Magnetic disk device

Abstract

The embodiment of the invention relates to a magnetic disk device. In the first writing period, if the determination unit (67) determines that the error correction of the first user data on the first data track does not exceed the limit, the determination unit (67) causes the write processing unit (62) to continue the write processing and causes the management unit (65) to execute the second management. When the determination unit (67) determines that the error correction has exceeded the limit, the determination unit (67) causes the write processing unit (62) to continue the write processing and causes the management unit (65) to execute the third management. The determination unit (67) causes the management unit (65) to execute a process for transferring the data belonging to the third group to the non-volatile recording medium during or after the first writing period.

Description

[0001] This application enjoys priority based on Japanese Patent Application No. 2024-158385 (filed on September 12, 2024). This application incorporates the entire contents of the basic application by reference to that basic application. Technical Field

[0002] Embodiments of the present invention relate to disk drives. Background Technology

[0003] As disk devices, known types include: conventional magnetic recording (CMR) type (or conventional recording type) disk devices that write multiple tracks at intervals in the radial direction of the disk; shingled magnetic recording (SMR) type disk devices that write multiple tracks overlapping in the radial direction of the disk; and hybrid recording type disk devices that selectively perform conventional recording and shingled recording. Summary of the Invention

[0004] One embodiment of the disk drive includes:

[0005] The disk has a first data track and a second data track that are adjacent to each other in the recording layer. Each of the first data track and the second data track includes a plurality of object sectors that are objects to be written data. The first data track is located in a first direction that is parallel to the radial direction of the disk when viewed from the second data track.

[0006] The head has a write head for writing data to the recording layer and a read head for reading data from the recording layer;

[0007] The read processing unit is capable of performing seek processing to cause the read head to seek;

[0008] The write processing unit is capable of performing write processing on the data to be written to the recording layer;

[0009] The error correction unit performs error correction on the data of one or more corrupted object sectors among the plurality of object sectors of the first data track that are determined to be corrupted.

[0010] The buffer memory is capable of holding multiple data, including the first user data and the second user data;

[0011] The management unit is capable of selectively executing the first management, the second management, and the third management. The first management prohibits overwriting the first user data in the buffer memory. The second management allows overwriting all the first user data in the buffer memory. The third management allows overwriting the data belonging to the first and second groups of the first user data in the buffer memory and prohibits overwriting the data belonging to the third group of the first user data in the buffer memory.

[0012] Correction limit determination unit; and

[0013] Judgment Department

[0014] The first write period is the period after the write processing unit performs the write process of writing first data including the first user data to the plurality of object sectors of the first data track, and is the period during which the write process of writing second data including the second user data to the plurality of object sectors of the second data track is performed.

[0015] During the first write,

[0016] The read processing unit performs a seek process to align the read head with the second data track.

[0017] Whenever the correction limit determination unit writes data to each of the target sectors of the second data track, it obtains information that the position of the write head exceeds the reference radius position in the first direction.

[0018] The management department performs the first management.

[0019] The judgment unit

[0020] If, based on the information obtained by the correction limit determination unit, it is determined that the error correction unit has not exceeded the limit in correcting the error of the first user data on the first data track, the write processing unit continues to perform the write processing on the second data track, and the management unit performs the second management instead of the first management.

[0021] If, based on the information, it is determined that the error correction unit has exceeded its limit in correcting the error of the first user data on the first data track, the write processing unit continues the write processing on the second data track, and the management unit performs the third management instead of the first management.

[0022] During or after the first write period,

[0023] The judgment unit causes the management unit to perform a process that transfers the data belonging to the third group to a non-volatile recording medium.

[0024] The data belonging to the first group is the original data of one or more object sectors in the plurality of object sectors of the first data track that have been determined to be without data corruption.

[0025] The data belonging to the second group is the original data of one or more first damaged object sectors among the plurality of object sectors of the first data track that have been determined to be corrupted, and is the original data of data within the range that can be corrected by the error correction unit.

[0026] The data belonging to the third group is the original data of one or more second damaged object sectors in the plurality of object sectors of the first data track that are judged to be corrupted, and is the original data of data that deviates (omits) from the range that can be corrected by the error correction unit.

[0027] According to this embodiment, a disk device can be provided that can increase the recording density of data on the disk and suppress the decline in write performance. Attached Figure Description

[0028] Figure 1 This is a block diagram illustrating the configuration of a disk drive according to one embodiment.

[0029] Figure 2 This is a perspective view showing a portion of the aforementioned disk drive, and a view showing multiple disks and multiple heads.

[0030] Figure 3 This is a schematic diagram illustrating an example of the configuration of multiple servo areas and multiple data areas of a disk according to the above embodiment.

[0031] Figure 4 It is shown Figure 3 The diagram shows the three tracks and the write head of the user data area of ​​the disk undergoing record processing.

[0032] Figure 5 It is shown Figure 3 The diagram shows the three tracks of the media cache and the write head of the disk used for normal recording processing.

[0033] Figure 6 This is a schematic diagram illustrating an example of data writing processes on a disk.

[0034] Figure 7 It is shown Figure 6 The diagram shows two bands and one guard band in the user data area.

[0035] Figure 8 It is shown Figure 6 The diagram shows three sectors in one track of the strip.

[0036] Figure 9 It is shown Figure 7 The diagram showing two strips and one guard strip is used to illustrate multiple object sectors and multiple unused sectors.

[0037] Figure 10 This diagram illustrates an example of tracks 1 and 2 assuming the disk device does not have the function of performing track-by-track error correction on the data of the tracks. It is a diagram used to explain the write processing of tracks 1 and 2. It is a diagram used to explain the state of continuously writing to track 2 until the error correction of track 1 on a sector-by-sector basis reaches its limit. It is a diagram that shows the change of BER relative to track 1 and the change of BER relative to positioning error using coordinate graphs.

[0038] Figure 11 This diagram illustrates an example of tracks 1 and 2 assuming the disk device does not have the function of performing track-by-track error correction on the data of the tracks. It is a diagram used to explain the write processing of tracks 1 and 2. It is a diagram used to explain the state where the write deviation of track 2 is stopped when the judgment value is set to be smaller than the track margin (strict) and the positioning error is detected to exceed the reference radius position. It is a diagram that plots the change of BER relative to track 1 and the change of BER relative to positioning error using coordinates.

[0039] Figure 12 This is a pattern showing an example of the first and second tracks of the aforementioned disk device, which has the function of performing track-by-track error correction on the data of the tracks. It is a diagram for explaining the write processing of the first and second tracks. It is a diagram for explaining the state in which the judgment value is set to a (loose) write deviation from the track limit that is larger than the track margin, and the write processing of the second track continues even if the track-by-track error correction of the first track exceeds the limit. It is a diagram that plots the change of BER relative to the first track and the change of BER relative to the positioning error using coordinates.

[0040] Figure 13 This is a diagram showing the presence or absence of ECC on the track in the first and second modes of the first and second write operations, the function name for controlling DOL, the handling content when the positioning error exceeds the reference radius position, the settings related to overwriting data in the buffer memory, and the settings related to transferring data in the buffer memory.

[0041] Figure 14 The graph shows the changes in positioning error and the cumulative number of damaged object sectors when the write process is performed on the second track in the first manner of the second write operation described above. The graph also shows the case where the cumulative number exceeds the PTS start threshold when the write process is performed on the nth object sector of the second track.

[0042] Figure 15 The graph shows the changes in positioning error and the cumulative number of damaged target sectors when the write process is performed on the second track in the second manner of the second write operation described above. The graph also shows the case where the cumulative number exceeds the upper limit when the write process is performed on the nth target sector of the second track.

[0043] Figure 16 The graph shows the changes in positioning error and cumulative measured excess when the write process is performed on the second track in the second manner of the second write operation described above. The graph shows the case where the cumulative measured excess exceeds the upper limit threshold when the write process is performed on the nth target sector of the second track.

[0044] Figure 17 This is a flowchart illustrating the write processing method for the nth target sector of the second track in the write processing method of the above embodiment. It is a diagram of the second mode in which the disk device adopts the second write operation during the first write.

[0045] Figure 18 It continues in Figure 17 The following is a flowchart illustrating the above-described write processing method.

[0046] Figure 19 It continues in Figure 17 The following is a variation of the flowchart of the above-described write processing method.

[0047] Explanation of reference numerals in the attached figures

[0048] 1…Disk drive, 60…MPU, 61…Read / write processing unit, 62…Write processing unit, 63…Read processing unit, 64…Error correction unit, 65…Management unit, 66…Correction limit determination unit, 67…Decision unit, 70…Volatile memory, 80…Buffer memory, 90…Non-volatile memory, 100…Host, 110…System controller, 120…Driver IC, 130…Head amplifier IC, 140…R / W channel, 150…HDC, 24…VCM, 30…Arm, DK…disk, L…recording layer, S…system area, U…user data area, BA…tape, TR, STR, CTR…track, SC…sector, RSC…object sector, CSC…damaged object sector, HD…head, WHD…write head, RHD…read head, PE…position error, TM…track margin, PO…reference radius position, WOS…write deviation from track limit, d1…radial direction, d2…travel direction, d3…rotation direction, d5…overlapping write direction, Da…first direction. Detailed Implementation

[0049] Hereinafter, a disk drive device 1 according to one embodiment will be described in detail with reference to the accompanying drawings. First, the configuration of the disk drive device 1 will be described. Figure 1 This is a block diagram illustrating the configuration of the disk device 1 according to this embodiment. In this embodiment, the disk device 1 is a hybrid recording type disk device that selectively performs both conventional recording and watt-hour recording. However, the techniques described later can also be applied to watt-hour recording disk devices, and also to conventional recording disk devices.

[0050] like Figure 1 As shown, the disk drive 1 includes multiple disks (DK) such as 1 to 10 disks as recording media, a spindle motor (SPM) 20 as a drive motor, a head stack assembly 22, a driver IC 120, a head amplifier integrated circuit (hereinafter referred to as head amplifier IC or preamplifier) ​​130, volatile memory 70, buffer memory (buffer) 80, non-volatile memory 90, and a system controller 110 as a single-chip integrated circuit. Furthermore, the disk drive 1 is connected to a host system (hereinafter referred to as host) 100.

