Televisions have been commercially available since their invention in the late 1920s. A Mormon inventor from Utah, Philo Taylor Farnsworth, is credited with invention of the first electronic television. He put his invention on public display September 1, 1928, and the exciting new development took off like skyrockets, until today television reaches not only around the globe, but into outer space. They have been for sale commercially since the 1930’s.
Televisions are sold with monochromatic (black and white) or color displays. Older televisions used a CRT (Cathode Ray Tube), and many had old style electronic tubes inside the set around the CRT. These were later replaced by transistor technology, and eventually a new main display screen was developed. Televisions are used for replaying captured video, in closed circuit systems, and for over the air broadcasts or transmissions from cable or satellite systems. They will display video and transmit audio.
Today there is an assortment of highly technological displays available on televisions. You can still get the CRT television sets, but also you can choose from other display screens and methods of viewing. These include:
– Projection TV (Rear Projection and Flat Panel)
– LCD (Liquid Crystal Display)
– LED (Light Emitting Diode)
– Plasma TV (Uses gases, not LCD)
– HDTV (High Definition Television)
– OLED (Organic Light Emitting Diode)
Most broadcasting transmissions used to work with analog signals, but recent technological advances have resulted in new digital signals. The broadcasting station or cable system sends out the digital signals for video and audio, and the televisions then receive, and convert the digital signals after decoding them to a visible image display and audio. The televisions use a system of scanning line by line to produce an image. The newest development in television broadcasting is the move to high definition (high resolution) broadcasting. HDTV sets receive these without a converted box. The video and audio are extremely clear and sharp.
A primary function of television, after basic communication, is to promote products and services through advertising. The advertisers pay for time on the air, and this helps offset the costs of broadcasting so the home viewers receive over the air programming without having to pay for it. With a cable or satellite system, the view pays a monthly fee to receive local stations and distant broadcasts, some with and some without commercials. Their signals are encrypted and the paying viewers are the only ones who can receive the signals. In some countries, the government controls television broadcasting, and in other countries, the broadcasting stations pay a license fee for the privilege. Government funded television is usually paid for by viewer taxation.
Television programming is offered in a variety of genres, including news, entertainment, talk shows, soap opera, game shows, documentary, and sports. A new development is the popularity of reality shows. Programming is produced by networks, and independent producers. Some programs are direct, and others are syndicated. Reruns of old shows are popular. Television is a social medium, and tends to affect society. Modern ecological concerns involve the use of metals and gases in televisions and their disposal.