Magnetic recording device and manufacturing method thereof

Abstract

To provide a magnetic recording device that can improve productivity and a manufacturing method thereof.SOLUTION: According to the embodiment, a magnetic recording device includes a magnetic recording medium, a magnetic head, and a control unit. The magnetic head includes a coil, a first magnetic pole, and a light-emission unit. The control unit performs a first operation and a second operation. In the first operation, the control unit records first servo position information to a first area of the magnetic recording medium. In the second operation, the control unit executes a repair operation when a first condition is not fulfilled. The first condition includes that the recording condition of the first servo position information is within a first range. In the repair operation, the control unit performs an erase operation for irradiating light from the light-emission unit to the first area, and performs a re-record operation for recording the first servo position information to the first area after the erase operation again.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a magnetic recording device and a method for manufacturing the same. [Background technology]

[0002] In a magnetic recording device, information is recorded on a magnetic recording medium such as an HDD (Hard Disk Drive) using a magnetic head, and improvement in productivity of the magnetic recording device is desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,911,446 Summary of the Invention [Problem to be solved by the invention]

[0004] An embodiment of the present invention provides a magnetic recording device and a manufacturing method thereof that can improve productivity. [Means for solving the problem]

[0005] According to an embodiment, a magnetic recording device includes a magnetic recording medium, a magnetic head, and a control unit. The magnetic head is configured to record information on the magnetic recording medium. The control unit is configured to control the magnetic recording medium and the magnetic head. The magnetic head includes a coil, a first magnetic pole, and a light emitting unit. The first magnetic pole is configured to generate a magnetic field corresponding to a recording current supplied to the coil. The light emitting unit is configured to irradiate the magnetic recording medium with light to locally increase the temperature of the magnetic recording medium. The control unit is configured to perform a first operation and a second operation. In the first operation, the control unit records first servo position information in a first region of the magnetic recording medium. In the second operation, the control unit performs a repair operation if a first condition is not satisfied. The first condition includes that a recording condition for the first servo position information is within a predetermined first range. In the repair operation, the control unit performs an erase operation in which the light emitting unit irradiates the first region with light, and then performs a re-recording operation in which the first servo position information is re-recorded in the first region after the erase operation. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic view illustrating the magnetic recording device according to the first embodiment. [Figure 2] FIG. 2 is a flowchart illustrating the operation of the magnetic recording device according to the first embodiment. [Figure 3] 3(a) to 3(c) are schematic plan views illustrating the magnetic recording device according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating a part of the magnetic recording device according to the first embodiment. [Figure 5] FIG. 5 is a schematic view illustrating the magnetic recording device according to the first embodiment. [Figure 6] FIG. 6 is a schematic view illustrating the magnetic recording device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] (First embodiment) FIG. 1 is a schematic view illustrating the magnetic recording device according to the first embodiment. 1, a magnetic recording device 210 according to the embodiment includes a magnetic recording medium 80, a magnetic head 110, and a control unit 75. The magnetic head 110 is configured to record information on the magnetic recording medium 80. The control unit 75 is configured to control the magnetic recording medium 80 and the magnetic head 110.

[0008] The magnetic head 110 includes a coil 30c and a first magnetic pole 31. The first magnetic pole 31 generates a magnetic field (recording magnetic field) corresponding to a recording current Iw supplied to the coil 30c. The generated magnetic field is applied to the magnetic recording medium 80. This controls the direction of magnetization 83 of the magnetic recording medium 80. The state of the magnetization 83 corresponds to the information to be recorded. In this example, the magnetic head 110 further includes a second magnetic pole 32. The first magnetic pole 31 is, for example, a main magnetic pole. The second magnetic pole 32 is, for example, a trailing shield.

[0009] The magnetic head 110 further includes a light emitting section 77. The light emitting section 77 is configured to irradiate the magnetic recording medium 80 with light 77L, thereby locally increasing the temperature of the magnetic recording medium 80.

[0010] For example, the light emitting unit 77 includes a light source 77S and a light guide 77G. Light 77L emitted from the light source 77S is guided by the light guide 77G. The light 77L emitted from the light guide 77G is emitted to the magnetic recording medium 80 via, for example, an optical element. The light source 77S is, for example, a laser.