[0051] Each disk drive (DK) is formed, for example, with a diameter of 97 mm (3.8 inches) and has a recording layer (magnetic recording layer) on both sides. Furthermore, in this embodiment, although the disk drive 1 has 1 to 11 disk drives, the number of disk drives is not limited to this.

[0052] The head stack assembly 22, driven by the voice coil motor (hereinafter referred to as VCM) 24, can control the head HD mounted on the arm 30 to move to the target position on the disk DK, that is, enable the head HD to perform track seeking. The VCM 24 functions as an actuator.

[0053] The disk DK allocates a user data area U, which can be used by the user, and a system area S, which is used to write information required for system management, in the area where data can be written.

[0054] The HD head records and reproduces information on the disk DK. The HD head uses a slider as its main body and includes a write head (WHD) and a read head (RHD) mounted on the slider. The write head (WHD) writes data to the recording layer of the disk DK. The read head (RHD) reads data from the data tracks of the recording layer of the disk DK.

[0055] Sometimes the "center part of the head HD" is called "head HD", the "center part of the write head WHD" is called "write head WHD", and the "center part of the read head RHD" is called "read head RHD". Sometimes the "center part of the write head WHD" is simply called "head HD", and sometimes the "center part of the read head RHD" is simply called "head HD".

[0056] The driver IC120 controls the drive of SPM20 and VCM24 according to the control of the system controller 110 (specifically, the MPU60 described later). SPM20 supports multiple disks DK and rotates them.

[0057] The head amplifier IC130 includes a read amplifier and a write driver. The read amplifier amplifies the read signal read from the disk DK and outputs it to the system controller 110 (specifically, the read / write (R / W) channel 140, described later). The write driver outputs a write current corresponding to the signal output from the R / W channel 140 to the head HD.

[0058] Volatile memory 70 is a semiconductor memory that retains data even when the power supply is cut off. Volatile memory 70 stores data required for processing in various parts of disk drive 1. Volatile memory 70 is random access memory (RAM). For example, volatile memory 70 is DRAM (Dynamic Random Access Memory). However, volatile memory 70 can also be SDRAM (Synchronous Dynamic Random Access Memory).

[0059] The buffer memory 80 is a semiconductor memory that temporarily records data transmitted and received between the disk drive 1 and the host computer 100. Furthermore, the buffer memory 80 may be integrated with the volatile memory 70. The buffer memory 80 is a volatile RAM. For example, the buffer memory 80 may be DRAM, SRAM (Static Random Access Memory), SDRAM, FeRAM (Ferroelectric Random Access Memory), MRAM (Magnetoresistive Random Access Memory), etc.

[0060] The buffer memory 80 includes areas used as read cache and write cache, temporarily storing commands received from the host 100, etc.

[0061] Non-volatile memory 90 is a semiconductor memory that records stored data even when the power supply is cut off. Non-volatile memory 90 is, for example, a NAND-type flash read-only memory (FROM). However, non-volatile memory 90 can also be a NOR-type FROM.

[0062] The system controller (controller) 110 is implemented, for example, using a large-scale integrated circuit (LSI) called a system-on-a-chip (SoC), which integrates multiple components onto a single chip. The system controller 110 includes a read / write (R / W) channel 140, a hard disk controller (HDC) 150, and a microprocessor (MPU) 60. The system controller 110 is electrically connected to a driver IC 120, a head amplifier IC 130, volatile memory 70, buffer memory 80, non-volatile memory 90, and a host 100.

[0063] R / W channel 140, in response to instructions from MPU 60 (described later), performs signal processing for read data transferred from disk DK to host 100 and write data transferred from host 100. R / W channel 140 includes circuitry or functions for modulating the write data. Additionally, R / W channel 140 includes circuitry or functions for measuring the signal quality of the read data. R / W channel 140 is electrically connected, for example, to head amplifier IC 130, HDC 150, MPU 60, etc.

[0064] HDC150 controls the data transfer between host 100 and R / W channel 140 in response to instructions from MPU60. HDC150 is electrically connected to, for example, R / W channel 140, MPU60, volatile memory 70, buffer memory 80, and non-volatile memory 90.

[0065] The HDC150 includes a gating generation unit. This unit generates various gating signals, such as write gating, read gating, and servo gating, in response to commands from the host 100 and instructions from the MPU60, and outputs them to the R / W channel 140, for example, a gating detection unit. Hereinafter, "activating a predetermined gating" may be referred to as "enabling a predetermined gating." Conversely, "disabling a predetermined gating" may be referred to as "disabling a predetermined gating." "Enabling a predetermined gating" and "disabling a predetermined gating" may also include the meaning of "generating a predetermined gating." Furthermore, the gating generation unit may also be included in the R / W channel 140 or the MPU60.

[0066] The R / W channel 140 has a gating detection unit. The gating detection unit detects whether various strobes, such as write strobe, read strobe, and servo strobe, are in a valid or invalid state.

[0067] For example, the gating detection unit performs write processing if it detects that the write gating is valid, and stops (pauses) the write processing if it detects that the write gating is invalid.

[0068] In addition, the gating detection unit also performs read processing if the read gating is detected as valid, and stops read processing if the read gating is detected as invalid. Similarly, the gating detection unit performs servo read processing if the servo gating is detected as valid, and stops servo read processing if the servo gating is detected as invalid. Furthermore, the gating detection unit can also be located within the HDC150 or MPU60.

[0069] MPU60 is the control unit that controls the various parts of disk drive 1, and is the main controller. MPU60 controls VCM24 via driver IC120 to perform servo control for positioning the head HD. MPU60 controls the write operation of data written to disk DK and selects the destination for the write data transferred from host 100. Additionally, MPU60 controls the read operation of data read from disk DK and controls the processing of read data transferred from disk DK to host 100. MPU60 is connected to various parts of disk drive 1. For example, MPU60 is electrically connected to driver IC120, R / W channel 140, HDC150, etc.

[0070] The MPU60 includes a read / write processing unit 61, an error correction unit 64, a management unit 65, a correction limit determination unit 66, and a judgment unit 67. The MPU60 executes the processing of these units, such as the read / write processing unit 61, error correction unit 64, management unit 65, correction limit determination unit 66, and judgment unit 67, on the firmware. Alternatively, the MPU60 may also include these units as circuitry.

[0071] The read / write processing unit 61 includes a write processing unit 62 and a read processing unit 63. According to commands from the host 100, the write processing unit 62 controls the data write process, and the read processing unit 63 controls the data read process, causing the read head RHD to read data from the disk DK. The read processing unit 63 can perform a seek process that causes the read head RHD to seek. The write processing unit 62 can perform a write process that writes data to the recording layer of the disk DK. The read / write processing unit 61 controls the VCM 24 via the driver IC 120 to position the head HD at a target position (a predetermined radius position) on the disk DK and perform read or write processing.

[0072] Figure 2 This is a perspective view showing a portion of disk drive 1, and a view showing multiple disks (DK) and multiple head (HD).

[0073] like Figure 2 As shown, in the circumferential direction, the direction of rotation of disk DK is called the rotation direction d3. Furthermore, in... Figure 2 In the example shown, the rotation direction d3 is shown counterclockwise, but it can also be the opposite direction (clockwise). Additionally, the direction of travel d2 of the head HD relative to the disk DK is opposite to the rotation direction d3. The direction of travel d2 is the direction in which the head HD sequentially writes and reads data from the disk DK in the circumferential direction; that is, the direction in which the head HD travels relative to the disk DK in the circumferential direction.

[0074] The disk drive 1 comprises i disks, namely disks DK1 to DKi, and j heads, namely heads HD1 to HDj. In this embodiment, the number of heads HD is twice the number of disks DK (j = 2 × i).

[0075] Disks DK1 to DKi are arranged coaxially and overlapped with intervals between them. Disks DK1 to DKi have the same diameter. Here, terms such as "same," "identical," "consistent," and "equivalent" naturally include the meaning of being completely identical, as well as the meaning of being different to a degree that is considered substantially the same. In addition, the diameters of disks DK1 to DKi may also be different from each other.

[0076] Each disk DK has recording layers L on both sides. For example, disk DK1 has a first recording layer La1 and a second recording layer Lb1 opposite to the first recording layer La1. Disk DK2 has a first recording layer La2 and a second recording layer Lb2 opposite to the first recording layer La2. Disk DKi has a first recording layer Lai and a second recording layer Lbi opposite to the first recording layer Lai. Each first recording layer La is sometimes referred to as the surface or recording plane. Each second recording layer Lb is sometimes referred to as the back side or recording plane.

[0077] However, each of the first recording layers La is sometimes referred to as the back side. In this case, each of the second recording layers Lb is sometimes referred to as the surface.

[0078] Each record layer L has a user data area U and a system area S. Record layer La1 has a user data area Ua1 and a system area Sa1. Record layer Lb1 has a user data area Ub1 and a system area Sb1. Record layer La2 has a user data area Ua2 and a system area Sa2. Record layer Lb2 has a user data area Ub2 and a system area Sb2. Record layer Lai has a user data area Uai and a system area Sai. Record layer Lbi has a user data area Ubi and a system area Sbi.

[0079] The track in user data area Ua1 (first recording layer La1) that is sandwiched between double dashed lines in the diagram is designated as track Ta1. The track in user data area Ub1 (second recording layer Lb1) that is located on the opposite side of track Ta1 is designated as track Tb1.

[0080] The track in user data area Ua2 (first recording layer La2) that is sandwiched between double dashed lines in the diagram is designated as track Tc1. The track in user data area Ub2 (second recording layer Lb2) that is located on the opposite side of track Tc1 is designated as track Td1.

[0081] The track in the user data area Uai (first recording layer Lai) that is sandwiched between double dashed lines in the diagram is designated as track Te1. The track in the user data area Ubi (second recording layer Lbi) that is located on the opposite side of track Te1 is designated as track Tf1.

[0082] In this embodiment, magnetic tracks Ta1, Tb1, Tc1, Td1, Te1, and Tf1 are located on the same cylindrical surface.

[0083] Header HD is opposite to disk DK. In this embodiment, there is one head HD opposite each recording layer L of disk DK. For example, head HD1 is opposite to the first recording layer La1 of disk DK1, and writes data to and reads data from the first recording layer La1. Header HD2 is opposite to the second recording layer Lb1 of disk DK1, and writes data to and reads data from the second recording layer Lb1.

