Multiplexed information signal receiving system

Abstract

A system for receiving a bi-level information signal multiplexed with a television signal or the like comprises a receiving circuit for receiving the television signal on which the bi-level information signal such as a still image video signal is superimposed during a vertical retrace period, an upper level detecting circuit for detecting an upper level of a start signal indicative of a reference phase and a reference amplitude inserted at a leading portion of the information signal and a lower level detecting circuit for detecting a lower level of the start signal. In response to output signals from the upper and lower limit detecting circuits, a slicing level of a slice circuit to which the information signal is fed is automatically controlled to a predetermined level so that the waveform is always reshaped at an exact slice level regardless of variations in the transmitted information level in order to assure exact reproduction of the information signal.

Dependencies are inferred from the claim text.