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First Electromehanical Television
As a 23-year-old German university student, Paul Nipkow proposed and patented the first electromechanical television system in 1884. Although he never built a working model of the system, variations of Nipkow's spinning-disk for television became exceedingly common, and remained in use until 1939.
http://www.nyu.edu/classes/stephens/History of Television page.htm
http://en.wikipedia.org/wiki/History_of_television -
Distant Electric Vision
In 1908 Alan Archibald Campbell-Swinton, fellow of the Royal Society, published a letter in the scientific journal Nature in which he described how "distant electric vision" could be achieved by using a cathode ray tube as both a transmitting and receiving device, apparently the first iteration of the electronic television method that would dominate the field until recently.
http://wiki.answers.com/Q/When_was_television_invented
http://www.thehistoryoftelevision.com/ -
Mirror Drum Scanner
In 1911, Boris Rosing and his student Vladimir Zworykin created a television system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, over wires to the "Braun tube" in the receiver. Moving images were not possible because, in the scanner, "the sensitivity was not enough and the selenium cell was very laggy". -
Electric Camera Tube
In 1923, he began to develop an electronic camera tube. But in a 1925 demonstration, the image was dim, had low contrast and poor definition, and was stationary. Zworykin's imaging tube never got beyond the laboratory stage. -
First Image
On September 7, 1927, Farnsworth's Image Dissector camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco.
http://en.wikipedia.org/wiki/Philo_Farnsworth -
Improved Camera Tube
In 1933 RCA introduced an improved camera tube that relied on Tihanyi's charge storage principle. Dubbed the Iconoscope by Zworykin, the new tube had a light sensitivity of about 75,000 lux, and thus was claimed to be much more sensitive than Farnsworth's image dissector. However, Farnsworth had overcome his power problems with his Image Dissector through the invention of a completely unique device that he began work on in 1930, and demonstrated in 1931. -
All-Electronic Television System
Philo Farnsworth gave the world's first public demonstration of an all-electronic television system, using a live camera, at the Franklin Institute of Philadelphia on August 25, 1934.
http://www.historyoftelevision.net/ -
First High-Definition Television
On November 2, 1936, a 405-line broadcasting service employing the Emitron began at studios in Alexandra Palace, and transmitted from a specially built mast atop one of the Victorian building's towers. It alternated for a short time with Baird's mechanical system in adjoining studios, but was more reliable and visibly superior. This was the world's first regular high-definition television service. -
Improving
In 1941, the United States implemented 525-line television. The world's first 625-line television standard was designed in the Soviet Union in 1944, and became a national standard in 1946.
http://inventors.about.com/od/tstartinventions/a/Television.htm -
First Broadcast
The first broadcast in 625-line standard occurred in 1948 in Moscow. The concept of 625 lines per frame was subsequently implemented in the European CCIR standard.
