Head positioning system for positioning a multiple head with respect to data and servo trasks of a recording medium

A head positioning system on a recording medium comprising:

• (a) a recording medium having periodic arrangement of data and servo track groups with a predetermined pitch period between tracks wherein a data track group had N.sub.d (N.sub.d is an integer equal to or larger than (1) number of data tracks, and a servo group has N.sub.s (N.sub.s is an integer equal to or larger than (2) number of servo tracks, each servo track having the same width and an M-phase servo pattern (M is an integer equal to or larger than 2), said data and servo track groups being disposed alternately on the recording medium;
• (b) a multi-head carrying a plurality of head elements equally spaced from one another and disposed in a direction perpendicular to the tracks, so that the distance between individual head elements is N.sub.h P where N.sub.h is an integer equal to or larger than 1 and P is a track pitch, and said multi-head is movable in a direction generally perpendicular to the direction of the tracks;
• (c) means for selecting a servo head for reading M-phase servo pattern on a servo track and a data head for reading a data track from among said head elements during a seek operation wherein a selected head is selected to reproduce a servo pattern on a servo track and a selected data head is determined according to the selected servo head;
• and
• (d) wherein the multi-head is positioned on a servo track in every 1/M track pitch of movement.