Magnetic recording medium and magnetic recording-reproduction system

• US 20050036224A1
• Filed: 11/19/2003
• Published: 02/17/2005
• Est. Priority Date: 11/20/2002
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Aoyama, Tsutomu
• Granted Patent: US 7,095,589 B2
• Time in Patent Office: Days
• US Class Current: 360/48
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• 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 5/09 Digital recording
• CPC Class Codes: G11B 5/4893 relative to moving tape
• CPC Class Codes: G11B 5/64 comprising only the magnetic material without bonding agent
• CPC Class Codes: G11B 5/743 Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks
• CPC Class Codes: G11B 5/82 Disk carriers

Abstract

A disc-shaped magnetic recording medium has magnetic tracks that are arranged thereon substantially concentrically for writing and reading magnetic information. Assuming that a saturation magnetic field in a width direction extending in a radial direction from the center of the disc-shaped magnetic recording medium is H_R, and a saturation magnetic field in a circumferential direction perpendicular to the radial direction is H_C, H_R/H_C is set to a value within a range of 0.5 to 0.95 in each of the magnetic tracks, and magnetization information is recorded in the width direction of each magnetic track. In gap portions between the magnetic tracks located adjacent to each other in the radial direction, discrete portions for magnetically separating the adjacent magnetic tracks are formed, respectively. With this configuration, it is possible to realize recording and reproduction in the magnetic track width direction.

Claims

1. A disc-shaped magnetic recording medium on which magnetic tracks for writing and reading magnetic information are arranged substantially concentrically,

wherein, assuming that a saturation magnetic field in a width direction extending in a radial direction from the center of the disc-shaped magnetic recording medium is H_R, and a saturation magnetic field in a circumferential direction perpendicular to said radial direction is H_C, H_R/H_C is set to a value within a range of 0.5 to 0.95 in each of said magnetic tracks, and magnetization information is recorded in the width direction of each magnetic track, and

wherein, in gap portions between the magnetic tracks located adjacent to each other in said radial direction, discrete portions for magnetically separating the adjacent magnetic tracks are formed, respectively.

2. The magnetic recording medium according to claim 1, wherein a relationship between a track pitch (T_P) of each magnetic track and a width (T_W) thereof satisfies 0.8≧

(T_W/T_P)≧

0.4.

3. The magnetic recording medium according to claim 1, wherein a relationship between a track pitch (T_P) of each magnetic track and a width (T_W) thereof satisfies 0.8≧

(T_W/T_P)≧

0.5.

4. The magnetic recording medium according to claim 1, wherein the value of H_R/H_C falls within a range of 0.6 to 0.9.

5. The magnetic recording medium according to claim 1, wherein the value of H_R/H_C falls within a range of 0.7 to 0.8.

6. The magnetic recording medium according to claim 1, wherein a thickness of a magnetic layer of each magnetic track falls within a range of 5 to 100 nm.

7. The magnetic recording medium according to claim 1, wherein a thickness of a magnetic layer of each magnetic track falls within a range of 50 to 100 nm.

8. The magnetic recording medium according to claim 1, wherein a coercivity of a magnetic layer of each magnetic track falls within a range of 300 to 4000 Oe.

9. The magnetic recording medium according to claim 1, wherein a coercivity of a magnetic layer of each magnetic track falls within a range of 300 to 1000 Oe.

10. A magnetic recording and reproducing system comprising a magnetic recording medium, and a magnetic head for writing or reading information relative to said magnetic recording medium,

wherein said magnetic recording medium is a disc-shaped magnetic recording medium on which magnetic tracks for writing and reading magnetic information are arranged substantially concentrically,

wherein, assuming that a saturation magnetic field in a width direction extending in a radial direction from the center of the disc-shaped magnetic recording medium is H_R, and a saturation magnetic field in a circumferential direction perpendicular to said radial direction is H_C, H_R/H_C is set to a value within a range of 0.5 to 0.95 in each of said magnetic tracks, and magnetization information is recorded in the width direction of each magnetic track,

wherein, in gap portions between the magnetic tracks located adjacent to each other in said radial direction, discrete portions for magnetically separating the adjacent magnetic tracks are formed, respectively,

wherein said magnetic head comprises a recording head portion having a recording gap for recording the magnetization information in the width direction of the magnetic track, and a reproducing head portion having a reproducing gap for taking in the magnetization information recorded in the width direction of the magnetic track,

wherein a relationship between a length (G1) of the recording gap of said magnetic head and a track width (T_W) of said magnetic recording medium satisfies 1.5≧

(G1/T_W)≧

0.9, and

wherein a relationship between a length (G2) of the reproducing gap of said magnetic head and the track width (T_W) of said magnetic recording medium satisfies 1.2≧

(G2/T_W)≧

0.75.

11. The magnetic recording and reproducing system according to claim 10, wherein a relationship between a track pitch (T_P) of each magnetic track and the track width (T_W) thereof satisfies 0.8≧

(T_W/T_P)≧

0.4.

12. The magnetic recording and reproducing system according to claim 10, wherein a relationship between a track pitch (T_P) of each magnetic track and the track width (T_W) thereof satisfies 0.8≧

(T_W/T_P)≧

0.5.

13. The magnetic recording and reproducing system according to claim 10, wherein the relationship between the length (G1) of the recording gap of said magnetic head and the track width (T_W) of said magnetic recording medium satisfies 1.2≧

(G1/T_W)≧

0.95.

14. The magnetic recording and reproducing system according to claim 10, wherein the relationship between the length (G2) of the reproducing gap of said magnetic head and the track width (T_W) of said magnetic recording medium satisfies 1.1≧

(G2/T_W)≧

0.9.

15. The magnetic recording and reproducing system according to claim 10, wherein the value of H_R/H_C falls within a range of 0.6 to 0.9.

16. The magnetic recording and reproducing system according to claim 10, wherein the value of H_R/H_C falls within a range of 0.7 to 0.8.

17. The magnetic recording and reproducing system according to claim 10, wherein a thickness of a magnetic layer of each magnetic track falls within a range of 5 to 100 nm.

18. The magnetic recording and reproducing system according to claim 10, wherein a thickness of a magnetic layer of each magnetic track falls within a range of 50 to 100 nm.

19. The magnetic recording and reproducing system according to claim 10, wherein a coercivity of a magnetic layer of each magnetic track falls within a range of 300 to 4000 Oe.

20. The magnetic recording and reproducing system according to claim 10, wherein a coercivity of a magnetic layer of each magnetic track falls within a range of 300 to 1000 Oe.