| Revision as of 04:08, 12 January 2010 view sourceClueBot (talk | contribs)1,596,818 editsm Reverting possible vandalism by Richdude24 to version by Rico402. False positive? Report it. Thanks, ClueBot. (521046) (Bot)← Previous edit | Revision as of 04:08, 12 January 2010 view source Richdude24 (talk | contribs)38 edits ←Replaced content with 'zh:电视'Next edit → | ||
| Line 1: | Line 1: | ||
| {{pp-semi|small=yes}} | |||
| {{Redirect|TV}} | |||
| ], ], 1958]] | |||
| '''Television''' ('''TV''') is a widely used ] ] for transmitting and receiving moving ], either ] ("black and white") or ], usually accompanied by ]. "Television" may also refer specifically to a ], ]ming or ]. The word is derived from mixed ] and ] roots, meaning "far sight": Greek ''tele'' ({{polytonic|τ{{Unicode|ῆ}}λε}}), far, and Latin ''visio'', sight (from ''video, vis-'' to see, or to view in the first person). | |||
| ], the television set has become a common communications receiver in homes, businesses and institutions, particularly as a source of ] and news. Since the 1970s the availability of ], ]s, ] and now ]s, have resulted in the television set frequently being used for viewing recorded as well as broadcast material. | |||
| Although other forms such as ] (CCTV) are in use, the most common usage of the medium is for ], which was modeled on the existing ] systems developed in the 1920s, and uses high-powered ] transmitters to ] the television signal to individual TV receivers. | |||
| Broadcast TV is typically disseminated via ] transmissions on designated channels in the 54–890 ] ]<ref>, CSGNetwork.com., a Division of Computer Support Group.</ref>. Signals are now often transmitted with ] and/or ] in many countries. Until the 2000s broadcast TV programs were generally recorded and transmitted as an ] signal, but in recent years public and commercial broadcasters have been progressively introducing ] broadcasting technology. | |||
| A standard television set comprises multiple internal ]s, including those for ] and decoding broadcast signals. A visual ] which lacks a tuner is properly called a ], rather than a television. A television system may use different technical standards such as ] (DTV) and ] (HDTV). Television systems are also used for surveillance, industrial process control, and guiding of weapons, in places where direct observation is difficult or dangerous. | |||
| ] (''ham TV'' or ''ATV'') is also used for experimentation, pleasure and public service events by ] operators. Ham TV stations were on the air in many cities before commercial TV stations came on the air.<ref>, ''Radio News'', April 1938. Early Television Museum and Foundation Website, retrieved 2009-07-19.</ref> | |||
| ==History== | |||
| {{Main|History of television}} | |||
| In its early stages of development, television employed a combination of ], mechanical and ] technologies to capture, transmit and display a visual image. By the late 1920s, however, those employing only optical and electronic technologies were being explored. All modern television systems rely on the latter, although the knowledge gained from the work on mechanical-dependent systems was crucial in the development of fully electronic television. | |||
| ] | |||
| The first time images were transmitted electrically were via early mechanical ] machines, including the ], developed in the late 1800s. The concept of electrically-powered transmission of television images in motion, was first sketched in 1878 as the ], shortly after the invention of the ]. At the time, it was imagined by early science fiction authors, that someday that ] could be transmitted over wires, as sounds were. | |||
| The idea of using ] to transmit images was put to actual practical use in 1881 in the pantelegraph, through the use of a ]-based scanning mechanism. From this period forward, scanning in one form or another, has been used in nearly every image transmission technology to date, including television. This is the concept of "]", the process of converting a visual image into a stream of electrical pulses. | |||
| In 1884 ], a 20-year old university student in Germany, patented the first electromechanical television system which employed a ], a spinning disk with a series of holes spiraling toward the center, for rasterization. The holes were spaced at equal ] intervals such that in a single rotation the disk would allow light to pass through each hole and onto a light-sensitive ] sensor which produced the electrical pulses. As an image was focused on the rotating disk, each hole captured a horizontal "slice" of the whole image. | |||