[0084] Header HD3 aligns with the first recording layer La2 of disk DK2, writing data to and reading data from the first recording layer La2. Header HD4 aligns with the second recording layer Lb2 of disk DK2, writing data to and reading data from the second recording layer Lb2. Header HDj-1 aligns with the first recording layer Lai of disk DKi, writing data to and reading data from the first recording layer Lai. Header HDj aligns with the second recording layer Lbi of disk DKi, writing data to and reading data from the second recording layer Lbi.

[0085] Figure 3 This is a schematic diagram illustrating an example of the configuration of multiple servo areas (SVs) and multiple data areas (DTRs) of a single disk (DK) in this embodiment. Figure 3 As shown, in the radial direction d1 of disk DK, the direction towards the outer periphery of disk DK is called the outer direction (outer side), and the direction opposite to the outer direction is called the inner direction (inner side).

[0086] exist Figure 3 In the data, the user data area U is divided into an inner peripheral region IR located in the inward direction, an outer peripheral region OR located in the outward direction, and a middle peripheral region MR located between the inner peripheral region IR and the outer peripheral region OR.

[0087] The disk DK has multiple servo areas (SVs) and multiple data areas (DTRs). The multiple servo areas (SVs) can, for example, extend radially in the radial direction of the disk DK and be discretely arranged at predetermined intervals in the circumferential direction. Alternatively, the multiple servo areas (SVs) can extend linearly from the inner circumference to the outer circumference and be discretely arranged at predetermined intervals in the circumferential direction. Or, the multiple servo areas (SVs) can extend spirally from the inner circumference to the outer circumference and be discretely arranged at predetermined intervals in the circumferential direction. Furthermore, the multiple servo areas (SVs) can, for example, be arranged in an island pattern in the radial direction and discretely arranged with varying predetermined intervals in the circumferential direction.

[0088] Hereinafter, a single servo region SV within a predetermined track is sometimes referred to as a "servo sector". Furthermore, a "servo region SV" is sometimes referred to as a "servo sector SV". A servo sector contains servo data. Hereinafter, the "configuration of several servo data items constituting a servo sector" is sometimes referred to as a "servo pattern". Furthermore, the "servo data written to a servo sector" is sometimes referred to as a "servo sector".

[0089] Multiple Data Regions (DTRs) are configured between multiple Servo Regions (SVs). For example, a Data Region DTR corresponds to the area between two consecutive Servo Regions (SVs) in the circumferential direction. Hereinafter, a single Data Region DTR within a predetermined track is sometimes referred to as a "data sector." Furthermore, the term "Data Region DTR" is sometimes referred to as "Data Sector DTR." A data sector includes user data. Additionally, the term "user data written to a data sector" is sometimes referred to as a "data sector." The term "data sector" is sometimes referred to as "user data." Furthermore, the term "a pattern composed of several data items" is sometimes referred to as a "data pattern." Figure 3 In the example shown, the data pattern of the predetermined track consists of multiple servo data (servo sectors) and multiple user data (data sectors).

[0090] A servo zone (SV) has multiple zone servo zones (ZSVs). In addition to the zone servo zones (ZSVs), a servo zone (SV) may also include: a region containing gaps (the offset of the circumferential positions of the two zone servo zones), a region containing servo data, and a data region (DTR), etc. Multiple zone servo zones (ZSVs) are discretely arranged along the radial direction (d1). Each zone servo zone (ZSV) extends along the radial direction (d1).

[0091] Sometimes, a single partitioned servo region (servo area) ZSV within a predetermined track is referred to as a "partitioned servo sector" or "servo sector". Furthermore, the "partitioned servo region (servo area) ZSV" is sometimes referred to as a "partitioned servo sector ZSV" or "servo sector ZSV". Sometimes, "servo data written to a partitioned servo sector" is referred to as a "partitioned servo sector" or "servo sector". Hereinafter, the "configuration of several servo data constituting a partitioned servo sector" is sometimes referred to as a "partitioned servo pattern" or "servo pattern". Hereinafter, a single servo area SV within a predetermined track is sometimes referred to as a "partitioned pattern sector".

[0092] In addition, "servo area SV" is sometimes referred to as "partition pattern sector". "At least one piece of data written to a partition pattern sector" is sometimes referred to as "partition pattern sector". A partition pattern sector includes at least one partition servo sector. Hereinafter, "the data pattern of a partition pattern sector" is sometimes referred to as "partition data pattern".

[0093] exist Figure 3 In the example shown, the servo region SV has partitioned servo regions ZSV0, ZSV1, and ZSV2. The partitioned servo regions ZSV0, ZSV1, and ZSV2 are arranged in an alternating pattern in the radial direction. Alternatively, the partitioned servo regions ZSV0, ZSV1, and ZSV2 can be arranged in a stepped pattern in the radial direction.

[0094] Partition servo region ZSV2 is located on the inner periphery side of partition servo region ZSV1. Partition servo region ZSV0 is located on the outer periphery side of partition servo region ZSV1. For example, partition servo region ZSV2 is configured from the inner periphery region IR to the middle periphery region MR, partition servo region ZSV1 is configured from the inner periphery region IR to the outer periphery region OR, and partition servo region ZSV0 is configured from the middle periphery region MR to the outer periphery region OR. Hereinafter, a predetermined region in the radial direction within a predetermined servo region SV, where multiple partition servo regions ZSV are configured in the circumferential direction, is sometimes referred to as a partition servo boundary region, a double servo region, or a double partition servo region ZB.

[0095] exist Figure 3 In the example shown, the master servo regions SVO and slave servo regions SVE are arranged alternately with intervals in the circumferential direction. For example, one slave servo region SVE is configured between two consecutive master servo regions SVO arranged with intervals in the circumferential direction. In other words, one slave servo region SVE is configured between two consecutive master servo regions SVO arranged with intervals in the circumferential direction. For example, when all servo regions SV of disk DK are assigned sequentially consecutive numbers, the master servo region SVO corresponds to the odd-numbered servo region SV, and the slave servo region SVE corresponds to the even-numbered servo region SV. Furthermore, more than two slave servo regions SVE can also be configured between two consecutive master servo regions SVO arranged with intervals in the circumferential direction.

[0096] The master servo region (SVO) and slave servo region (SVE) can, for example, consist entirely of a servo region that reads and demodulates servo data (hereinafter, sometimes referred to as a normal servo region). Hereinafter, "reading and demodulating servo data" is sometimes referred to as "performing servo reading." The master servo region (SVO) and slave servo region (SVE) can also, for example, consist of a normal servo region and a servo region that reads servo data in a circumferential direction that is smaller than the servo data read in the normal servo region (hereinafter, sometimes referred to as a short servo region).

[0097] A media cache M is allocated to the disk DK. However, the media cache M may not be configured in the disk DK.

[0098] By using the aforementioned multiple servo data, for example, it is possible to derive the positioning error of the head HD (e.g., the written head WHD).

[0099] In this embodiment, the case where the disk DK has 3 partitions is used as an example, but the number of partitions in the disk DK can be varied. The number of partitions in the disk DK can also be 30 to 40. In addition, each partition has multiple bands. For example, each partition has hundreds of bands.

[0100] Figure 4 It is shown Figure 3 The diagram shows the three tracks (STR) and the write head (WHD) of the user data area U on the disk DK, which is the tape recording area. Within the user data area U, data can be written sequentially in tape units, i.e., tape recording is permitted.

[0101] like Figure 4 As shown, the write head WHD can sequentially write data to disk DK in the direction of travel d2. Figure 3 The read head RHD shown can also sequentially read data written to disk DK in the direction of travel d2.

[0102] The direction in which multiple tracks STR, which are multiple data tracks, are continuously recorded in a direction parallel to the radial direction d1, that is, the direction in the radial direction d1 that overlaps with the previously written track STR with the next track STR to be written, is called the overlapping write direction or recording direction. Figure 4 In the BAe shown, the overlapping write direction d5 is the inward direction, but the overlapping write direction can also be the outward direction.

[0103] For example, the overlapping write direction applicable to multiple BAs (multiple partitions Z) located on the outer periphery of a position beyond a specific radius position, and the overlapping write direction applicable to multiple BAs (multiple partitions Z) located on the inner periphery of a position beyond the aforementioned specific radius position, can be opposite to each other.

[0104] The BAe has multiple tracks STR, including tracks STRe, STRe+1, and STRe+2. Tracks STRe, STRe+1, and STRe+2 are written sequentially in the overlapping write direction d5 in the order they are written. Track STRe corresponds to the track where data was written first, and track STRe+2 corresponds to the track where data was written last.

[0105] Track STRe has a center track STCe at the center of radial direction d1, provided that no other tracks have been written overlaid. Track STRe+1 has a center track STCe+1 at the center of radial direction d1, provided that no other tracks have been written overlaid. Track STRe+2 has a center track STCe+2 at the center of radial direction d1, provided that no other tracks have been written overlaid.

[0106] exist Figure 4 In the example shown, tracks STRe, STRe+1, and STRe+2 are written with a pitch (track spacing) STP. The track center STCe of track STRe and the track center STCe+1 of track STRe+1 are separated by a pitch STP in the radial direction d1. The track center STCe+1 of track STRe+1 and the track center STCe+2 of track STRe+2 are separated by a pitch STP in the radial direction d1. Tracks STRe to STRe+2 can also be written with different pitches.

[0107] The radial width d1 of the region in track STR that is not written overlappingly to track STR+1 is the same as the radial width d1 of the region in track STR+1 that is not written overlappingly to track STR+2. Alternatively, the radial width d1 of the region in track STR that is not written overlappingly to track STR+1 can be different from the radial width d1 of the region in track STR+1 that is not written overlappingly to track STR+2.

[0108] exist Figure 4 For ease of explanation, each track STR is shown as rectangular, but in reality, each track STR is curved along the circumferential direction. Alternatively, each track STR can also be wavy, varying in the radial direction d1 while extending circumferentially. Furthermore, in... Figure 4 In this context, overlapping writes can be performed on 3-track STRs, but overlapping writes can also be performed on 2-track STRs, or on more than 3-track STRs.

[0109] The write processing unit 62 can select a watt-type recorder that writes data overlappingly to multiple tracks STR in the overlapping write direction d5, so that the write head WHD can perform writing of data to each track BA. Figure 4 In the example shown, the write processing unit 62 performs tile recording on tracks STRe to STRe+2 in the tape BAe in an inward direction (overlapping write direction d5) with a spacing STP sequence. Since the user data area U is the area where data is written in tile recording mode, it is possible to increase the recording density of the user data area U.

