Apparatus and method for preventing unauthorized dubbing of a recorded signal

Claim 1

In a reproducing and recording system, the combination of: a reproducing apparatus for reproducing, from a first tape, recorded composite data which includes field arrangements of pulse code modulate information data mixed with control data for each field which has first and second states for indicating that re-recording of the associated information data is to be prevented and permitted, respectively; a recording apparatus for recording on a second tape composite data reproduced from said first tape; detecting means for detecting said states of said control data in said composite data reproduced from said first tape; means for generating a dubbing protect control signal, including counting means for counting the number of successive fields of the reproduced composite data in which the respective control data are detected to be in said first state thereof, and means providing said dubbing protect control signal only when said counting means counts to a predetermined value substantially greater than one; means for transmitting said reproduced composite data from said reproducing apparatus to said recording apparatus; and switching means interposed in said means for transmitting and being operated by said dubbing protect control signal to interrupt the transmission of said reproduced composite data to said recording apparatus and thereby prevent recording of said reproduced composite data on said second tape.