[0011] An example of the operation of the control unit 75 will now be described. FIG. 2 is a flowchart illustrating the operation of the magnetic recording device according to the first embodiment. 3(a) to 3(c) are schematic plan views illustrating the magnetic recording device according to the first embodiment.

[0012] As shown in FIG. 2, the control unit 75 is configured to perform a first operation OP1 and a second operation OP2.

[0013] 3A corresponds to the first operation OP1. In the first operation OP1, the control unit 75 records the first servo position information 81s in the first region 81r of the magnetic recording medium 80 (step S10 in FIG. 2). For example, a recording current Iw corresponding to the first servo position information 81s is supplied to the coil 30c. A recording magnetic field based on the recording current Iw is applied to the magnetic recording medium 80, and the first servo position information 81s is recorded in the target first region 81r.

[0014] In the second operation OP2, the control unit 75 performs the repair operation RO if the following first condition is not met (step S20 in FIG. 2). The first condition includes that the recording conditions of the first servo position information 81s are within a predetermined first range. If the first condition is met, the recording conditions of the first servo position information 81s are within the appropriate first range. On the other hand, if the first condition is not met, the recording conditions of the first servo position information 81s are inappropriate.

[0015] The control unit 75 determines whether or not such a first condition is satisfied (step S21). If the first condition is not satisfied in step S21, the control unit 75 performs a repair operation RO. In the repair operation RO, the control unit 75 performs an erase operation ER and a re-recording operation RW.

[0016] 3(b) illustrates an erase operation ER. In the erase operation ER, the control unit 75 irradiates the first region 81r with light 77L from the light emitting unit 77 (step S22 in FIG. 2). For example, the temperature of the first region 81r irradiated with the light 77L increases, and the magnetization state of the first region 81r returns to the initial state.

[0017] 3(c) illustrates a re-recording operation RW. The re-recording operation RW is performed after the erase operation ER. In the re-recording operation RW, the control unit 75 re-records the first servo position information 81s in the first region 81r after the erase operation ER (step S23 in FIG. 2).

[0018] This makes it possible to correctly record the first servo position information 81s when an error occurs in which the first condition is not satisfied, thereby repairing a defective magnetic recording medium 80. According to the embodiment, it is possible to provide a magnetic recording device that can improve productivity.

[0019] As shown in FIG. 2, in step S21, the control unit 75 may determine that the first condition is satisfied. In this case, it is estimated that the first servo position information 81s is properly recorded in the first operation OP1. In this case, the repair operation RO is not performed. In this way, the control unit 75 does not perform the repair operation RO when the first condition is satisfied in the second operation OP2.

[0020] In the erase operation ER, the recording current Iw is not supplied to the coil 30c. Alternatively, the current supplied to the coil 30c in the erase operation ER is smaller than the current supplied to the coil in the first operation OP1. This allows the first servo position information 81s of the error recorded on the magnetic recording medium 80 to be stably and effectively erased.

[0021] For example, in the first operation OP1, the control unit 75 may record the first servo position information 81s in the first area 81r while irradiating the magnetic recording medium 80 with light 77L. For example, the first servo position information 81s may be recorded by thermally assisted recording.

[0022] As described above, the first condition includes that the recording conditions of the first servo position information 81s are within a predetermined first range. When thermally assisted recording is performed, the recording conditions of the first servo position information 81s may include the power supplied to the light source 77S in the first operation OP1. For example, the value of the current supplied to the laser light source 77S is recorded. If the recorded current value is within a predetermined range (first range), the first condition is met. It is assumed that the first servo position information 81s has been recorded normally.

[0023] The recording conditions for the first servo position information 81s may further include the recording current Iw supplied to the coil 30c in the first operation OP1. For example, if the recording current Iw is normal, the first condition is met. It is estimated that the first servo position information 81s has been recorded normally.

[0024] The recording conditions for the first servo position information 81s may further include the temperature of the magnetic head 110 in the first operation OP1. The temperature of the magnetic head 110 is detected. If the detected temperature is within a normal range, the first condition is met. It is estimated that the first servo position information 81s has been recorded normally.

