Matsushita Electric Industrial Co., Ltd.

Tetsurou Takaoka

Ryosuke Shimizu

Noriaki Wakabayashi

Tsukasa Yoshiura

In the head positioning apparatus of a disk-shaped information recording medium using the sector-servo-method, track codes are recorded in advance so as to be repeated every 12 tracks in the servo sectors of the disk-shaped information recording medium, the track are reproduced with a head, and a distance between the current position of the head and a target track is detected from the reproduced signal of the track codes with a resolution of 1/2.sup.7 of track width, then the head is moved to the target track so as to decrease the distance, when the head reaches the range of the width of .+-.6 tracks of the target track, an expanded head position signal having the resolution of 1/2.sup.7 is generated, and the head is controlled on the basis of the expanded head position signal and is finally settled to the target track.

Resolution enhancement of absolute track position using iterative

Track codes are recorded in advance so as to be repeated every 12 tracks, and burst signals .alpha. and .beta. are also recorded in advance so as to be repeated every 2 tracks, in the servo sectors of the disk-shaped information recording medium; the track codes and the burst signals .alpha. and .beta. are reproduced with a data head, and a distance between the current position of the data head and a target track is detected from the reproduced signal of the track codes with a resolution of 1/2.sup.2 of track width, then the data head is moved to the target track so as to decrease the distance; when the data head reaches the range of the width of .+-.6 tracks of the target track, an expanded data head position signal having the resolution of 1/2.sup.2 is generated; and thereby the data head is controlled.

A head position recognition method, a speed calculation method, and a head movement speed control device which provide for an overall improvement in storage device performance without increasing the seek time of the data head. Discrete servo sectors are provided circumferentially to the recording medium, four servo patterns with a minimum repeat cycle of 24 tracks are written into each servo sector. The range of the head seek distance that should be obtained at the current servo sector is estimated based on the previously calculated head seek distance, and the calculated head seek speed is corrected to the true head seek distance.

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Uwajima, Japan

Tetsurou Takaoka