Magnetic disk device

Abstract

Provided is a magnetic disk device capable of improving the quality of data recorded on a disk while increasing the capacity of the disk. A magnetic disk device includes a disk, a write head, an adjustment unit, and a write processing unit. The adjustment unit adjusts each of the first to third adjustment values. The write processing unit is capable of selecting a shingled recording pattern and executing write processing based on the first to third adjustment values. The number of the plurality of tracks STRe with BAe is set as t + 1, and the number of unused sectors among the plurality of sectors with BAe is set as e. The adjustment unit adjusts the first to third adjustment values in order to satisfy e < t.

Description

[0001] This application claims the priority of Japanese Patent Application No. 2023-147532 (filing date: September 12, 2023) as a basic application. The present application incorporates the entire contents of the basic application by reference. Technical Field

[0002] An embodiment of the present invention relates to a magnetic disk device. Background Art

[0003] As magnetic disk devices, known are conventional recording (Conventional Magnetic Recording: CMR) type (or previous recording type) magnetic disk devices that write to multiple tracks with intervals in the radial direction of the disk, shingled recording (Shingled write Magnetic Recording: SMR or Shingled Write Recording: SWR) type magnetic disk devices that write to multiple tracks in an overlapping manner in the radial direction of the disk, and hybrid recording type magnetic disk devices that selectively perform conventional recording type and shingled recording type. Summary of the invention

[0004] Embodiments of the present invention provide a magnetic disk device capable of increasing the capacity of a disk and improving the quality of data recorded on the disk.

[0005] A magnetic disk device according to one embodiment comprises: a disk having a band including a plurality of tracks, each of the tracks including a plurality of sectors; a write head for writing data to the disk; an adjustment unit for adjusting a first adjustment value, a second adjustment value and a third adjustment value, respectively, the first adjustment value being the number of the plurality of sectors of each of the tracks of the band, the second adjustment value being the length of each of the sectors in the circumferential direction of the disk, and the third adjustment value being the number of the plurality of tracks of the band; and a write processing unit capable of selecting a shingle recording format for writing data to the plurality of tracks in an overlapping manner in a radial direction of the disk, performing write processing based on the first adjustment value to the third adjustment value, wherein when the number of the plurality of tracks of the band is set to t+1 and the number of unused sectors among the plurality of sectors of the band is set to e, the adjustment unit adjusts the first adjustment value to the third adjustment value in order to make e<t hold.

[0006] In addition, a magnetic disk device involved in one embodiment comprises: a disk, which has a belt including a plurality of tracks, each of which includes a plurality of sectors; a write head, which writes data to the disk; an adjustment unit, which adjusts a first adjustment value and a second adjustment value, respectively, the first adjustment value being the number of the plurality of sectors of each of the tracks of the belt, and the second adjustment value being the length of each of the sectors in the circumferential direction of the disk; and a write processing unit, which can select a shingle recording type for writing data to the plurality of tracks in an overlapping manner in the radial direction of the disk, and execute a write operation based on the first adjustment value. and the writing processing of the second adjustment value, when the recording capacity of the band is set to Cb, the recording capacity of each of the sectors is set to Cs, the number of the multiple sectors of each of the tracks of the band is set to n, the number of the multiple tracks of the band is set to t+1, the variable is set to k, and the number of unused sectors in the multiple sectors of the band is set to e, Cb / Cs=n×t+k, n=e+k, the adjustment unit obtains the information of Cb, Cs and t, and finally determines each of the n, e and k in order to make e<t hold. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a block diagram showing the structure of a magnetic disk device according to one embodiment.

[0008] Figure 2 This is a perspective view showing a part of the magnetic disk device, showing a plurality of disks and a plurality of heads.

[0009] Figure 3 This is a schematic diagram showing an example of the arrangement of a plurality of servo areas and a plurality of data areas on a disk according to the above-mentioned embodiment.

[0010] Figure 4 Yes means Figure 3 The diagram shows three tracks and a write head in the user data area of ​​a disk that is subjected to shingle recording.

[0011] Figure 5 Yes means Figure 3 The diagram shows three tracks of a media cache and a write head for normal recording processing of a disk.

[0012] Figure 6 This is a schematic diagram showing an example of data writing processing on a disk.

[0013] Figure 7 Yes means Figure 6 Schematic diagram of two bands and one guard band in the user data area.

[0014] Figure 8 Yes means Figure 6 A schematic diagram of three sectors in one track of a tape is shown.

[0015] Fig. 9 1 is a schematic diagram showing one band in the user data area of ​​a disk according to a comparative example, and is a diagram for explaining an example in which the adjustment unit does not adjust the number of unused sectors in the band.

[0016] Fig.10 This is a schematic diagram showing one band in the user data area of ​​the disk according to the above embodiment, and is a diagram for explaining an example in which an adjustment unit adjusts the number of unused sectors in the above band.

[0017] Description of Reference Numerals

[0018] 1 disk device; 60 MPU; 61 read / write processing unit; 61a write processing unit; 62 adjustment unit; 100 host; 110 system controller; 120 driver IC; 130 head amplifier IC; 140 R / W channel; 150 HDC; DK disk; L recording layer; Z zone; BA band; STR track; SC sector; GB guard band; GTR guard track; WHD write head; W width; Ls length; Cb, Cs recording capacity; n, t, e number; k variable; d1 radial direction; d2 travel direction; d3 rotation direction; d4 seek direction. DETAILED DESCRIPTION

[0019] (One embodiment)

[0020] Hereinafter, a magnetic disk device 1 according to an embodiment will be described in detail with reference to the drawings. First, the configuration of the magnetic disk device 1 will be described. Figure 1 1 is a block diagram showing the structure of the magnetic disk device 1 according to the present embodiment. In the present embodiment, the magnetic disk device 1 is a hybrid recording type magnetic disk device that selects and executes the normal recording type and the shingle recording type. However, the technology described below can also be applied to the shingle recording type magnetic disk device.

