a television camera tube that amplifies the output signal by excited (induced) conduction. The electrons radiated by the photocathode of an ibikon upon exposure to light (photoelectrons) are accelerated by an electric field and strike the surface of a target that consists of a dielectric film that is covered (on the side of the photocathode) with a fine aluminum film. The aluminum coating is transparent to electrons moving at high velocities. Upon passing through the dielectric film the electrons greatly increase its electrical conductivity (by a factor of 1,000 or more in some substances), which is proportional to the number of electrons. This phenomenon is called excited (induced) conductivity. On the other side, the entire dielectric film is charged to an identical potential by the electron beam, which scans the television image. As a result of the induced conductivity in the dielectric film, the charges discharge on the aluminum film, which is connected to the output electrode of the ibikon. The greater the flux of photoelectrons that strikes each point of the target from the photocathode, the greater the intensity of the charging current and, consequently, the greater the output signal of the ibikon. Ibikons may operate at low lighting levels and are used in various television equipment.
P. V. TIMOFEEV