Magnetic recording apparatus and magnetic recording and reproducing apparatus

Abstract

In a magnetic recording apparatus, a magnetic recording medium has a RAM area on which rewritable information can be recorded. The magnetic recording medium also has a ROM area having a pattern area in which first-type segment sequence of magnetically rewritable magnetic segments and magnetically non-rewritable nonmagnetic segments is fixedly recorded as first-type modulation information. Predetermined segments in the first-type segment sequence are magnetized and changed to magnetized segments. A segment sequence of first and second segments magnetized in one and opposite directions is used to magnetically record second-type modulation information in the pattern area.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIGS. 1A and 1B are plan views schematically showing how data is recorded on a recording medium by first- and second-type modulation schemes A and B which are different from each other and which are utilized for a magnetic recording scheme according to an embodiment;

FIGS. 2A, 2B, and 2C are plan views schematically showing that recording segments on which recording has been executed by the first-type modulation scheme A shown in FIG. 1A are demagnetized and additional recording is then executed on the recording segments by the second-type modulation scheme B shown in FIG. 1B;

FIGS. 3A and 3B are plan views schematically showing how data is recorded on recording medium by first- and second-type modulation schemes A and B which are different from each other, utilizing a magnetic recording scheme according to a second embodiment;

FIGS. 4A to 4C are plan views schematically showing that recording segments on which recording has been executed by the first-type modulation scheme A shown in FIG. 3A are demagnetized and additional recording is then executed on the recording segments by the second-type modulation scheme B shown in FIG. 3B;

FIGS. 5A and 5B are plan views schematically showing how data is recorded on a recording medium by a first-type modulation scheme A utilizing a magnetic recording scheme according to a third embodiment;

FIG. 5C is a plan view schematically showing how data is recorded on a recording medium by a second-type modulation scheme B different from the first type utilizing the magnetic recording scheme according to the third embodiment;

FIGS. 6A to 6C are plan views schematically showing that recording segments on which recording has been executed by the first-type modulation scheme A shown in FIG. 5A are demagnetized and additional recording is then executed on the recording segments by the second-type modulation scheme B shown in FIG. 5B;

FIGS. 7A and 7B are plan views schematically showing how data is recorded on recording medium by a first- and second-type modulation schemes A and B which are different from each other, utilizing a magnetic recording scheme according to a fourth embodiment;

FIGS. 8A to 8C are plan views schematically showing that additional recording is executed, by the second-type modulation scheme B shown in FIG. 7B, on the recording segments on which recording has been executed by the first-type modulation scheme A shown in FIG. 7A, and the recording segments based on the second-type modulation method B shown in FIG. 7B are reproduced without demagnetization;

FIG. 9 is a flowchart showing a procedure of a reproduction method of reproducing the recording segments based on the second-type modulation method B shown in FIG. 7B without demagnetization, according to an embodiment;

FIGS. 10A to 10G are sectional views schematically showing the steps of a method of manufacturing a recording medium according to an embodiment;

FIGS. 11A to 11G are sectional views schematically showing the steps of a method of manufacturing a recording medium according to another embodiment of the present invention; and

FIG. 12 is a block diagram schematically showing a recording and reproducing apparatus according to an embodiment of the present invention.

Claims

1. A magnetic recording apparatus comprising: a magnetic recording medium including a ROM area, and a RAM area on which rewritable information is magnetically recorded, the ROM area having a pattern of a first-type segment sequence indicating first-type modulation information which is fixedly recorded on the ROM area, the first-type segment sequence being formed as a sequence of magnetic and nonmagnetic segments, anda recording unit configured to record second-type modulation information on the ROM area, the recording unit selectively magnetizing the magnetic segments in the pattern to record a second-type segment sequence of first and second segments magnetized in one and opposite directions, which indicates the second-type modulation information.

2. The apparatus according to claim 1, further comprising: a first demodulating unit configured to demodulate the first-type modulation information into first-type recording information; anda second demodulating unit configured to demodulate the second-type modulation information into second-type recording information.

3. The apparatus according to claim 1, wherein the magnetic recording medium comprises a substrate and a magnetic layer formed on the substrate, recesses and protrusions being formed on the substrate and a formation corresponding to the recesses and protrusions being formed on the magnetic layer, which corresponds to the first-type segment sequence of the magnetic and nonmagnetic segments.

