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In 1897, English physicist J. J. Thomson was able, in his three well-known experiments, 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 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. In 1906 the Germans Max Dieckmann and Gustav Glage produced raster images for the first time in a CRT. In 1907, Russian scientist Boris Rosing used a CRT in the receiving end of an experimental video signal to form a picture. He managed to display simple geometric shapes onto the screen.