Tracking control apparatus for use in apparatus for reproducing video signals from a rotary recording medium

A tracking control system in a reproducing apparatus having a transducer for reproducing signals recorded on a rotary recording medium in which a main information signal has been recorded in a plurality of adjacent tracks, first and second reference signals having different frequencies, each of said reference signals being alternately recorded at intermediate positions between longitudinal center lines of the adjacent tracks, and a third reference signal being recorded at positions corresponding to a switching of the first and second reference signals, said first, second and third reference signals being in a frequency band which is lower than the frequency band of the main information signal, said tracking control apparatus comprising:

• means for controlling the reproducing transducer to correctly track along the main information signal track;
• a first separating means for filtering and separating a low frequency band component including at least the first, second and third reference signals from the signal reproduced by the reproducing transducer;
• a second separating means for separating the low frequency band component into the first, second and third reference signals;
• means for detecting the separated first and second reference signals;
• means for selectively switching the separated first and second reference signals responsive to the separated third reference signal, said switched first and second reference signals being supplied to the detecting means;
• a control signal producing means for producing a control signal in response to the outputs of the detecting means and for applying the control signal to the tracking control means;
• and
• automatic gain control means for bringing the levels of the separated first, second and third reference signals to a predetermined level, said automatic gain control means being in a signal transmission path between the first separating means and the control signal producing means.