Patent ID: 7158340

Claim:
A magnetic recording and reproducing apparatus comprising a magnetic recording medium having a data information recording portion and a servo information portion for tracking, and a magnetic head for detecting servo information of said servo information portion and recording and reproducing data information on and from said data information recording portion, wherein said servo information portion is composed of a magnetic recording layer formed in a predetermined convex-concave pattern, said servo information portion comprises a burst portion where burst signals for tracking are recorded, said burst portion comprises a first burst, a second burst, a third burst, and a fourth burst each composed of a plurality of convex-portion magnetic recording layers where the burst signals are recorded, said first and second bursts are arranged such that the convex-portion magnetic recording layers are formed so as to have their center lines at positions that are offset from each other by one track pitch in a track width direction, while, said third and fourth bursts are arranged such that the convex-portion magnetic recording layers are formed so as to have their center lines at positions that are offset from the center lines of said first and second bursts by half the track pitch in the track width direction, each convex-portion magnetic recording layer of said convex-portion magnetic recording layers has substantially trapezoidal shapes in the track width direction and in a track circumferential direction, respectively, (truncated quadrangular pyramid shape) and a condition of Tp≧Wr>W 2 >W 1 is satisfied where W 1 represents an upper side corresponding to an upper surface of the convex-portion magnetic recording layer and W 2 a lower side corresponding to a lower surface of the convex-portion magnetic recording layer in the trapezoidal shape in the track width direction, Tp represents a data track pitch of the data information recording portion, and Wr represents a read width of the magnetic head.