JP2000123492A - Disk type recording medium, manufacturing method for disk type recording medium, recording and reproducing method, and disk drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk type recording medium, a disk drive device, and the like that yield can be improved, complexness of control can be reduced, and reduction of performance can be suppressed. SOLUTION: Recording line density of a recording plane (e.g. 1c) of which a software error rate(SER) is bad is reduced, and recording line density of recording planes (e.g. 1a, 1b, 1d, 1e, 1f) of which SER is not so bad is increased. A control section 4e or a control section 5a changes a table in accordance with recording line density of each recording plane 1a-1f at the time of recording and reproducing, and changes recording and reproducing characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a disk-shaped recording medium, a method for manufacturing a disk-shaped recording medium, a recording / reproducing method, and a disk drive device, which have improved yield and performance.

[0002]

2. Description of the Related Art In recent years, disk drives using magnetic disks as recording media have been increasing in capacity and recording density.

The soft error rate of a magnetic disk (SE
R) has a positive correlation with an increase in the recording linear density (BPI: bits / inch), which is the number of bits per predetermined length in the track direction, as shown in FIG. It has been found that as the recording linear density increases, the error rate increases. The SER is displayed as a logarithm of the number of errors / the number of data (the number of samples). FIG. 2 shows a change in SER when the recording linear density is changed with respect to a predetermined recording linear density (1) on the horizontal axis. From FIG. 2,
For example, when the recording linear density is a predetermined recording linear density (1), the SER is about −5 (the error rate is about 10 ⁻⁵ ), but the recording linear density is 10% of the predetermined recording linear density.
When it becomes low, SER becomes -6 (error rate is 10 ^-6 ).
It can be seen that the error rate is reduced by about one digit.

For this reason, a method has been considered in which the recording linear density is made uniform over the recording surface of the magnetic disk so that the SER becomes almost uniform over the entire recording surface of the magnetic disk.

[0005] For example, in the disk drive device according to the invention disclosed in Japanese Patent Application Laid-Open No. 7-147059, as shown in FIG. 3, the recording surface of the magnetic disk is divided into several regions (zones (Z) 0, Z1, Z2,...), And the number of data sectors to be recorded between servo sectors in each zone is changed in accordance with the position in the radial direction, thereby achieving a uniform recording linear density of the recording tracks in each zone. .

As described above, by making the recording linear density uniform, the SER can be made substantially uniform over the entire recording surface of the magnetic disk.

By the way, in a disk drive device, an upper limit of SER is determined in order to ensure reliability.
Generally, a disk drive device is provided with a plurality of recording surfaces and a plurality of heads corresponding to each recording surface.
SER greatly varies depending on the magnetic characteristics of the head and the magnetic disk. Therefore, in a disk drive device having a plurality of recording surfaces, the SER differs for each recording surface because the recording linear density of each recording surface is uniform.

However, conventionally, in such a disk drive device, the SE that exceeds the upper limit of the SER at least on one side is used.
If there was a recording surface having R, it was treated as a defective product. For this reason, there has been a problem that the yield decreases and the cost increases.

As a disk drive that solves such a problem, for example, a disk drive disclosed in Japanese Patent Application Laid-Open No. 8-255412 is known. In this disk drive device, the SER of the entire recording surface is reduced by changing the zone boundary in the recording surface and setting the track pitch in the zone according to the actually measured recording / reproducing characteristics.

[0010]

However, in the disk drive disclosed in Japanese Patent Application Laid-Open No. 8-255412, the control is complicated because the zone boundaries are different for each recording surface, and the track pitch is particularly non-uniform. Therefore, there was a problem that the seek characteristics were lowered and the performance was lowered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can improve yield and contribute to cost reduction, reduce control complexity and reduce performance. It is an object of the present invention to provide a disc-shaped recording medium, a method of manufacturing a disc-shaped recording medium, a recording / reproducing method, and a disc drive device that can be suppressed.

[0012]

A disk-shaped recording medium according to the present invention has a first recording surface having a first recording linear density at a predetermined radial position, and a first recording surface at a predetermined radial position.
And a second recording surface having a second recording linear density different from the recording linear density.

Each of the first and second recording surfaces has a plurality of recording regions having a constant recording frequency irrespective of the position in the disk radial direction, and the boundary between the recording regions on the second recording surface in the disk radial direction Is set as a position different from the position of the boundary on the first recording surface, or a different recording frequency is set for the same recording region in the radial direction of the disc between the first recording surface and the second recording surface. By doing so, the first and second recording linear densities may be set.

According to a method of manufacturing a disk-shaped recording medium according to the present invention, the recording / reproducing characteristics of each recording surface of a disk-shaped recording medium having a plurality of recording surfaces are measured.
A plurality of recording surfaces are divided into a first recording surface having a first recording linear density at a predetermined radial position, and a second recording surface having a second recording linear density different from the first recording linear density at a predetermined radial position.
The recording surface is set to the recording surface of

According to the recording / reproducing method of the present invention, a first recording surface having a first recording linear density at a predetermined radial position, and a second recording line different from the first recording linear density at a predetermined radial position are provided. A recording / reproducing method for performing recording / reproducing on a disk-shaped recording medium having a second recording surface having a density, wherein a recording surface on which recording / reproducing is performed is selected according to a designated address, and recording is performed according to the selected recording surface. It is characterized in that the recording linear density for reproduction is changed, and recording / reproducing is performed by changing recording / reproducing characteristics according to the changed recording linear density.