[0021] like Figure 1 As shown, the magnetic disk device 1 includes a plurality of (e.g., 1 to 10) disks (magnetic disks) DK 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 a head amplifier IC or a pre-amplifier) ​​130, a volatile memory 70, a buffer memory (cache) 80, a nonvolatile memory 90, and a system controller 110 as an integrated circuit on one chip. In addition, the magnetic disk device 1 is connected to a host system (hereinafter referred to as a host) 100.

[0022] Each disk DK is formed to have a diameter of, for example, 95 mm (3.5 inches) and has recording layers (magnetic recording layers) on both sides thereof. In addition, in the present embodiment, the magnetic disk device 1 has 1 to 10 disks DK, but the number of disks DK is not limited thereto. In addition, the magnetic disk device 1 may also have a single disk DK.

[0023] The head stack assembly 22 can control the movement of the head HD mounted on the arm 30 to a target position on the disk DK by driving a voice coil motor (hereinafter referred to as VCM) 24 , that is, can perform seek.

[0024] The disk DK has a data-writable area in which a user data area U that can be used by a user and a system area S in which information required for system management is written are allocated.

[0025] The head HD records and reproduces information on the disk DK. The head HD has 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 track of the recording layer of the disk DK.

[0026] The driver IC 120 controls the driving of the SPM 20 and the VCM 24 under the control of the system controller 110 (more specifically, the MPU 60 described later). The SPM 20 supports and rotates the plurality of disks DK.

[0027] The head amplifier IC 130 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 (more 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.

[0028] The volatile memory 70 is a semiconductor memory in which the stored data is lost when the power supply is disconnected. The volatile memory 70 stores data required for processing of each part of the magnetic disk device 1, etc. The volatile memory 70 is, for example, a DRAM (Dynamic Random Access Memory) or an SDRAM (Synchronous Dynamic Random Access Memory).

[0029] The buffer memory 80 is a semiconductor memory that temporarily records data transmitted and received between the magnetic disk device 1 and the host 100. In addition, the buffer memory 80 may be formed integrally with the volatile memory 70. The buffer memory 80 is, for example, a DRAM, an SRAM (Static Random Access Memory), an SDRAM, a FeRAM (Ferroelectric Random Access Memory), or an MRAM (Magnetoresistive Random Access Memory).

[0030] The nonvolatile memory 90 is a semiconductor memory that records stored data even when power supply is turned off. The nonvolatile memory 90 is, for example, a NOR type or NAND type flash ROM (Flash Read Only Memory: FROM).

[0031] The system controller (controller) 110 is implemented, for example, using a large-scale integrated circuit (LSI) called a system-on-a-Chip (SoC) in which a plurality of components are integrated into 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, a volatile memory 70, a buffer memory 80, a nonvolatile memory 90, and a host 100.

[0032] The R / W channel 140 performs signal processing of read data transmitted from the disk DK to the host 100 and write data transmitted from the host 100 according to instructions from the MPU 60 described later. The R / W channel 140 has a circuit or function for modulating write data. In addition, the R / W channel 140 has a circuit or function for measuring the signal quality of read data. The R / W channel 140 is electrically connected to, for example, the head amplifier IC 130, the HDC 150, the MPU 60, and the like.

[0033] The HDC 150 controls data transfer between the host 100 and the R / W channel 140 according to instructions from the MPU 60 described later. The HDC 150 is electrically connected to the R / W channel 140, the MPU 60, the volatile memory 70, the buffer memory 80, the nonvolatile memory 90, and the like.

[0034] The MPU 60 is a control unit that controls each part of the magnetic disk device 1 and is a main controller. The MPU 60 controls the VCM 24 via the driver IC 120 and performs servo control for positioning the head HD. The MPU 60 controls the writing operation of writing data to the disk DK and selects the storage destination of the written data transmitted from the host 100. In addition, the MPU 60 controls the reading operation of reading data from the disk DK and controls the processing of the read data transmitted from the disk DK to the host 100. The MPU 60 is connected to each part of the magnetic disk device 1. For example, the MPU 60 is electrically connected to the driver IC 120, the R / W channel 140, the HDC 150, etc.

[0035] The MPU 60 includes a read / write processing unit 61, an adjustment unit 62, etc. The MPU 60 executes processing of each of these units, for example, the read / write processing unit 61, the adjustment unit 62, etc., on firmware. Alternatively, the MPU 60 may include each of these units as a circuit.

[0036] The read / write processing unit 61 includes a write processing unit 61a and a read processing unit 61b. The write processing unit 61a controls the writing process of data, and the read processing unit 61b controls the reading process of data according to a command from the host 100. The read / write processing unit 61 controls the VCM 24 via the driver IC 120, positions the head HD at a target position (predetermined radial position) on the disk DK, and performs a reading process or a writing process.

[0037] Figure 2 1 is a perspective view showing a part of the magnetic disk device 1, and is a view showing a plurality of disks DK and a plurality of heads HD.

[0038] like Figure 2 As shown in FIG. 1 , in the circumferential direction, the direction in which the disk DK rotates is referred to as the rotation direction d3. Figure 2 In the example shown, the rotation direction is indicated by the counterclockwise direction, but it may be the opposite direction (clockwise direction). In addition, the travel direction d2 of the head HD relative to the disk DK is the opposite direction to the rotation direction d3. The travel direction d2 is the direction in which the head HD writes and reads data to and from the disk DK in a sequential manner in the circumferential direction, that is, the direction in which the head HD travels relative to the disk DK in the circumferential direction.

[0039] The magnetic disk device 1 includes i disks, namely disks DK1 to DKi, and j heads, namely heads HD1 to HDj. In the present embodiment, the number of heads HD is twice the number of disks DK (j=2×i).

