commercially funded tv despite early tv mogul roy thomson likened broadcasting licence licence print money restrictions mean big three national commercial tv channels itv channel channel show average seven minutes advertising per hour eight minutes peak


period broadcasters must average nine minutes twelve peak means many imported tv shows us unnatural pauses british company utilize narrative breaks intended frequent us advertising advertisements must inserted course certain specific proscribed types programs last less half hour scheduled duration list includes news current affairs programs documentaries programs children additionally advertisements may carried program designed broadcast reception schools


religious broadcasting service devotional program formal royal ceremony occasion also must clear demarcations time programs advertisements bbc strictly non commercial allowed show advertisements television uk although many advertising funded channels abroad majority budget comes television license fees see broadcast syndication sale content broadcasters ireland broadcast advertising regulated broadcasting authority ireland subscription tv channels partly funded subscriptions therefore signals encrypted


pts united kingdom bbc television united states pbs british broadcasting corporation 's tv service carries television advertising uk channels funded annual television licence paid occupiers premises receiving live telecasts estimated approximately nbsp million uk private domestic households owned televisions approximately million tv licences premises force television license fee set government bbc answerable controlled government two main bbc tv channels watched almost


population week overall share total viewing despite fact homes multi channel access free air channels via satellite another access channels via freeview licence funds advertising free bbc tv channels cost colour tv licence black white tv licence free reduced groups australian broadcasting corporation 's television services australia carry advertising external sources banned ''australian broadcasting corporation act ''


also ensures editorial independence abc receives funding australian government revenue received commercial division suffered progressive funding cuts liberal governments since howard government particularly deep cuts turnbull government ongoing indexation freeze funds provide abc 's television radio online international outputs although abc australia broadcasts throughout asia pacific region receives additional funds dfat advertising channel france government funded channels carry advertisements yet television


sets pay annual tax la redevance audiovisuelle japan nhk paid license fees known japanese broadcast law governs nhk 's funding stipulates television equipped receive nhk required pay fee standardized discounts office workers students commute well general discount residents okinawa prefecture broadcast programming broadcast programming tv listings united kingdom practice organizing television programs schedule broadcast automation used regularly change scheduling tv programs


build audience new show retain audience compete broadcasters' programs social aspects american family watching television circa television played pivotal role socialization th st centuries many aspects television addressed including negative issues media violence current research discovering individuals suffering social isolation employ television create termed parasocial faux relationship characters favorite television shows movies way deflecting feelings loneliness social deprivation ref name scientificamericancom butler


fionnuala cynthia pickett imaginary friends ''scientific american'' july web march http wwwscientificamericancom articlecfmid imaginary friends ref several studies found educational television many advantages article good things television ref name good things tv ref argues television powerful effective learning tool children used wisely respect faith many christian denominations use television religious broadcasting opposition methodist denominations conservative holiness movement allegheny wesleyan methodist connection evangelical wesleyan church eschew use television ref name marty ref baptists affiliated pensacola christian college also


eschew television many traditional catholic congregations society saint pius x sspx laestadian lutherans oppose presence television household teaching occasion sin ref name lamport ref negative impacts children especially aged younger risk injury falling televisions ref name ferguson ref crt style television falls child weight hit equivalent force falling multiple stories building newer flat screen televisions top heavy narrow bases means small child easily pull one ref name safekids ref


tv tip overs responsible injuries per year children us cost million per year emergency care ref name ferguson ref name safekids study ''the journal human resources'' found exposure cable television reduced cognitive ability high school graduation rates boys effect stronger boys educated families article suggests mechanism light television entertainment crowds cognitively stimulating activities high lead content crts rapid diffusion new flat panel display technologies


lcds use lamps contain mercury growing concern electronic waste discarded televisions related occupational health concerns exist well disassemblers removing copper wiring materials crts environmental concerns related television design use relate devices' increasing electrical energy requirements see also b television broadcast safe content discovery platform information action ratio list countries number television broadcast stations list television manufacturers list years television lists television channels media psychology microled sign language television telephilia television studies tv accessory references reading pierre bourdieu


