Abstract: In computer monitors having a picture tube, it may be seen that a small white picture area is displayed with the same white value as a large white picture area. If it were intended to achieve the same result for a television receiver with a picture tube, a voltage supply is necessary in which the power is permitted to fluctuate between 60 and 300 watts given a stable output voltage. On account of the lower luminous efficiency, this effect would have considerably intensified repercussions on the power consumption of plasma screens. The invention is based on the object of providing a simplified method for regulating the picture power in a television receiver. The method according to the invention is distinguished by the following steps. The power consumption of the picture power is obtained by the video voltage R, G, B. The video voltage is converted into an information item which is then a measure of the picture power. This information item is subsequently fed to two regulating loops.

Abstract: A circuit for controlling beam current in a picture tube, which circuit calculates current pictures for the R, G, B beam currents in the picture tube, which largely correspond to real beam currents in the color picture tube. The circuit comprises a comparator/integrator which compares a sum of these current pictures with a beam current information item for the purpose of controlling the R, G, B beam currents and/or the picture sharpness. Gamma correction is carried out in the circuit. The circuit may be of analog or digital construction and may advantageously be integrated in a video processor IC. The present circuit is particularly applicable for television sets or computer monitors.

Abstract: A convergence adjustment device for color video-projectors having three monochrome tubes, each projecting an image of a give color on a screen. This device acts on the scanning of the second and third tubes for superimposing, on the screen, their images on that of the first tube. This device is of the digital type. It comprises a RAM in which correction values are stored corresponding to correction of the scanning currents for the different zones into which the image is divided. These values are restored in synchronism with the scanning of the zones during normal operation. The device also comprises a microprocessor for modifying, during the adjustment phase, the stored values as a function of the ordes issued by the user who makes this adjustment by observing the image. The user's actions in a manual mode affect only a single one of the zones. In an automatic mode, adjustments are effective on groups of zones.

Abstract: A geometry adjustment device for a color video projector having three monochrome tubes each projecting an image of a given color on a screen, comprising a geometry correction circuit adjustable by the user for providing, by acting on a single signal, vertical amplitude, vertical linearity and horizontal trapezoid corrections of the images projected on the screen by the tubes.