[0040] The disks DK1 to DKi are coaxially arranged and overlapped with each other at intervals. The disks DK1 to DKi have the same diameter. Here, the terms "same", "identical", "consistent", "equivalent" and the like include not only the meaning of being completely identical, but also the meaning of being different to the extent that they can be regarded as substantially the same. In addition, the diameters of the disks DK1 to DKi may be different from each other.

[0041] 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 on the opposite side of the first recording layer La1. Disk DK2 has a first recording layer La2 and a second recording layer Lb2 on the opposite side of the first recording layer La2. Disk DKi has a first recording layer Lai and a second recording layer Lbi on the opposite side of the first recording layer Lai. Each first recording layer La is sometimes referred to as a surface or a recording surface. Each second recording layer Lb is sometimes referred to as a back side or a recording surface.

[0042] Each recording layer L has a user data area U and a system area S. The first recording layer La1 has a user data area Ua1 and a system area Sa1. The second recording layer Lb1 has a user data area Ub1 and a system area Sb1. The first recording layer La2 has a user data area Ua2 and a system area Sa2. The second recording layer Lb2 has a user data area Ub2 and a system area Sb2. The first recording layer Lai has a user data area Uai and a system area Sai. The second recording layer Lbi has a user data area Ubi and a system area Sbi.

[0043] The track enclosed by the double dashed line in the user data area Ua1 (first recording layer La1) is referred to as track Ta1. The track located on the opposite side of track Ta1 in the user data area Ub1 (second recording layer Lb1) is referred to as track Tb1.

[0044] The track enclosed by the double dashed line in the user data area Ua2 (first recording layer La2) is referred to as track Tc1. The track located on the opposite side of track Tc1 in the user data area Ub2 (second recording layer Lb2) is referred to as track Td1.

[0045] The track enclosed by the double dashed line in the user data area Uai (first recording layer Lai) is referred to as track Te1. The track located on the opposite side of track Te1 in the user data area Ubi (second recording layer Lbi) is referred to as track Tf1.

[0046] In this embodiment, the tracks Ta1, Tb1, Tc1, Td1, Te1, and Tf1 are located on the same cylinder.

[0047] The head HD faces the disk DK. In the present embodiment, one head HD faces each recording layer L of the disk DK. For example, the head HD1 faces the first recording layer La1 of the disk DK1, writes data to the first recording layer La1, and reads data from the first recording layer La1. The head HD2 faces the second recording layer Lb1 of the disk DK1, writes data to the second recording layer Lb1, and reads data from the second recording layer Lb1.

[0048] The head HD3 faces the first recording layer La2 of the disk DK2, writes data to the first recording layer La2, and reads data from the first recording layer La2. The head HD4 faces the second recording layer Lb2 of the disk DK2, writes data to the second recording layer Lb2, and reads data from the second recording layer Lb2. The head HDj-1 faces the first recording layer Lai of the disk DKi, writes data to the first recording layer Lai, and reads data from the first recording layer Lai. The head HDj faces the second recording layer Lbi of the disk DKi, writes data to the second recording layer Lbi, and reads data from the second recording layer Lbi.

[0049] Figure 3 FIG. 2 is a schematic diagram showing an example of the arrangement of a plurality of servo areas SV and a plurality of data areas DTR of a disk DK according to the present embodiment. Figure 3 As shown, in the radial direction d1 of the disk DK, the direction toward the outer periphery of the disk DK is called the outer direction (outer side), and the direction opposite to the outer direction is called the inner direction (inner side).

[0050] exist Figure 3 In the diagram, the user data area U is divided into an inner peripheral area IR located inward, an outer peripheral area OR located outward, and a middle peripheral area MR located between the inner peripheral area IR and the outer peripheral area OR.

[0051] The disk DK has a plurality of servo areas SV and a plurality of data areas DTR. The plurality of servo areas SV may, for example, extend radially in the radial direction of the disk DK and be discretely arranged at predetermined intervals in the circumferential direction. The plurality of servo areas SV may, for example, extend linearly from the inner circumference to the outer circumference and be discretely arranged at predetermined intervals in the circumferential direction. The plurality of servo areas SV may, for example, extend spirally from the inner circumference to the outer circumference and be discretely arranged at predetermined intervals in the circumferential direction. In addition, the plurality of servo areas SV may, for example, be arranged in an island shape in the radial direction and be discretely arranged by changing the predetermined intervals in the circumferential direction.

[0052] Hereinafter, a servo area SV in a predetermined track may be referred to as a "servo sector". In addition, a "servo area SV" may be referred to as a "servo sector SV". A servo sector includes servo data. Hereinafter, "the configuration of several servo data constituting a servo sector" may be referred to as a "servo pattern". In addition, "servo data written to a servo sector" may be referred to as a "servo sector".

[0053] A plurality of data regions DTR are respectively arranged between a plurality of servo regions SV. For example, the data region DTR is equivalent to the region between two consecutive servo regions SV in the circumferential direction. Hereinafter, a data region DTR in a predetermined track is sometimes referred to as a "data sector". In addition, a "data region DTR" is sometimes referred to as a "data sector DTR". A data sector contains user data. In addition, "user data written to a data sector" is sometimes referred to as a "data sector". A "data sector" is sometimes referred to as "user data". In addition, a "pattern composed of several data" is sometimes referred to as a "data pattern". Figure 3 In the example shown, the data pattern of a predetermined track is composed of a plurality of servo data (servo sectors) and a plurality of user data (data sectors).

[0054] The servo area SV includes a plurality of partitioned servo areas ZSV, etc. In addition, the servo area SV may also include an area including a gap (an offset between the circumferential positions of two partitioned servo areas), an area including servo data, and a data area DTR, etc., in addition to the partitioned servo area ZSV. The plurality of partitioned servo areas ZSV are discretely arranged along the radial direction. The plurality of partitioned servo areas ZSV extend in the radial direction, respectively.