[0025] The first condition may further include the result of detecting the first servo position information 81s recorded in the first area 81r by the first operation OP1 being within a predetermined second range. For example, after the first operation OP1, the recorded first servo position information 81s is detected (reproduced). If the detected state is within the predetermined second range, the first condition is met. It is detected that the first servo position information 81s has been properly recorded.

[0026] In one example, the intensity of the light 77L in the erase operation ER (erasing intensity) is higher than the intensity of the light 77L in the first operation OP1 (recording intensity). Stable erasure can be performed. For example, the erasing intensity may be 1.1 to 3 times the recording intensity. The erasing intensity may be the same as the recording intensity.

[0027] For example, the power (eg, current) supplied to the light source 77S in the erase operation ER may be greater than the power (eg, current) supplied to the light source 77S in the first operation OP1.

[0028] 3A, the first servo position information 81s may be recorded in each of the plurality of first regions 81r. For example, the first operation OP1 may be repeatedly performed until a desired number of the plurality of first servo position information 81s are recorded.

[0029] For example, as shown in FIG. 2, after step S23 and when it is determined in step S21 that the first condition is satisfied, the control unit 75 performs step S30. In step S30, the control unit 75 determines whether the number of times the first servo position information 81s has been recorded has reached a predetermined number. If the number of times the first servo position information 81s has been recorded has not reached the predetermined number, the control unit 75 returns to step S10, for example. If the number of times the first servo position information 81s has been recorded has reached the predetermined number, the control unit 75 ends the process, for example.

[0030] In the embodiment, the control unit 75 may be configured to repeatedly perform the first operation OP1 and the second operation OP2.

[0031] The control unit 75 may be configured to perform a plurality of first operations OP1 in succession, and then to perform a plurality of second operations OP2 in succession.

[0032] 3(a), the first region 81r may be spiral. In an embodiment, the first servo position information 81s may be included in an intermediate pattern for self-servo writing.

[0033] FIG. 4 is a schematic cross-sectional view illustrating a part of the magnetic recording device according to the first embodiment. 4, a plurality of magnetic recording media 80 and a plurality of magnetic heads 110 may be provided. The control unit 75 may be configured to perform a first operation OP1 and a second operation OP2 on the plurality of magnetic recording media 80 and the plurality of magnetic heads 110.

[0034] 5 and 6 are schematic views illustrating the magnetic recording device according to the first embodiment. 5, the magnetic head 111 included in the magnetic recording device 210 according to the embodiment further includes a second magnetic pole 32 and a magnetic element 20. Except for this, the configuration of the magnetic head 111 may be the same as the configuration of the magnetic head 110.

[0035] The magnetic element 20 is provided between the first magnetic pole 31 and the second magnetic pole 32. The control unit 75 may be configured to supply an element current i c to the magnetic element 20 when the magnetic head 111 records information on the magnetic recording medium 80. As shown in FIG. 5 , the magnetic element 20 may include a first magnetic layer 21. The element current i c controls the magnetization of the first magnetic layer 21. For example, the direction of the recording magnetic field emitted from the first magnetic pole 31 is controlled by the first magnetic layer 21. The recording magnetic field is efficiently applied to the magnetic recording medium 80. High-density recording is possible.

[0036] 6, in a magnetic head 112 included in a magnetic recording device 210 according to the embodiment, the magnetic element 20 further includes a second magnetic layer 22. Except for this, the configuration of the magnetic head 112 may be similar to the configuration of the magnetic head 111.

[0037] The control unit 75 may be configured to supply an element current i c to the magnetic element 20 when the magnetic head 112 records information on the magnetic recording medium 80. The element current i c causes the magnetization of the magnetic layer included in the magnetic element 20 to oscillate. An AC magnetic field is generated from the magnetic element 20 and applied to the magnetic recording medium 80. High-density recording is possible.