According to the disk drive apparatus of the present invention, there is provided a first recording surface having a first recording linear density at a predetermined radial position, and a second recording line different from the first recording linear density at a predetermined radial position. A disk-shaped recording medium having a second recording surface having a density, a recording / reproducing means for performing recording / reproduction on the disk-shaped recording medium, and a recording surface selecting means for selecting a recording surface for performing recording / reproduction from a designated address ,
A recording linear density changing means for changing the recording linear density according to the recording surface selected by the recording surface selecting means, and a recording / reproducing characteristic of the recording / reproducing means changing according to the recording linear density changed by the recording linear density changing means. And control means for performing the operation.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a block diagram showing a configuration of a disk drive according to a first embodiment of the present invention.

This disk drive device supplies a magnetic disk (disk-shaped recording medium) 1 as a recording medium, a head 2 for performing recording / reproduction on the magnetic disk 1, and a recording signal to the head 2. , An arm electronic circuit (arm electronics: AE) 3 for picking up (amplifying) the reproduction output of the head 2, a channel IC (recording / reproduction control means) 4 for performing mutual conversion between analog signals and digital data, and this channel IC 4. Hard disk controller (HDC) 5 for controlling the operation of the entire device
And

In this disk drive device, for example, three magnetic disks 1 are provided. Each magnetic disk 1 has a recording surface on both sides, and a head 2 and an AE 3 are provided for each recording surface.

As shown in FIG. 1, the channel IC 4 includes a buffer 4a for holding data from the HDC 5 or data for the HDC 5, and an encoder for encoding (encoding) recording data and decoding (decoding) reproduction data. / Decoder (ENDEC) 4b, and a serial / parallel converter 4 that converts encoded recording data into a serial signal and converts a reproduced signal into parallel data.
c, a CLK generation unit 4d for generating a reference clock for recording / reproduction (a reference to RDWTCLK), a control unit 4e for controlling the operation of the entire channel IC 4, and a pulse detector 4g for reproducing a servo signal. .

The HDC 5 includes a control unit 5a having an MPU and the like, a memory 5b for holding a cache of recording / reproduction data, various tables used for operation control, and the like.
A timing detector 5c for detecting the recording / reproducing timing of the data for which recording / reproduction has been instructed.

On the recording surface of the magnetic disk 1, as shown in FIG. 4, a region where a track 50 is recorded is formed concentrically with a predetermined width. Each area is provided with a servo area 51 in which a servo sector for performing tracking control is recorded and a data area 52 in which a data sector is recorded. FIG. 4 is omitted for simplification.

The servo area 51 is provided at every predetermined rotation angle (for example, 360 ° / 66) on the surface of the magnetic disk 1. In the servo area 51, for example, a cylinder ID (CYL) for identifying each physical servo sector at the time of manufacturing is used.
ID), physical servo sector number (PHSN: Physical S)
Identifier information such as sector numbers, and physical servo sector information including servo patterns are recorded.

The physical servo sectors in the servo area 51 include:
For example, at the time of manufacture, a servo sector is recorded with a clock having a constant frequency regardless of the position in the radial direction.

As shown in FIG. 5, the data area 52 is divided into several zones (physical zones) in the radial direction. In FIG. 5, for conceptual explanation, 2 tracks are assigned to one track in zone Z0 which is the outermost physical zone.
Five data sectors are recorded, two data sectors are recorded on one track in zone Z1, 1.5 data sectors are recorded on one track in zone Z2, and one data track is recorded on one track in zone Z3. The case where one data sector is recorded is illustrated in a simplified manner. On the actual recording surface, for example, ten zones (Z0 to
Z9) is provided, and for example, 1000 tracks are recorded in each zone.

Each physical zone is assigned one of the logical zones as shown in Table 1 below.

[Table 1] As shown in Table 1, each logical zone (L0 to L1)
In (0), the number of data sectors to be recorded on one track in each logical zone is determined in advance. When focusing on one recording surface, a logical zone having a small number of sectors is assigned to the inner physical zone.

In the data area 52 (physical servo sector) in one track, data sectors are recorded / reproduced by a clock (reference clock) having a frequency corresponding to the number of data sectors to be recorded.

By the way, while 66 physical servo sectors are provided for each predetermined rotation angle by being divided by the servo area 51 provided as described above, the number of data sectors is assigned to each physical zone. Since the number of data sectors differs for each zone, the number of data sectors in a servo sector is not limited to an integer. As shown in FIG. 5 described above, a data sector may be divided at an arbitrary position and recorded in a plurality of servo sectors.

The position at which the data sector is divided in this way is determined by the number of data sectors recorded in the data area 52 set for each zone (logical zone) and the physical servo sector number (assigned for each servo sector). ) Is uniquely obtained from the position of each data area 52 indicated by (the value).

Information indicating the position where this data sector is divided (for example, the nth data sector in a certain zone is divided, and p bytes are recorded in the mth physical servo sector and q bytes are recorded in the (m + 1) th physical servo sector). Information) is recorded as a track format table in a non-volatile memory included in the HDC 5, a predetermined area on a disk, or the like, together with information indicating the position of each data sector and the presence or absence of division.

In this disk drive, the length of the data sector is 546 bytes, and as shown in FIG.
It can be divided at the position of 5 bytes from the beginning.

Therefore, as shown in FIG. 7, the track format table contains information indicating which physical servo sector has the sector corresponding to the data sector number (physical servo sector number PHS of the physical servo sector).
N) and information (offset amount) indicating whether or not the data sector is divided or, if divided, how many bytes are recorded in the data area. ing.

