The Evolution of Television Technology

Development of Television: A Historical Overview

• Television was the result of the work of several 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.

• Development of television was interrupted by the Second World War, and after the war, all-electronic methods of scanning and displaying images became standard.

• Several different standards for addition of color to transmitted images were developed with different regions using technically incompatible signal standards.

• Television broadcasting expanded rapidly after World War II, becoming an important mass medium for advertising, propaganda, and entertainment.

• Television broadcasts can be distributed over the air by VHF and UHF radio signals from terrestrial transmitting stations, by microwave signals from Earth orbiting satellites, or by wired transmission to individual consumers by cable TV.

• Many countries have moved away from the original analog radio transmission methods and now use digital television standards, providing additional operating features and conserving radio spectrum bandwidth.

• Television programming can also be distributed over the Internet.

• Television broadcasting may be funded by advertising revenue, by private or governmental organizations prepared to underwrite the cost, or in some countries, by television license fees paid by owners of receivers.

• Mechanical television was invented by several inventors including Alexander Bain, Frederick Bakewell, Paul Julius Gottlieb Nipkow, Georges Rignoux, A. Fournier, Boris Rosing, and Vladimir Zworykin.

• John Logie Baird created his first prototypes in Hastings, where he was recovering from a serious illness, and he gave the first public demonstration of televised silhouette images in motion at Selfridge's Department Store in London in March 1925.

• Charles Francis Jenkins also pioneered the television, and he was granted U.S. patent 1,544,156 (Transmitting Pictures over Wireless) on June 30, 1925.

• Herbert E. Ives and Frank Gray of Bell Telephone Laboratories gave a dramatic demonstration of mechanical television on April 7, 1927, transmitting images over two paths: first, a copper wire link from Washington to New York City, then a radio link from Whippany, New Jersey.The Evolution of Television Technology

• In 1928, WRGB was started as the world's first television station in Schenectady, New York.

• Léon Theremin developed a mirror drum-based television in the Soviet Union, achieving an image of 100 lines in 1927.

• Anton Codelli developed a single-line mechanical television system in 1929, which was based on his understanding of peripheral vision.

• Mechanical television systems produced low-resolution images, ranging from about 30 to 120 lines.

• The introduction of all-electronic television marked the end of mechanical systems as the dominant form of television.

• The earliest version of the cathode-ray tube (CRT) was invented by Karl Ferdinand Braun in 1897 and became the foundation of 20th-century television.

• Kálmán Tihanyi solved the problem of low sensitivity to light in transmitting or "camera" tubes with his charge-storage technology in 1924.

• Philo Farnsworth demonstrated the first electronic television system using the image dissector camera tube in 1927.

• Vladimir Zworykin experimented with the CRT to create and show images, but his imaging tube never got beyond the laboratory stage.

• The EMI engineering team led by Isaac Shoenberg developed the Emitron camera for the BBC in 1932, which was more reliable and visually superior to mechanical systems.

• The super-Emitron camera tube developed by the EMI team was between ten and fifteen times more sensitive than the original Emitron and iconoscope tubes.

• The image iconoscope became the industrial standard for public broadcasting in Europe from 1936 until 1960, competing against the American tradition represented by the image orthicon.the development of digital television and smart TVs, the history of television includes several other significant milestones:

• The first color transmission was demonstrated by John Logie Baird in 1928, and the first color broadcast was made in 1938.

• The first practical hybrid electro-mechanical field-sequential color system was also pioneered by Baird in 1939.

• The National Television Systems Committee in the US approved an all-electronic compatible color system developed by RCA in 1953, which represented a major technical achievement.

• Digital TV became a possibility in the 1990s, and the FCC made critical decisions to ensure that the new ATV standard could provide a genuine HDTV signal with at least twice the resolution of existing television images.

• The final standard adopted by the FCC did not require a single standard for scanning formats, aspect ratios, or lines of resolution, resulting from a dispute between the consumer electronics industry and the computer industry over which of the two scanning processes—interlaced or progressive—is superior.

• The digital television transition started in the late 2000s, and all governments across the world set the deadline for analog shutdown by the 2010s.

• Smart TVs are television sets with integrated Internet and Web 2.0 features, and are an example of technological convergence between computers and television sets and set-top boxes.

• Smart TVs come pre-loaded with an operating system, including Android or a derivative of it, Tizen, webOS, Roku OS, and SmartCast.

• Smart TVs should not be confused with Internet TV, IPTV, or Web TV.

• The first patent for an "intelligent" television system, linked with data processing systems, by means of a digital or analog network was filed in 1994.Overview of Television Broadcasting in Different Countries

• Smart TVs have the ability to download necessary software routines and process user needs.

• Major TV manufacturers have announced production of smart TVs only, for middle-end and high-end TVs in 2015.

• Stereoscopic 3D television was first demonstrated in 1928 and the first 3D TV was produced in 1935.

• 3D programming has largely failed to make inroads among the public, resulting in many 3D television channels shutting down.

• Programming is broadcast by television stations, called "channels," which are licensed by their governments to broadcast only over assigned channels in the television band.

• The Canadian Broadcasting Corporation (CBC) adopted the American NTSC 525-line B/W 60 field per second system as its broadcast standard in 1952.

• Regular television broadcasts in Prague started on May 1, 1953, and by 1961 more than a million citizens owned a television set.

• In France, the first experiments in television broadcasting began in the 1930s, and the first official channel appeared in 1935.

• Television broadcasting in Germany began in 1929, but was banned by the victorious Allies after World War II, resuming in 1948.

• Television broadcasting in Japan started in 1953, and in 1979, NHK first developed a consumer high-definition television.

• When KFMB-TV in San Diego signed on in 1949, Baja California became the first state to receive a commercial television station over the air in Mexico.