The concept of television (distance vision) can be traced back to Galileo Galileiand his telescope. However, not until 1884, with the invention of Paul Nipkowdisk Nipkow when made significant progress to create a medium. The changewould bring the television as we know it today was invented by VladimirZworkyny iconoscope Philo Taylor Farnsworth. This would lead to all-electronictelevision, which had a much better frame rate, sharper image and self-luminous.
First developments
In 1910, the Nipkow disk was used in developing television systems of the earlytwentieth century, in 1925 Scottish inventor John Logie Baird made the first realexperience using two disks, one in the emitter and the receiver that wereattached 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 inBerlin by the local branch of the National Socialist German Workers Party, butthose 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 onApril 30, 1939, coinciding with the opening of the Expo Deneuve York.Scheduled broadcasts were interrupted during World War II and resumed when it ended.
IMAGE PRODUCTION
The image on a TV is produced by what is called "cathode ray tube" (CRT). this element
was created long before the invention of the TV and, of course, is a cornerstoneof television
besides being one of the main elements of it as a primary influence on
the size, shape and price of the device (Figure 1).
The CRT is basically composed of four elements.
First is an "electron emitter." this
element is made, usually of a hollow cylinder of nickel coated on one end foremitting electrons substances such as barium and strontium oxide.
An electron-emitting substance is a substance that
enough hot electrons are able to blow, something like a "tiny bomb" that was constantly exploding and releasing electrons in all directions while stayingwarm.
By having a cylindrical shape, you get a kind of canyon effect and only leave outthose
electrons move in the direction pointed to by the electron emitter.
Hence, this device is also known by the name of electron gun.
Once the electrons are fired out of the issuer are an "electron accelerator" which gives them even faster than they were
to be issued. The electron accelerator consists simply of two plates spacedenough
What is TV?
Television has come a long way in recent years, at first there were only blackand white and then color television introduced. Today it continues to improvethe quality of picture and sound using all the advances in electronics, such as integrated circuits in television sets.
First, a camera receives light from the stage, introduced into his system and a series of lenses they lead to several photodiodes located on a CCD chip. Thatbecomes the light of the scene in a video signal. At the same time, a microphone picks up sound and converts it into an electrical signal also audio.The two combined signals are sent to a satellite and at the same time it sendsto a receiver that picks up the signal through an antenna, a satellite or cable.The TV receives signals. There, the leading audio signal to an amplifier and a speaker.
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