| Nipkow's design would not be practical until advances in ] ] technology became available. The device was only useful for transmitting still "]" images — represented by equally spaced dots of varying size — over telegraph or ]s. {{Citation needed|date=January 2010}} Later designs would use a rotating mirror-drum scanner to capture the image and a ] (CRT) as a display device, but moving images were still not possible, due to the poor sensitivity of the ] sensors. In 1907 Russian scientist ] became the first inventor to use a CRT in the receiver of an experimental television system. He used mirror-drum scanning to transmit simple geometric shapes to the CRT.<ref name='crthistory'> {{cite web|url=http://inventors.about.com/od/cstartinventions/a/CathodeRayTube.htm |title=History of the Cathode Ray Tube |accessdate=2009-10-04 |work=About.com }}</ref> | |||
| Scottish inventor ] demonstrated the transmission of moving silhouette images in ] in 1925, and of moving, ] images in 1926. Baird's scanning disk produced an image of 30 lines resolution, just enough to discern a human face, from a double spiral of ]s.{{Citation needed|date=January 2009}}. Remarkably, in 1927 Baird also invented the world's first ] system, "Phonovision" — by modulating the output signal of his ] down to the audio range he was able to capture the signal on a 10-inch wax audio disc using conventional audio recording technology. A handful of Baird's 'Phonovision' recordings survive and these were finally decoded and rendered into viewable images in the 1990s using modern digital signal-processing technology<ref></ref>. | |||
| In 1926, ] engineer ] designed a television system utilizing fully electronic scanning and display elements, and employing the principle of "charge storage" within the scanning (or "camera") tube.<ref>{{cite web | title = Hungary - ] 1926 Patent Application 'Radioskop' | work = Memory of the World | publisher = ] | url = http://portal.unesco.org/ci/en/ev.php-URL_ID=23240&URL_DO=DO_TOPIC&URL_SECTION=201.html| accessdate = 2008-02-22}}</ref><ref name=US2133123>United States Patent Office, Patent No. 2,133,123, Oct. 11, 1938.</ref><ref name=US2158259>United States Patent Office, Patent No. 2,158,259, May 16, 1939</ref><ref>{{cite web|url=http://www.bairdtelevision.com/zworykin.html |title=Vladimir Kosma Zworykin, 1889-1982 |publisher=Bairdtelevision.com |date= |accessdate=2009-04-17}}</ref> | |||
| By 1927, Russian inventor ] developed a mirror drum-based television system which used ] to achieve an ] of 100 lines. | |||
| Also in 1927, ] of ] transmitted moving images from a 50-] disk producing 16 frames per minute over a ] from ] to ], and via ] from ]. Ives used viewing screens as large as 24 by 30 inches (60 by 75 ]s). His subjects included ] ]. | |||
| In 1927, ] made the world's first working television system with electronic scanning of both the pickup and display devices,<ref name=autogenerated1>, ''The Virtual Museum of the City of San Francisco''</ref> which he first demonstrated to the press on 1 September 1928.<ref name=autogenerated1 /><ref name="EGF_DV">Farnsworth, Elma G., ''Distant Vision: Romance and Discovery on an Invisible Frontier'', Salt Lake City, PemberlyKent, 1989, p. 108.</ref> | |||
| The first practical use of television was in Germany. Regular television broadcasts began in Germany in 1929 and in 1936 the ] in Berlin were broadcast to television stations in Berlin and Leipzig where the public could view the games live.<ref>{{cite web|url=http://www.tvhistory.tv |title=TV History |publisher=Gadgetrepublic |date=2009-05-01 |accessdate=2009-05-01}}</ref> | |||
| In 1936, ] described the principle of ], the first flat panel system.<ref>http://ewh.ieee.org/r2/johnstown/downloads/20090217_IEEE_JST_Trivia_Answers.pdf</ref><ref>http://www.scitech.mtesz.hu/52tihanyi/flat-panel_tv_en.pdf</ref> | |||
| ==Geographical usage== | |||
| [[Image:TV-introduction-world-map.svg|350px|thumb|Television introduction by country | |||
| {{legend|#ff0000|1930 to 1939}} | |||
| {{legend|#ff5400|1940 to 1949}} | |||
| {{legend|#ffa800|1950 to 1959}} | |||
| {{legend|#ffff00|1960 to 1969}} | |||
| {{legend|#a8ff00|1970 to 1979}} | |||
| {{legend|#54ff00|1980 to 1989}} | |||
| {{legend|#00ff00|1990 to 1999}} | |||
| {{legend|Grey|No data}} | |||
| ]] | |||
| {{Main|Geographical usage of television}} | |||
| *] | |||
| ==Content== | |||
| ===Programming=== | |||
| {{See also|Television program|Category:Television genres}} | |||
