JPS6415866A - Detecting device for autocorrelation degree - Google Patents

Abstract

PURPOSE:To detect the autocorrelation degree in response to a TV signal by forming an integration circuit with an increase/decrease counter and its control circuit for reduction of the circuit constitution and securing the variable threshold value of a comparator as well as the variable delay value, by integrating the information by the integrator based on the absolute value of the difference between two digital signals. CONSTITUTION:An 8-bit TV signal 101 and an input signal 102 having a large autocorrelation degree with the signal 101 are inputted and an absolute value converting circuit 2 converts the difference signal into the absolute value to supply this to a terminal A. This absolute value is compared with the threshold value of a terminal B. The output of a comparator 3 is set at 'H' with B<A. This output is inputted to a 6-clock delay circuit 4 containing 6 pieces of 1-bit data latch circuits 7. Then the circuit 4 is totally reset when an up-down counter 6 is reset. The input signals X and Y to be inputted to the circuit 4 are supplied to a counter control circuit 5. Then the counter 6 performs the addition when signals X and Y are set at H and L and then the subtraction vice versa and otherwise stops its counting action respectively. Thus the autocorrelation degree is detected based on the output 103 of the counter 6.