Jitter compensation system in a rotary recording medium reproducing apparatus

Claim 1

A jitter compensation system in a rotary recording medium reproducing apparatus having a reproducing transducer including a reproducing element for reproducing recorded signals from a rotary recording medium, said rotary recording medium having recorded thereon an information signal and also recorded thereon reference signals for tracking control with a predetermined period, said reference signals for tracking control recorded on said rotary recording medium comprising first and second reference signals for tracking control, said first and second reference signals being changed over for each recorded track turn of the information signal on said rotary recording medium and alternately recorded between each track turn, said rotary recording medium also having recorded thereon a third reference signal for indicating the changeover of said first and second reference signals, said first and second reference signals not being recorded in an interval in which said third reference signals exists, said jitter compensation system comprising: separation means for separating said reference signals from a signal reproduced by said reproducing transducer; detection means for detecting the separated reference signals and for obtaining at least one detection signal having a period which is dependent on a jitter; standard signal supplying means for supplying a standard signal having a period equal to said predetermined period; Phase comparing means for comparing means for comparing phases of said standard signal from said standard signal supplying means and at least one detection signal from said detection means, to produce a phase comparison error signal; displacing means for displacing the reproducing element of said reproducing transducer along a relative scanning direction with respect to said rotary recording medium, in response to the output error signal of said phase comparing means; and interrupting means responsive to the separated third reference signal, for interrupting the output of said phase comparing means during the interval in which said third reference signal exists.