JPH11273010A - Disk storage device and data recording/reproducing device to be applied to the storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an error checking and correcting(ECC) function having relatively high correcting capacity and to resultantly increase the capacity of user data by dividing the user data and ECC data into respective data recording areas by a system for utilizing data recording areas consisting of two layers, i.e., the surface layer and depth layer of a disk. SOLUTION: The disk storage device adopts the system for using a 1st magnetic layer formed on the surface layer of a disk 1 and a 2nd magnetic layer formed in the depth layer of the disk 1 as data recording areas. A recording element 5 constituting a head 4 records recording data W2 mainly constituted of ECC data in the 2nd magnetic layer and records recording data W1 mainly constituted of user data in the 1st magnetic layer. A reproducing element 7 simultaneously reads out respective recoded data from the 1st and 2nd magnetic layers. A reproducing system separates the user data and the ECC data from a signal reproduced by the element 7 and reproduces the user data and the ECC data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk serving as a storage medium having two layers of data recording areas, each of which can record data of different frequencies (high recording density and low recording density). The present invention relates to a disk storage device applied to a magnetic disk device.

[0002]

2. Description of the Related Art Conventionally, a hard disk drive (HD)
In magnetic disk devices such as D), it has been promoted to realize a high recording density of data to be recorded on a disk serving as a storage medium, thereby increasing the capacity.

As shown in FIG. 13, in an HDD, a large number of data sectors (physical blocks or physical sectors) are formed on a disk 1, and data recording / reproduction (read / write) is performed in units of each data sector. ) The operation is performed. On the disk 1, for example, tracks are formed from a plurality of data sectors of about 50, and a format in which a number of tracks are arranged concentrically is formed.

A data sector usually has a data area of, for example, 512 bytes (DATA section) as shown in FIG.
In addition to the above, a PLL-Sync section that is an area for generating a clock for data detection, an AM section that is an area for identifying the head of the DATA section, and a gap (GAP) that is an area for responding to rotation fluctuation and the like. ) Section and an ECC section in which ECC data including an error detection / correction code (ECC code) is recorded. Data area (DA
In the TA section), original data called user data and used by the host computer is recorded. The host computer corresponds to, for example, a personal computer using the HDD as an external storage device.

The ECC section records ECC data to be added to the user data when the user data is read from the DATA section and reproduced. The controller (HDC) of the HDD uses the ECC data to execute an ECC process for detecting and correcting an error (read error) of the reproduced user data. As the ECC data, a well-known Reed-Solomon code (referred to as an RS code)
Is used.

Here, the error rate when reproducing user data, which is digital data, from a reproduction signal (analog signal) read from a disk is, for example, 10 ⁻⁶ (ie, 1).
0 If one of the ^six data is a constant) the error data, error correction processing using ECC data (ECC
The processing) improves the error rate to, for example, about 10 ⁻¹² .

As described above, in recent years, in order to increase the storage capacity, there is an increasing demand for higher-density data recording on a disk. In general, as the recording density increases, the quality of a reproduction signal from a disc deteriorates, and the error rate during data reproduction processing increases. For this reason, an ECC function having a high error correction capability is required as the recording density increases. In general, the correction capability of the ECC function increases as the length of redundancy, that is, the length of ECC data relative to the length of user data increases. Specifically, for example, error correction capability is higher when adding 100-byte ECC data to 512-byte user data than when adding 50-byte ECC data.

On the other hand, in order to increase the capacity, it is necessary to store as much user data as possible in a fixed storage area on a disk. Therefore, the redundancy is lower (that is, ECC data is smaller). The smaller the amount). Here, even with the same redundancy, the error correction capability differs depending on the type of ECC. The RS code is E
This is a type of block code to which parity data called CC is added, and is an ECC having relatively high error correction capability.
At present, RS code of at most about 50 bytes is ECC
It is added as data, and the redundancy is less than 10%.

[0009] Even with the same redundancy, the larger the user data per block, the higher the correction capability. However,
The effect is small unless the value is set to a considerably large value which is 10 times or more of 512 bytes. However, the current HDD
In this case, due to the limitation of the host computer OS (Operating System), 512 data sectors per data sector.
It is not possible to make the amount of user data of bytes too large. Further, in a disk storage device other than the HDD, such as an optical disk device, for example, the inner code (R
A product code system in which ECC data is arranged two-dimensionally, such as (S code) × outer code (RS code), is used.
A method that can further increase the error correction capability even with the same redundancy is employed. In this method, a plurality of data sectors over a plurality of tracks are generally treated as one error correction block. Therefore, in this method, 1
When recording and reproducing data of a part of the data sector included in one error correction block, it is necessary to access a plurality of data sectors over a plurality of tracks included in one error correction block.