[0110] The write processing unit 62 writes to track STR+1 in the inward direction of track STR with a spacing STP, and overlaps the writing of track STR+1 on a portion of the inner peripheral side of track STR. The write processing unit 62 writes to track STR+2 in the inward direction of track STR+1 with a spacing STP, and overlaps the writing of track STR+2 on a portion of the inner peripheral side of track STR+1.

[0111] Figure 5 It is shown Figure 3 The diagram shows the three tracks (CTR) and write head (WHD) of the media cache M on disk DK, which are used for normal recording processing. The media cache M and... Figure 3 The system area S shown is the normal recording area. Random data writing, i.e., normal recording, is permitted within both the media cache M and the system area S.

[0112] like Figure 5 As shown, the media cache M has multiple tracks CTR, including tracks CTRe, CTRe+1, and CTRe+2. These multiple tracks CTR are data tracks. For example, tracks CTRe, CTRe+1, and CTRe+2 have the same width (track width) in the radial direction d1. Alternatively, the track widths of tracks CTRe to CTRe+2 can be different from each other.

[0113] Track CTRe has a track center CTCe at the center of radial direction d1, track CTRe+1 has a track center CTCe+1 at the center of radial direction d1, and track CTRe+2 has a track center CTCe+2 at the center of radial direction d1. Figure 5 In the example shown, tracks CTRe, CTRe+1, and CTRe+2 are written with a spacing (typically recording track spacing) CTP. The track center CTCe of track CTRe is separated from the track center CTCe+1 of track CTRe by a spacing CTP. The track center CTCe+1 of track CTRe+1 is separated from the track center CTCe+2 of track CTRe+2 by a spacing CTP.

[0114] Tracks CTRe and CTRe+1 are separated by a gap GP. Tracks CTRe+1 and CTRe+2 are also separated by a gap GP. Furthermore, tracks CTRe to CTRe+2 can be written with different spacings. Figure 5 For ease of explanation, each track CTR is shown in a rectangular shape, but in reality, each track CTR is curved along the circumferential direction. Alternatively, each track CTR can also be wavy, varying in the radial direction d1 while extending in the circumferential direction.

[0115] The write processing unit 62 can select a typical recording type that writes data to multiple tracks CTR at intervals along the radial direction d1 of the disk DK to perform write processing. Figure 5 In the example shown, the write processing unit 62 positions the write head WHD at the center of the track CTCe in a predetermined area of ​​the disk DK to perform normal recording on the track CTRe or a predetermined sector of the track CTRe.

[0116] The write processing unit 62 positions the write head WHD at the center of track CTCe+1, which is located inward from the center CTCe of track CTRe at a distance from CTP, and performs normal recording on a predetermined sector of track CTRe+1. The write processing unit 62 then positions the write head WHD at the center of track CTCe+2, which is located inward from the center CTCe+1 of track CTRe+1 at a distance from CTP, and performs normal recording on a predetermined sector of track CTRe+2.

[0117] The write processing unit 62 can also perform normal recording sequentially on tracks CTRe, CTRe+1, and CTRe+2 in a predetermined area of ​​the disk DK, or it can perform normal recording randomly on predetermined sectors of track CTRe, predetermined sectors of track CTRe+1, and predetermined sectors of track CTRe+2.

[0118] Figure 6 This is a schematic diagram illustrating an example of data write processing in a disk DK. Tracks STR and CTR are the data tracks, respectively. Figure 6 As shown, the user data area U has bands BAa, BAb, and Bac. Bands BAa, BAb, and Bac belong to the same partition Ze. Within partition Ze, bands BAa, BAb, and Bac are discontinuously arranged in the overlapping write direction according to their recorded order.

[0119] BAa and BAb are adjacent in the radial direction d1, and BAb and BAc are adjacent in the radial direction d1.

[0120] Band BAa includes tracks STRa0, STRa1, STRa2, ..., STRa(x-3), STRa(x-2), and STRa(x-1), totaling x tracks. Tracks STRa0 to STRa(x-1) are recorded in the overlapping write direction d5 in the order they are written. In band BAa, track STRa0 corresponds to the track at the beginning of the first data written, and track STRa(x-1) corresponds to the track at the end of the last data written.

[0121] The tape BAb includes tracks STRb0, STRb1, STRb2, ..., STRb(x-3), STRb(x-2), and STRb(x-1), totaling x tracks. Tracks STRb0 to STRb(x-1) are recorded in the overlapping write direction d5 in the order they are written. In tape BAb, track STRb0 corresponds to the track at the beginning of the first data written, and track STRb(x-1) corresponds to the track at the end of the last data written.

[0122] The tape BAc includes x tracks: STRc0, STRc1, STRc2, ..., STRc(x-3), STRc(x-2), and STRc(x-1). Tracks STRc0 to STRc(x-1) are recorded in the overlapping write direction d5 in the order they are written. In tape BAc, track STRc0 corresponds to the first track where data is written, and track STRc(x-1) corresponds to the last track where data is written.

[0123] Each band BA belonging to the same partition Z has the same number of tracks STR. For example, each band BA belonging to partition Ze has the same number of tracks STR. In other words, the number of tracks STR in each band BA is fixed for each partition Z. In this example, each band BA belonging to partition Ze has x tracks STR.

[0124] exist Figure 6 The diagram shows tracks CTR(x-2) and CTR(x-1). Figure 6 In this system, tracks CTR(x-2) and CTR(x-1) are normally recorded in the media cache M or system region S. Tracks CTR(x-2) and CTR(x-1) are adjacent in the radial direction d1.

[0125] Figure 7 It is shown Figure 6 The diagram shows two bands BAa and BAb and one guard band GB in the user data area U. (See diagram.) Figure 7 As shown, in the watt recording mode, unlike the usual recording mode, the MPU60 manages the track group of the user data area U in units called watts, based on the feature of overlapping writing of a portion of the track STR.

[0126] A guard band (GB) is typically provided between adjacent bands (BA) in the radial direction d1. The guard band (GB) includes a guard track (GTR). Alternatively, unlike this embodiment, the guard band (GB) may include multiple guard tracks (GTRs). The guard band (GB) serves to suppress interference between adjacent bands (BA). Using the guard band (GB), wattage recording can be performed on a unit of one band (BA). Furthermore, the guard band (GB) allows for the separation of sequentially written areas (bands (BA)).

[0127] For example, the center STCa(x-3) of track STa(x-3), the center STCa(x-2) of track STa(x-2), the center STCa(x-1) of track STa(x-1), the center GTC of the protection track GTR, the center STCb0 of track STRb0, the center STCb1 of track STRb1, and the center STCb2 of track STRb2 are located at equal intervals in the overlapping write direction d5.

[0128] Apart from the guard band (GB), the recording capacity of each band (BA) in the user data area U is typically predetermined based on user requirements. The MPU60 can record the same amount of data in each BA. Generally, the recording capacity of each BA is 128 MiB or 256 MiB.

[0129] Figure 8 It is shown Figure 6 The diagram shows three sectors SCe, SC(e+1), and SC(e+2) in track STRa0 with BAa. Figure 8 As shown, each track STR has multiple sectors SC. Track STRa1 has multiple sectors SC including sectors SCe, SC(e+1), and SC(e+2).

[0130] When sector SC(e+1) of track STRa0 is designated as the nth sector, sector SC(e+2) is the (n+1)th sector following sector SC(e+1) in the travel direction d2, and sector SCe is the (n-1)th sector preceding sector SC(e+1) in the travel direction d2. Tracks STR belonging to the same partition Z have the same number of sectors SC. In this embodiment, each track STR belonging to partition Ze has y sectors SC.

[0131] Each sector SC has a length Ls in the circumferential direction of disk DK. Sometimes, each sector SC is also a segmented sector separated by servo sectors SV. In this case, the length of sector SC may not be Ls.

[0132] The write head (WHD) is a magnetic head for energy-assisted recording (EAMR). In this embodiment, the write head (WHD) is configured to utilize energy other than magnetism, but it is not limited to this; the write head (WHD) may also be a magnetic head that is not configured to perform energy-assisted recording.

[0133] Figure 9 It is shown Figure 7 The diagram shown, with two bands BAa and BAb and one guard band GB, is used to illustrate multiple object sector RSCs and multiple unused sector VSCs.

[0134] exist Figure 9 For ease of explanation, each track STR is shown as a rectangle, but in reality, each track STR is curved along the circumference. Furthermore, although multiple track STRs are arranged non-overlappingly in the overlapped write direction d5, they are actually arranged overlappingly in the overlapped write direction d5. Additionally, dot patterns are added to the target sector RSC in the diagram. Unused sectors VSC are represented without patterns.

[0135] like Figure 9 As shown, the track number with BAa is set to "a", and the track number with BAb is set to "b". The track numbers for each BA are set to "0" to "x-1". The sector numbers for each track STR are set to "0" to "y-1". Hereinafter, the following designation "SC (track number, sector number)" is sometimes used to identify each sector SC with BA.

[0136] In this embodiment, band BAa is the band adjacent to band BAb, and is located upstream of band BAb in the overlapping write direction d5.

[0137] Each track STR with BAa includes G object sector RSCs (more than one object sector RSC) that have been written with valid data. For example, track STa0 has y object sector RSCs (G = y). All sectors SC of track STa0 are object sector RSCs. Track STa(x-1) has 5 object sector RSCs (G = 5). The remaining sectors SC of track STa(x-1) are unused sectors VSCs that have not been written with valid data.

[0138] Based on the above, the number of target sector RSCs in track STa0 is different from the number of target sector RSCs in track STa(x-1).

[0139] In each band BA of partition Ze, all sectors SC of track x-1 (from track 0 to track x-2) are object sectors RSC (written with valid data) and record sectors USC (written with valid data). In the (x-1)th track STR of each band BA of partition Ze, the 5 sectors SC from track 0 to track 4 are object sectors RSC and record sectors USC. On the other hand, in the (x-1)th track STR, the remaining sectors SC from track 5 to track y-1 are unused sectors VSC (not written with valid data).

