Abstract: A method for adjusting convergence in a projection television receiver, in which a marker contained in a projected image is adjusted by a manipulated variable to illuminate a photosensor arranged adjacent to the projection screen. The method employs two markers which are moved towards the sensor from opposite directions with a varying step size. The sensor supplies an output voltage indicating lighting by the two markers in conjunction with two mutually spaced manipulated variables. A mean value of the two manipulated variables is used as the manipulated variable for the marker.

Abstract: A method for adjusting convergence in a projection television receiver, in which a marker contained in a projected image is adjusted by a manipulated variable to illuminate a photosensor arranged adjacent to the projection screen. The method employs two markers which are moved towards the sensor from opposite directions with a varying step size. The sensor supplies an output voltage indicating lighting by the two markers in conjunction with two mutually spaced manipulated variables. A mean value of the two manipulated variables is used as the manipulated variable for the marker.

Abstract: A Circuit for convergence setting in a projection television display, having a display screen with a photosensor for detecting impingement of a marker contained in a projected picture. The photosensor generates an output signal having a specific time characteristic. The circuit comprises an integrating element coupled to receive the output signal from the sensor when impinged by a blue marker. The integrating element is dimensioned in such a way that the time characteristic of the output signal of the sensor when impinged by the blue marker is approximately equal to the time characteristic of output signals from the sensor when impinged by a red or green marker.

Abstract: A set of coarse or initial convergence correction values for a model line of projection television receivers is defined in digital form prior to production using a fine grid or grating pattern. The set of coarse convergence correction values is digitally stored in all the receivers of the model line. A receiver-specific set of fine or final convergence correction values is defined in digital form for each receiver in the model line using a coarse grid or grating pattern. In each receiver, the receiver-specific set of fine or final convergence correction values is combined with the stored set of coarse convergence correction values. Convergence correction during subsequent operation of each receiver is based on the combined convergence correction values. Some of the coarse and fine convergence correction values can be located horizontally outside of the visible picture area of the receivers.

Abstract: An apparatus for electron beam deflection in a cathode ray tube, in particular in a picture tube of a television set, comprises a deflection coil arrangement for horizontal and vertical deflection of the electron beam, an auxiliary deflection coil arrangement, by means of which the electron beam can be influenced for the purpose of convergence correction, and a compensation coil arrangement for producing a magnetic compensation field. The compensation coil arrangement is arranged and designed such that the compensation field essentially compensates for the stray magnetic field of the deflection coil arrangement in the physical region of the auxiliary deflection coil arrangement.

Abstract: At high frequencies, a video amplifier draws a higher current and normally is biased to provide such current. However, since high frequencies are rarely encountered, the present circuit controls the operating point as a function of the frequency. More specifically, a controlled variable which controls the operating point of the amplifier stage is obtained in dependence on the frequency to which the amplifier stage is driven.