The position PHSN indicates the servo sector number to which the head of the data sector belongs. The value of the offset amount is 00 when the data sector is not divided.
h, and in the case of division, the value of the quotient obtained by dividing the number of bytes of data recorded in the data area 52 by 5 (01
h to 6Dh [= 545/5 = 109: 10 decimal]).

This table shows that the maximum number of data sectors per track is 400 according to Table 1 above,
Two bytes are required for one data sector (one byte for PHSN, one byte for the quotient value, and if the data sector number is stored as an address pointer, there is no need to store the data sector number itself).
Bytes are required.

This table is prepared for each logical zone because the number of data sectors per track differs for each logical zone. This table is stored in a predetermined area on the disk or in a RO such as HDC5.
M, and is stored in the memory 5b of the HDC 5 during operation.
And so on.

By the way, data is recorded / reproduced from an information processing apparatus such as a personal computer or a workstation to this hard disk drive by using LBA (logical block address) instead of cylinder ID, physical servo sector number and data sector. It is specified.
Since the LBA is sequentially assigned as a serial number from a recordable position, a table for converting the LBA into a corresponding cylinder ID, physical servo sector number, and data sector number is required.

For this reason, in this hard disk drive, conversion between LBA and data sector number is performed using an address conversion table as shown in FIG. More specifically, the address conversion table includes other parameters (Z: zone,
H: head, C: cylinder), and also includes data indicating correspondence with other parameters not shown.

It should be noted that this address conversion table does not necessarily need to be held as a table.
It may be calculated from a BA, a zone assignment table described later, or the like.

In this disk drive, L
As shown in the address conversion table in the figure, the allocation of the data sector corresponding to the BA is performed on the data sectors in the track having the same CYLID over a plurality of recording surfaces, and then sequentially adjacent. This is performed for a data sector in a track. When the zone boundary is changed as described later, the order of assigning the data sectors corresponding to the LBA is changed, but the details will be described in the operation description.

In this address conversion table, the logical head number indicates the logical head in which the data sector assigned to the corresponding LBA exists, and the data sector number indicates the data sector number of the data sector assigned to the corresponding LBA. Is shown.

In this disk drive device, the time required for switching the head 2 by switching inside the AE 3 (for example, 10 physical servo sectors) is compared with the time required for seeking the head to an adjacent track (for example, for 18 physical servo sectors). 8), the performance of the disk drive device is improved by allocating as shown in FIG.

By the way, in this disk drive apparatus, at the time of manufacture, a soft error rate (SER) inspection is performed for each pair of each recording surface and head.

Conventionally, a disc drive is considered to be good only when the SER of all recording surfaces is within a specified value, and when at least one of the recording surfaces has a SER not less than a specified value, the disc drive is deemed to be non-defective. It was defective.

On the other hand, when manufacturing this disk drive device, if the SER of all the recording surfaces is within a specified value, the recording linear density (BPI: bits / inch) of all the recording surfaces is reduced. Although the recording surface is kept uniform, if there is a recording surface whose SER is equal to or more than a specified value, the recording linear density of this recording surface is reduced to lower the SER. In this case, the track pitch is constant.

The case where the upper limit of the SER is -5 (corresponding to the case where the error rate is 10 ^-5 because the SER is displayed in a logarithm with the error rate being base 10) will be specifically described. For example, as shown in FIG. 9, among the six recording surfaces, the SER of the recording surface corresponding to the head HD3 is -4.8, which is equal to or greater than the specified value, and this SER is within the allowable range (for example, If one digit, SER is-
4), the boundary of the physical zone on each recording surface is changed.

It is known from FIG. 2 that if the recording linear density is reduced by about 10%, the SER is reduced by about one digit.
If the recording linear density of the recording surface (corresponding to No. 3) is reduced by about 10%, the SER of this recording surface can be expected to be about -5.8, which is below the specified value.

To reduce the recording linear density, there is a method of increasing the period of a clock used for recording and reproduction. For example, this disk drive device is designed to reduce the recording linear density as shown in FIG. Change physical zone boundaries.

FIG. 11 shows a change in the recording linear density (BPI) of the entire recording surface when the zone boundary of the physical zone is moved while keeping the correspondence between the physical zone and the logical zone constant. The horizontal axis shows the movement of the zone boundary by the track pitch, and shows a state where the positive direction is moved to the outer peripheral side of the magnetic disk 1. The vertical axis shows the change in the recording linear density in percentage. According to this, when the zone boundary is moved outward by about 1500 tracks (corresponding to 1.5 zones), the recording linear density becomes 10
% Can be reduced.

By the way, it is necessary to secure a predetermined capacity for the entire disk. If the capacity of the recording surface HD3 decreases by 10% in proportion to the recording linear density, this reduction is used for other recording. It must be compensated by increasing the surface capacity.

Therefore, in this example, the other recording surface (HD
0 to HD2, HD4, HD5)
Change to the position where the recording linear density increases by 2%. As a result, the same capacity as that of the entire disk drive device in which the zone boundaries are not changed can be secured.

As described above, the other recording surfaces (HD0 to HD
2, HD4, HD5), the SER does not increase so much even if the recording linear density is increased by 2%, and the SER of these recording surfaces before the zone boundary change is originally low as shown in FIG. The SER after the boundary change is also below the specified value.

After the zone boundaries are changed as described above, a table (zone boundary table) indicating the boundaries of the physical zones on the recording surface of each disk is stored in the ROM of the HDC 5 or a predetermined area on the magnetic disk 1. Record. Alternatively, a function corresponding to the zone boundary table may be realized as the above-described address conversion table or a corresponding logical design (calculation formula).