4. The apparatus according to claim 1, wherein the magnetic recording medium comprises a substrate, and a arrangement of magnetic and non-magnetic layer portions formed on the substrate, the arrangement of the magnetic and non-magnetic layer portions corresponding to the first-type segment sequence of the magnetic and nonmagnetic segments.

5. The apparatus according to claim 4, wherein the non-magnetic layer portions are formed by selectively removing parts of a magnetic layer formed on the substrate, and the magnetic layer portions are formed by un-removing the remaining parts of a magnetic layer formed on the substrate.

6. The apparatus according to claim 1, wherein a maximum inversion interval between the first-type magnetic and nonmagnetic segments is equal to or less than a minimum magnetization inversion interval based on the second-type segment modulation scheme.

7. Magnetic recording medium comprising: a RAM area on which rewritable information is magnetically recorded; anda ROM area having a pattern of a first-type segment sequence indicating first-type modulation information which is fixedly recorded on the ROM area, the first-type segment sequence being formed as a sequence of magnetic and nonmagnetic segments, the magnetic segments in the pattern being selectively magnetized to record a second-type segment sequence of first and second segments magnetized in one and opposite directions on the ROM area, which indicates the second-type modulation information.

8. The medium according to claim 7, wherein the magnetic recording medium comprises a substrate and a magnetic layer formed on the substrate, recesses and protrusions being formed on the substrate and a formation corresponding to the recesses and protrusions being formed on the magnetic layer, which corresponds to the first-type segment sequence of the magnetic and nonmagnetic segments.

9. The medium according to claim 7, wherein the magnetic recording medium comprises a substrate, and a arrangement of magnetic and non-magnetic layer portions formed on the substrate, the arrangement of the magnetic and non-magnetic layer portions corresponding to the first-type segment sequence of the magnetic and nonmagnetic segments.

10. The medium according to claim 6, wherein the non-magnetic layer portions are formed by selectively removing parts of a magnetic layer formed on the substrate, and the magnetic layer portions are formed by un-removing the remaining parts of a magnetic layer formed on the substrate.

11. The medium according to claim 6, wherein a maximum inversion interval between the first-type magnetic and nonmagnetic segments is equal to or less than a minimum magnetization inversion interval based on the second-type segment modulation scheme.

12. The medium according to claim 6, wherein a maximum interval between the first-type non-magnetized segments in the pattern area is equal to or smaller than a minimum magnetization inversion interval for the second-type magnetized segments.

13. A method of magnetically recording first-type and second-type modulation information and rewritable information on a magnetic recording medium, the magnetic recording medium including a ROM area and a RAM area on which the rewritable information is magnetically recorded, the ROM area having a pattern of a first-type segment sequence indicating the first-type modulation information which is fixedly recorded on the ROM area, the first-type segment sequence being formed as a sequence of magnetic and nonmagnetic segments, said method comprising: recording the second-type modulation information on the ROM area, which includes selectively magnetizing the magnetic segments in the pattern to record a second-type segment sequence of first and second segments magnetized in one and opposite directions, which indicates the second-type modulation information.

14. The method according to claim 13, further comprising providing first-type recording information which is modulated in accordance with a first-type modulation scheme to convert the first-type modulation information.

15. The method according to claim 13, further comprising providing second-type recording information which is modulated in accordance with a second-type modulation scheme to convert the second-type modulation information.

16. The method according to claim 13, further comprising: demodulating the first-type modulation information into the first-type recording information, anddemodulating the second-type modulation information into the second-type recording information.

17. The method according to claim 13, wherein the magnetic recording medium comprises a substrate and a magnetic layer formed on the substrate, recesses and protrusions being formed on the substrate and a formation corresponding to the recesses and protrusions being formed on the magnetic layer, which corresponds to the first-type segment sequence of the magnetic and nonmagnetic segments.

18. The method according to claim 13, wherein the magnetic recording medium comprises a substrate, and a arrangement of magnetic and non-magnetic layer portions formed on the substrate, the arrangement of the magnetic and non-magnetic layer portions corresponding to the first-type segment sequence of the magnetic and nonmagnetic segments.

19. The method according to claim 18, wherein the non-magnetic layer portions are formed by selectively removing parts of a magnetic layer formed on the substrate, and the magnetic layer portions are formed by un-removing the remaining parts of a magnetic layer formed on the substrate.

20. The apparatus according to claim 1, wherein a maximum inversion interval between the first-type magnetic and nonmagnetic segments is equal to or less than a minimum magnetization inversion interval based on the second-type segment modulation scheme.