[0140] Figure 10 This diagram illustrates an example of tracks STR0 and STR1, assuming disk device 1 does not have the function of performing error correction on track TR. It is a diagram illustrating the write process to tracks STR0 and STR1, a diagram illustrating the state of continuously writing to track STR1 until the error correction for each sector of track STR0 reaches its limit, and a diagram plotting the change in Bit Error Rate (BER) relative to track STR0 and the change in BER relative to Position Error (PE) on coordinates. In use... Figure 10 In the description, disk device 1 is set to not have Figure 1 The error correction section 64 will be used for explanation. Additionally, in Figure 10 In the text, for ease of explanation, the first magnetic track STR0 is depicted as a straight line in the circumferential direction.

[0141] like Figure 10 As shown, in the recording layer L, multiple tracks STR are adjacent in the radial direction d1. Track 1 STR0 and track 2 STR1 are data tracks, adjacent to each other. All sectors SC of track 1 STR0 and all sectors (data sectors) SC of track 2 STR1 are object sectors RSC. The write operation to track 1 STR0 is ideally performed without positioning error PE (PE≈0 or PE=0).

[0142] When the disk device 1 is affected by external vibrations or other factors during write processing, a positioning error PE is generated during the positioning of the write head WHD. The positioning error PE is the offset of the write head WHD from the target position in the radial direction d1. By setting the track margin TM, the allowable range that ensures data can be read from adjacent tracks can be determined.

[0143] For example, during a write operation on track 2 STR1 when the positioning error PE exceeds the track margin TM, if the target sectors RSCe, RSC(e+1), and RSC(e+2) of track 1 STR0 are adjacent to the write head WHD in the radial direction d1, the data in these sectors is considered (predictably) corrupted. Lower BER is better, but the BER of the data in these sectors exceeds the threshold BERTH. Furthermore, from... Figure 10 As shown in the coordinate graph on the right, the larger the positioning error PE, the greater the adverse effect of ATI (Adjacent Track Interference), and the higher the BER of the data of track STR0, which is excessively affected by ATI.

[0144] Therefore, in track STR0, target sectors RSCe, RSC(e+1), and RSC(e+2) are identified as damaged target sectors CSC1, CSC2, and CSC3, respectively. This results in signal quality degradation when reading data from damaged target sectors CSC1 to CSC3, and the data in damaged target sectors CSC1 to CSC3 may be erased.

[0145] In use Figure 10 In the example used for illustration, disk device 1 does not have the function of performing track-by-track error correction on the data of track TR. Here, track-by-track error correction is also called track-by-track error correction, track ECC (Error Checking and Correcting), etc. Therefore, the target sector RSCe, target sector RSC(e+1), and target sector RSC(e+2) remain unchanged as damaged target sector CSC1, damaged target sector CSC2, and damaged target sector CSC3.

[0146] Here, in Figure 10 In the previous section, it was explained that all object sectors RSC of track TR had the same track margin TM. This will be discussed later. Figure 11 as well as Figure 12 The description also assumes that all target sectors RSC of track TR have the same track margin TM. However, the above setting of track margin TM is an example, and the track margin TM can also be different on a per-target sector RSC basis.

[0147] Figure 11This diagram illustrates an example of tracks STR0 and STR1, assuming disk device 1 does not have the function of performing track-by-track error correction on data in track TR. It is a diagram illustrating the write processing of tracks STR0 and STR1. It is a diagram illustrating the state where the write process on track STR1 ends when the judgment value is set to a (strict) write deviation from track limit WOS smaller than track margin TM, and the positioning error PE is detected to exceed the reference radius position PO. It is a diagram plotting the changes in BER relative to track STR0 and the changes in BER relative to the positioning error PE using coordinates. Figure 11 In the diagram, for ease of explanation, the first magnetic track STR0, etc., are depicted as a straight line along the circumference. When using... Figure 11 In the description, disk device 1 is set to not have Figure 1 The error correction section 64 will be used for explanation.

[0148] like Figure 11 As shown, track STR0 and track STR1 are data tracks, and all sectors SC of track STR0 and all sectors (data sectors) SC of track STR1 are object sectors RSC. Write operations on track STR0 are ideally performed without positioning error PE (PE≈0 or PE=0). Track STR0 is located on the first direction Da, which is parallel to the radial direction d1 when viewed from track STR1.

[0149] The write processing unit 62 is a watt-type recorder that can write data of the second track STR1 in an overlapping write direction d5 opposite to the first direction Da, where the data of the first track STR0 overlaps with the data of the second track STR1.

[0150] To prevent or suppress write operations when the positioning error PE exceeds the track margin TM, the disk device 1 has a write offset track limit (WOS). The reference radius position PO is offset from the center STC1 of track STR1 in the first direction Da by the write offset track limit WOS. During the writing of data to track STR1, if it is determined that the positioning error PE exceeds the reference radius position PO, the writing of data to track STR1 can be paused. The remaining target sectors RSC of track STR1 where data writing is suspended become free sectors ESC without any data being written. By avoiding the situation where the positioning error PE exceeds the track margin TM, it is possible to prevent the generation of corrupted target sectors CSC on track STR0.

[0151] In addition, the track STR has servo sectors outside the sector SC that is a data sector. In the track STR, generally, data sectors and servo sectors are alternately arranged. The head HD (read head RHD) can derive the positioning error PE together with the servo sectors. Therefore, generally, the positioning error PE is information obtained intermittently.

[0152] In order not to have PE > TM, it is necessary to set the write off-track limit WOS in such a way that WOS ≤ TM. In order to avoid the situation where PE > TM, it is preferable to set the write off-track limit WOS in such a way that WOS < TM. Thereby, it is possible to pause the write process to the second track STR1 before the positioning error PE exceeds the track margin TM, and it is possible to avoid the situation where the quality of the data in the first track STR0 deteriorates.

[0153] However, the smaller the write off-track limit WOS is set, the easier the write process is to pause, and it is necessary to pay attention to the fact that this may cause a decrease in the write performance of the disk device 1. In addition, in the disk device 1 that does not have the function of performing track-based error correction, when the write process to the second track STR1 is paused, a write retry process is executed in which the rotation of the disk DK is waited until PE ≤ WOS and then the write process to the second track STR1 is started again. Through the write retry process, the free sector ESC of the second track STR1 can be changed to a recorded sector USC, and thus, it is possible to avoid the situation where the utilization efficiency of the second track STR1 remains low as it is.

[0154] Here, in Figure 11 it has been described that all the target sectors RSC of the track TR have the same write off-track limit WOS. In the description of Figure 12 to be described later, it is also described that all the target sectors RSC of the track TR have the same write off-track limit WOS. However, the setting of the above write off-track limit WOS is an example, and the write off-track limit WOS can also be different for each target sector RSC.

[0155] Figure 12 is a diagram showing an example of the first track STR0 and the second track STR1 of the disk device 1 having the function of performing track-based error correction on the data of the track TR, is a diagram for explaining the write process to the first track STR0 and the second track STR1, is a diagram for explaining the state in which the determination value is set to a (loose) write off-track limit WOS larger than the track margin TM and the write process to the second track STR1 is continuously performed until the track-based error correction of the first track STR0 reaches the limit, and is a diagram showing the changes in BER with respect to the first track STR0 and the changes in BER with respect to the positioning error PE in coordinate diagrams. In Figure 12 In the text, for ease of explanation, the first magnetic track STR0 is depicted as a straight line in the circumferential direction.

[0156] like Figure 12 As shown, the write process for track STR0 is ideally performed without positioning error PE (PE≈0 or PE=0).

[0157] The disk device 1 includes an error correction unit 64. When a corrupted target sector (CSC) is generated on track ST, the read processing unit 63, together with the head amplifier IC 130, can detect this situation, and the error correction unit 64 can perform error correction processing to recover the data from the corrupted target sector CSC. For example, if a corrupted target sector CSC is generated on track STR0, the error correction unit 64 can recover the data from the corrupted target sector CSC based on the user data of multiple target sector RSCs on track STR0 and the parity bits of the parity sectors.

[0158] The parity sector described above is generated based on user data from multiple target sector RSCs of track STR0, and can be set within a portion of the multiple target sector RSCs of track STR0. For example, one or two target sector RSCs in track STR0 can be used as parity sectors. However, the parity sector described above can also be set on a track TR other than track STR0. Alternatively, the parity sector described above can also be set in memory outside the disk (e.g., non-volatile memory 90).

[0159] As described above, even if a corrupted sector CSC is generated on track STR0, the error correction unit 64 can perform error correction processing to recover the data in the corrupted sector CSC. Therefore, it is permissible for a corrupted sector CSC to be generated on track STR0. In the disk device 1 equipped with the error correction unit 64, the write offset track limit WOS can be set to WOS≥TM.

[0160] Furthermore, it should be noted that the number of damaged sectors that the error correction unit 64 can perform track-by-track error correction on a track-by-track basis has an upper limit. For example, if the number of damaged sector CSCs on track STR0 exceeds the upper limit (e.g., 12), the error correction unit 64 may have difficulty recovering the data of all the damaged sector CSCs.

[0161] Figure 13This is a diagram showing the presence or absence of track ECC, the function name for controlling DOL, the handling when the positioning error PE exceeds the reference radius position PO, the settings related to overwriting data in the buffer memory 80, and the settings related to transferring data in the buffer memory 80 under the first and second modes of the first and second write operations, in a table format.

[0162] like Figure 13 , Figure 11 as well as Figure 1 As shown, assuming that disk device 1 does not have ECC functionality, disk device 1 can perform the first write operation. The function name for controlling DOL (Drift-Off Level) is DDOL (Dynamic Drift-Off Level). The first write operation is related to the use of... Figure 11 The write action shown corresponds to this.

[0163] If, during the first write operation while writing to track STR1, the positioning error PE exceeds the reference radius position PO, the write operation to track STR1 is paused before the positioning error PE exceeds the track margin TM. Then, the write retry process for writing to track STR1 is initiated after waiting for disk DK to rotate until PE ≤ WOS.

[0164] When disk device 1 uses the first write operation, write retries such as disk DK rotation wait operations may occur frequently, making it difficult to improve the write performance of disk device 1. Therefore, in order to improve the write performance of disk device 1, disk device 1 using the second write operation has track ECC functionality. In disk device 1 using the second write operation, the function name for controlling DOL is iDDOL (intelligence dynamic drift-offlevel).

