Television or TV is a telecommunication medium used for transmitting moving images in monochrome (black-and-white), or in color, and in two or three dimensions and sound. It can refer to a television set, a television program (“TV show”), or the medium of television transmission. Television is a mass medium, for entertainment, education, news, and advertising.
Television became available in crude experimental forms in the late 1920s, but these did not sell to the public. After World War II, an improved form of black-and-white TV broadcasting became popular in the United States and Britain, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing public opinion. In the mid-1960s, color broadcasting was introduced in the US and most other developed countries. The availability of storage media such as Betamax (1975), VHS tape (1976), DVDs (1997), and high-definition Blu-ray Discs (2006) enabled viewers to watch prerecorded material at home, such as movies. At the end of the first decade of the 2000s, digital television transmissions greatly increased in popularity. Another development was the move from standard-definition television (SDTV) (576i, with 576 interlaced lines of resolution and 480i) to high-definition television (HDTV), which provides a resolution that is substantially higher. HDTV may be transmitted in various formats: 1080p, 1080i and 720p. Since 2010, with the invention of smart television, Internet television has increased the availability of television programs and movies via the Internet through streaming video services such as Netflix, iPlayer, Hulu, Roku and Chromecast.
In 2013, 79% of the world’s households owned a television set. The replacement of early bulky, high-voltage cathode ray tube (CRT) screen displays with compact, energy-efficient, flat-panel alternative technologies such as plasma displays, LCDs (both fluorescent-backlit and LED), and OLED displays was a hardware revolution that began with computer monitors in the late 1990s. Most TV sets sold in the 2000s were flat-panel, mainly LEDs. Major manufacturers announced the discontinuation of CRT, DLP, plasma, and even fluorescent-backlit LCDs by the mid-2010s. LEDs are expected to be replaced gradually by OLEDs in the near future. Also, major manufacturers have announced that they will increasingly produce smart TV sets in the mid-2010s. Smart TVs with integrated Internet and Web 2.0 functions became the dominant form of television by the late 2010s.
Television signals were initially distributed only as terrestrial television using high-powered radio-frequency transmitters to broadcast the signal to individual television receivers. Alternatively television signals are distributed by coaxial cable or optical fiber, satellite systems and, since the 2000s via the Internet. Until the early 2000s, these were transmitted as analog signals but countries started switching to digital, this transition is expected to be completed worldwide by late 2010s. A standard television set is composed of multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display device which lacks a tuner is correctly called a video monitor rather than a television.
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Projects with this TAG (2)
TV signals on ultra-wideband optical fibre networks
Optical fibres are now increasingly popular in telecommunications, due to their extremely high bandwidth, their very low attenuation, their complete immunity to electromagnetic interference and their reduced diameter and weight.
For these reasons, they are playing an increasing role in trasporting TV content, both for in-building TV signal distribution within the multi-service optical infrastructure, which is mandated in all new buildings (Italian Law 164, 2014) and for TV consumption via broadband networks, which will benefit from ongoing investments in FTTH (Fiber to The Home) architectures, where the fibre is terminated at each building. In Italy, network operators are launching massive optical fiber investment plans over the next five years, not only to cover the most densely populated areas (A and B) but also for less profitable areas (C and D).
Stretched TV for improved accessibility
TV adapted to its time
The film and television have undergone an extraordinary evolution in the technical means as in content. The need to keep up with the times and with a society living in ever-increasing pace has profoundly changed the way of realizing television and radio programs. The manner of conducting the programs has changed dramatically from the fifties to the present, from a television in black and white that “entered” into the homes with discretion and played just a few hours of the day of a program like the present with channels broadcasting 24 hours daily and characterized by fast tempos and rhythms. the user is also changed, now the viewer quickly select with the remote control a number of channels to decide what to watch and with TVs connected to the network selects the contents and realizes its own schedule. People with disabilities and the elderly, by contrast, strongly demanding the reduction of the complexity of television and the reduction of technological barriers. The project Stretch TV, launched by RAI – Centre for Research and Technological Innovation and RAI – Social Secretariat, aims to develop a technological solution that allows to significantly improve the usability of television content by persons with sensory disabilities and / or cognitive and the elderly.