The Electronics Revolution Inventing the Future

28 Seeing by Electricity: Development of Television
Fig. 4.2 Baird with an early television scanner showing the Nipkow disk and the dummy’s
head he used. Source: Burns R W, The First Demonstration of Television, IEE Electronics and
Power 9 October 1975
Six months later, signals were broadcast from the new London Regional Station at
Brookman’s Park, which could transmit both sound and vision simultaneously. By this
time, Baird had found backers and set up the Baird Television Company, which started selling
the receivers, or ‘televisors’ as he called them, manufactured by the Plessey company. 16
Some of these were complete but around a 1000 kits were sold because many of those
interested were radio experimenters. The ‘televisors’ were used in conjunction with a radio
receiver; they were based around a Nipkow disk of about 20 in. in diameter and produced
an image about 1.5 in 2 . This was viewed through a lens in a rectangular opening to one side
of the front of the set. Unlike most other experimenters Baird used vertical scanning instead
of horizontal, which he claimed gave a better picture at this resolution (Fig. 4.3). 17
While this was going on, others had recognized Campbell Swinton’s message or come
to the same conclusion. What was needed was an electronic camera based on some combination
of the cathode ray tube and the photocell. First into the field was Vladimir
Zworykin, another Russian, who even more importantly had been a student of, and assistant
to, Boris Rosing in St Petersburg.
In 1919, Zworykin went to America and it was there in 1923 that he filed a patent for a
television system. 18 It was remarkably like Campbell Swinton’s proposals and was so contested
that patent wasn’t granted until 1938! He worked on trying to produce a system
while employed by the Westinghouse Labs, but they weren’t interested in his rather
unpromising results.
Philo T. Farnsworth was a farm boy turned inventor. By 1926, he had talked some backers
into supporting his efforts financially and setting him up in a laboratory. In 1927, he
filed a patent for his television system employing an electronic tube camera, which he
called an ‘image dissector’. 19 The following year he was able to demonstrate a crude