[0165] It allows for a certain number of damaged object sectors (CSCs) to be generated in the track STR, which can increase TPI (Track Per Inch).

[0166] (Second method of the second write operation)

[0167] Next, the second method of the second write operation will be explained.

[0168] like Figure 13 , Figure 1 as well as Figure 12As shown, the error correction unit 64 can perform error correction on the data of one or more corrupted object sectors CSC that are judged to be corrupted in the multiple object sectors RSC of the first track STR0.

[0169] The buffer memory 80 is capable of holding multiple data, including first user data and second user data.

[0170] The management unit 65 can selectively execute the first management, the second management, and the third management. The first management prohibits overwriting the first user data in the buffer memory 80. The second management allows overwriting all the first user data in the buffer memory 80. The third management allows overwriting the data belonging to the first group and the second group of the first user data in the buffer memory 80 and prohibits overwriting the data belonging to the third group of the first user data in the buffer memory 80.

[0171] Here, the write processing unit 62 focuses on the first write period, which is the period after performing write processing of writing first data including first user data to multiple object sectors of the first track STR0 by RSC, and the period after performing write processing of writing second data including second user data to multiple object sectors of the second track STR1 by RSC.

[0172] During the first write operation, the read processing unit 63 performs a seek process that causes the read head RHD to seek the track, and aligns the write head WHD with the second track STR1.

[0173] The correction limit determination unit 66 obtains information that the position of the write head WHD exceeds the reference radius position PO in the first direction Da whenever data is written to each target sector RSC of the second track STR1.

[0174] Management Department 65 shall implement the above-mentioned Management 1.

[0175] If the judgment unit 67 determines, based on the information obtained by the correction limit judgment unit 66, that the error correction unit 64 has not exceeded the limit for correcting the first user data on the first track STR0, the write processing unit 62 can continue to write to the second track STR1 and the management unit 65 can perform the second management instead of the first management.

[0176] Since it is not necessary to pre-store the first user data in the buffer memory 80, it is possible to overwrite the first user data in the buffer memory 80, thereby increasing the amount of new data that the buffer memory 80 can accept.

[0177] Furthermore, if the judgment unit 67 determines, based on the above information, that the error correction unit 64 has exceeded the limit for correcting the first user data on the first track STR0, it can enable the write processing unit 62 to continue writing to the second track STR1 and enable the management unit 65 to perform the third management instead of the first management.

[0178] Furthermore, during or after the first write operation, the determination unit 67 can instruct the management unit 65 to transfer the data belonging to the third group to the system area S of the recording layer L of a non-volatile recording medium, such as a disk DK. The data transferred to the system area S can be permanently stored in the system area S.

[0179] Furthermore, the data belonging to the first group in the first user data in the buffer memory 80 is the original data of more than one object sector RSC in the multiple object sectors RSC of the first track STR0 that is determined to be without data corruption.

[0180] The data belonging to the second group in the first user data in the buffer memory 80 is the original data of one or more first damaged object sectors CSCs in the multiple object sectors RSC of the first track STR0 that are judged to be corrupted, and is the original data of data within the range that can be corrected by the error correction unit 64.

[0181] The data belonging to the third group in the first user data in the buffer memory 80 is the original data of one or more second damaged object sectors CSC that are judged to be corrupted in the multiple object sectors RSC of the first track STR0, and is the original data of data that deviates from the range that the error correction unit 64 can correct.

[0182] Even if the error correction performed by the error correction unit 64 exceeds the limit, the writing process to track STR1 can continue. Therefore, the degradation of write performance can be suppressed.

[0183] Furthermore, for the amount of corrupted data in track STR0 that exceeds the error correction limit performed by the error correction unit 64, the original data of this excessive corrupted data can be transferred from the buffer memory 80 to the system area S. This indirectly protects the excessive corrupted data on track STR0. The error correction unit 64 can use the first user data and the first parity bit on track STR0, as well as the original data transferred to the system area S, to perform error correction processing to recover the data of all corrupted sectors CSC on track STR0. Since the quality of the data on track STR0 can be improved, the situation where the signal quality deteriorates when reading data from track STR0 remains unchanged can be avoided.

[0184] On the other hand, when using the first method of the second write operation, it is unacceptable for the error correction unit 64 to exceed its limit. The frequency of pausing (or ending) the write process on the second track STR1 may increase. Furthermore, when the write process ends, the frequency of initiating the Partial Track Slip (PTS), which transfers the remaining data that cannot be written to the second track STR1, may increase. Therefore, the first method of the second write operation is unlikely to improve the write performance of the disk device 1.

[0185] Next, we focus on the first track STR0 and the second track STR1 after the write processing of the first track STR0 and the second track STR1 using the second method of the second write operation is completed.

[0186] The first user data was written to all object sectors of track STR0. Alternatively, both the first user data and the first parity bit generated based on the first user data were written to all object sectors of track STR0.

[0187] The second user data was written to all object sectors of track STR1. Alternatively, both the second user data and the second parity bit generated based on the second user data were written to all object sectors of track STR1.

[0188] In the second mode of the second write operation, since PTS is not initiated, the target sector RSCs of track 1 STR0 and track 2 STR1 will not become free sectors ESCs. Therefore, the utilization efficiency of track 1 STR0 and track 2 STR1 can be improved.

[0189] Next, the information obtained by the correction limit determination unit 66 is the cumulative measured excess amount of the positioning error PE exceeding the reference radius position PO in the first direction Da.

[0190] Whenever second data is written to each target sector RSC of track STR1, the correction limit determination unit 66 can measure the measured excess amount by which the position of the write head WHD exceeds the reference radius position PO in the first direction Da, and update the cumulative measured excess amount, i.e., the cumulative measured excess amount. The information obtained by the correction limit determination unit 66 is the cumulative measured excess amount.

[0191] During the first write operation, if the determination unit 67 determines that the accumulated measured amount is below the upper limit threshold, it can cause the write processing unit 62 to continue writing to the second track STR1, and cause the management unit 65 to perform second management instead of first management. Here, the aforementioned upper limit threshold represents the limit of the range within which error correction can be performed on the first track STR0.

[0192] During the first write operation, if the determination unit 67 determines that the cumulative measured excess exceeds the upper limit threshold, the write processing unit 62 can continue to write to the second track STR1, and the management unit 65 can perform the third management instead of the first management. Furthermore, the correction limit determination unit 66 can subtract the measured excess measured each time a second damaged target sector CSC is formed on the first track STR0 from the cumulative measured excess, thereby updating the cumulative measured excess at any time.

[0193] Based on the relationship between the cumulative measured excess and the upper limit threshold, the judgment unit 67 can determine whether to allow or prohibit the overwriting of the original data in the buffer memory 80, and can determine whether it is necessary to transfer the original data from the buffer memory 80 to the system area S.

[0194] When the determination unit 67 transfers the original data from the buffer memory 80 to the system region S, it is preferable to prioritize transferring the original data of the most severely damaged data in the first track STR0. This is because the cumulative measured excess can be updated with the minimum amount, making it difficult for the cumulative measured excess to exceed the upper limit threshold.

[0195] In this case, the second measured excess is greater than or equal to the first measured excess. Specifically, the measured excess is the first measured excess when one or more first damaged sector CSCs are formed on track STR0. Furthermore, the measured excess is the second measured excess when one or more second damaged sector CSCs are formed on track STR0.

[0196] Next, we will explain the case where the information obtained by the correction limit determination unit 66 is the cumulative number of damaged sector CSCs.

[0197] The correction limit determination unit 66 is capable of counting the number of damaged target sectors (CSCs) in one or more tracks STR0 of the first track and updating the cumulative number of such counts. The information obtained by the correction limit determination unit 66 is the cumulative number.

[0198] During the first write operation, if the determination unit 67 determines that the cumulative number of errors is below the upper limit, it can cause the write processing unit 62 to continue writing to the second track STR1, and cause the management unit 65 to perform second management instead of first management. Here, the upper limit refers to the maximum number of errors that can be corrected on the first track STR0.

[0199] During the first write operation, if the determination unit 67 determines that the cumulative number exceeds the upper limit, the write processing unit 62 can continue to write to the second track STR1, and the management unit 65 can perform the third management instead of the first management. Furthermore, the correction limit determination unit 66 can subtract the number of second damaged sector CSCs counted each time more than one second damaged sector CSC is formed on the first track STR0 from the cumulative number, thereby updating the cumulative number at any time.

[0200] Furthermore, if the cumulative number exceeds the upper limit, the total number of CSCs with more than one first damaged object sector is the same as the upper limit.

[0201] Based on the relationship between the cumulative number and the upper limit number, the judgment unit 67 can determine whether to allow or prohibit the overwriting of the original data in the buffer memory 80, and can determine whether it is necessary to transfer the original data from the buffer memory 80 to the system area S.

[0202] Next, we will explain the case where the information obtained by the correction limit determination unit 66 is both the cumulative measured excess and the cumulative number.

[0203] During the first write operation, if the determination unit 67 determines that the cumulative measured quantity is below the upper limit threshold and the cumulative number is below the upper limit number, the write processing unit 62 can continue to perform the write processing on the second track STR1, and the management unit 65 can perform the second management instead of the first management.

[0204] During the first write operation, if the determination unit 67 determines that the cumulative measured excess exceeds the upper limit threshold, the write processing unit 62 can continue to write to the second track STR1, and the management unit 65 can perform the third management instead of the first management. Furthermore, the correction limit determination unit 66 can subtract the measured excess measured each time a second damaged target sector CSC is formed on the first track STR0 from the cumulative measured excess, thereby updating the cumulative measured excess at any time.

[0205] During the first write operation, if the determination unit 67 determines that the cumulative number exceeds the upper limit, the write processing unit 62 can continue to write to the second track STR1, and the management unit 65 can perform the third management instead of the first management. Furthermore, the correction limit determination unit 66 can subtract the number of second damaged sector CSCs counted each time more than one second damaged sector CSC is formed on the first track STR0 from the cumulative number, thereby updating the cumulative number at any time.

[0206] Next, the non-volatile recording medium that serves as the destination for transferring the original data within the buffer memory 80 will be described.

[0207] Track 1 STR0 and track 2 STR1 are located in the user data area U of recording layer L. The non-volatile recording medium may be, for example, a system area S in recording layer L that is different from the user data area U.

