Method and apparatus for successively recording two EFM-modulated signals enabling detection of boundary condition for transitioning between signals

摘要

A method and apparatus for successively recording a first and a second information signal on a record carrier track which is pre- recorded with track position-code signals alternating with track position- synchronizing signals. Each information signal is converted into a respective modulated digital signal having successive subcode frames, each subcode frame including subcode synchronizing signals and successive information frames which include time code signals. Upon completion of recording of the information in the first modulated signal, recording of succeeding information frames thereof is continued for a predetermined time interval thereafter so that recording of such signal terminates at a boundary position located between successive subcode synchronizing signals on the track. Generation of the second modulated signal is initiated the aforesaid time interval prior to recording, so that recording thereof begins at the boundary position of the first modulated signal. Consequently, the subcode synchronizing signals and the track position- code signals are maintained without interruption during the transition between recording of successive information signals, thereby making it possible to continuously maintain a fixed phase relation therebetween and so avoid loss of information therein in the vicinity of such transition.