My speciality. Шепелева М.А - 22 стр.

      3.4 Text 4 The Ripening of Electronic TV

      3.4.1 Read the text and answer the question:

1. What are the main developing stages of Electronic TV?
        During these years of mechanical television's well-intentioned but ill-
destined progression, discoveries that would lead to today's electronic system were
taking a different course. In 1878, British physicist Sir William Crookes invented
the cathode ray tube. Simply put, this tube was a glass container to house
highspeed electrons. These electrons possessed the capability of being deflected
and focused by electrical and magnetic fields. By 1897, Germanys Carl Ferdinand
Braun had built a similar tube and was actually able to direct the path of cathode
rays through the primitive manipulation of magnets. Braun also added a
fluorescent surface to the tube to increase its light-sensitivity properties
significantly. The cathode ray tube would prove to be the cornerstone of electronic
television in the same way that the scanning disc was central to the mechanical
method.
         Ten years later, Russian scientist Boris Rosing used Braun's tube as the
basis for a prototype wireless television receiver. For a time, a young student
named Vladimir Zworykin worked as Rosing's laboratory assistant at the St.
Petersburg Institute of Technology. By 1917, Zworykin had decided to leave
crumbling Czarist Russia and immigrate to the United States in order to pursue this
television research. In two years, he was working for Westinghouse and had
persuaded his reluctant superiors to allow him to phase out of his job as a
production-line assembler of vacuum tubes and into research exploration of
electronic television. Before 1923 was over, the Russian-born inventor had
developed an all-electronic television pickup tube he called toe iconoscope. This
device used a scanning gun or eye rather than a spinning disc to convert a light
image into electrical energy for transmission.
         Meanwhile, Philo Famsworth, a young Salt Lake City scientist, was
completing his own work on a similar device labeled the electronic image dissector
camera Before long, Zworykin, Farnsworth, and several lesser inventors became
embroiled in patent litigation over their competing devices. Farnsworth would
eventually be paid a million dollar settlement by RCA so that it could continue to
develop Zworykin's concepts with a free hand.
         By 1933, both Famsworth and Zworykin had developed their still-
competing systems to the point at which they could electronically transmit pictures
of 240 lines of resolution. At the receiving end, however, these lines were still
being assembled via mechanical means.
         Still, the electronic transmitter was a tremendous improvement over its
mechanical counterpart. With the cathode ray scanning device, the entire picture
surface was illuminated all the time, and the heat and friction caused by rotating
discs were eliminated. By 1935, RCA engineers had produced a television picture
of 343 lines. This was a great improvement over the 50- or 60-line images of just a