If necessary, the above-described address conversion table is created and recorded in the ROM of the HDC 5 or a predetermined area on the magnetic disk 1. As described above, a calculation formula corresponding to the address conversion table may be set.

Thus, what was conventionally treated as a defective product can be remedied as a non-defective product, and the yield can be improved and the cost can be reduced.

Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 8-255412, recording / reproducing characteristics (the above-mentioned SE
There is a disk drive device that changes the track pitch according to R), but it has not been considered to keep the recording capacity constant in the entire disk drive device. Further, in the disk drive device disclosed in the publication, the seek characteristics may be degraded because the track pitch is not constant.

On the other hand, in this disk drive device, the same capacity as in the case where the zone boundary is not moved can be secured as the whole disk drive device.
Further, in this disk drive device, since the track pitch is constant, there is no deterioration in the seek characteristics due to the uneven track pitch.

In the above description, S on one recording surface
The case where ER is equal to or greater than the specified value has been described.
Even when there are two or more recording surfaces having an ER equal to or more than the specified value, similarly, the recording linear density of these recording surfaces may be reduced and the recording linear densities of other recording surfaces may be increased. This allows
The yield can be further reduced.

Further, depending on the SER value deviating from the prescribed value, the amount of movement of the zone boundary may be changed. For example, if it is sufficient to lower the recording linear density by 5%, it can be seen from FIG. 11 that it is sufficient to move the zone boundary outward by about 775 tracks. In this case, for the other recording surfaces, the recording linear density may be increased by 1%.

Alternatively, the recording linear density of one or more surfaces having a poor SER may be reduced, and the recording linear densities of all recording surfaces may be increased in advance to set recording zone boundaries. Alternatively, the zone boundaries of the recording surface may be changed. This makes it possible to unify the manufacturing process and contribute to a reduction in manufacturing cost.

In general, since the SER of the recording surface varies, even if there is no recording surface having a SER exceeding the specified value, the recording linear density of the recording surface having the worst SER is reduced to reduce the SER. By lowering the SER, it is possible to improve the SER of the entire disk drive and contribute to the improvement of reliability.

The operation of the disk drive configured as described above will be described below.

Based on an address conversion table for obtaining a data sector number from a logical block address held in the memory 5b, the control unit 5a controls an LBA (logical address: Logical Address) for which recording or reproduction is instructed from an external device. From the Block Address), a parameter ZCHS (Z: zone, H: logical head, C: cylinder (CYLID), S: data sector) indicating a position on the magnetic disk is obtained. Alternatively, these parameters may be obtained by the calculation formula set as described above.

Further, the control section 5a reads the above-mentioned track format table corresponding to the obtained zone and stores it in a predetermined area on the memory 5b. Further, an actual head (physical head) corresponding to the obtained logical head is obtained, and the control unit 4 outputs the output of the physical head to the serial / parallel conversion unit 4c and the CLK generation unit 4d.
The switching of the head 2 by the AE 3 is controlled via e.

Further, the control unit 5a determines the determined cylinder (CY
Based on the LID, a seek control system (not shown) is controlled to move the head 1 to a target track.

Further, the control unit 5a obtains the actual recording position from the data sector obtained as described above based on the track format table for obtaining the actual recording position from the data sector number. Control behavior.

As a result, the timing detecting section 5c records / records via the control section 4e under the control of the control section 5b.
The reproduction timing is controlled, and recording / reproduction is performed at a position corresponding to a predetermined LBA on the recording surface of the disk 1.

Hereinafter, the operation will be described in more detail.

The CLK generator 4d reproduces the reference clock and the servo data from the reproduction output of the recording track supplied from the AE 3 during the reproduction of the physical servo sector. The reproduction of the reference clock and the servo data is performed by the channel IC.
4 or the HDC 5 may use a signal supplied from the pulse detector 4g.

At the time of recording in the data area 52, recording data is supplied from the HDC 5 in parallel (8 bits), for example, and the data is temporarily stored in the buffer 4a. E
The NDEC 4b reads out data of a predetermined number of bits based on control from the control unit 4e, and performs, for example, 8-9 encoding so that 0s and 1s do not continue. Further, the CLK generating unit 4d provides a clock (RDWTC) for reproducing and recording data.
LK). The serial / parallel conversion unit 4c
The data encoded by the ENDEC 4b is converted into a serial signal according to a reference clock, and is supplied to the head 2 via the AE3.

When the data area 52 is reproduced, the reproduced signal from the head 2 is transmitted to the channel IC 4 via the AE 3.
Supplied to The serial / parallel converter 4c reproduces a clock from the reproduced output of the head 2, and converts a serial signal (reproduced output) into parallel data based on the clock based on the reference clock generated by the CLK generator 4d. The playback output converted to parallel data is END
H is decoded by the EC 4b and passed through the buffer 4a.
It is supplied to DC5.

When there is a recording surface having a poor SER as described above and the boundary of the physical zone is changed, the correspondence between the logical head and the physical head and the allocation of the data sector to the LBA are changed.

When the boundary of the physical zone has not been changed, the data sector corresponding to the LBA is allocated to the track having the same CYLID over a plurality of recording surfaces as described above. Thereafter, the operation is sequentially performed on the adjacent tracks.

When such data sectors are allocated, in a recording / reproducing operation, for example, as shown in FIG. 12, tracks having the same CYLID are transferred via six heads H0 to H5. After performing the sequential access, the track having the next CYLID is accessed via the heads H0 to H5,
Thereafter, the same access is performed sequentially by increasing CYLID.