[0055] A partition servo area (servo area) ZSV in a predetermined track is sometimes referred to as a "partition servo sector" or "servo sector". In addition, a "partition servo area (servo area) ZSV" is sometimes referred to as a "partition servo sector ZSV" or "servo sector ZSV". "Servo data written to a partition servo sector" is sometimes referred to as a "partition servo sector" or "servo sector". Hereinafter, "the configuration of several servo data constituting a partition servo sector" is sometimes referred to as a "partition servo pattern" or "servo pattern". Hereinafter, a servo area SV in a predetermined track is sometimes referred to as a "partition pattern sector".

[0056] In addition, "servo area SV" is sometimes referred to as "partition mode sector". "At least one data written to a partition mode sector" is sometimes referred to as "partition mode sector". A partition mode sector includes at least one partition servo sector. Hereinafter, "data pattern of a partition mode sector" is sometimes referred to as "partition data pattern".

[0057] exist Figure 3 In the example shown, the servo area SV includes sub-area servo areas ZSV0, ZSV1, and ZSV2. The sub-area servo areas ZSV0, ZSV1, and ZSV2 are arranged in a staggered manner in the radial direction. The sub-area servo areas ZSV0, ZSV1, and ZSV2 may also be arranged in a stepwise manner in the radial direction.

[0058] The partitioned servo area ZSV2 is located at a position closer to the inner circumference than the partitioned servo area ZSV1. The partitioned servo area ZSV0 is located at a position closer to the outer circumference than the partitioned servo area ZSV1. For example, the partitioned servo area ZSV2 is arranged from the inner circumference area IR to the middle circumference area MR, the partitioned servo area ZSV1 is arranged from the inner circumference area IR to the outer circumference area OR, and the partitioned servo area ZSV0 is arranged from the middle circumference area MR to the outer circumference area OR. Hereinafter, a predetermined area in the radial direction in which a plurality of partitioned servo areas ZSV are arranged in the circumferential direction in a predetermined servo area SV is sometimes referred to as a partitioned servo boundary area, a dual servo area, or a dual partitioned servo area ZB.

[0059] exist Figure 2 In the example shown, the master servo area SVO and the slave servo area SVE are alternately arranged at intervals in the circumferential direction. For example, one slave servo area SVE is arranged between two master servo areas SVO arranged continuously at intervals in the circumferential direction. In other words, one slave servo area SVE is arranged between two master servo areas SVO arranged continuously at intervals in the circumferential direction. For example, in the case where all servo areas SV of the disk DK are assigned sequentially consecutive numbers, the master servo area SVO corresponds to the odd-numbered servo area SV, and the slave servo area SVE corresponds to the even-numbered servo area SV. In addition, two or more slave servo areas SVE may be arranged between two master servo areas SVO arranged continuously at intervals in the circumferential direction.

[0060] The master servo area SVO and the slave servo area SVE may be composed of, for example, only a servo area for reading and demodulating servo data as a whole (hereinafter sometimes referred to as a normal servo area). Hereinafter, "reading and demodulating servo data" may also be referred to as "servo reading". The master servo area SVO and the slave servo area SVE may be composed of, for example, a normal servo area and a servo area for servo reading a circumferential range of servo data smaller than the circumferential range of servo data for servo reading in the normal servo area (hereinafter sometimes referred to as a short servo area).

[0061] The media buffer M is allocated to the disk DK. However, the media buffer M may not be arranged on the disk DK.

[0062] By using the above-mentioned plurality of servo data, it is possible to position the head HD so as to obtain a predetermined off-track amount, or to detect the swing amount and swing direction of the head HD.

[0063] In the description of this embodiment, the case where the number of partitions of the disk DK is 3 is used as an example, but the number of partitions of the disk DK can be changed in various ways. The number of partitions of the disk DK can also be 30 to 40. In addition, each partition has a plurality of bands. For example, each partition has hundreds of bands.

[0064] Figure 4 Yes means Figure 3 The schematic diagram of the three tracks STR and the write head WHD of the user data area U of the disk DK for shingle recording is shown. The user data area U is a shingle recording area. Data can be written sequentially in bands in the user data area U, that is, shingle recording is allowed.

[0065] like Figure 4 As shown, the write head WHD is capable of writing data to the disk DK in a sequential manner in the travel direction d2. Figure 3 The shown read head RHD is also capable of reading data written to the disk DK in a sequential manner in the direction of travel d2.

[0066] The direction in which multiple tracks STR are continuously recorded in a direction parallel to the radial direction d1, that is, the direction in which the track STR written next overlaps the track STR written previously in the radial direction d1 is called the overlapping writing direction or the recording advancing direction. Figure 4 In the band BAe shown, the overlap writing direction is the inner direction, but the overlap writing direction may also be the outer direction.

[0067] For example, the overlapping writing direction applied to multiple bands BA (multiple partitions Z) located on the outer side of a specific radial position and the overlapping writing direction applied to multiple bands BA (multiple partitions Z) located on the inner side of a specific radial position may be opposite to each other.

[0068] The band BAe has a plurality of tracks STR including tracks STRe, STRe+1 and STRe+2. Tracks STRe, STRe+1 and STRe+2 are continuously overlapped in the overlap writing direction in the order in which they are recorded. Track STRe among tracks STRe, STRe+1 and STRe+2 is equivalent to the track to which data is written first, and track STRe+2 is equivalent to the track to which data is written last.

[0069] Track STRe has a track center STCe at the center in the radial direction d1 when no overlapping writing is performed on other tracks. Track STRe+1 has a track center STCe+1 at the center in the radial direction d1 when no overlapping writing is performed on other tracks. Track STRe+2 has a track center STCe+2 at the center in the radial direction d1 when no overlapping writing is performed on other tracks.

[0070] exist Figure 4 In the example shown, tracks STRe, STRe+1, and STRe+2 are written at a pitch (Watt recording track pitch) 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 may also be written at different pitches.