[0038] (Second embodiment) The second embodiment relates to a method for manufacturing a magnetic recording device 210. As already described, the magnetic recording device 210 includes any magnetic head according to the embodiment (hereinafter, magnetic head 110). The magnetic recording device 210 includes a magnetic recording medium 80, a magnetic head 110 configured to record information on the magnetic recording medium 80, and a control unit 75 configured to control the magnetic recording medium 80 and the magnetic head 110. The magnetic head 110 includes a coil 30c, a first magnetic pole 31, and a light emitting unit 77. The first magnetic pole 31 generates a magnetic field corresponding to a recording current Iw supplied to the coil 30c. The light emitting unit 77 is configured to irradiate the magnetic recording medium 80 with light 77L to locally increase the temperature of the magnetic recording medium 80.

[0039] In the second embodiment, the control unit 75 is configured to perform a first operation OP1 and a second operation OP2. In the first operation OP1, the control unit 75 records first servo position information 81s in a first region 81r of the magnetic recording medium 80. In the second operation OP2, the control unit 75 performs a repair operation RO if a first condition is not satisfied. The first condition includes that the recording conditions of the first servo position information 81s are within a predetermined first range. In the repair operation RO, the control unit 75 performs an erase operation ER in which light 77L is irradiated onto the first region 81r from the light emitting unit 77, and then performs a re-write operation RW in which the first servo position information 81s is re-recorded in the first region 81r after the erase operation ER.

[0040] According to the method for manufacturing the magnetic recording device 210 according to the second embodiment, it is possible to provide a method for manufacturing a magnetic recording device that can improve productivity.

[0041] In the second embodiment, the first condition may further include that the result of detecting the first servo position information 81s recorded in the first area 81r by the first operation OP1 is within a defined second range.

[0042] In the second embodiment, in the first operation OP1, the control unit 75 may record the first servo position information 81s in the first region 81r while irradiating the magnetic recording medium 80 with light 77L. The erasing intensity of the light 77L in the erase operation ER may be higher than the recording intensity of the light 77L in the first operation OP1.

[0043] As already explained, the light emitting section 77 may include the light source 77S. The recording conditions for the first servo position information 81s may include the power supplied to the light source 77S in the first operation OP1.

[0044] The embodiments may include the following technical solutions. (Technical proposal 1) a magnetic recording medium; a magnetic head configured to record information on the magnetic recording medium; a control unit configured to control the magnetic recording medium and the magnetic head; Equipped with The magnetic head comprises: A coil and a first magnetic pole configured to generate a magnetic field in accordance with a recording current supplied to the coil; a light emitting unit configured to irradiate the magnetic recording medium with light to locally increase the temperature of the magnetic recording medium; Including, the control unit is configured to perform a first operation and a second operation; In the first operation, the control unit records first servo position information in a first area of ​​the magnetic recording medium; In the second operation, the control unit performs a repair operation when the first condition is not satisfied; the first condition includes that a recording condition of the first servo position information is within a defined first range; In the repair operation, the control unit performs an erasure operation in which the light is irradiated from the light emitting unit onto the first area, and after the erasure operation, performs a re-recording operation in which the first servo position information is re-recorded in the first area.

[0045] (Technical proposal 2) The magnetic recording device according to Technical Solution 1, wherein the control unit does not perform the repair operation if the first condition is satisfied in the second operation.

[0046] (Technical proposal 3) The magnetic recording device described in Technical Solution 1 or 2, wherein the first condition further includes that the result of detecting the first servo position information recorded in the first area by the first operation is within a predetermined second range.

[0047] (Technical proposal 4) In the first operation, the control unit records the first servo position information in the first area while irradiating the magnetic recording medium with the light, The magnetic recording device according to any one of Technical Solutions 1 to 3, wherein the erasing intensity of the light in the erasing operation is higher than the recording intensity of the light in the first operation.

[0048] (Technical proposal 5) The magnetic recording device according to Technical Solution 4, wherein the erase strength is 1.1 times or more and 3 times or less than the write strength.

[0049] (Technical proposal 6) the light emitting unit includes a light source, The magnetic recording device according to Technical Solution 4 or 5, wherein the recording conditions of the first servo position information include power supplied to the light source in the first operation.

[0050] (Technical proposal 7) The magnetic recording device according to Technical Solution 6, wherein the recording conditions of the first servo position information further include the recording current supplied to the coil in the first operation.

