Reproducing method, reproducing apparatus, recording and reproducing apparatus, and magnetic recording medium
View Patent ↗A recording and reproducing apparatus includes: a recording section for recording an information signal in a magnetic recording medium in which a magnetic layer containing hexagonal ferrite is formed; and a reproducing section for reproducing the information signal recorded in the magnetic recording medium, the reproducing section including: a reproducing head for reading the information signal from the magnetic recording medium; and an equalizer for equalizing the information signal read from the magnetic recording medium, wherein in the equalized information signal, coefficients a, b, c, d of PR(1, a, b, c, d) meet conditions that 0.1≦a<2.0, −0.9≦b<−0.0, −2.0<c≦−0.3, and −1.0<d≦−0.1. A corresponding reproducing method, a corresponding reproducing apparatus, and the magnetic recording medium are also disclosed.
1. A method for reproducing an information signal recorded in a magnetic recording medium in which a magnetic layer containing hexagonal ferrite is formed, the method comprising:
reproducing the information signal using PR(1, a, b, c, d) ML signal processing,
wherein coefficients a, b, c, d of PR(1, a, b, c, d) meet conditions that 0.1≦a<2.0, −0.9≦b<0.0, −2.0<c≦−0.3, and −1.0<d≦−0.1.
2. The method according to claim 1 ,
wherein 0.1≦a≦1.0, −0.9≦b≦−0.5, −1.0≦c≦−0.3, and −0.5≦d≦−0.1.
3. The method according to claim 2 ,
wherein the reproduced information signal shows a normalized line density which meets a condition that K≦4.7.
4. The method according to claim 3 ,
wherein the hexagonal ferrite comprises barium ferrite.
5. The method according to claim 2 ,
w wherein an isolated inversion waveform produced when the magnetic recording medium is reproduced shows a ratio γ (%) which indicates an asymmetry and which meets a condition that 9.8≦γ≦50.
6. The method according to claim 5 ,
wherein the hexagonal ferrite comprises barium ferrite.
7. The method according to claim 2 ,
wherein the hexagonal ferrite comprises barium ferrite.
8. The method according to claim 1 ,
wherein the reproduced information signal shows a normalized line density which meets a condition that K≦4.7.
9. The method according to claim 8 ,
wherein the hexagonal ferrite comprises barium ferrite.
10. The method according to claim 1 ,
wherein an isolated inversion waveform produced when the magnetic recording medium is reproduced shows a ratio γ (%) which indicates an asymmetry and which meets a condition that 9.8≦γ≦50.
11. The method according to claim 10 ,
wherein the hexagonal ferrite comprises barium ferrite.
12. The method according to claim 1 ,
wherein the hexagonal ferrite comprises barium ferrite.
13. A reproducing apparatus for reproducing, by using PR(1, a, b, c, d) ML signal processing, an information signal recorded in a magnetic recording medium in which a magnetic layer containing hexagonal ferrite is formed, the apparatus comprising:
a reproducing head for reading the information signal from the magnetic recording medium;
an equalizer for equalizing the information signal read from the magnetic recording medium,
wherein in the equalized information signal, coefficients a, b, c, d of PR(1, a, b, c, d) meet conditions that 0.1≦a<2.0, −0.9≦b<−0.0, −2.0<c≦−0.3, and −1.0<d≦−0.1.
14. The reproducing apparatus according to claim 13 ,
wherein 0.1≦a≦1.0, −0.9≦b≦−0.5, −1.0≦c≦−0.3, and −0.5≦d≦−0.1.
15. The reproducing apparatus according to claim 14 ,
wherein an isolated inversion waveform produced when the magnetic recording medium is reproduced shows a ratio γ (%) which indicates an asymmetry and which meets conditions that 9.8≦γ≦50.
16. The reproducing apparatus according to claim 15 ,
wherein the hexagonal ferrite comprises barium ferrite.
17. The reproducing apparatus according to claim 13 ,
wherein an isolated inversion waveform produced when the magnetic recording medium is reproduced shows a ratio γ (%) which indicates an asymmetry and which meets a condition that 9.8≦γ≦50.
18. The reproducing apparatus according to claim 17 ,
wherein the hexagonal ferrite comprises barium ferrite.
19. A magnetic recording medium being used by the recording and reproducing apparatus according to claim 13 .
20. A recording and reproducing apparatus comprising:
a recording means for recording an information signal in a magnetic recording medium in which a magnetic layer containing hexagonal ferrite is formed; and
a reproducing means for reproducing the information signal recorded in the magnetic recording medium,
the reproducing means comprising:
a reproducing head for reading the information signal from the magnetic recording medium; and
an equalizer for equalizing the information signal read from the magnetic recording medium, wherein in the equalized information signal, coefficients a, b, c, d of PR(1, a, b, c, d) meet conditions that 0.1≦a<2.0, −0.9≦b<0.0, −2.0<c≦−0.3, and −1.0<d≦−0.1.