[0071] The width in the radial direction d1 of the area in track STRe where the overlapping writing of track STRe+1 is not performed is the same as the width in the radial direction d1 of the area in track STRe+1 where the overlapping writing of track STRe+2 is not performed. In addition, the width in the radial direction d1 of the area in track STRe where the overlapping writing of track STRe+1 is not performed may be different from the width in the radial direction d1 of the area in track STRe+1 where the overlapping writing of track STRe+2 is not performed.

[0072] exist Figure 4 In the figure, for the sake of convenience, each track STR is shown as a rectangle, but in fact, each track STR is curved along the circumferential direction. In addition, each track STR may also be a wave shape that varies in the radial direction d1 while extending in the circumferential direction. Figure 4 In the example, overlapping writing is performed on three tracks STR, but overlapping writing can also be performed on more than three tracks STR.

[0073] The write processing unit 61a can select a shingle recording mode in which data is written to a plurality of tracks STR in an overlapping manner in the radial direction d1 of the disk DK, and perform write processing. Figure 4 In the example shown, the write processing unit 61a performs tile recording on the tracks STRe to STRe+2 in sequence at a pitch STP in the inner direction (overlap writing direction) in the band BAe.

[0074] The write processing unit 61a writes to the track STRe+1 at a pitch STP in the inner direction of the track STRe, and performs overlapping writing of the track STRe+1 on a portion of the inner circumference of the track STRe. The write processing unit 61a writes to the track STRe+2 at a pitch STP in the inner direction of the track STRe+1, and performs overlapping writing of the track STRe+2 on a portion of the inner circumference of the track STRe+1.

[0075] Figure 5 Yes means Figure 3 Schematic diagram of the three tracks CTR and the write head WHD of the media buffer M for normal recording processing of the disk DK shown. The media buffer M and Figure 3 The system area S shown is a normal recording area. In the media buffer M and the system area S, data can be written randomly, that is, normal recording is allowed.

[0076] like Figure 5 As shown, the media buffer M has a plurality of tracks CTR including tracks CTRe, CTRe+1, and CTRe+2. For example, the widths (track widths) of tracks CTRe, CTRe+1, and CTRe+2 in the radial direction d1 are the same. In addition, the track widths of tracks CTRe to CTRe+2 may be different from each other.

[0077] The center of the track CTRe in the radial direction d1 has the track center CTCe, the center of the track CTRe+1 in the radial direction d1 has the track center CTCe+1, and the center of the track CTRe+2 in the radial direction d1 has the track center CTCe+2. Figure 4 In the example shown, tracks CTRe, CTRe+1, and CTRe+2 are written at a pitch (normal recording track pitch) CTP. The track center CTCe of track CTRe and the track center CTCe+1 of track CTRe+1 are spaced apart by the pitch CTP. The track center CTCe+1 of track CTRe+1 and the track center CTCe+2 of track CTRe+2 are spaced apart by the pitch CTP.

[0078] Track CTRe and track CTRe+1 are separated by a gap GP. Track CTRe+1 and track CTRe+2 are separated by a gap GP. In addition, tracks CTRe to CTRe+2 may be written at different pitches. Figure 5 In the figure, for the sake of convenience, each track CTR is shown as a rectangle, but in fact, each track CTR is curved along the circumferential direction. In addition, each track CTR may be a wave shape extending in the circumferential direction while changing in the radial direction d1.

[0079] The write processing unit 61a can select a normal recording mode in which data is written to a plurality of tracks CTR at intervals in the radial direction d1 of the disk DK, and execute the write processing. Figure 4 In the illustrated example, the write processing unit 61a positions the write head WHD at the track center CTCe in a predetermined area of ​​the disk DK, and performs normal recording on the track CTRe or a predetermined sector of the track CTRe.

[0080] The write processing unit 61a positions the write head WHD at the track center CTCe+1 which is away from the pitch CTP in the inner direction from the track center CTCe of the track CTRe, and performs normal recording on the track CTRe+1 or a predetermined sector of the track CTRe+1. The write processing unit 61a positions the write head WHD at the track center CTCe+2 which is away from the pitch CTP in the inner direction from the track center CTCe+1 of the track CTRe+1, and performs normal recording on the track CTRe+2 or a predetermined sector of the track CTRe+2.

[0081] The write processing unit 61a can normally record the tracks CTRe, CTRe+1 and CTRe+2 in sequence in a predetermined area of ​​the disk DK, or can randomly record the predetermined sectors of the track CTRe, the predetermined sectors of the track CTRe+1 and the predetermined sectors of the track CTRe+2.

[0082] Figure 6 FIG. 2 is a schematic diagram showing an example of data writing processing in the disk DK. Figure 6 As shown, the user data area U has bands BAa, BAb, and BAc. The bands BAa, BAb, and BAc belong to the same partition Ze. In the partition Ze, the bands BAa, BAb, and BAc are arranged discontinuously in the overlap writing direction in the order in which they are written.

[0083] The bands BAa and BAb are adjacent to each other in the radial direction d1 , and the bands BAb and BAc are adjacent to each other in the radial direction d1 .

[0084] Band BAa includes tracks STRa1, STRa2, STRa3, ..., STRa(x-2), STRa(x-1), and STRax. Tracks STRa1 to STRax are tile-recorded in the overlapping writing direction in the order in which they are recorded. In band BAa, track STRa1 is equivalent to the leading track to which data is first written, and track STRax is equivalent to the last track to which data is last written.

[0085] The band BAb includes tracks STRb1, STRb2, STRb3, ..., STRb(x-2), STRb(x-1), and STRbx. Tracks STRb1 to STRbx are tile-recorded in the overlapping writing direction in the order in which they are recorded. In the band BAb, track STRb1 is equivalent to the leading track to which data is first written, and track STRbx is equivalent to the last track to which data is last written.