[0208] Here, the tape including track STR0 and track STR1 from the multiple tapes BA is designated as tape 1 BA. The management unit 65 needs to use the write head WHD to transfer data belonging to group 3 to system area S.

[0209] As the timing for the management department 65 to transfer data belonging to the 3rd group to the system area S, it is possible to cite the completion of the write process of writing the second data to multiple target sectors RSC of track STR1 after the first write period (after the first write period).

[0210] Alternatively, as the timing for the management department 65 to transfer data belonging to the 3rd group to the system area S, it is possible to exemplify this after the write processing of multiple tracks STR of the 1st BA is completed (after the 1st write period).

[0211] Non-volatile recording media may also be, for example, non-volatile memory 90 on the outside of the disk DK.

[0212] In this case, the timing for the management unit 65 to transfer data belonging to the third group to the non-volatile memory 90 can be determined after the timing when the error correction of the first user data on the first track STR0 exceeds the limit (midway through the first write period). This is because the write process to the second track STR1 and the transfer operation to the non-volatile memory 90 can be performed simultaneously.

[0213] Alternatively, as the timing for the management unit 65 to transfer data belonging to the third group to the non-volatile memory 90, it is possible to exemplify this after the write process of writing the second data to multiple target sectors RSC of track STR1 has ended (after the first write period).

[0214] Alternatively, as the timing for the management unit 65 to transfer data belonging to the third group to the non-volatile memory 90, it can be taken after the write process of writing data to multiple tracks STR of the first BA is completed (after the first write period).

[0215] (An example of the first method of the second write operation)

[0216] Next, the first method of the second write operation will be illustrated. Figure 14 The graph shows the change in positioning error PE and the change in the cumulative number of damaged object sectors CSC when a write operation is performed on track STR1 in the first manner of the second write operation. The graph shows the case where the cumulative number exceeds the PTS start threshold when the write operation is performed on the nth object sector RSCn of track STR1.

[0217] like Figure 14 As shown, multiple object sectors RSC (Data Area DTR) and multiple servo sectors SSC (Servo Area SV) are arranged in a circular direction. Whenever the read head RHD passes through a servo sector SSC, the position of the head HD in the radial direction d1 can be corrected. This is effective when the head HD is in a vibrating state due to seek operations, etc. However, the proportion (size) of the servo sector SSC in the track STR is smaller than that of the object sector RSC in the track STR. Therefore, it is difficult to fully correct the position of the head HD in the radial direction d1.

[0218] Therefore, when performing write processing on multiple target sector RSCs of track STR1, the positioning error PE sometimes exceeds the reference radius position PO multiple times. The determination unit 67 can determine whether to activate PTS by monitoring whether the cumulative number of damaged target sector CSCs related to track STR0 exceeds the PTS activation threshold.

[0219] exist Figure 14 In the example, we focus on the point in time when the write processing unit 62 has performed the write processing up to the nth object sector RSCn of track 2 STR1. At this point in time, it is known that the cumulative number exceeds the PTS start threshold. The determination unit 67 can enable PTS start. That is, the determination unit 67 can refrain from performing write processing on the object sectors RSC(n+1) and beyond of the (n+1)th object sector RSC of track 2 STR1, and instead transfer the remaining data that cannot be written to track 2 STR1 to tracks other than track 1 STR0 and track 2 STR1.

[0220] The reason why write processing cannot be performed on the object sector RSC of the second track STR1 after the (n+1)th object sector RSC(n+1) is that the error correction performed by the error correction unit 64 cannot be allowed to exceed the limit. As described above, the first method of the second write operation is unlikely to improve the write performance of the disk device 1.

[0221] (Example of the second method of the second write operation) (Information: Cumulative number)

[0222] Next, an example of the second method for the second write operation will be provided. Figure 15 This is a graph showing the change in positioning error PE and the change in the cumulative number of damaged target sectors CSC when writing to the second track STR1 in the second manner of the second write operation. It is also a graph showing the case where the cumulative number exceeds the upper limit when writing to the nth target sector RSCn of the second track STR1. Here, the information obtained by the correction limit determination unit 66 is the cumulative number.

[0223] like Figure 15 As shown, the judgment unit 67 can determine which management unit 65 should perform among the first to third management by monitoring whether the cumulative number of damaged target sectors CSCs related to the first track STR0 exceeds the upper limit.

[0224] exist Figure 15 In the example, we focus on the point in time when the write processing unit 62 has performed the write processing up to the nth object sector RSCn of track STR1. At this point in time, it is known that the accumulated number exceeds the upper limit. Even if the accumulated number exceeds the upper limit, the determination unit 67 can still enable the write processing unit 62 to continue the write processing of track STR1, thus suppressing the degradation of write performance.

[0225] Furthermore, by instructing the management unit 65 to perform the third management step, the judgment unit 67 can update the cumulative count by subtracting the number of the second damaged sector CSC from the cumulative count by the correction limit judgment unit 66. In other words, in Figure 15 In this process, the accumulated count can be updated from the state shown by the dashed line to the state shown by the solid line. Therefore, it is possible to maintain the state where the error correction on a track-by-track basis for track STR0 has not reached its limit.

[0226] (Example of the second method of the second write operation) (Information: Cumulative measured quantity exceeded)

[0227] Next, an example of the second method for the second write operation will be provided. Figure 16This is a graph showing the change in positioning error PE and the change in cumulative measured excess when writing to the second track STR1 in the second manner of the second write operation. It is also a graph showing the situation where the cumulative measured excess exceeds the upper limit threshold during the write operation to the nth target sector RSCn of the second track STR1. Here, the information obtained by the correction limit determination unit 66 is the cumulative measured excess.

[0228] like Figure 16 As shown, the judgment unit 67 can determine which of the following management functions, the first to the third management, should be executed by the management unit 65 by monitoring whether the cumulative measured excess related to the damaged sector CSC of the first track STR0 exceeds the upper limit threshold.

[0229] exist Figure 16 In the example, we focus on the point in time when the write processing unit 62 has performed write processing up to the nth object sector RSCn of track STR1. At this point in time, it is known that the cumulative measured excess exceeds the upper limit threshold. Even if the cumulative measured excess exceeds the upper limit threshold, the determination unit 67 can still enable the write processing unit 62 to continue writing to track STR1, thus suppressing the degradation of write performance.

[0230] Furthermore, by instructing the management unit 65 to perform the third management step, the judgment unit 67 enables the correction limit judgment unit 66 to subtract the measured excess from the accumulated measured excess, thereby updating the accumulated measured excess. In other words, in Figure 16 In this process, the accumulated measured excess can be updated from the state shown by the dashed line to the state shown by the solid line. Therefore, it is possible to maintain the state where the error correction on a track-by-track basis for track STR0 has not reached its limit.

[0231] Here, we focus on the case where, during the write process of the 0th object sector RSC0 to the nth object sector RSCn of track STR1, the measured excess became the largest during the write process of the αth object sector RSCα.

[0232] When the determination unit 67 transfers the original data from the buffer memory 80 to the system area S, the determination unit 67 can prioritize transferring the original data of the most severely damaged target sector RSCα in track STR0 to the system area S. In this case, the correction limit determination unit 66 can update the accumulated measured excess by subtracting the measured excess during the write process of the target sector RSCα on track STR1 from the accumulated measured excess. Since the accumulated measured excess can be updated with the minimum amount, it is unlikely that the accumulated measured excess will exceed the upper limit threshold.

[0233] Next, a flowchart is used to illustrate the second method of the second write operation. Figure 17This is a flowchart illustrating the write processing method for the nth target sector RSCn of the second track STR1 in the write processing method of this embodiment. It is a diagram of the second mode in which the disk device 1 adopts the second write operation during the first write. Figure 18 It continues in Figure 17 The following is a flowchart illustrating the write processing method.

[0234] like Figure 17 , Figure 1 as well as Figure 12 As shown, in the second mode of starting the second write operation, firstly, in step ST1a, the write processing unit 62 performs a write process to write first data including the first user data to the first track STR0. Next, in step ST2a, the management unit 65 performs a first management process to prevent overwriting of the first user data in the buffer memory 80. Then, in step ST3a, the write processing unit 62 performs a write process to write second data including the second user data to the second track STR1.

[0235] In step ST4a, during the write process of writing data to the nth object sector RSCn of track STR1, the positioning error PE exceeds the reference radius position PO. Next, in step ST5a, the determination unit 67 determines whether the error correction of the first user data on track STR0 exceeds the limit based on the information obtained by the correction limit determination unit 66.

[0236] like Figure 18 , Figure 1 as well as Figure 12 As shown, if the error correction of the first user data on the first track STR0 exceeds the limit (step ST5a, "Yes"), the process moves to step ST6a, and the determination unit 67 transfers the original data of one of the multiple damaged target sectors CSC of the first track STR0 from the buffer memory 80 to the recording medium (e.g., system area S), and then moves to step ST7a.

[0237] On the other hand, if the error correction of the first user data on the first track STR0 does not exceed the limit (step ST5a, "No"), proceed to step ST7a.

[0238] In step ST7a, the determination unit 67 determines whether the nth target sector RSCn of track STR1 is the final target sector RSC in track STR1 where the second user data is written. If the nth target sector RSCn of track STR1 is the aforementioned final target sector RSC (step ST7a, "Yes"), the process moves to step ST8a, and the write processing unit 62 performs the write processing of writing the second parity bit in the second data to the (n+1)th target sector RSC(n+1) of track STR1. By completing the write of the second parity bit of track STR1, the write processing of track STR0 and track STR1 is completed.

[0239] On the other hand, if the nth target sector RSCn of track STR1 is not the final target sector RSC mentioned above (step ST7a, "No"), the process moves to step ST9a, and the write processing unit 62 performs the write processing of data to the (n+1)th target sector RSC(n+1) of track STR1. That is, the write processing unit 62 continues to perform the write processing of the second user data to track STR1. Then, the write processing of track STR0 and track STR1 ends by completing the write of the second user data and the second parity bit of track STR1.

[0240] Figure 18 Step ST6a can be modified. Figure 19 It continues in Figure 17 The following is a variation of the flowchart showing the write processing method.

[0241] like Figure 19 , Figure 1 as well as Figure 12 As shown, it is able to Figure 18 Step ST6a is replaced with Figure 19 Step ST6b. Furthermore, in Figure 19 In, except for step ST6b, and with Figure 18 They are all the same.