[0010] With the current HDD, it is difficult to format the disk on which the above-mentioned product code system is adopted, due to the restrictions imposed by the OS of the host computer and the like. Also, tracks included in one error correction block are not always adjacent. In the HDD, when there is a defective track, a defect processing (defect processing) for replacing the defective track with an alternative track is executed. In this case, 1
The replacement track included in one error correction block may be replaced with a track located far away from a track in the same block. For this reason, the data access time is reduced, which is a factor that cannot be adopted in the HDD.

[0011]

As described above, the HD
In the case of D, it is necessary to increase the recording density of the disk (to increase the areal recording density) in order to increase the capacity, but with this, the quality of the reproduced signal deteriorates and the data detection error rate increases. In order to reduce the data detection error rate, an ECC function having a high correction capability by increasing the ratio of ECC data added to the user data, that is, the redundancy, is required. For this reason, when the areal recording density is increased, the amount of ECC data also increases, which does not lead to an increase in the amount of stored user data in proportion to the areal recording density. In addition, as the amount of ECC data increases, the amount of circuits required for ECC processing increases. Further, a method of improving the error correction capability by adopting the above-described product coding method of arranging the ECC data in a two-dimensional manner may be considered. However, since the disk format is restricted by the OS of the host computer and the access time is reduced, it is required. It is difficult to adopt it in the current HDD. In short, especially in HDD, EC
The ECC function with a high correction capability by increasing the amount of C data (by increasing the redundancy) cannot be used as an effective means for increasing the capacity of user data.

Accordingly, an object of the present invention is to provide a method in which user data and ECC data can be divided into respective data recording areas by using a data recording area consisting of two layers, a surface layer and a deep layer of a disk, so that relative data recording areas can be divided. E with high correction ability
An object of the present invention is to realize a CC function to increase the capacity of user data as a result.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a disk storage device of a system using a first recording area provided on a surface layer of a disk and a second recording area provided on a deep layer as a data recording area. is there. The head unit of the present apparatus includes a recording head for recording data of different recording frequencies in each of the first recording area and the second recording area, and a reproducing head for reproducing each recording data. Further, the present apparatus includes a recording signal processing unit and a reproduction head for transmitting each recording signal for recording data of a recording frequency corresponding to each of the first recording area and the second recording area to the recording head. There is provided a reproduction signal processing means for separating and reproducing different recording data from the read reproduction signal.

[0014] More specifically, the recording head is composed of each electromagnetic induction type head (inductive head) corresponding to each of the first recording area and the second recording area. The reproducing head is a single MR (including GMR) head,
Data is simultaneously read from the first and second recording areas.
The reproduction signal processing means decodes and reproduces different data recorded in each recording area from the reproduction signal from the reproduction head.

In such a configuration, in the present invention, user data used by the host computer is recorded in the first recording area, and ECC data to be added to the user data is recorded in the second recording area. In this case, ECC
The data amount is smaller than the user data. Therefore, the data recording density of the second recording area is relatively lower than that of the first recording area. By storing the ECC data in the second recording area, which is a deep layer of the disc,
An area for recording ECC data can be deleted from the first recording area on the surface layer. Therefore, the first surface layer
In the recording area, the storage capacity of user data can be increased with the same storage area as compared with the conventional method. On the other hand, in the present invention, since the second recording area can be used as a so-called dedicated recording area for ECC data, the storage area for ECC data can be greatly increased as compared with the ECC section in the conventional data format. .

In other words, according to the method of the present invention, it is possible to increase the amount of user data and increase the amount of ECC data to be added to the user data to perform ECC processing, thereby increasing the redundancy. . Therefore, when the storage capacity of the user data is increased, the ECC function can be enhanced accordingly, and as a result, a large-capacity and highly reliable data storage device can be provided.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a magnetic disk device related to the embodiment, FIG. 2 is a partially enlarged view of the disk of the embodiment, and FIG. 3 is a diagram showing a sector format of the disk of the embodiment. It is. (Structure of Apparatus) In this embodiment, an HDD which is a magnetic disk apparatus is assumed as a disk storage apparatus. Further, as shown in FIG. 2, the disc 1 as a disc storage medium has a first recording area (hereinafter, referred to as a first magnetic layer) 2 formed on a surface layer and a second recording area formed on a deep layer in a thickness direction. It has two data recording areas (magnetic layers) consisting of recording areas (hereinafter referred to as second magnetic layers) 3.