television new press tim brooks earle march ''the complete guide prime time network cable tv shows'' th ed ballantine jacques derrida bernard stiegler ''echographies television'' polity press david e fisher marshall j fisher ''tube invention television'' counterpoint washington dc steven johnson ''everything bad good today 's popular culture actually making us smarter'' new york riverhead penguin jerry mander ''four arguments elimination television'' perennial jerry mander ''in absence sacred'' sierra club books


neil postman ''amusing death public discourse age show business'' new york penguin us evan schwartz ''the last lone inventor tale genius deceit birth television'' new york harper paperbacks beretta e smith shomade ''shaded lives african american women television'' rutgers university press alan taylor ''we media pedagogic intrusions us mainstream film television news broadcasting rhetoric'' peter lang amanda lotz ''the television revolutionized'' new york university press external links advertising medium media formats broadcasting consumer


electronics digital technology performing arts video hardware technology technology telecommunications related introductions telecommunications related introductions american inventions british inventions german inventions russian inventions television industry introductions introductions th century inventions


annotated color version original carnot heat engine showing hot body boiler working body system steam cold body water letters labeled according stopping points carnot cycle '''thermodynamics''' branch physics deals heat work temperature relation energy entropy physical properties matter radiation behavior quantities governed four laws thermodynamics convey quantitative description using measurable macroscopic physical quantities may explained terms microscopic constituents statistical mechanics thermodynamics applies


wide variety topics science engineering especially physical chemistry biochemistry chemical engineering mechanical engineering also complex fields meteorology historically thermodynamics developed desire increase efficiency early steam engines particularly work french physicist nicolas l onard sadi carnot believed engine efficiency key could help france win napoleonic wars scots irish physicist lord kelvin first formulate concise definition thermodynamics ref name kelvin ref stated thermo dynamics subject relation heat forces


acting contiguous parts bodies relation heat electrical agency initial application thermodynamics mechanical heat engines quickly extended study chemical compounds chemical reactions chemical thermodynamics studies nature role entropy process chemical reactions provided bulk expansion knowledge field ref name gibbs ref ref name duhem duhem pmm ''le potential thermodynamique et ses applications'' hermann paris ref ref name lewis randall ref ref name guggenheim guggenheim ea ''modern thermodynamics methods jw gibbs'' methuen london ref ref name guggenheim guggenheim ea ''thermodynamics


advanced treatment chemists physicists'' st edition th edition north holland amsterdam ref ref name fermi ref ref name perrot ref formulations thermodynamics emerged statistical thermodynamics statistical mechanics concerns statistical predictions collective motion particles microscopic behavior constantin carath odory presented purely mathematical approach axiomatic formulation description often referred ''geometrical thermodynamics'' introduction description thermodynamic system employs four laws thermodynamics form axiomatic basis first law specifies energy transferred physical systems heat work transfer


properties combined express internal energy thermodynamic potentials useful determining conditions equilibrium spontaneous processes tools thermodynamics used describe systems respond changes environment applied wide variety topics science engineering engines phase transitions chemical reactions transport phenomena even black holes results thermodynamics essential fields physics chemistry chemical engineering corrosion engineering aerospace engineering mechanical engineering cell biology biomedical engineering materials science economics name


''on equilibrium heterogeneous substances'' launching chemical thermodynamics ref name auto http wwweohtinfo page schools thermodynamics schools thermodynamics eohtinfo ref history history thermodynamics scientific discipline generally begins otto von guericke built designed world 's first vacuum pump demonstrated vacuum using magdeburg hemispheres guericke driven make vacuum order disprove aristotle 's long held supposition 'nature abhors vacuum' shortly guericke anglo irish physicist chemist robert boyle learned guericke 's designs coordination english scientist robert hooke built air pump using


pump boyle hooke noticed correlation pressure temperature volume time boyle 's law formulated states pressure volume inversely proportional based concepts associate boyle 's named denis papin built steam digester closed vessel tightly fitting lid confined steam high pressure generated later designs implemented steam release valve kept machine exploding watching valve rhythmically move papin conceived idea piston cylinder engine