In the case shown in FIG. 12, each head H0
In the recording surfaces corresponding to H5 to H5, the physical zone and the logical zone assigned to the physical zone match, and the boundary of the physical zone matches, so that if the tracks have the same CYLID, one track Each recording surface can be accessed using the format table.

However, if there is a recording surface whose physical zone boundary is different from the others as described above, the same CYLID
, The logical zone may differ depending on the recording surface. When an access similar to that of FIG. 12 is performed in such a state,
It is necessary to rewrite the track format table before and after accessing the recording surface of a different logical zone. For example, in the case shown in FIG.
Is different from the zone boundary of the recording surface corresponding to the recording surface and the zone boundary of the other recording surface. The format table needs to be rewritten.

As described above, since the track format table has a length of about 800 bytes, rewriting of this table is not negligible compared to the switching time due to switching of the AE3. Further, at the time of recording / reproduction, the memory 5b is also used as a buffer for recording / reproduction, and is also used by a control program by the control unit 5a. The access of 5b is apparently slow. For these reasons, an increase in the number of times the table is rewritten causes a decrease in the performance of the disk drive device.

For this reason, in the disk drive device, when the boundary of the physical zone is moved, the allocation of the data sector to the LBA is changed to suppress the performance degradation.

Specifically, first, logical head numbers are continuously assigned to heads other than the head (the head HD3 in FIG. 13) whose recording linear density has been reduced. Thereby, the heads HD0, HD1, HD2, HD4, HD5
Logical head numbers 0, 1,
2, 3, and 4 are assigned.

Further, data sectors are assigned to LBAs according to the order of logical head numbers.
The recording is performed in the order of the recording surfaces corresponding to D1, HD2, HD4, and HD5, and the CYLID is sequentially increased and distributed to each recording surface.

Then, at a predetermined interval, for example, a predetermined number of LBs
For each A or every predetermined number of tracks, the remaining head HD
3 on the recording surface corresponding to 3 (second group)
The data sectors of the recording tracks having the YLID (the number of recording tracks of the second group corresponding to the tracks of the first group to which the data sectors have been allocated so far) are continuously allocated. At this time, for example, data sectors are sequentially allocated in a direction in which the CYLID decreases.

When the assignment is completed, the combination of the head, CYLID, and data sector corresponding to each LBA becomes
The address conversion table shown in FIG. 8 or a calculation formula corresponding to this table is recorded in, for example, a nonvolatile memory provided in the HDC 5 or a predetermined area on a disk.

When accessing the disk drive device to which the data sector has been allocated as described above,
For example, as shown in FIG. 14, the number of rewrites of the track format table is reduced. Therefore, the overhead due to the rewriting of the table is reduced, and the performance of the disk drive device is improved.

As described above, the first group (HD
0, HD1, HD2, HD4, and HD5), when allocating data sectors on
When assigning by sequentially increasing IDs and assigning data sectors on the second group (HD3),
By sequentially reducing the CYLID and performing the allocation, the number of relatively long seeks (seek between track n and track n + 3 in FIG. 14) can be reduced to shorten the seek time, further improving performance. Can contribute. This effect becomes remarkable when the number of recording surface groups having different physical zone boundaries increases.

In the above description, a case has been described where only the zone boundary of one recording surface is different from the other recording surface. However, when the zone boundary of two or more recording surfaces is different from the other recording surface, LBA is allocated as follows.

Other recording surface group (first group)
Recording surface having a zone boundary different from the second (second group)
Have the same zone boundaries as each other, first the first
Heads in the second group are assigned consecutive logical head numbers, and heads in the second group are assigned consecutive logical numbers.

Then, at a predetermined interval, for example, a predetermined number of LBs
In the same manner as described above, data sectors in the first group and data sectors in the second group are alternately assigned to A or each track. At this time, the increment of CYLID at the time of assignment is reversed between the first group and the second group.

When the disk drive to which the data sector is allocated to the LBA is accessed, the number of times of rewriting the track format table can be reduced as shown in FIG.

When the zone boundaries of the recording surfaces in the second group are different, first, CYLID is sequentially increased to allocate data sectors in the first group, and a predetermined interval, for example, a predetermined number of data sectors is allocated. Data sectors are allocated while the increment of CYLID is alternately changed for each recording surface for each recording surface of the second group for each LBA or track.

More specifically, as shown in FIG. 16, data sectors in the first group (recording surfaces corresponding to HD0, HD1, HD2, HD4, HD5) are assigned by sequentially increasing CYLID, Head H of the second group
The data sector on the recording surface corresponding to D5 is assigned by sequentially decreasing the CYLID, and the data sector on the recording surface corresponding to the head HD3 of the second group is CYLID.
Assignment is performed by sequentially increasing D.

When accessing the disk drive to which such data sectors are allocated, the number of times of rewriting the track format table can be reduced as shown in FIG.

As described above, in the disk drive device according to this embodiment, the yield can be improved by lowering the recording linear density of the recording surface of the SER and improving the SER, and further, the data for the LBA can be improved. Changing the allocation order of the sectors can contribute to the improvement of the performance of the disk drive device.

Second Embodiment A disk drive according to a second embodiment of the present invention has the same configuration as that of FIG.