| Getting TV programming shown to the public can happen in many different ways. After production the next step is to market and deliver the product to whatever markets are open to using it. This typically happens on two levels: | |||
| #'''Original Run''' or '''First Run''': a producer creates a program of one or multiple episodes and shows it on a station or ] which has either paid for the production itself or to which a license has been granted by the producers to do the same. | |||
| #''']''': this is the terminology rather broadly used to describe secondary programming usages (beyond original run). It includes secondary runs in the country of first issue, but also international usage which may or may not be managed by the originating producer. In many cases other companies, ] or individuals are engaged to do the syndication work, in other words to sell the product into the markets they are allowed to sell into by contract from the copyright holders, in most cases the producers. | |||
| First run programming is increasing on subscription services outside the U.S., but few domestically produced programs are syndicated on domestic ] (FTA) elsewhere. This practice is increasing however, generally on digital-only FTA channels, or with subscriber-only first-run material appearing on FTA. | |||
| Unlike the U.S., repeat FTA screenings of a FTA network program almost only occur on that network. Also, ]s rarely buy or produce non-network programming that is not centred around local events. | |||
| ===Funding=== | |||
| {{Globalize|section|date=January 2010}} | |||
| [[Image:TV users.svg|thumb|400px|right|Television sets per 1000 people of the world {{legend|#10547C|1000+}} | |||
| {{legend|#1674AB|500–1000}} | |||
| {{legend|#1B8BCF|300–500}} | |||
| {{legend|#3CA6E6|200–300}} | |||
| {{legend|#70BEED|100–200}} | |||
| {{legend|#9DD2F2|50–100}} | |||
| {{legend|#CCE8F9|0–50}} | |||
| {{legend|Grey|No data}}]] | |||
| Around the globe, broadcast television is financed by either government, advertising, licensing (a form of tax), subscription or any combination of these. To protect revenues, subscription TV channels are usually encrypted to ensure that only subscription payers receive the decryption codes to see the signal. Non-encrypted channels are known as '''free to air''' or '''FTA'''. | |||
| ====Advertising==== | |||
| Television's broad reach makes it a powerful and attractive medium for ]s. Many ]s and stations sell blocks of broadcast time to advertisers ("sponsors") in order to fund their programming. | |||
| =====United States===== | |||
| Since inception in the U.S. in 1940, ] have become one of the most effective, persuasive, and popular method of selling products of many sorts, especially consumer goods. U.S. ] rates are determined primarily by ]. The time of the day and popularity of the channel determine how much a television commercial can cost. For example, the highly popular ] can cost approximately $750,000 for a thirty second block of commercial time; while the same amount of time for the ] and the ] can cost several million dollars. | |||
| In recent years, the paid program or ] has become common, usually in lengths of 30 minutes or one hour. Some ] and other businesses have even created "news" items for broadcast, known in the industry as ]s, paying ]s to use them.<ref>] of "]" was mock-outraged at this, saying, "That's what we do!", and calling it a new form of television, "infoganda".</ref> | |||
| Some TV programs also weave advertisements into their shows, a practice begun in film and known as ]. For example, a character could be drinking a certain kind of soda, going to a particular ], or driving a certain make of car. (This is sometimes very subtle, where shows have vehicles provided by manufacturers for low cost, rather than wrangling them.) Sometimes a specific brand or ], or music from a certain artist or group, is used. (This excludes guest appearances by artists, who perform on the show.) | |||
| =====United Kingdom===== | |||
| The TV regulator oversees TV advertising in the United Kingdom. Its restrictions have applied since the early days of commercially funded TV. Despite this, an early TV mogul, ], likened the broadcasting licence as being a "licence to print money". Restrictions mean that the big three national commercial TV channels: ], ], and ] can show an average of only seven minutes of advertising per hour (eight minutes in the peak period). Other broadcasters must average no more than nine minutes (twelve in the peak). This means that many imported TV shows from the US have unnatural breaks where the UK company has edited out the breaks intended for US advertising. Advertisements must not be inserted in the course of certain specific proscribed types of programs which last less than half an hour in scheduled duration, this list includes any news or current affairs program, documentaries, and programs for children. Nor may advertisements be carried in a program designed and broadcast for reception in schools or in any religious service or other devotional program, or during a formal Royal ceremony or occasion. There also must be clear demarcations in time between the programs and the advertisements. | |||