condenser resulted large increase steam engine efficiency drawing previous work led sadi carnot father thermodynamics publish ''reflections motive power fire'' discourse heat power energy engine efficiency book outlined basic energetic relations carnot engine carnot cycle '''motive power''' marked start thermodynamics modern science ref name perrot first thermodynamic textbook written william rankine originally trained physicist civil mechanical engineering professor university glasgow


first second laws thermodynamics emerged simultaneously primarily works william rankine rudolf clausius william thomson lord kelvin foundations statistical thermodynamics set physicists james clerk maxwell ludwig boltzmann max planck rudolf clausius j willard gibbs years american mathematical physicist josiah willard gibbs published series three papers famous ''on equilibrium heterogeneous substances'' ref name gibbs showed thermodynamic processes including chemical reactions could graphically analyzed studying energy entropy


volume temperature pressure thermodynamic system manner one determine process would occur spontaneously also pierre duhem th century wrote chemical thermodynamics ref name duhem early th century chemists gilbert n lewis merle randall ref name lewis randall e guggenheim ref name guggenheim ref name guggenheim applied mathematical methods gibbs analysis chemical processes etymology etymology ''thermodynamics'' intricate history ref name eoht ref first spelled hyphenated form adjective ''thermo dynamic'' noun


''thermo dynamics'' represent science generalized heat engines ref name eoht american biophysicist donald haynie claims ''thermodynamics'' coined greek root ''therme'' meaning heat ' 'dynamis'' meaning power pierre perrot claims term ''thermodynamics'' coined james joule designate science relations heat power ref name perrot however joule never used term used instead term ''perfect thermo dynamic engine'' reference thomson 's ref name kelvin phraseology ref name eoht ''thermo dynamics'' functional term used william thomson 's paper account carnot 's theory


motive power heat ref name kelvin kelvin william account carnot 's theory motive power heat numerical results deduced regnault 's experiments steam ''transactions edinburg royal society xvi january '' http visualiseurbnffr visualiseurdestination gallica numm scanned copy ref branches thermodynamics study thermodynamical systems developed several related branches using different fundamental model theoretical experimental basis applying principles varying types systems classical thermodynamics classical thermodynamics description states thermodynamic systems near equilibrium uses macroscopic measurable properties


given transformation equilibrium thermodynamics equilibrium thermodynamics study transfers matter energy systems bodies agencies surroundings driven one state thermodynamic equilibrium another term 'thermodynamic equilibrium' indicates state balance macroscopic flows zero case simplest systems bodies intensive properties homogeneous pressures perpendicular boundaries equilibrium state unbalanced potentials driving forces macroscopically distinct parts system central aim equilibrium


thermodynamics given system well defined initial equilibrium state given surroundings given constitutive walls calculate final equilibrium state system specified thermodynamic operation changed walls surroundings non equilibrium thermodynamics non equilibrium thermodynamics branch thermodynamics deals systems thermodynamic equilibrium systems found nature thermodynamic equilibrium stationary states continuously discontinuously subject flux matter energy systems thermodynamic study


non equilibrium systems requires general concepts dealt equilibrium thermodynamics many natural systems still today remain beyond scope currently known macroscopic thermodynamic methods laws thermodynamics thermodynamics principally based set four laws universally valid applied systems fall within constraints implied various theoretical descriptions thermodynamics laws may expressed seemingly differing forms prominent formulations following zeroth law zeroth law thermodynamics states ''if two systems thermal equilibrium third


also thermal equilibrium other'' statement implies thermal equilibrium equivalence relation set thermodynamic systems consideration systems said equilibrium small random exchanges eg brownian motion lead net change energy law tacitly assumed every measurement temperature thus one seeks decide whether two bodies temperature necessary bring contact measure changes observable properties time law provides


empirical definition temperature justification construction practical thermometers zeroth law initially recognized separate law thermodynamics basis thermodynamical equilibrium implied laws first second third laws explicitly stated already found common acceptance physics community importance zeroth law definition temperature realized impractical renumber laws named ''zeroth law'' first law first law thermodynamics states ''in process without transfer matter


