Preparation of sensor signals for evaluation for colour projection TV - superimposing signal on each sensor output signal indicating when measurement parameter is present and superimposing at diode stage when both sensor signals are present.

摘要

A signal is superimposed on each signal from at least two photosensitive diode sensors (10,11). The value of the superimposed signal depends upon whether the presence of a measurement parameter has been detected. If both sensor input signals are present they, or signals derived from them, are superimposed via a diode stage. The superimposed signals are each compared (19,22,23) with a reference voltage (Ur). The sensor output signals, the derived signals, the superimposed signals and/or the processed signals are stored. USE/ADVANTAGE - Eg for regulation of display. Prepares signals for digital or analogue evaluation. Sensors can be magneto-resistive, Hall, capacitive, heat or electrical sensors. Enables positive indication to be given of whether both sensors are receiving identical signals or both are receiving no signal, e.g. quantity of light incident upon them.