In the above-described first embodiment, the boundary of the physical zone on the recording surface having a poor SER is moved in the direction in which the recording linear density decreases. However, in the disk drive device according to the second embodiment, Do not move the boundaries of the physical zone,
By changing the logical zone assigned to the physical zone on the recording surface having a poor ER, the recording linear density can be reduced and SE can be reduced.
R has been improved.

More specifically, at the time of manufacturing the disk drive, a soft error rate (SER) test is performed for each pair of each recording surface and head, as in the first embodiment.

Then, the logical zone corresponding to the physical zone on the recording surface having a poor SER is changed.

The case where the upper limit of the SER is −5 (as described above, the SER is displayed in a logarithm with the error rate being base 10), which corresponds to the case where the error rate is 10 ⁻⁵ . More specifically, for example, as in the case shown in FIG.
-4.8 when the SER of the recording surface corresponding to D3 is equal to or more than the specified value.
This SER is within an allowable range (for example, when the allowable range is 1).
If the SER is -4 or less in the case of a digit), the physical zone in the recording surface corresponding to the head HD3 is
For example, a logical zone one step lower than other recording surfaces is assigned.

That is, as shown in FIG.
On the recording surface corresponding to the heads other than D3, the physical zones Z0, Z1,... On the outer peripheral side and the logical zones L0, L1,. .. Are assigned to the recording surface corresponding to the head HD3 from the outer physical zones Z0, Z1,... To the inner physical zones, logical zones L1, L2,.
・ Is assigned.

By assigning the logical zone to the physical zone as described above, the SER of the recording surface corresponding to HD3 has a recording linear density of 6.5% from FIG.
It can be expected that the SER decreases by about 0.7 from FIG. 2 and the SER of this recording surface becomes about -5.5, which is below the specified value.

The assignment of the logical zone to the physical zone is recorded in the ROM of the HDC 5 or a predetermined area on the magnetic disk 1 as an address conversion table, as in the first embodiment. Alternatively, it may be implemented as a logical design (calculation formula) corresponding to the address conversion table.

Therefore, in this embodiment, as in the first embodiment, by lowering the recording linear density of the recording surface having a poor SER and improving the SER, the yield is improved and the product cost is reduced. Can be reduced.

Further, in order to realize a predetermined capacity as a disk drive device, it is necessary to compensate for a shortage of capacity due to a decrease in recording linear density. In the first embodiment, since the zone boundaries were moved, fine adjustment of the capacity was possible. On the other hand, in this embodiment, since the logical zone assigned to the physical zone is changed, it is difficult to finely adjust the capacity.
A zone boundary may be set in advance so that a logical zone is changed so that a recording surface with a good SER is assigned a shortage of capacity due to a decrease in recording linear density on a recording surface with a bad SER.

Instead of assigning logical zones to physical zones on a one-to-one basis as described above, in order to maintain a constant capacity, for example, logical zones are assigned to physical zones Z0, Z1,. (L0, L1), (L1, L2),
.. May be changed as appropriate.

Alternatively, the number of data sectors to be recorded on a track in each logical zone is designed in advance by lowering the recording linear density on a recording surface having a poor SER, and as a result of the measurement, the worst SER is obtained. The logical zone assigned to the physical zone in the recording surface may be different from the other recording surfaces.

By performing such a design, it is possible to simplify the manufacturing process and to contribute to a reduction in manufacturing cost. Further, even if there is no recording surface having a SER exceeding the specified value, the SER of the entire disk drive is improved by lowering the recording linear density of the recording surface having the worst SER to lower the SER, thereby improving reliability. Can be improved.

The operation of the disk drive configured as described above will be described below.

In this disk drive, the head H
Logical head numbers 0 to 6 are continuously assigned to 0 to H6,
As in FIGS. 12 and 13 described above, data sectors on tracks having the same CYLID are sequentially assigned to LBAs over a plurality of recording surfaces, and then CYLID is sequentially increased to obtain similar data sectors. Make an assignment.

When access is made to the disk drive to which data sectors have been allocated in this way, FIG.
As shown in (1), it is necessary to rewrite the above-mentioned track format table when switching from the head HD2 to the head HD3 and when switching from the head HD3 to the head HD4 for each reproduction of each track.

By rewriting such a track format table, access can be performed in the same head switching order as in the prior art.

However, rewriting the track format table for each track according to the head switch increases the control load. If the track format table is frequently rewritten as described above, the performance of the disk drive may be reduced.

For this reason, two track format tables may be prepared in the memory 5b, and the table to be used may be selected according to the switching of the head. As a result, the frequency of rewriting the track format table can be reduced, which can contribute to an improvement in performance.

Incidentally, the capacity of this track format table is relatively large as described above, and
Is limited, it may be difficult or inefficient to store two tables.

In such a case, even if the logical head number is changed, the performance can be improved.

Specifically, for example, the heads HD0 to HD0 other than the head HD3 corresponding to the recording surface are reduced by lowering the recording linear density.
Logical head numbers 0 to 4 are successively assigned to HD2, HD4, and HD5, and then logical head number 5 is assigned to head HD3. Make an assignment.

When accessing the disk drive device to which data sectors are allocated in this way, as shown in FIG. 19, for example, when switching from the head HD3 of the track n + 2 to the head HD0 of the track n + 3, the track format table is changed. There is no need to rewrite. As a result, the frequency of rewriting the track format table is reduced, and a decrease in performance can be suppressed.

When switching from the head HD3 of each track to the head HD0 of the next track, since the seek to the adjacent track is performed at the same time as the rewriting of the track format table, the switching between other heads is temporally performed. There is some leeway compared to sometimes. For this reason, even if the track format table is rewritten at the time of this switching, the performance does not relatively deteriorate.