change internal energy'' math delta u math '' thermodynamic system equal energy gained heat'' math q math '' less thermodynamic work'' math w math '' done system surroundings'' ref group nb sign convention q heat supplied ''to'' system w work done ''by'' system rudolf clausius opposite sign convention customary chemical thermodynamics ref math delta u q w math processes include transfer matter statement needed ''with due account respective fiducial reference states systems two systems may


different chemical compositions initially separated impermeable wall otherwise isolated combined new system thermodynamic operation removal wall then'' math u u u math ''where'' ' 'denotes internal energy combined system and'' ''and'' ' 'denote internal energies respective separated systems'' adapted thermodynamics law expression principle conservation energy states energy transformed changed one form another cannot created destroyed internal energy principal property


thermodynamic state heat work modes energy transfer process may change state change internal energy system may achieved combination heat added removed work performed system function state internal energy depend manner path intermediate steps system arrived state second law traditional version second law thermodynamics states ''heat spontaneously flow colder body hotter''


second law refers system matter radiation initially inhomogeneities temperature pressure chemical potential intensive properties due internal 'constraints' impermeable rigid walls within externally imposed forces law observes system isolated outside world forces definite thermodynamic quantity entropy increases constraints removed eventually reaching maximum value thermodynamic equilibrium inhomogeneities practically vanish systems initially far thermodynamic equilibrium though several proposed


known general physical principle determines rates approach thermodynamic equilibrium thermodynamics deal rates many versions second law express irreversibility approach thermodynamic equilibrium macroscopic thermodynamics second law basic observation applicable actual thermodynamic process statistical thermodynamics second law postulated consequence molecular chaos third law third law thermodynamics states ''as temperature system approaches absolute zero processes cease entropy system approaches minimum value''


law thermodynamics statistical law nature regarding entropy impossibility reaching absolute zero temperature law provides absolute reference point determination entropy entropy determined relative point absolute entropy alternate definitions include entropy systems states system smallest absolute zero equivalently impossible reach absolute zero temperature finite number processes absolute zero activity would stop possible achieve nbsp c degrees celsius


nbsp f degrees fahrenheit k kelvin r degrees rankine system models diagram generic thermodynamic system important concept thermodynamics thermodynamic system precisely defined region universe study everything universe except system called ' 'surroundings'' system separated remainder universe ''boundary'' may physical notional serve confine system finite volume segments ''boundary'' often described ''walls'' respective defined 'permeabilities' transfers energy


work heat matter system surroundings take place walls according respective permeabilities matter energy pass across boundary effect change internal energy system need accounted energy balance equation volume contained walls region surrounding single atom resonating energy max planck defined body steam air steam engine sadi carnot defined system


could also one nuclide ie system quarks hypothesized quantum thermodynamics looser viewpoint adopted requirement thermodynamic equilibrium dropped system body tropical cyclone kerry emanuel theorized field atmospheric thermodynamics event horizon black hole boundaries four types fixed movable real imaginary example engine fixed boundary means piston locked position within constant volume process might occur piston allowed


move boundary movable cylinder cylinder head boundaries fixed closed systems boundaries real open systems boundaries often imaginary case jet engine fixed imaginary boundary might assumed intake engine fixed boundaries along surface case second fixed imaginary boundary across exhaust nozzle generally thermodynamics distinguishes three classes systems defined terms allowed cross boundaries time passes isolated system internal differences pressures densities temperatures tend


reversible processes states processes system equilibrium given set conditions said definite thermodynamic state state system described number state quantities depend process system arrived state called intensive variables extensive variables according change size system changes properties system described equation state specifies relationship variables state may thought


instantaneous quantitative description system set number variables held constant thermodynamic process may defined energetic evolution thermodynamic system proceeding initial state final state described process quantities typically thermodynamic process distinguished processes energetic character according parameters temperature pressure volume etc held fixed furthermore useful group processes pairs variable held constant one member conjugate pair several commonly studied thermodynamic