[0051] (Technical proposal 8) The magnetic recording device according to Technical Solution 6 or 7, wherein the recording conditions of the first servo position information further include the temperature of the magnetic head in the first operation.

[0052] (Technical proposal 9) The magnetic recording device according to any one of Technical Solutions 1 to 8, wherein the recording current is not supplied to the coil during the erase operation.

[0053] (Technical proposal 10) The magnetic recording device according to any one of Technical Solutions 1 to 8, wherein the current supplied to the coil in the erase operation is smaller than the current supplied to the coil in the first operation.

[0054] (Technical proposal 11) The magnetic recording device according to any one of Technical Solutions 1 to 10, wherein the control unit is configured to repeatedly perform the first operation and the second operation.

[0055] (Technical proposal 12) The magnetic recording device described in any one of Technical Solutions 1 to 10, wherein the control unit is configured to perform a plurality of the first operations in succession, and then to perform a plurality of the second operations in succession.

[0056] (Technical proposal 13) The magnetic recording device according to any one of Technical Solutions 1 to 12, wherein the first area is spiral.

[0057] (Technical proposal 14) The magnetic recording device according to any one of Technical Solutions 1 to 13, wherein the first servo position information is included in an intermediate pattern for self-servo writing.

[0058] (Technical proposal 15) a plurality of the magnetic recording media and a plurality of the magnetic heads are provided; A magnetic recording device described in any one of Technical Solutions 1 to 14, wherein the control unit is configured to perform the first operation and the second operation for the plurality of magnetic recording media and the plurality of magnetic heads.

[0059] (Technical proposal 16) the magnetic head includes a second magnetic pole and a magnetic element provided between the first magnetic pole and the second magnetic pole; The magnetic recording device described in Technical Solution 1, wherein the control unit is configured to supply an element current to the magnetic element when the magnetic head records the information on the magnetic recording medium.

[0060] (Technical proposal 17) a magnetic recording medium; a magnetic head configured to record information on the magnetic recording medium; a control unit configured to control the magnetic recording medium and the magnetic head; 1. A method for manufacturing a magnetic recording device, comprising: The magnetic head comprises: A coil and a first magnetic pole that generates a magnetic field according to a recording current supplied to the coil; a light emitting unit configured to irradiate the magnetic recording medium with light to locally increase the temperature of the magnetic recording medium; Including, the control unit is configured to perform a first operation and a second operation; In the first operation, the control unit records first servo position information in a first area of ​​the magnetic recording medium; In the second operation, the control unit performs a repair operation when the first condition is not satisfied; the first condition includes that a recording condition of the first servo position information is within a defined first range; A method for manufacturing a magnetic recording device, wherein in the repair operation, the control unit performs an erase operation in which light is irradiated from the light emitting unit onto the first area, and after the erase operation, performs a re-recording operation in which the first servo position information is re-recorded in the first area.

[0061] (Technical proposal 18) The method for manufacturing a magnetic recording device described in Technical Proposal 17, wherein the first condition further includes that the result of detecting the first servo position information recorded in the first area by the first operation is within a predetermined second range.

[0062] (Technical proposal 19) In the first operation, the control unit records the first servo position information in the first area while irradiating the magnetic recording medium with the light, 19. The method for manufacturing a magnetic recording device according to Technical Solution 17 or 18, wherein the erasing intensity of the light in the erasing operation is higher than the recording intensity of the light in the first operation.

[0063] (Technical proposal 20) the light emitting unit includes a light source, The method for manufacturing a magnetic recording device described in Technical Solution 19, wherein the recording conditions of the first servo position information include power supplied to the light source in the first operation.

[0064] According to the embodiment, it is possible to provide a magnetic recording device and a manufacturing method thereof that can improve productivity.

[0065] In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include variations in the manufacturing process, and may mean substantially vertical and substantially parallel.

[0066] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configurations of the elements included in the magnetic recording device, such as the magnetic recording medium, magnetic head, and control unit, are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from known ranges.

[0067] Any combination of two or more elements of each embodiment to the extent technically possible is also included within the scope of the present invention as long as it encompasses the gist of the present invention.