[0086] Band BAc includes tracks STRc1, STRc2, STRc3, ..., STRc(x-2), STRc(x-1), and STRcx. Tracks STRc1 to STRcx are tile-recorded in the overlapping writing direction in the order in which they are recorded. In band BAc, track STRc1 is equivalent to the leading track to which data is first written, and track STRcx is equivalent to the last track to which data is last written.

[0087] 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 of a band BA is fixed for each partition Z.

[0088] exist Figure 6 Tracks CTRx-1 and CTRx are shown in FIG. Figure 6 In the embodiment, tracks CTRx-1 and CTRx are normally recorded in the media buffer M or the system area S. Tracks CTRx-1 and CTRx are adjacent to each other in the radial direction d1.

[0089] Figure 7 Yes means Figure 6 FIG. 1 is a schematic diagram of two bands BAa, BAb and one guard band GB in the user data area U. Figure 7 As shown, in the tile recording method, unlike the normal recording method, due to the characteristic of performing overlapping writing on a part of the track STR, the MPU 60 manages the track group of the user data area U in units called bands.

[0090] A guard band GB is generally provided between adjacent bands BA in the radial direction d1. The guard band GB includes a guard track GTR. The guard band GB may also include a plurality of guard tracks GTR, which is different from the present embodiment. The guard band GB has the function of suppressing interference between adjacent bands BA. The guard band GB enables watt recording to be performed in units of one band BA. In addition, the guard band GB enables separation of a range (band BA) to be written in a sequential manner.

[0091] For example, the track center STCa(x-2) of track STRa(x-2), the track center STCa(x-1) of track STRa(x-1), the track center STCax of track STRax, the track center GTC of the protection track GTR, the track center STCb1 of track STRb1, the track center STCb2 of track STRb2, and the track center STCb3 of track STRb3 are arranged at equal intervals in the radial direction d1.

[0092] Except for the guard band GB, the recording capacity of each band BA of the user data area U is usually predetermined based on the specification required by the user. The MPU 60 can record the same amount of data in each band BA. Generally, the recording capacity of each band BA is 128 MiB or 256 MiB.

[0093] Figure 8 Yes means Figure 6 Schematic diagram of three sectors SCe, SC(e+1) and SC(e+2) in one track STRa1 with BAa. Figure 8 As shown, each track STR has a plurality of sectors SC. Track STRa1 has a plurality of sectors SC including sectors SCe, SC(e+1), and SC(e+2). Each track STR belonging to the same partition Z has the same number of sectors SC.

[0094] Each sector SC has a length Ls in the circumferential direction of the disk DK.

[0095] The write head WHD has a width W in the seek direction d4. The widths W of the respective write heads WHD fall within the reference range. The widths W of the write heads WHD have individual differences.

[0096] Next, a method of setting the band BA will be described.

[0097] Fig. 9 1 is a schematic diagram showing a band BAe in the user data area U of the disk DK according to the comparative example, and is a diagram for explaining an example in which the adjustment unit 62 does not adjust the number of unused sectors of the band BAe. Fig. 9 In FIG. 1 , the belt BAe is represented as a rectangle, but in reality, the belt BAe is bent along the circumferential direction.

[0098] like Fig. 9As shown, in band BAe, the number of multiple sectors SC of each track STRe is set to n, the number of multiple tracks STRe is set to t+1, the number of unused sectors in which no data is written in the multiple sectors SC of band BAe is set to e, and the difference obtained by subtracting the above e from the above n is set to k. In addition, the recording capacity of band BAe is set to Cb, and the recording capacity of each sector SC is set to Cs.

[0099] The adjustment unit 62 obtains information on the recording capacity Cb, the recording capacity Cs, and the number n of sectors SC. Based on the recording capacity Cs and the number n of sectors SC, the adjustment unit 62 can calculate information on the linear recording density as the recording capacity per inch in the circumferential direction. The linear recording density can be represented by BPI (bit per inch).

[0100] Alternatively, the adjustment unit 62 may obtain information on the linear recording density instead of the number n of sectors SC, and calculate the number n of sectors SC based on the recording capacity Cs and the information on the linear recording density.

[0101] The number of tracks STRe per inch in the radial direction d1 is called track density. Track density can be represented by TPI (track per inch).

[0102] The number of sectors SC with BAe required to obtain the recording capacity Cb is Cb / Cs. When the number n of sectors SC of a track STRe, i.e., BPI, is determined, the respective values ​​of t and k can be calculated by the following formula 1. The relationship among n, e, and k can be expressed by the following formula 2.

[0103] Cb / Cs=n×t+k···(Formula 1)

[0104] n=e+k···(Formula 2)

[0105] The adjustment unit 62 can finally determine the values ​​of t, e, and k based on the information of the recording capacity Cb, the recording capacity Cs, and the number n of sectors SC. Fig. 9 In the shingle recording format, the area marked with a dot pattern is an area where 128 MiB or 256 MiB of data is recorded by the shingle recording process, and is an area used to ensure the recording capacity Cb. The area without a dot pattern (blank area) is an unused area. In the shingle recording format, the recording capacity Cb of each band is fixed, so there is an unused area (unused sector) as shown in the figure.

[0106] exist Fig. 9In the example of , the adjustment unit 62 does not adjust the number of unused sectors with Bae, and therefore, the adjustment unit 62 sets the above n, the above t, the above k, and the above e to the following values, respectively, based on the determined BPI.

[0107] n=200t=100k=10e=190

[0108] n>t,e≥t. Fig. 9 In the example of , it can be seen that there are unused sectors equal to or greater than the number t in band BAe. Since there are too many unused sectors in band BAe, it is difficult to reduce the BPI of band BAe.

