<P> In 1897, J.J. Thomson, an English physicist, in his three famous experiments was able to deflect cathode rays, a fundamental function of the modern Cathode Ray Tube (CRT). The earliest version of the CRT was invented by the German physicist Karl Ferdinand Braun in 1897 and is also known as the Braun tube . It was a cold - cathode diode, a modification of the Crookes tube with a phosphor - coated screen . A cathode ray tube was successfully demonstrated as a displaying device by the German Professor Max Dieckmann in 1906, his experimental results were published by the journal Scientific American in 1909 . In 1908 Alan Archibald Campbell - Swinton, fellow of the Royal Society (UK), 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 (or "Braun" tube) as both a transmitting and receiving device . He expanded on his vision in a speech given in London in 1911 and reported in The Times and the Journal of the Röntgen Society . In a letter to Nature published in October 1926, Campbell - Swinton also announced the results of some "not very successful experiments" he had conducted with G.M. Minchin and J.C.M. Stanton . They had attempted to generate an electrical signal by projecting an image onto a selenium - coated metal plate that was simultaneously scanned by a cathode ray beam . These experiments were conducted before March 1914, when Minchin died . They were later repeated in 1937 by two different teams, H. Miller and J.W. Strange from EMI, and H. Iams and A. Rose from RCA . Both teams succeeded in transmitting "very faint" images with the original Campbell - Swinton's selenium - coated plate . Although others had experimented with using a cathode ray tube as a receiver, the concept of using one as a transmitter was novel . The first cathode ray tube to use a hot cathode was developed by John B. Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922 . </P> <P> In 1926, Hungarian engineer Kálmán Tihanyi designed a television system utilizing fully electronic scanning and display elements and employing the principle of "charge storage" within the scanning (or "camera") tube . The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved with the introduction of charge - storage technology by Kálmán Tihanyi beginning in 1924 . His solution was a camera tube that accumulated and stored electrical charges ("photoelectrons") within the tube throughout each scanning cycle . The device was first described in a patent application he filed in Hungary in March 1926 for a television system he dubbed "Radioskop". After further refinements included in a 1928 patent application, Tihanyi's patent was declared void in Great Britain in 1930, and so he applied for patents in the United States . Although his breakthrough would be incorporated into the design of RCA's "iconoscope" in 1931, the U.S. patent for Tihanyi's transmitting tube would not be granted until May 1939 . The patent for his receiving tube had been granted the previous October . Both patents had been purchased by RCA prior to their approval . Charge storage remains a basic principle in the design of imaging devices for television to the present day . </P> <P> On December 25, 1926, Kenjiro Takayanagi demonstrated a TV system with a 40 - line resolution that employed a CRT display at Hamamatsu Industrial High School in Japan . This was the first working example of a fully electronic television receiver . Takayanagi did not apply for a patent . </P> <P> On September 7, 1927, Philo Farnsworth's image dissector camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco . By September 3, 1928, Farnsworth had developed the system sufficiently to hold a demonstration for the press . This is widely regarded as the first electronic television demonstration . In 1929, the system was further improved by elimination of a motor generator, so that his television system now had no mechanical parts . That year, Farnsworth transmitted the first live human images with his system, including a three and a half - inch image of his wife Elma ("Pem") with her eyes closed (possibly due to the bright lighting required). </P>

When did the first television picture broadcast in the u.s