The Rev. John Kerr, F.R.S., Inventor of the Kerr Cell

Abstract

ONE of the many problems in television reception is that of modulating the brightness of the spot of light that, travelling very rapidly over the screen, gives the sensation of a completely moving picture. In one system a neon lamp is used, and the brightness of the lamp is varied by the incoming signals being allowed, after suitable amplification, to alter the voltage across the lamp. A noon lamp is not very bright, compared with a filament or arc lamp; and the next development was the use of a bright lamp, the brightness of the beam of light being altered after the light had left the lamp.