Further, as described above, if a configuration is adopted in which two track format tables are stored in the memory 5b, a decrease in performance can be further suppressed.

The allocation of the data sector to the LBA is performed in the same manner as in the case shown in FIG.
After the data sector is allocated to the track having the CYLID, the CYLID is sequentially increased and the allocation is performed, and the CYLID is reduced at predetermined intervals for the data sector in the adjacent track on the recording surface where the recording linear density is not reduced. The assignment may be performed while making the assignment.

When the SER of two or more recording surfaces is equal to or more than a specified value, the recording linear density of the two or more recording surfaces may be reduced. In this case, for example, FIG.
As shown in FIG.
Logical head numbers 0 to 3 are successively assigned to HD2 and HD4, and logical head numbers 5 and 4 are assigned to heads HD3 and HD5 corresponding to the recording surface for decreasing the recording linear density.
When allocating data sectors to LBAs, data sectors are allocated in the order of logical head numbers.

When the logical head numbers are assigned in this manner, the frequency of rewriting the track format table at the time of access is reduced as shown in FIG.
Performance degradation due to rewriting can be reduced, which can contribute to preventing performance degradation.

The data sectors are allocated to the LBAs in the same manner as in FIG. 15 described above. First, the data sectors are allocated to tracks having the same CYLID between the recording surfaces where the recording linear density is not reduced, and then the data sectors are sequentially allocated. CYLID
Are allocated, and at predetermined intervals, data sectors are allocated to tracks having the same CYLID on the recording surface where the recording linear density is not reduced, and CYLIDs are sequentially assigned.
May be assigned while decreasing.

[0121]

According to the present invention, a disk-shaped recording medium is provided with a first recording surface and a second recording surface having a recording linear density different from that of the first recording surface in accordance with recording / reproducing characteristics. Therefore, conventionally, when the recording linear density was set uniformly on each recording surface, it was possible to rescue a medium that was determined to be defective,
The yield can be improved and the cost can be reduced.

Further, by using such a disk-shaped recording medium in a disk drive, it is possible to suppress a decrease in the performance of the disk drive.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a disk drive device according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a relationship between a linear density of data recorded on a magnetic disk and an error rate;

FIG. 3 is a diagram showing an example of a recording format on a magnetic disk of a conventional disk drive device;

FIG. 4 is a diagram showing an example of a recording format on a magnetic disk of the disk drive device according to the first embodiment of the present invention;

FIG. 5 is a diagram showing an example of zones provided in a radial direction on a magnetic disk;

FIG. 6 is a diagram showing an example of a recording format of a data sector recorded on a magnetic disk;

FIG. 7 is a diagram showing an example of a track format table showing correspondence between data sector numbers and actual recording positions on a magnetic disk;

FIG. 8 is a diagram illustrating an example of an address conversion table indicating correspondence between a logical block address and a data sector number;

FIG. 9 is a diagram showing an example of a position of a boundary of a physical zone;

FIG. 10 is a diagram showing an example of a position of a boundary of a physical zone;

FIG. 11 is a diagram showing the relationship between the position of the boundary of the physical zone and the SER;

FIG. 12 is a diagram showing an example of the operation of the disk drive device.

FIG. 13 is a diagram showing an example of the operation of the disk drive device;

FIG. 14 is a diagram showing an example of the operation of the disk drive device;

FIG. 15 is a diagram showing an example of the operation of the disk drive device;

FIG. 16 is a diagram showing an example of the operation of the disk drive device;

FIG. 17 is a diagram showing an example of a logical zone assigned to a physical zone in the disk drive according to the second embodiment of the present invention;

FIG. 18 is a diagram showing an example of the operation of the disk drive device;

FIG. 19 is a diagram showing an example of the operation of the disk drive device;

FIG. 20 is a diagram illustrating an example of the operation of the disk drive device.

[Explanation of symbols]

Reference Signs List 1 magnetic disk, 2 heads, 3 AE, 4 channel IC, 4a buffer, 4b ENDEC, 4c serial / parallel conversion, 4d CLK generation unit, 4e control unit, 4g pulse detector, 5 HDC, 5a control unit, 5b memory, 5c timing Detection unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Keiji Kobayashi 1 Kirihara-cho, Fujisawa-shi, Kanagawa Prefecture IBM Japan, Ltd. Fujisawa Office (72) Inventor Tsutsuaki Kowa 1 Kirihara-cho, Fujisawa-shi, Kanagawa Address IBM Japan, Ltd. Fujisawa Office (72) Inventor Satoshi Hashimoto 1 Kirihara-cho, Fujisawa-shi, Kanagawa Japan IBM Corporation Fujisawa Office F-term (reference) 5D044 BC01 BC08 BC04 CC04 DE43 DE49 DE76 GK10 5D091 AA08 BB08 GG15 GG27 HH04

Claims (15)

