Abstract :
This paper gives a preliminary outline of work with a new, entirely electrical, television system having no moving mechanical parts. The registration of the image is accomplished by a special device, which is a true electric eye. The device has been named the ¿iconoscope,¿ and it consists of a vacuum tube containing an electron-emitting gun and a photo-sensitive surface of a unique type. This photo-sensitive surfa ce is scanned by an electron beam from the gun, which serves as a type of inertialess commutator. A new principle of operation permits the storing of the energy from the light of the image and enormously increases the output as compared with that of conventional types of television scanners. The sensitivity of the iconoscope, at present, is approximately equal to that of a photographic film operating at the speed of a motion picture camera. The resolution of the iconoscope is high, much higher than is necessary for television of the highest quality. The reproduction of the image is accomplished by another cathode-ray tube with a fluorescent screen, which has been named the ¿kinescope¿. Here the impulses from the transmitter modulate the intensity of the electron beam; and this, in turn, is transformed by the fluorescent screen into variations of light. The scanning is linear and is synchronized at the end of each line. The synchronizing impulses are transmitted through the same channel as the picture signal. The whole system is completely automatic and the receiving sets are almost as easy to operate as the ordinary radio receivers. The paper describes the theory, characteristics, and mode of operation of the system.
