Patent ID: 6912009

Claim:
A data slice circuit for separating data added to a prescribed signal of predetermined specifications superposed on a video signal based on a slice level, comprising: a composite synchronous signal separation circuit for separating a composite synchronous signal from a video signal; a line detection circuit for detecting a line on which a desired prescribed signal is superposed from the composite synchronous signal separation circuit and outputting a line detection pulse only during a period of the detected line; a window pulse generation circuit for receiving the line detection pulse of the line detection circuit, outputting a pulse during a period for averaging the prescribed signal superposed on the detected line and changing a period for generating the pulse by the specifications of the superposed prescribed signal; a data slice reference voltage detection circuit for sampling and holding an average voltage of the prescribed signal only during a period of the pulse output by the window pulse generation circuit and detecting a data slice reference voltage; and a data slice level generation circuit for generating the slice level by adding a direct current voltage to an output voltage of the data slice reference voltage detection circuit and changing the direct current voltage to be added in accordance with the line detected by the line detection circuit.