System for detecting the position of a read-write head on a disk recording medium having data and servo sectors

Claim 2

A disk recording medium having a plurality of data sectors (2) each having concentric data tracks and servo sectors (1) each having concentric servo tracks and embedded between adjacent data sectors, characterized in that each servo sector has K (an integer of not less than 3) servo information patterns which consist of a first servo pattern (7) consisting of a first pair of alternate pattern arrays (7a, 7b) having a period of four tracks and arranged in a staggered fashion, and a second pair of alternate pattern arrays (7c, 7b) having a period of four tracks and arranged in a staggered fashion, said first and second pairs of alternate pattern arrays being displaced by one track with respect to each other; a second servo pattern (8) consisting of a pair of alternate pattern arrays (8a, 8b) having a period of 2 K+1 tracks and displaced by 2 K-1 tracks with respect to each other; and a kth servo pattern (9) consisting of an alternate pattern array (9a) having a period of 2 K ― k+3 (k includes all intergers of not less than 3 and not more than K) tracks and displaced by 2 K-k+1 tracks with respect to a (k-l)th servo pattern.

Claim 3

A medium according to claim 1, characterized in that K is 3.

Claim 4

A medium according to claim 1, characterized in that K is 4.

Claim 5

A medium according to claim 1, characterized in that said pair of alternate pattern arrays of said second servo pattern are formed at one side of said first servo pattern.

Claim 6

A medium, according to claim 1, characterized in that K is 3, and said second and third servo patterns are formed at opposite sides of said third servo pattern.

Claim 7

A medium, according to claim 1, characterized in that each of said servo patterns consists of a dibit pattern.

Claim 8

A tracking servo system for positioning a read-write head on a target track of a disk recording medium having a plurality of data sectors each having concentric data tracks and servo sectors each having concentric servo tracks and embedded between adjacent data sectors, each servo sector having K (an integer of not less than 3) servo patterns which consist of a first servo pattern consisting of a first pair of alternate pattern arrays having a period of four tracks and arranged in a staggered fashion, and a second pair of alternate pattern arrays having a period of four tracks and arranged in a staggered fashion, said first and second pairs of alternate pattern arrays being displaced by one track with respect to each other; a second servo pattern consisting of a pair of alternate pattern arrays having a period of 2K+l tracks and displaced by 2 K-1 tracks with respect to each other; and a kth servo pattern consisting of an alternate pattern array having a period of 2 K-k+3 (k includes all intergers of not less than 3 and not more than K) tracks and displaced by 2 K-k+1 tracks with respect to a (k-l)th servo pattern, comprising: head driving means (12) for driving said read-write head in the radial direction of said disk recording medium; detecting means (17, 19, 21 to 27) for detecting servo signals, corresponding to said pattern arrays of said servo patterns from an output signal of said read-write head obtained at each of said servo sectors; and controlling means (28, 29, 31 to 37) responsive to the servo signals from said detecting means for controlling said head driving means to position said read-write head on the target track.

Claim 9

A tracking servo system for positioning a read-write head on a target track of a disk recording medium having a plurality of data sectors each having concentric data tracks and servo sectors each having concentric servo tracks and embedded between adjacent data sectors, each servo sector having K (an integer of not less than 3) servo patterns which consist of a first servo pattern consisting of a first pair of alternate pattern arrays having a period of four tracks and arranged in a staggered fashion, and a second pair of alternate pattern arrays having a period of four tracks and arranged in a staggered fashion, said first and second pairs of alternate pattern arrays being displaced by one track with respect to each other; a second servo pattern consisting of a pair of alternate pattern arrays having a period of 2K+l tracks and displaced by 2 K-1 tracks with respect to each other; and a kth servo pattern consisting of an alternate pattern array having a period of 2 K-k+3 (k includes all intergers of not less than 3 and not more than K) tracks and displaced by 2 K-k+1 tracks with respect to a (k-l)th servo pattern, comprising: head driving means (12) for driving said read-write head in the radial direction of said disk recording medium; detecting means (17, 19, 21 to 27) for detecting servo signals, corresponding to said pattern arrays of said servo patterns from an output signal of said read-write head obtained at each of said servo sectors; and controlling means (28, 29, 31 to 37) responsive to the servo signals from said detecting means for controlling said head driving means to position said read-write head on the target track.