[0109] Fig.10 1 is a schematic diagram showing a band BAe in the user data area U of the disk DK according to the above-mentioned embodiment, and is a diagram for explaining an example in which the adjustment unit 62 adjusts the number of unused sectors of the band BAe. Fig.10 In FIG. 1 , the belt BAe is shown as a rectangle, but in reality, the belt BAe is curved along the circumferential direction. Fig.10 In the above, k is a variable. In addition, Fig. 9 Similarly, in Fig.10 In the figure, the area marked with a dot pattern is an area where 128 MiB or 256 MiB of data is recorded by the tile recording process, and the blank area is an unused area.

[0110] like Fig.10 and Figure 1 As shown, the adjustment unit 62 can adjust the first to fourth adjustment values ​​respectively. The first adjustment value is the number n of multiple sectors SC of each track STRe with BAe. The second adjustment value is the length Ls of each sector SC in the circumferential direction of the disk DK. The third adjustment value is the number t+1 of multiple tracks STRe with BAe. The fourth adjustment value is the frequency of data written to the BAe.

[0111] The write processing unit 61a can select the shingle recording mode and perform the write processing based on the first to third adjustment values. The adjustment unit 62 can adjust the first to third adjustment values ​​so that e<t holds. In the present embodiment, the write processing unit 61a can select the shingle recording mode and perform the write processing based on the first to fourth adjustment values. The adjustment unit 62 can adjust the first to fourth adjustment values ​​so that e<t holds.

[0112] exist Fig.10In the example, there are no unused sectors greater than the number t in band BAe. The number e of unused sectors in band BAe can be reduced. The BPI of band BAe can be reduced accordingly with the reduction of the above e, so the quality of track STRe can be improved, and the recording quality of data on track STRe can be improved.

[0113] The adjustment unit 62 can adjust the first to third adjustment values ​​to further make n>t hold. In the present embodiment, the adjustment unit 62 can adjust the first to fourth adjustment values ​​to make n>t hold. The adjustment unit 62 can make e<t<n hold. The adjustment unit 62 can eliminate the relationship of e<n≤t. Therefore, the adjustment unit 62 can effectively reduce the number e of unused sectors and can reduce the number of sectors SC of each track STRe.

[0114] The adjustment unit 62 can finally determine the value of t by acquiring information on the recording capacity Cb, the recording capacity Cs, and the number n of sectors SC, and can also temporarily determine the values ​​of n, e, and k.

[0115] Before the adjustment unit 62 adjusts the number of unused sectors of the band BAe, the adjustment unit 62 determines that Fig.10 In that case, when e<t originally, the adjustment unit 62 can finally determine each of the above n, the above e, and the above k without changing the numerical values.

[0116] On the other hand, before the adjustment unit 62 adjusts the number of unused sectors of the band BAe, the adjustment unit 62 determines that Fig. 9 In such a case of e≥t, in order to make e<t hold, the adjustment unit 62 can reduce the value of n, increase the value of k, and reduce the value of e, and finally determine each of n, e, and k.

[0117] For example, when the value of n is decreased, the value of k is increased, and the value of e is decreased, the adjustment unit 62 can decrease the value of n by 1, increase the value of k by t, and decrease the value of e by t. Fig. 9 The status changes to Fig.10 status.

[0118] As mentioned above, in Fig.10 In the example of , the adjustment unit 62 adjusts the number of unused sectors with BAe, and therefore, the adjustment unit 62 sets the above n, the above t, the above k, and the above e to the following values, respectively.

[0119] n=199t=100k=110e=89

[0120] The adjustment unit 62 does not perform adjustment to change the numerical value of t. The adjustment unit 62 makes 1≤e<t hold.

[0121] In addition, the adjustment unit 62 can increase the length Ls of each sector SC and reduce the frequency of data written to the band BAe by reducing the number n of sectors SC. By making e<t hold, the BPI can be set low and the recording quality can be improved.

[0122] Furthermore, the adjustment unit 62 can adjust the above-mentioned first adjustment value and the second adjustment value based on the characteristics of the write head WHD. The larger the width W of the write head WHD, the larger the adjustment unit 62 can adjust the above-mentioned first adjustment value and the second adjustment value to values. That is, the larger the width W is, the larger the area of ​​the write head WHD facing the disk DK is, and the larger the magnetic field irradiated to the disk DK is, so that the recording quality can be improved. As a result, the larger the width W is, the higher the BPI can be. In addition, although the width W has a great influence on the BPI, the width W has a small influence on the TPI. According to the above content, the adjustment unit 62 preferably adjusts the above-mentioned first to fourth adjustment values ​​according to the head partition (according to each write head WHD and according to each partition Z).

[0123] According to the magnetic disk device 1 of this embodiment configured as described above, the magnetic disk device 1 includes a disk DK, a write head WHD, an adjustment unit 62, and a write processing unit 61a. By adopting the shingle recording method, it is possible to increase the capacity of the disk DK. The shingle recording method has a feature that the capacity of the band BAe is predetermined. Fig. 9 The recording capacity Cb with BAe is Fig.10 The recording capacity of BAe and Cb is the same, for example, 256 MiB respectively. In the case of firmware, Fig. 9 The recording capacity Cb with BAe is Fig.10 There is no difference in the recording capacity Cb of band BAe.

[0124] on the other hand, Fig. 9 The number of unused sectors with BAe is Fig.10 The number of unused sectors with BAe varies greatly. Fig.10 As shown in FIG. 1 , the number of unused sectors in band BAe is reduced by the adjustment of the adjustment unit 62. Fig.10 In the example, the BPI of band BAe can be adjusted to be low, the frequency of writing data to band BAe can be reduced, and thus the recording quality of data in band BAe can be improved.

[0125] Even if Fig.10 BPI with BAe Fig. 9The BPI of the band BAe is low, and the recording capacity Cb of the two bands BAe is the same. According to the above, the magnetic disk device 1 can achieve a larger capacity of the disk DK and improve the quality of data recorded on the disk DK.

