Abstract: A color television camera has an optical color separation system provided in an optical path for scene light so as to produce pictures of different colors on pickup areas of pickup elements. The scene light extends along optical axes in the system which are central axes of the pickup areas. To synchronize picture signals so that picture coverage is optimized on the joint display thereof, the camera comprises a test image projector and an adjusting circuit. So as to obtain a compact optical system without using a movable reflecting surface for the test image, which surface would be moved in and out of the optical path, the light of the test image is projected at an oblique angle with respect to the optical axes into the color separation system and strikes the pickup areas at an oblique angle. Optical imaging errors produced thereby are precompensated. Optical precompensation means are provided in the form of an obliquely arranged test image slide and a cylindrical plano-convex correction lens.

Abstract: In a television camera having at least one pickup tube, it is desirable to generate an electron beam with a current intensity which is greater than that necessary for obtaining a picture signal with a nominal amplitude between a black level and a white value. This prevents comet tails from being produced on the display behind brighter, moving scene portions. The electron beam intensity is adjusted by blanking the electron beam periodically during at least one field period and within the field period during at least a portion of a line period of a number of consecutive lines. The electron beam is properly set when the picture signal amplitude is observed to be maximum at a substantially minimum beam current intensity.

Abstract: Method for automatically setting up a television camera by means of a microcomputer. The setup is effected in two separate steps, a test pattern being used in each step. An external test pattern is present on a test chart in front of the camera and an internal test pattern is present in the camera in the optical path between a camera lens system and a camera pickup arrangement. During the setup with the internal test pattern, the lens system is optically blocked and correction information is stored in a memory. During or after the setup with the external test pattern, the correction information associated with the internal test pattern is subtracted from the correction information associated with the external test pattern. The resulting correction difference information is lens correction information and is stored in a memory associated with the lens system.

Abstract: A communication system comprising a connecting line and stations connected thereto, each station having free access to the connecting line. In a station which requests or has access, a transmitting stage and a receiving stage are both connected to the line, the output impedance of the transmitting stage on the supply of a predetermined logic value being temporarily increased to at least the order of magnitude of the characteristic impedance of the line, and a detector which is coupled to an output of the receiving stage producing a detection signal which switches off the transmitting station when the receiving stage receives a value which differs from the predetermined logic value.

Abstract: A colour-separating prism arrangement having surfaces which adjoin dichroic layers of mutually different colors with either the lower limit of the second dichroic layer which reflects the red light being substantially equal to the upper limit of the first dichroic layer, or the upper limit of the second dichroic layer which reflects the blue light being substantially equal to the lower limit of the first dichroic layer.