[Claims] 1. A first recording surface having a first recording linear density at a predetermined radius position, and a second recording surface having a second recording linear density different from the first recording linear density at the predetermined position. A disk-shaped recording medium comprising a recording surface. 2. The recording apparatus according to claim 1, wherein the first and second recording surfaces have a plurality of recording regions each having a constant recording frequency irrespective of a position in a radial direction of the disk, and a boundary between the recording regions on the second recording surface. 2. The disk-shaped recording medium according to claim 1, wherein the first and second recording linear densities are set such that a position in a disk radial direction is different from a position of a boundary on the first recording surface. 3. The first and second recording surfaces have a plurality of recording areas where the recording frequency is constant irrespective of the position in the disk radial direction. 2. The disk-shaped recording medium according to claim 1, wherein the first and second recording linear densities are set by setting different recording frequencies for recording areas having the same position in the disk radial direction. 4. According to the recording / reproducing characteristics of each recording surface,
4. The disk-shaped recording medium according to claim 1, wherein the first and second recording linear densities are set. 5. A recording / reproducing characteristic of each recording surface of a disk-shaped recording medium having a plurality of recording surfaces is measured, and the plurality of recording surfaces are placed in a first radial position at a predetermined radial position in accordance with the recording / reproducing characteristics. A disc set on a first recording surface having a recording linear density and a second recording surface having a second recording linear density different from the first recording linear density at the predetermined radial position. Manufacturing method of a shape recording medium. 6. When setting the first recording surface, the first recording surface
A plurality of recording areas where the recording frequency is constant irrespective of the position in the radial direction of the disk are provided on the recording surface of, and when the second recording surface is set, the position of the radial direction of the disk is set on the second recording surface. By providing a plurality of recording areas where the recording frequency is constant, and by setting the position of the boundary of the recording area in the disc radial direction to a position different from the boundary of the recording area on the first recording surface, 6. The method according to claim 5, wherein the second recording linear density is set. 7. When setting the first recording surface, a first recording surface is set.
A plurality of recording areas where the recording frequency is constant irrespective of the position in the radial direction of the disk are provided on the recording surface of, and when the second recording surface is set, the position of the radial direction of the disk is set on the second recording surface. By providing a plurality of recording areas where the recording frequency is constant, and by setting the recording frequency of each recording area to a recording frequency different from that of the recording area on the first recording surface in the same radial direction, the first and second recording areas are set. 6. The method according to claim 5, wherein the recording linear density is set. 8. The method according to claim 5, wherein a soft error rate of each of the recording surfaces is used as the recording / reproducing characteristic. 9. A first recording surface having a first recording linear density at a predetermined radial position, and a second recording surface having a second recording linear density different from the first recording linear density at the predetermined radial position. A recording / reproducing method for performing recording / reproducing on a disk-shaped recording medium having a recording surface having a recording surface, comprising: selecting a recording surface on which recording / reproducing is performed according to an instructed address; A recording / reproducing method, wherein recording / reproducing is performed by changing recording / reproducing characteristics according to the changed recording linear density. 10. A first recording surface having a first recording linear density at a predetermined radial position, and a second recording surface having a second recording linear density different from the first recording linear density at the predetermined radial position. A disk-shaped recording medium having a recording surface; recording / reproducing means for performing recording / reproduction on the disk-shaped recording medium; recording surface selecting means for selecting a recording surface on which recording / reproduction is performed from a designated address; Means for changing the recording linear density according to the recording surface selected by the means, and control for changing the recording / reproducing characteristics of the recording / reproducing means according to the recording linear density changed by the recording linear density changing means. And a disk drive device. 11. The first and second recording surfaces have a plurality of recording areas where the recording frequency is constant irrespective of the position in the radial direction of the disk, and the disk at the boundary between the recording areas on the second recording surface. The radial position is different from the first recording surface, and the first
And setting a second recording linear density, wherein the recording linear density changing means changes the recording linear density according to the recording surface selected by the recording surface selecting means, and wherein the control means comprises: a recording linear density changing means. Therefore, according to the changed recording linear density and the recording area for performing recording and reproduction,
11. The disk drive according to claim 10, wherein a recording / reproducing frequency of said recording / reproducing means is changed. 12. A recording apparatus comprising: a plurality of the first recording surfaces; a plurality of the second recording surfaces; and a recording / reproducing means for recording data of a predetermined length in a recording area of each of the recording surfaces. Recording / reproducing for each unit (data sector); and address conversion means for obtaining the data sector corresponding to the designated address for each recording area. When sequentially assigning data sectors in the plurality of first recording surfaces having the same radial position,
The allocation is performed by sequentially changing the position in the radial direction, and at predetermined intervals, the data sector in the second recording surface having the continuous position in the radial direction is changed to the first position in the radial direction.
12. The disk drive device according to claim 11, wherein the data sectors are allocated in reverse to the data sectors in the recording surface. 13. The first and second recording surfaces have a plurality of recording areas where the recording frequency is constant irrespective of the position in the disk radial direction, and the recording frequency of the recording area of the second recording surface is Setting the first and second recording linear densities as recording frequencies different from the recording frequency of the recording area on the first recording surface having the same radial position; Changing the recording linear density according to the recording surface selected by the means, the control means, the recording linear density changed by the recording linear density changing means, according to the recording area to perform recording and reproduction,
11. The disk drive according to claim 10, wherein a recording / reproducing frequency of said recording / reproducing means is changed. 14. A recording apparatus comprising: a plurality of the first recording surfaces; a plurality of the second recording surfaces; and a recording / reproducing means for recording data of a predetermined length in a recording area of each recording surface. Recording / reproducing for each unit (data sector); and address conversion means for obtaining the data sector corresponding to the designated address for each recording area. When sequentially assigning data sectors in the plurality of first recording surfaces having the same radial position,
14. The disk drive device according to claim 13, wherein data sectors in the second recording surface having the same radial position are sequentially allocated. 15. A disk drive device having at least two recording surfaces, comprising a first recording linear density having a first recording linear density at a predetermined radial position.
And a second recording surface having a second recording linear density different from the first recording linear density at the predetermined radial position.