[0126] (Modification of the above embodiment)

[0127] Next, this variation is described. The magnetic disk device 1 is constructed in the same manner as the magnetic disk device 1 of the above-mentioned embodiment except for the structure described in this variation. When the number t+1 of multiple tracks STRe with BAe is pre-specified, the adjustment unit 62 may adjust the above-mentioned first adjustment value and the second adjustment value respectively, and not adjust the above-mentioned third adjustment value. The write processing unit 61a is capable of selecting the watt recording type and performing write processing based on the above-mentioned first adjustment value and the second adjustment value. The adjustment unit 62 is capable of adjusting the above-mentioned first adjustment value and the second adjustment value in order to make e<t hold.

[0128] In this modification, when the number t+1 of the plurality of tracks STRe with BAe is pre-specified, the adjustment unit 62 may adjust the first adjustment value, the second adjustment value, and the fourth adjustment value, respectively. The write processing unit 61a may select the shingle recording mode and perform write processing based on the first adjustment value, the second adjustment value, and the fourth adjustment value. The adjustment unit 62 may adjust the first adjustment value, the second adjustment value, and the fourth adjustment value so that e<t holds.

[0129] The adjustment unit 62 can finally determine the respective numerical values ​​of n, e, and k so that e<t holds by acquiring the information of the recording capacity Cb, the recording capacity Cs, and t.

[0130] In this modification, the same effects as those of the above-described embodiment can be obtained.

[0131] The embodiments of the present invention are described above, but the above embodiments are presented as examples and are not intended to limit the scope of the invention. The above new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the purpose of the invention. The above embodiments and their variations are included in the scope and purpose of the invention, and are included in the invention described in the claims and their equivalents.

[0132] For example, the above-mentioned technology is not limited to hybrid recording type magnetic disk devices, but can also be applied to shingle recording type magnetic disk devices.

[0133] As in the above-described embodiment, the adjustment unit 62 sets unused sectors in the band BA so that 1≤e<t holds. Thus, even if a sector SC with write failure occurs when writing to the band BA using the shingle recording method, the unused sector can be used as a replacement sector.

[0134] However, it is not essential to provide unused sectors for band BA. Therefore, the adjustment unit 62 may make 0≤e<t hold. When e=0, the BPI of band BA can be adjusted to the minimum.

Claims

1. A magnetic disk device comprising: a disk having a strip including a plurality of tracks, each of said tracks including a plurality of sectors; a write head for writing data to the disk; an adjustment unit that adjusts a first adjustment value, a second adjustment value, and a third adjustment value, respectively, the first adjustment value being the number of the plurality of sectors of each of the tracks of the belt, the second adjustment value being the length of each of the sectors in the circumferential direction of the disk, and the third adjustment value being the number of the plurality of tracks of the belt; and a write processing unit capable of selecting a shingle recording type for writing data to the plurality of tracks in an overlapping manner in a radial direction of the disk, and performing a write process based on the first to third adjustment values, When the number of the plurality of tracks of the tape is set to t+1, and the number of unused sectors among the plurality of sectors of the tape is set to e, The adjustment unit adjusts the first to third adjustment values ​​so that e<t holds.

2. The magnetic disk device according to claim 1, When the number of the plurality of sectors of each of the tracks of the tape is set to n, The adjustment unit adjusts the first to third adjustment values ​​so that n>t also holds.

3. The magnetic disk device according to claim 2, When the recording capacity of the band is set to Cb, the recording capacity of each sector is set to Cs, and the variable is set to k, Cb / Cs=n×t+k, n=e+k, The adjustment unit, Obtain information about Cb, Cs, and n, finally determine t, and provisionally determine n, e, and k. When it is determined that e<t, n, e, and k are finally determined without changing the numerical values. When it is determined that e≥t, in order to make e<t hold, the value of n is decreased, the value of k is increased, and the value of e is decreased, and finally n, e, and k are determined.

4. The magnetic disk device according to claim 3, When it is determined that e≥t, the adjustment unit decreases the value of n by 1, increases the value of k by t, and decreases the value of e by t.

5. The magnetic disk device according to claim 3 or 4, When the adjustment unit determines that e≥t, the adjustment unit increases the length of each of the sectors and reduces the frequency of writing the data to the tape.

6. The magnetic disk device according to claim 1, The adjustment unit further adjusts a fourth adjustment value which is the frequency of the data, The write processing unit is capable of selecting the shingle recording type and executing write processing based on the first adjustment value to the fourth adjustment value. The adjustment unit adjusts the first to fourth adjustment values ​​so that e<t holds.

7. A magnetic disk device comprising: a disk having a strip including a plurality of tracks, each of said tracks including a plurality of sectors; a write head for writing data to the disk; an adjustment unit that adjusts a first adjustment value and a second adjustment value, the first adjustment value being the number of the plurality of sectors of each of the tracks of the tape, and the second adjustment value being the length of each of the sectors in the circumferential direction of the disk; and a write processing unit capable of selecting a shingle recording type for writing data to the plurality of tracks in an overlapping manner in a radial direction of the disk, and performing a write process based on the first adjustment value and the second adjustment value, When the recording capacity of the tape is set to Cb, the recording capacity of each of the sectors is set to Cs, the number of the plurality of sectors of each of the tracks of the tape is set to n, the number of the plurality of tracks of the tape is set to t+1, a variable is set to k, and the number of unused sectors in the plurality of sectors of the tape is set to e, Cb / Cs=n×t+k, n=e+k, The adjustment unit obtains information on the Cb, the Cs, and the t, and finally determines each of the n, the e, and the k so that e<t holds.

8. The magnetic disk device according to claim 1 or 7, The adjustment unit, adjusting the first adjustment value and the second adjustment value based on the characteristics of the write head, The first adjustment value and the second adjustment value can be adjusted to larger values ​​as the width of the write head in the seek direction increases.

9. The magnetic disk device according to claim 1 or 7, The adjustment unit makes 1≤e<t hold.

Images