Magnetic digital storage method and system wherein magnetic transition points in adjacent recorded tracks are out of phase with each other

• US 5,786,952 A
• Filed: 11/22/1995
• Issued: 07/28/1998
• Est. Priority Date: 11/25/1994
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tsuchiya, Reijiro, Saito, Atsushi, Shiroishi, Yoshihiro, Akagi, Kyo, Hamaguchi, Takehiko, Kawabe, Takashi, Wakabayashi, Kouichirou, Umemoto, Masuo
• Primary Examiner(s): Psitos, Aristotelis M.
• Assistant Examiner(s): HOLDER, REGINA NEAL
• Application Number:
  US08/562,203
• Time in Patent Office: 979 Days
• Field of Search: 360/22, 360/51, 360/48, 360/64, 360/77.08
• US Class Current: 360/48
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/035 Equalising
• CPC Class Codes: G11B 5/09 Digital recording
• CPC Class Codes: G11B 5/4886 relative to rotating disc
• CPC Class Codes: G11B 5/4976 Disposition of heads, e.g. matrix arrangement
• CPC Class Codes: G11B 5/5526 Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof G11B5/556 takes precedence
• CPC Class Codes: G11B 5/59633 Servo formatting G11B5/59627, G11B5/59677, G11B5/59683, G11B5/59688 take precedence

Abstract

A magnetic digital storage method and system which can improve a recording density and can reduce a cross-talk upon reproducing. An inputted high-speed digital signal is converted to a plurality of low-speed digital signal sequences by a recording circuit and each of the low-speed signal sequence is recorded onto a plurality of adjacent recorded tracks of a recording medium by integrated parallel recording heads. One servo signal is commonly recorded to the plurality of recorded tracks. Further, when recording the digital signal to the adjacent recorded tracks of the recording medium, a delay of a signal that is applied to each recording head is adjusted such that the phases of magnetic transition points given by the recording signal in the adjacent recorded tracks are not identical in the circumferential direction.

Claims

1. A magnetic digital storage method comprising the steps of:

converting a continuous digital signal to a plurality of digital signal sequences;

recording said plurality of digital signal sequences onto a plurality of adjacent recording tracks on a recording medium as recording bits each having a recording bit length with a plurality of integrated recording heads;

reproducing said plurality of digital signal sequences recorded onto said plurality of adjacent recording tracks with a plurality of integrated reproducing heads; and

converting said plurality of digital signal sequences reproduced by said plurality of reproducing heads to an original continuous digital signals;

wherein said step of converting a continuous digital signal to a plurality of digital signal sequences includes the step of delaying one of said plurality of digital signal sequences to be recorded onto one recording track of said adjacent recording tracks by a delay time smaller than a time corresponding to the recording bit length relative to another one of said plurality of digital signal sequences to be recorded onto another recording track of said adjacent recording tracks adjacent to said one recording track to cause a phase of a magnetic transition point in said one recording track to be different from a phase of a magnetic transition point in said other recording track adjacent to said one recording track when said plurality of digital signal sequences are recorded onto said plurality of adjacent recording tracks.

2. A method according to claim 1, wherein said recording medium is a magnetic disk;

and

wherein said plurality of adjacent recording tracks are a plurality of adjacent concentric recording tracks on said magnetic disk.

3. A method according to claim 1, wherein said plurality of adjacent recording tracks share one servo signal which is common to said plurality of adjacent recording tracks.

4. A magnetic digital storage system comprising:

a recording circuit for converting a continuous digital signal to a plurality of digital signal sequences;

a plurality of integrated recording heads for recording said plurality of digital signal sequences onto a plurality of adjacent recording tracks on a recording medium as recording bits each having a recording bit length;

a plurality of integrated reproducing heads for reproducing said plurality of digital signal sequences recorded onto said plurality of adjacent recording tracks; and

a reproduction processing circuit for converting said plurality of digital signal sequences reproduced by said plurality of reproducing heads to an original continuous digital signal;

wherein said recording circuit includes a delay circuit for delaying one of said plurality of digital signal sequences to be recorded onto one recording track of said adjacent recording tracks by a delay time smaller than a time corresponding to the recording bit length relative to another one of said plurality of digital signal sequences to be recorded onto another recording track of said adjacent recording tracks adjacent to said one recording track to cause a phase of a magnetic transition point in said one recording track to be different from a phase of a magnetic transition point in said other recording track adjacent to said one recording track when said plurality of digital signal sequences are recorded onto said plurality of adjacent recording tracks.

5. A system according to claim 4, wherein said reproduction processing circuit includes a circuit for performing a discrete process of a decision (or discriminating) interval of said plurality of digital signal sequences.

6. A system according to claim 5, wherein said circuit for performing the discrete process of said reproduction processing circuit includes a sampling circuit for sampling said plurality of digital signal sequences reproduced by said reproducing heads, thereby generating a discrete signal.

7. A system according to claim 4, wherein said plurality of integrated recording heads simultaneously record in parallel said plurality of digital signal sequences onto said plurality of adjacent tracks on said recording medium;

and

wherein said plurality of integrated reproducing heads simultaneously reproduce in parallel said plurality of digital signal sequences recorded onto said Plurality of adjacent recording tracks.

8. A system according to claim 4, wherein one of said plurality of digital signal sequences is designated as a reference digital signal sequence;

and

wherein said delay circuit delays remaining ones of said plurality of digital signal sequences relative to said reference digital signal sequence such that magnetic transition points in each of said adjacent recording tracks do not coincide with magnetic transition points in any other one of said adjacent recording tracks.

9. A system according to claim 4, wherein said recording medium is a magnetic disk;

and

wherein said plurality of adjacent recording tracks are a plurality of adjacent concentric recording tracks on said magnetic disk.

10. A system according to claim 4, wherein said plurality of adjacent recording tracks share one servo signal which is common to said plurality of adjacent recording tracks.