There was not just one inventor of television. Experiments had
been carried out in 1862 by the Abbe Caselli, an Italian priest
living in France, who invented a system of transmitting pictures
of handmade drawings and written messages.
In 1881
Shelford Bidwell, an Englishman, was able to demonstrate an
early form of television which used a cell of selenium (a
photoelectric cell) moving up and down mechanically in a box.
But he thought that the only way to produce a good picture was
to make use of 90,000 photoelectric cells, each attached by a
separate wire - and that was beyond him.
A
Scottish electrical engineer, Alan Campbell-Swinton, hearing of
Bidwell’s experiments and knowing that Ferdinanad Braun, of
Austria, had invented the Cathode ray Oscilloscope (rather like
a modern television tube, but designed for showing electrical
waves), put the two ideas together.
He realised that an electronic switch was needed to switch on
the photoelectric cells in turn, and that the oscilloscope tube
could be used to receive pictures.
He also
designed a camera to go with it, which stored the light falling
on to the photoelectric cells so that when it was switched on
all the variations of light were transmitted at the same time.
That was in 1911, and became the basis of the television system
which went into operation by the BBC at Alexandra Palace,
London, in 1936.
Meanwhile, in Russia, Boris Rosing had invented his own
television apparatus in 1907 which did not work very well. But
one of Rosing’s students, Vladimir Zworykin, left Russia for
America in 1919, and invented his camera tube which used
Campbell-Swinton’s storage of light principle in 1923. His first
pictures were still not very good, but by 1928 he had improved
the system considerably.
John Logie Baird, working in London, gave his demonstration of
‘real’television in 1926. This was the first proper television
picture ever transmitted, but baird was using a mechanical
system instead of an electrical one (although he developed an
electronic receiver later).
The
race was then on between the RCA Company, of America and
Marconi-EMI of England, to develop television. The Marconi-EMI
team, under Issac Schoenberg, solved the final problems with the
invention of the Emitron camera in 1934.
Meanwhile, John Baird was still working on his television
system. In 1928 he produced the first television picture in
color rather than in black and white, the high-definition color
television picture in 1938, and in 1941 the large screen color
television receiver. Unfortunately, he always refused to accept
that electronic transmission of pictures was essential, rather
than mechanical methods, so none of his inventions are now
present in modern television sets.