In this embodiment, data (user data) used by the host computer is mainly recorded on the first magnetic layer 2, and ECC processing is performed on the second magnetic layer 3 in addition to the user data. (For example, ECC data composed of an RS error correction code) is mainly recorded. FIG. 3 shows a specific example of a data format (sector format) of each of the magnetic layers 2 and 3. That is, the data sector of the first magnetic layer 2 contains the user data 36.
Other than the DATA part which is the recording area of
It comprises an L-Sync unit 34, an AM unit 35, and a GAP unit 37. On the other hand, the sectors of the second magnetic layer 3 are the same as the PLL-Sync section 38, the AM section 39 and the GA section as in the first magnetic layer 2.
In addition to the P section 41, E which is a recording area of the ECC data 40
It consists of a CC section.

A head (magnetic head) 4 for recording / reproducing data to / from the disk 1 having such a configuration.
Is a recording head of an electromagnetic induction type including a recording element 5 for recording data mainly including ECC data 40 on the second magnetic layer 3, and recording data mainly including user data 36 on the first magnetic layer 2. And a reproducing head including a reproducing element (MR element or GMR element) 7 for simultaneously reproducing each recorded data from each of the magnetic layers 2 and 3. This is a composite head.

Each of the recording elements 5 and 6 constituting the recording head
In the same data track 8 on the disk 1
The data tracks 30 corresponding to the first magnetic layer 2 and the data tracks 31 corresponding to the second magnetic layer 3 are provided so that the respective radial positions and track widths are substantially the same. This is because each data can be simultaneously read from the data tracks 30 and 31 by using the same reproducing element 7 (common to each of the magnetic layers 2 and 3).

The recording element 5 of the head 4 is arranged on the inflow end side in the rotation direction of the disk 1 with respect to the position of the recording element 6. In this case, the order of the positions of the reproducing elements 7 may be arbitrary. When ECC data is recorded on the second magnetic layer 3, the recording magnetic field generated from the recording element 5
And the data is recorded on the second magnetic layer 3. In this case, the data of the DATA portion is also recorded on the first magnetic layer 2 closer to the head 4 than the second magnetic layer 3. Here, as described above, the recording element 6 is arranged closer to the outflow end side of the disk than the recording element 5, so that the data recording operation by the recording element 6 is executed immediately after the data recording operation by the recording element 5. If such control is performed, the ECC data of the recording element 5 and the user data of the recording element 6 are overwritten on the first magnetic layer 2. The recording magnetic field generated from the recording element 5 is made to reach the second magnetic layer 3 sufficiently, and the recording magnetic field generated from the recording element 6 is made to reach the first magnetic layer 2 sufficiently, but the second magnetic layer In order to prevent magnetic influence, the structure such as the gap length of the recording elements 5 and 6 and the thickness of the first and second magnetic layers 2 and 3 and the depth of the second magnetic layer 3 are taken into consideration. Perform the designed design. (Structure of Head) As shown in FIG. 6 (FIG. 6B is a view of FIG. 6B as viewed from the surface facing the disk 1 with respect to FIG. The recording element 5, the reproducing element 7, and the recording element 6 are formed on the head base 50 in this order from the inflow end side of the disk. Recording element 5
Is a recording core 52 serving as a magnetic path and a recording coil 5 for applying a recording current.
Consists of one. The recording element 6 is also an electromagnetic induction type recording head, and includes a recording core 54 and a recording coil 53.
The reproducing element 7 constitutes an MR (magnetoresistive effect) type or GMR type reproducing head, and has an M element whose resistance changes according to the amount of magnetic flux.
Electrode 5 for supplying sense current to R film 55 and MR film
6 and a magnetic shield 57.

Further, as shown in FIG. 7 (FIG. 7 (B) is a view of FIG. 7 (B) viewed from the surface facing the disk 1), the head 4 of this embodiment is used for an air bearing slider. The recording element 5 and the reproducing element 7 and the recording element 6 are integrally formed on the head base 50 in this order from the disk inflow end side. The reproducing element 7 and the recording element 6 share a core (recording / reproducing core 64) serving as a magnetic path. The reproducing element 7 includes a reproducing core 64, an MR film 65 whose resistance changes according to the amount of magnetic flux,
And an electrode 66 for supplying a sense current. Recording element 6
Is a recording core 64 and a recording coil 6 for applying a recording current.
Consists of three. The recording element 5 includes a recording core 62 and a recording coil 61 for applying a recording current.

The head 4 of the present embodiment may have a structure in which the gap of the recording element 5 for recording on the second magnetic layer 3 is formed not parallel to the gap of the reproducing element 7 but at an angle. FIG. 8 shows a structure of a head including a recording element 58 having a gap formed at an angle with respect to the gap of the recording element 5 of the head 4 shown in FIG. FIG. 9 shows FIG.
5 shows a structure of a head including a recording element 68 having a gap formed at an angle with respect to the gap of the recording element 5 of the head 4 shown in FIG. (Data Recording / Reproducing Circuit and Data Recording / Reproducing Operation) As shown in FIG. 1, the data recording / reproducing circuit of this embodiment is roughly divided into a recording system including recording current drivers (write amplifier circuits) 9 and 10, a reproducing amplifier 11 And a data controller 29 for controlling data input / output.