| The ], being strictly ] is not allowed to show advertisements on television in the UK, although it has many advertising-funded channels abroad. The majority of its budget comes from TV licencing (see below) and the sale of content to other broadcasters. | |||
| =====Republic of Ireland===== | |||
| The ] ('''BCI''') ({{lang-ga|Coimisiún Craolacháin na hÉireann}})<ref>http://www.bci.ie/</ref> oversees advertising on television and radio within the ] on both private and state owned broadcasters. Similar to other European countries, advertising is found on both private and state owned broadcasters. There are some restrictions based on advertising, especially in relation to the advertising of alcohol. Such advertisements are prohibited until after 7pm. Broadcasters in the ] adhere to broadcasting legislation implemented by the ] and the ]. Sponsorship of current affairs programming is prohibited at all times. | |||
| As of October 1, 2009 the responsibilities held by the BCI are gradually being transferred to the ]. | |||
| ====Taxation or license==== | |||
| Television services in some countries may be funded by a ], a form of taxation which means advertising plays a lesser role or no role at all. For example, some channels may carry no advertising at all and some very little, including: | |||
| * ] (]) | |||
| * ] (]) | |||
| * ] (]) | |||
| * ] (]) | |||
| The ] carries no advertising on its UK channels and is funded by an annual licence paid by all households owning a television. This licence fee is set by government, but the BBC is not answerable to or controlled by government and is therefore genuinely independent. | |||
| The two main BBC TV channels are watched by almost 90 percent of the population each week and overall have 27 per cent share of total viewing.<ref>{{cite web|url=http://www.barb.co.uk/viewingsummary/weekreports.cfm?report=multichannel&requesttimeout=500&flag=viewingsummary |title=viewing statistics in UK |publisher=Barb.co.uk |date= |accessdate=2009-04-17}}</ref> This in spite of the fact that 85% of homes are multichannel, with 42% of these having access to 200 free to air channels via satellite and another 43% having access to 30 or more channels via ].<ref></ref> The licence that funds the seven advertising-free BBC TV channels currently costs £139.50 a year (about US$215) irrespective of the number of TV sets owned. When the same sporting event has been presented on both BBC and commercial channels, the BBC always attracts the lion's share of the audience, indicating viewers prefer to watch TV uninterrupted by advertising. | |||
| The ] (ABC) carries no advertising (except for internal promotional material) as it is banned under the . The ABC receives its funding from the Australian Government every three years. In the 2008/09 Federal Budget the ABC received A$1.13 Billion <ref>http://www.abc.net.au/corp/pubs/documents/budget2008-09.pdf</ref>. The funds assist in providing the ABC's Television, Radio, Online and International outputs. The ABC also receives funds from its many ABC Shops across Australia. However funded by the Australian Government the editorial independence of the ABC is ensured through law. | |||
| In ] and the ] government-funded channels carry advertisements yet those who own television sets have to pay an annual tax ("la redevance audiovisuelle").<ref></ref> | |||
| ====Subscription==== | |||
| Some TV channels are partly funded from subscriptions and therefore the signals are encrypted during broadcast to ensure that only paying subscribers have access to the decryption codes. Most subscription services are also funded by advertising. | |||
| ===Genres=== | |||
| Television ]s include a broad range of programming types that entertain, inform, and educate viewers. The most expensive entertainment genres to produce are usually drama and dramatic miniseries. However, other genres, such as historical Western genres, may also have high production costs. | |||
