Abstract: The invention concerns a signal frequency processing device for measuring the frequency of an input signal with the aid of very simple counters. The input signal to be measured is divided into two, four or even more partial signals, each partial signal having a frequency which is half, a fourth or an even higher fraction of the input signal's frequency. In this way rather slow, cheap and small counting devices can be used for counting fractions of the input signal which are later accumulated again to end up with a frequency which is identical with the frequency of the input signal. The input signal is thus retrieved.

Abstract: The invention relates to a device for measuring the speed or length of a moved surface, where a measuring light beam from a laser is used. The laser light beam reflected from the surface to be measured is frequency-shifted by the Doppler effect so that the overlaying of the outgoing light beam and the incoming one results in a beat which is a measure of the speed of the surface. Before the speed can be determined, digital signals occurring in large numbers must be processed in an evaluation system. The evaluation system is characterized in that there is downstream of a counter intended for detecting the incoming signals and having a high counting speed an intermediate store which is connected to an adding mechanism for pulse-wise monitoring of the counter contents. A control mechanism handles coordination of the counter, the intermediate store and the adding mechanism, upstream of which is a pulse generator.