TV
HISTORY
The concept of television (distance vision) can be traced back to Galileo Galilei and his telescope. However, not until 1884, with the invention of Paul Nipkow disk Nipkow when made significant progress to create a medium. The change would bring the television as we know it today was invented by Vladimir iconoscope Zworkyn and Philo Taylor Farnsworth. This would lead to all-electronic television, which had a much better frame rate, sharper image and self-luminous.
EARLY DEVELOPMENTS
In 1910, the Nipkow disk was used in developing television systems of the early twentieth century, in 1925 Scottish inventor John Logie Baird made the first real experience using two disks, one in the emitter and the receiver that were attached to the same axis so that its rotation was synchronous and separated by 2 mm. The first public television broadcasts of the BBC made in England in 1927 and the CBS and NBC in the U.S. in 1930. In both cases, mechanical systems and programs will not be issued with a regular schedule. The first station with regularly scheduled programming was created in 1930 in Berlin by the local branch of the National Socialist German Workers Party, but those responsible for Nazi propaganda were not aware of the possibilities of the medium and continued to use the radio. The emissions program started in England in 1936, and the United States on April 30, 1939, coinciding with the opening of the Expo in New York. Scheduled broadcasts were interrupted during World War II and resumed when it ended.
During the story the media have been traditionally regarded as the historical memory of peoples, through their societies can remember their past, live live the present and project what your future will be. Television is no exception, particularly Colombia and reflects a society in constant transformation, eagerly seeking an identity in the midst of the current paradigms of technology and globalization. The contents of this page are intended to give a quick and educational tour through what they have been these five decades of television, its beginnings, evolution, characters, highlights, big issues in order to cover all the topics that this important period ofColombian history. For a quick reference for dates, we have a timeline at the top of the page. All you have to do is press on the year of interest and thus obtain the information you need. And in the left menu more specific sections that address different subjects involved in the history of television in Colombia.
http://www.banrepcultural.org/blaavirtual/exhibiciones/historia_tv/index.htm
A) analogue broadcasting: Until recently, television was totally analog, and how to get the viewers it was due to radio waves in the VHF and UHF bvandas.Soon came the cable networks distributed channels cities. This distribution is done with an analog signal, the cable network had a band assigned. Its development depends on the laws of each country. The permitted commercial satellite to distribute television signals and performs two functions: to allow the links of the signals from one point to another of the world and the distribution of the signal distribution.
B) DIGITAL BROADCAST: The type of signal is very resistant to transfer and the emission standard is designed for good reception. A number of extras that come with the television signal, adding value to the programming. The spread of digital television is based on the DVB (Digital Video Broadcasting), which is the system used in Europe. This system has a common part for the spread of satellite, cable and terrestrial. The non-common is it adapts to each mode of transmission.
C) TV LAND: Analogue broadcasting by road is made as follows: The center of the issuer are audio and video signals to the main transmitters. These cover a wide area which is filled with referrers. Transmission is in the UHF and VHF bands, although the latter is seldom used. The spread of digital television land, known as DTT, is performed in the same band of analogue broadcasting. Digital terrestrial television system within the DVE-T uses OFDM (Orthogonal Frequency Division Multiplex), which gives high immunity to the echoes. American television has been developed based on small local stations is sometimes joined to the transmission of certain events, unlike Europe where there has been mostly large national chains. Digital broadcast systems will replace analog. In Europe, the switch-off is scheduled for 2012.
D) Cable TV: Born by the need to bring television to the home of subscribers, they have no receivers, antennas and sophisticated players. The advantage of cable is to have a back channel that lets you use a service without having to use other infrastructure. The difficulty of laying a cable network in areas of low population means that only urban areas have access to these services.
E) Satellite TV: Satellite broadcasting began with the development of space industry allowed to orbit satellites that broadcast television signals, which are picked up by satellite dishes. The advantage of reaching the entire surface of a concrete territory provides access to very remote and isolated areas. This makes TV programs reach all parts. Satellite broadcasting is made under the DVB-S standard, the energy of the signals reaching the antenna is very small, although the bandwidth is usually very large.
http://html.rincondelvago.com/creacion-y-evolucion-de-la-television.html
TYPES OF SCREENS
A) CRT (Cathode Ray Tube): They are still the least expensive and can have a great picture quality. Because they have a fixed resolution, can display different resolutions sources with good quality. The frequency of a NTSC TV is 29.97 Hz and 25 Hz for PAL normal TVs. The resolution of NTSC is 480 lines, and PAL 575.
B) REAR: Big screen TVs use projection technology. Uses three types of projection systems: CRT, LCD and DLP. They do not give good results in the light of day or brightly lit rooms.
C) FLAT PANEL (LCD): Technology uses active matrix liquid crystal or plasma. They may have just a couple of inches wide. Some models can also be used as computer monitors.
D) LED TECHNOLOGY: They have become one of the options for video on location, since the advent of light emitting diodes and circuits. Allow to create scalable ultra large screens. Comitee National Television System (a system of encoding and transmission of analog TV) Phase Alternation Line (another encoding and transmission of analog TV)
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