System for precisely editing audio signals on a videotape

Claim 1

An editing system for audio signals recorded on magnetic tape comprising: a helical scan videotape recorder including means for recording and reproducing said audio signals longitudinally on said magnetic tape, address signal reproducing means for reproducing address signals recorded on said tape at predetermined intervals, tape transporting means for moving said tape, mode selecting means for selecting an operating mode of said videotape recorder, and means receiving said address signals reproduced by said address signal reproducing means for generating pulse signals corresponding to a moving speed of said tape and occuring in synchronism with the reproduced address signals at a frequency higher than the frequency of said address signals as reproduced by said reproducing means, whereby said pulse signals represent finer divisions of said tape than said predetermined intervals; monitor means for monitoring said audio signals reproduced by said videotape recorder; and editing control means including speed control means for controlling said tape transport means to change said speed of said tape, address signal reading means for reading said address signals reproduced by said videotape recorder, counting means for counting said pulse signals, memory means for storing output signals from said reading means and said counting means, and controller means responsive to said output signals stored in said memory means for controlling said mode selecting means and said tape transport means to locate precisely an editing point on said tape as defined by one of said finer divisions of said tape.