[0068] In addition, all magnetic recording devices and methods of manufacturing magnetic recording devices that can be implemented by a person skilled in the art by making appropriate design modifications based on the magnetic recording device and method of manufacturing a magnetic recording device described above as embodiments of the present invention also fall within the scope of the present invention, as long as they include the gist of the present invention.

[0069] In addition, within the scope of the concept of the present invention, a person skilled in the art may come up with various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0070] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0071] 20: magnetic element, 21, 22: first and second magnetic layers, 30c: coil, 31, 32: first and second magnetic poles, 75: control unit, 77: light emitting unit, 77G: light guide, 77L: light, 77S: light source, 80: magnetic recording medium, 81r: first region, 81s: first servo position information, 83: magnetization, 110-112: magnetic head, 210: magnetic recording device, ER: erase operation, Iw: recording current, OP1, OP2: first and second operations, RO: repair operation, RW: re-recording operation, ic: element current

Claims

1. a magnetic recording medium; a magnetic head configured to record information on the magnetic recording medium; a control unit configured to control the magnetic recording medium and the magnetic head; Equipped with The magnetic head comprises: A coil and a first magnetic pole configured to generate a magnetic field in accordance with a recording current supplied to the coil; a light emitting unit configured to irradiate the magnetic recording medium with light to locally increase the temperature of the magnetic recording medium; Including, the control unit is configured to perform a first operation and a second operation; In the first operation, the control unit records first servo position information in a first area of ​​the magnetic recording medium; In the second operation, the control unit performs a repair operation when the first condition is not satisfied; the first condition includes that a recording condition of the first servo position information is within a defined first range; In the repair operation, the control unit performs an erasure operation in which the light is irradiated from the light emitting unit onto the first area, and after the erasure operation, performs a re-recording operation in which the first servo position information is re-recorded in the first area.

2. The magnetic recording device according to claim 1 , wherein the control unit does not perform the repair operation if the first condition is satisfied in the second operation.

3. 2. The magnetic recording device according to claim 1, wherein the first condition further includes a result of detecting the first servo position information recorded in the first area by the first operation being within a predetermined second range.

4. In the first operation, the control unit records the first servo position information in the first area while irradiating the magnetic recording medium with the light, 4. The magnetic recording device according to claim 1, wherein the erasing intensity of the light in the erasing operation is higher than the recording intensity of the light in the first operation.

5. the light emitting unit includes a light source, 5. The magnetic recording apparatus according to claim 4, wherein the recording conditions of the first servo position information include power supplied to the light source in the first operation.

6. 6. The magnetic recording apparatus according to claim 5, wherein the recording conditions of the first servo position information further include the recording current supplied to the coil in the first operation.

7. 6. The magnetic recording apparatus according to claim 5, wherein the recording conditions of the first servo position information further include a temperature of the magnetic head in the first operation.

8. 2. The magnetic recording device according to claim 1, wherein the recording current is not supplied to the coil during the erase operation.

9. 2. The magnetic recording device according to claim 1, wherein the current supplied to the coil in the erase operation is smaller than the current supplied to the coil in the first operation.

10. a magnetic recording medium; a magnetic head configured to record information on the magnetic recording medium; a control unit configured to control the magnetic recording medium and the magnetic head; 1. A method for manufacturing a magnetic recording device, comprising: The magnetic head comprises: A coil and a first magnetic pole that generates a magnetic field according to a recording current supplied to the coil; a light emitting unit configured to irradiate the magnetic recording medium with light to locally increase the temperature of the magnetic recording medium; Including, the control unit is configured to perform a first operation and a second operation; In the first operation, the control unit records first servo position information in a first area of ​​the magnetic recording medium; In the second operation, the control unit performs a repair operation when the first condition is not satisfied; the first condition includes that a recording condition of the first servo position information is within a defined first range; A method for manufacturing a magnetic recording device, wherein, in the repair operation, the control unit performs an erase operation in which light is irradiated from the light emitting unit onto the first area, and after the erase operation, performs a re-recording operation in which the first servo position information is re-recorded in the first area.

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