CIRCUIT SYSTEM FOR COMPENSATING THE INFLUENCE OF THE BACK-GROUND RADIATION ON THE PICTURE DISPLAY IN AN INFRA-RED CAMERA

摘要

In an infra-red (IR) camera system a scene is line scanned to provide a video signal which includes a picture signal representing the object being monitored and background signal representing the temperature changing background region. Portions of the video signal are controllably sensed during particular times of the line scans to generate a compensating signal which is superimposed on the video signal to minimize effects of the changing background signal on the average value of the picture signal.