Digital terrestrial televisionDigital terrestrial television (DTTV or DTT, or DTTB with "broadcasting") is a technology for terrestrial television in which land-based (terrestrial) television stations broadcast television content by radio waves to televisions in consumers' residences in a digital format. DTTV is a major technological advance over the previous analog television, and has largely replaced analog which had been in common use since the middle of the 20th century.
Terrestrial televisionTerrestrial television or over-the-air television (OTA) is a type of television broadcasting in which the signal transmission occurs via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an antenna. The term terrestrial is more common in Europe and Latin America, while in Canada and the United States it is called over-the-air or simply broadcast.
Broadcast television systemsBroadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals. Analog television systems were standardized by the International Telecommunication Union (ITU) in 1961, with each system designated by a letter (A-N) in combination with the color standard used (NTSC, PAL or SECAM) - for example PAL-B, NTSC-M, etc.). These analog systems for TV broadcasting dominated until the 2010s.
Professional video cameraA professional video camera (often called a television camera even though its use has spread beyond television) is a high-end device for creating electronic moving images (as opposed to a movie camera, that earlier recorded the images on film). Originally developed for use in television studios or with outside broadcast trucks, they are now also used for music videos, direct-to-video movies (see digital movie camera), corporate and educational videos, wedding videos, among other uses.
Television setA television set or television receiver (more commonly called TV, TV set, television, telly, or tele) is an electronic device for the purpose of viewing and hearing television broadcasts, or as a computer monitor. It combines a tuner, display, and loudspeakers. Introduced in the late 1920s in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tube (CRT) technology.
NTSCThe first American standard for analog television broadcast was developed by the National Television System Committee (NTSC) in 1941. In 1961, it was assigned the designation System M. In 1953, a second NTSC standard was adopted, which allowed for color television broadcast compatible with the existing stock of black-and-white receivers. It is one of three major color formats for analog television, the others being PAL and SECAM. NTSC color is usually associated with the System M.
SECAMSECAM, also written SÉCAM (sekam, Séquentiel de couleur à mémoire, French for color sequential with memory), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. It was one of three major analog color television standards, the others being PAL and NTSC. Like PAL, a SECAM picture is also made up of 625 interlaced lines and is displayed at a rate of 25 frames per second (except SECAM-M).
Television showA television show – or simply TV show – is the general reference to any content produced for viewing on a television set which is broadcast via over-the-air, satellite, or cable. This includes content made by television broadcasters and content made for broadcasting by film production companies. It excludes breaking news, advertisements, or trailers that are typically placed between shows. Television shows are most often scheduled for broadcast well ahead of time and appear on electronic guides or other TV listings, but streaming services often make them available for viewing anytime.
PhilcoPhilco (an acronym for Philadelphia Battery Company)is an American electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchased by Ford and, from 1966, renamed "Philco-Ford". Ford sold the company to GTE in 1974, and it was purchased by Philips in 1981. In North America, the Philco brand is owned by Philips. In other markets, the Philco International brand is owned by Electrolux.
Mechanical televisionMechanical television or mechanical scan television is an obsolete television system that relies on a mechanical scanning device, such as a rotating disk with holes in it or a rotating mirror drum, to scan the scene and generate the video signal, and a similar mechanical device at the receiver to display the picture. This contrasts with vacuum tube electronic television technology, using electron beam scanning methods, for example in cathode ray tube (CRT) televisions.
History of televisionThe concept of television is the work of many individuals in the late 19th and early 20th centuries. The first practical transmissions of moving images over a radio system used mechanical rotating perforated disks to scan a scene into a time-varying signal that could be reconstructed at a receiver back into an approximation of the original image. Development of television was interrupted by the Second World War. After the end of the war, all-electronic methods of scanning and displaying images became standard.
TelevisionTelevision (TV) is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, entertainment, news, and sports. Television became available in crude experimental forms in the late 1920s, but only after several years of further development was the new technology marketed to consumers.
Analog televisionAnalog television (analogue television) is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference.
Color photographyColor photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray-monochrome photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray. In color photography, electronic sensors or light-sensitive chemicals record color information at the time of exposure. This is usually done by analyzing the spectrum of colors into three channels of information, one dominated by red, another by green and the third by blue, in imitation of the way the normal human eye senses color.
Digital televisionDigital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV.
Quadrature amplitude modulationQuadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signals, or two digital bit streams, by changing (modulating) the amplitudes of two carrier waves, using the amplitude-shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analog modulation scheme.