| ] genres include action-oriented shows such as police, crime, detective dramas, horror, or thriller shows. As well, there are also other variants of the drama genre, such as medical dramas and daytime ]s. ] shows can fall into either the drama or action category, depending on whether they emphasize philosophical questions or high adventure. Comedy is a popular genre which includes ] (sitcom) and animated shows for the adult demographic such as '']''. | |||
| The least expensive forms of entertainment programming are ]s, ]s, ]s, and ]. Game shows show contestants answering questions and solving puzzles to win prizes. Talk shows feature interviews with film, television and music celebrities and public figures. Variety shows feature a range of musical performers and other entertainers such as comedians and magicians introduced by a host or ]. There is some crossover between some talk shows and variety shows, because leading talk shows often feature performances by bands, singers, comedians, and other performers in between the interview segments. | |||
| ''Reality TV'' shows "regular" people (''i.e.'', not ]) who are facing unusual challenges or experiences, ranging from arrest by police officers ('']'') to weight loss ('']''). A variant version of reality shows depicts celebrities doing mundane activities such as going about their everyday life ('']'') or doing manual labour ('']''). | |||
| ==Social aspects== | |||
| {{Main|Social aspects of television}} | |||
| Television has played a pivotal role in the socialization of the 20th and 21st centuries. There are many aspects of television that can be addressed, including ]. | |||
| ==Environmental aspects== | |||
| ]]] | |||
| With high ] content in ], and the rapid diffusion of new, flat-panel display technologies, some of which (]s) use lamps containing ], there is growing concern about ] from discarded televisions. Related ] concerns exist, as well, for disassemblers removing copper wiring and other materials from CRTs. Further environmental concerns related to television design and use relate to the devices' increasing ] requirements.<ref>{{cite web |url=http://www.energysavingtrust.org.uk/uploads/documents/aboutest/Riseofthemachines.pdf |publisher=Energy Saving Trust |title=The Rise of the Machines: A Review of Energy Using Products in the Home from the 1970s to Today |date=July 3, 2006 |format=PDF |accessdate=2007-08-31}}</ref> | |||
| ==In numismatics== | |||
| Television has had such an impact in today's life, that it has been the main motif for numerous collectors' coins and medals. One of the most recent ones is the ] minted in March 9, 2005. The obverse of the coin shows a "]", while the reverse shows several milestones in the history of television. | |||
| ==See also== | |||
| {{Portal|Television|Television icon.png}} | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| * ] | |||
| ==References== | |||
| {{reflist|2}} | |||
| ==Further reading== | |||
| * Albert Abramson, ''The History of Television, 1942 to 2000'', Jefferson, NC, and London, McFarland, 2003, ISBN 0786412208. | |||
| * ], ''On Television'', The New Press, 2001. | |||
| * Tim Brooks and Earle March, ''The Complete Guide to Prime Time Network and Cable TV Shows'', 8th ed., Ballantine, 2002. | |||
| * ] and ], ''Echographies of Television'', Polity Press, 2002. | |||
| * David E. Fisher and Marshall J. Fisher, ''Tube: the Invention of Television'', Counterpoint, Washington, DC, 1996, ISBN 1887178171. | |||
| * ], ''Everything Bad is Good for You: How Today's Popular Culture Is Actually Making Us Smarter'', New York, Riverhead (Penguin), 2005, 2006, ISBN 1594481946. | |||
| * ], ''Four Arguments for the Elimination of Television'', Perennial, 1978. | |||
| * Jerry Mander, ''In the Absence of the Sacred'', Sierra Club Books, 1992, ISBN 0871565099. | |||
| * ], '']: Public Discourse in the Age of Show Business'', New York, Penguin US, 1985, ISBN 0670804541. | |||
| * Evan I. Schwartz, ''The Last Lone Inventor: A Tale of Genius, Deceit, and the Birth of Television'', New York, Harper Paperbacks, 2003, ISBN 0060935596. | |||
| * Beretta E. Smith-Shomade, ''Shaded Lives: African-American Women and Television'', Rutgers University Press, 2002. | |||
| * Alan Taylor, ''We, the Media: Pedagogic Intrusions into US Mainstream Film and Television News Broadcasting Rhetoric'', Peter Lang, 2005, ISBN 3631518528. | |||
| ==External links== | |||
| {{sisterlinks}} | |||
| * at the ] | |||
| * at the ] | |||
| * ] | |||
| * | |||
| * | |||
| {{Video formats}} | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| {{Link FA|ms}} | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | |||
| ] | ] | ||