Signal processing apparatus

Claim 1

APPARATUS USEFUL IN INTRODUCING A DELAY OF $T TIME UNITS BETWEEN A FIRST AND A SECOND SIGNAL CONDITIONALLY HAVING DIFFERENT FREQUENCY COMPONENTS WITHOUT IMPOSING SUBSTANTIAL UNLIKE NONLINEAR PHASE DISTORTION UPON THE COMPONENTS OF EACH SIGNALS, COMPRISING IN COMBINATION: FIRST AND SECOND INPUT TERMINAL MEANS ADAPTED INDEPENDENTLY TO ACCEPT SAID FIRST AND SAID SECOND ELECTRICAL SIGNALS RESPECTIVELY; MEANS COUPLED TO SAID UNPUT TERMINAL MEANS FOR RECORDING SAID FIRST SIGNAL ON A MOVING RECORDING MEDIUM TRAVELING IN A GIVEN DIRECTION; MEANS POSITIONED IN DISPLACED RELATION TO SAID FIRST SIGNAL RECORDING MEANS IN THE DIRECTION OF SAID TRAVEL FOR PLAYING BACK SAID FIRST SIGNAL AT A TIME TD TIME UNITS SUBSEQUENT TO ITS RECORDING, SAID RECORDING AND REPRODUCING CYCLE INTRODUCING KNOWN NONLINEAR PHASE DISTORTION UPON THE COMPONENTS OF SAID FIRST SIGNAL; MEANS COUPLED TO SAID SECOND INPUT TERMINAL MEANS FOR RECORDING SAID SECOND SIGNAL ON A LIKE-ASSOCIATED RECORDING MEDIUM MOVING IN A GIVEN DIRECTION; MEANS POSITIONED IN DISPLACED RELATION TO SAID SECOND RECORDING MEANS IN THE DIRECTION OF TRAVEL OF SAID ASSOCIATED RECORDING MEDIUM FOR PLAYING BACK SAID SECOND SIGNAL AT A TIME TD+$T TIME UNITS SUBSEQUENT TO ITS RECORDING, SAID RECORDING AND REPRODUCING MEANS AND RECORDING MEDIUM HANDLING SAID SECOND SIGNAL BEING ARRANGED TO INTRODUCE SUBSTANTIALLY THE SAME NONLINEAR PHASE DISTOTION UPON THE COMPONENTS OF SAID SECOND SIGNAL, ATTRIBUTABLE TO THE RECORDING AND REPRODUCING CYCLE THEREOF, AS SAID KNOWN NONLINEAR PHASE DISTORTION IMPOSED ON SAID FIRST SIGNAL, WHEREBY THE PLAYED-BACK SIGNALS PRODUCED BY SAID PLAYING BACK MEANS FOR SAID FIRST AND SECOND SIGNALS RESPECTIVELY REPRESENT LIKE VERSIONS OF SAID TWO SIGNALS BUT DELAYED WITH RESPECT TO ONE ANOTHER BY A TIME INTERVAL OF $T TIME UNITS; AND SIGNAL ACCEPTANCE MEANS COUPLED TO BOTH OF SAID PLAYING BACK MEANS FOR SAID FIRST AND SECOND SIGNALS WHEREBY SAID FIRST AND SECOND SIGNALS MAY BE COMPARED.