[0242] In step ST6b, the determination unit 67 can transfer the original data of the damaged object sector CSC, which has the most severely damaged data, from the buffer memory 80 to the recording medium (e.g., system area S) in the 0th object sector RSC0 to the nth object sector RSCn of the first track STR0, from the buffer memory 80 to the recording medium (e.g., system area S) and move it to step ST7a.

[0243] According to one embodiment of the disk device 1 configured as described above, the disk device 1 includes a disk DK, a header HD, a read processing unit 63, a write processing unit 62, an error correction unit 64, a buffer memory 80, a management unit 65, a correction limit determination unit 66, and a determination unit 67.

[0244] During the first write operation, the read processing unit 63 performs a seek process to align the read head RHD with the write head WHD and position it opposite the second track STR1. The correction limit determination unit 66 obtains information that the position of the write head WHD exceeds the reference radius position PO in the first direction Da whenever data is written to each target sector RSC of the second track STR1. The management unit 65 performs the first management operation.

[0245] If, based on the information obtained by the correction limit determination unit 66, the determination unit 67 determines that the error correction unit 64 has not exceeded the limit for correcting the first user data on the first track STR0, it can enable the write processing unit 62 to continue writing to the second track STR1, and enable the management unit 65 to perform second management instead of first management. If, based on the above information, the determination unit 67 determines that the error correction unit 64 has exceeded the limit for correcting the first user data on the first track STR0, it can enable the write processing unit 62 to continue writing to the second track STR1, and enable the management unit 65 to perform third management instead of first management.

[0246] Furthermore, during or after the first write operation, the determination unit 67 can enable the management unit 65 to perform a process that transfers the data belonging to the third group to a non-volatile recording medium.

[0247] This avoids situations where writing to track STR1 is halted or terminated, thus contributing to improved write performance of disk device 1.

[0248] Moreover, unlike PTS at startup, it does not require reading the separated data during the seek operation, thus also contributing to improved read performance.

[0249] Furthermore, since there is no PTS activation, the target sector RSCs of tracks 1 (STR0) and 2 (STR1) will not become free sectors (ESCs). Therefore, the utilization efficiency of tracks 1 (STR0) and 2 (STR1) can be improved, thereby increasing the recording density (ADC: Areal Density Capability) of the data on the disk DK.

[0250] Furthermore, for the damaged data on track STR0 that exceeds the error correction limit performed by the error correction unit 64, the original data of this damaged data can be transferred from the buffer memory 80 to the recording medium (e.g., system area S). This indirectly protects the damaged data on track STR0. Through the above, a disk drive 1 that can increase the recording density of data on disk DK and suppress the degradation of write performance can be obtained.

[0251] The embodiments of the present invention have been described above, but these embodiments are merely illustrative examples and are not intended to limit the scope of the invention. The novel embodiments described above can be implemented in a variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above embodiments and their variations are included in the scope and spirit of the invention, and are also included within the scope of the claims and their equivalents.

Claims

1. A disk drive, comprising: The disk has a first data track and a second data track that are adjacent to each other in the recording layer. Each of the first data track and the second data track includes a plurality of object sectors that are objects to be written data. The first data track is located in a first direction that is parallel to the radial direction of the disk when viewed from the second data track. The head has a write head for writing data to the recording layer and a read head for reading data from the recording layer; The read processing unit is capable of performing seek processing to cause the read head to seek; The write processing unit is capable of performing write processing on the data to be written to the recording layer; The error correction unit performs error correction on the data of one or more corrupted object sectors among the plurality of object sectors of the first data track that are determined to be corrupted. The buffer memory is capable of holding multiple data, including the first user data and the second user data; The management unit is capable of selectively executing the first management, the second management, and the third management. The first management prohibits overwriting the first user data in the buffer memory. The second management allows overwriting all the first user data in the buffer memory. The third management allows overwriting the data belonging to the first and second groups of the first user data in the buffer memory and prohibits overwriting the data belonging to the third group of the first user data in the buffer memory. Correction limit determination unit; as well as Judgment Department The first write period is the period after the write processing unit performs the write process of writing first data including the first user data to the plurality of object sectors of the first data track, and is also the period during which the write processing unit performs the write process of writing second data including the second user data to the plurality of object sectors of the second data track. During the first write, The read processing unit performs a seek process to align the read head with the second data track. Whenever data is written to each of the target sectors of the second data track, the correction limit determination unit obtains information that the position of the write head exceeds the reference radius position in the first direction. The management department performs the first management. The judgment unit If, based on the information obtained by the correction limit determination unit, it is determined that the error correction unit has not exceeded the limit in correcting the error of the first user data on the first data track, the write processing unit continues to perform the write processing on the second data track, and the management unit performs the second management instead of the first management. If, based on the information, it is determined that the error correction unit has exceeded its limit in correcting the error of the first user data on the first data track, the write processing unit continues the write processing on the second data track, and the management unit performs the third management instead of the first management. During or after the first write period, The judgment unit causes the management unit to perform a process that transfers the data belonging to the third group to a non-volatile recording medium. The data belonging to the first group is the original data of one or more object sectors in the plurality of object sectors of the first data track that have been determined to be without data corruption. The data belonging to the second group is the original data of one or more first damaged object sectors among the plurality of object sectors of the first data track that have been determined to be corrupted, and is the original data within the range of data that can be corrected by the error correction unit. The data belonging to the third group is the original data of one or more second damaged object sectors in the plurality of object sectors of the first data track that are judged to be corrupted, and is the original data of data that deviates from the range that can be corrected by the error correction unit.

2. The disk drive according to claim 1, For all object sectors of the first data track, write the first user data, or write both the first user data and the first parity bit generated based on the first user data. For all object sectors of the second data track, write the second user data, or write both the second user data and the second parity bit generated based on the second user data.

3. The disk drive according to claim 1, Whenever the second data is written to each of the target sectors of the second data track, the correction limit determination unit measures the measured excess amount by which the position of the write head exceeds the reference radius position in the first direction, and updates the cumulative measured excess amount, i.e., the accumulated measured excess amount. The information obtained by the correction limit determination unit is the cumulative measured excess. During the first write, The judgment unit If it is determined that the cumulative measured amount exceeds the upper limit threshold, the write processing unit continues to perform the write processing on the second data track, and the management unit performs the second management. The upper limit threshold is a value representing the limit of the range within which error correction can be performed on the first data track. If it is determined that the cumulative measured excess exceeds the upper limit threshold, the write processing unit continues to perform the write processing on the second data track, the management unit performs the third management, and the correction limit determination unit subtracts the measured excess measured each time when one or more second damaged target sectors are formed on the first data track from the cumulative measured excess, so that the cumulative measured excess is updated at any time.

4. The disk drive according to claim 3, When the measured excess amount is set as the first measured excess amount when one or more first damaged target sectors are formed on the first data track, and the measured excess amount is set as the second measured excess amount when one or more second damaged target sectors are formed on the first data track, The second measured excess is greater than the first measured excess.

5. The disk drive according to claim 3, The correction limit determination unit counts the number of one or more damaged sectors in the first data track, and updates the cumulative count. The information obtained by the correction limit determination unit also includes the cumulative number. During the first write, The judgment unit If it is determined that the cumulative measured quantity exceeds the upper limit threshold and the cumulative number is below the upper limit number, the write processing unit continues to perform the write processing on the second data track, and the management unit performs the second management. The upper limit number represents the limit of the range within which error correction can be performed on the first data track. If it is determined that the cumulative measured excess exceeds the upper limit threshold, the write processing unit continues to perform the write processing on the second data track, the management unit performs the third management, and the correction limit determination unit subtracts the measured excess measured each time when one or more second damaged sectors are formed on the first data track from the cumulative measured excess, thereby updating the cumulative measured excess at any time. If it is determined that the cumulative number exceeds the upper limit, the write processing unit continues to write to the second data track, the management unit performs the third management, and the correction limit determination unit subtracts the number of second damaged sectors counted each time one or more second damaged sectors are formed on the first data track from the cumulative number, thereby updating the cumulative number at any time. If the cumulative number exceeds the upper limit, the total number of the more than one first damaged object sector is the same as the upper limit.

6. The disk drive according to claim 1, The correction limit determination unit counts the number of one or more damaged sectors in the first data track, and updates the cumulative count. The information obtained by the correction limit determination unit is the cumulative number. During the first write, The judgment unit If it is determined that the cumulative number is below the upper limit, the write processing unit continues to perform the write processing on the second data track, and the management unit performs the second management. The upper limit is the number of elements that represent the limit of the range within which error correction can be performed on the first data track. If it is determined that the cumulative number exceeds the upper limit, the write processing unit continues to write to the second data track, the management unit performs the third management, and the correction limit determination unit subtracts the number of second damaged sectors counted each time one or more second damaged sectors are formed on the first data track from the cumulative number, thereby updating the cumulative number at any time. If the cumulative number exceeds the upper limit, the total number of the more than one first damaged object sector is the same as the upper limit.

7. The disk drive according to claim 1, The first data track and the second data track are located in the user data area of ​​the recording layer. The non-volatile recording medium is the system region of the recording layer.

8. The disk drive according to claim 7, The user data area has multiple strips, and each strip has multiple data tracks. The plurality of bands have a first band including the first data track and the second data track. The management department schedules the transfer of data belonging to the third group to the system area at regular intervals. This occurs either after the write process of writing the second data to the plurality of object sectors of the second data track is completed, or after the write process of writing data to the plurality of data tracks of the first band is completed.

9. The disk drive according to claim 1, The non-volatile recording medium is a non-volatile memory located on the outer side of the disk.

10. The disk drive according to claim 9, The user data area of ​​the recording layer has multiple strips, each strip having multiple data tracks. The plurality of bands have a first band including the first data track and the second data track. The management department schedules the transfer of data belonging to the third group to the system area of ​​the recording layer at regular intervals. The error correction time for the first user data on the first data track exceeds the limit, or the write process for writing the second data to the plurality of object sectors of the second data track ends, or the write process for writing data to the plurality of data tracks of the first track ends.

11. The disk drive according to claim 1, The write processing unit is a watt-type recorder that writes the first data of the first data track to the second data of the second data track in an overlapping write direction opposite to the first direction.

Images