The recording current driver 10 transmits an ECC sent from the data controller 29 in synchronization with the clock F2.
The recording data W2 mainly including the data 40 (the second recording data W2 shown in FIG. 3)
The data 38 to 41) of the magnetic layer 3 are converted into a recording current and output to the recording element 5. On the other hand, the recording current driver 9 converts the recording data W1 (data 34 to 37 of the first magnetic layer 2 shown in FIG. 3) mainly including the user data 36 transmitted from the data controller 29 in synchronization with the clock F1. And outputs it to the recording element 6.

On the other hand, as a reproducing system, a reproducing amplifier 11
Amplifies the reproduction signal simultaneously read from the first magnetic layer 2 and the second magnetic layer 3 by the reproducing element 7 and outputs the amplified signal to the high-frequency cutoff filter (HPF) 12 and the low-frequency cutoff filter (LPF) 19. The HPF 12 is for removing a reproduction signal (a signal of a relatively low frequency) from the second magnetic layer 3 shown in FIG. Here, HPF12, LPF13,
Equalization circuit 14, peak detection circuit 15, data discrimination circuit 1
6 and the PLL circuit 17 are connected to the first magnetic layer 2 of the disk 1.
And a reproduction signal processing circuit that reproduces the user data 36 and outputs the processed data to the data controller 29. That is, the reproduced signal output from the HPF 12 passes through a LPF 13 for band limitation (removal of noise) to a required band and an equalizing circuit 14 for equalizing a desired waveform with a minimum peak detection error. The signal is sent to the detection circuit 15. The peak detection signal detected by the peak detection circuit 15 is sent to the data discrimination circuit 16 and the PLL circuit 17. The PLL circuit 17 generates a discrimination clock and supplies it to the data discrimination circuit 16. The data discrimination circuit 16 discriminates the reproduced signal into binary (“0” or “1”) data,
User data 36 substantially synchronized with the frequency of clock F1
Is detected and sent to the data controller 29.

On the other hand, the LPF 19 is for removing a reproduction signal (a signal of a relatively high frequency) from the first magnetic layer 2 shown in FIG. Here, the LPF 19, the equalization circuit 20, the peak detection circuit 21, the data discrimination circuit 22,
The PLL circuit 23 reproduces the ECC data 40 from the second magnetic layer 3 of the disk 1 and
9 constitutes a reproduction signal processing circuit that outputs the reproduced signal to the reproduction signal processing circuit 9. LPF
The reproduced signal output from 19 is sent to a peak detection circuit 21 via an equalization circuit 20 for equalizing to a desired waveform that minimizes a peak detection error. Peak detection circuit 2
The peak detection signal detected in step 1
And the PLL circuit 23. The PLL circuit 23 generates a discrimination clock and supplies it to the data discrimination circuit 22.
The data discrimination circuit 22 discriminates the reproduced signal into binary (“0” or “1”) data, detects the reproduced data R2 mainly including the ECC data 40 substantially synchronized with the frequency of the clock F2, and detects the reproduced data R2. To send to.

The data controller 29 is connected to a host computer (not shown) and encodes the recording data transferred from the host computer to record data W1.
Is output. Further, the data controller 29 inputs the user data 36 and the ECC data 40 reproduced by the reproduction system, and uses the ECC data 40 to perform an ECC process on the user data 36 (error detection and correction process).
To transfer the normally decrypted user data (recorded data) to the host computer.

As described above, by the data recording / reproducing circuit,
User data of a relatively high frequency (high recording density) is recorded on the first magnetic layer 2 of the disk 1, and ECC of a relatively low frequency (low recording density) is recorded on the second magnetic layer 3.
The data is recorded. And at the time of data reproduction operation,
The user data and the ECC data are reproduced at the same time and sent to the data controller 29. The data controller 29 uses the ECC data to generate the EC of the user data.
C processing will be performed.

In this embodiment, it is assumed that the second magnetic layer 3 is used as a recording area for ECC data. This is because the second magnetic layer 3 has a large spacing loss during recording and reproduction. The spacing loss is a phenomenon in which the recording and reproducing signal quality deteriorates in proportion to the distance between the head 4 and the magnetic layer. Therefore, the deep second magnetic layer 3 is used as a recording area of ECC data that can be handled at a low recording density (low frequency) with respect to the user data 36 stored in the first magnetic layer 2. Is desirable. However, the number of rotations of the disk 1 when recording and reproducing user data and ECC data is the same.

Referring now to FIG. 5, the first magnetic layer 2 and the second
The difference in the recording / reproducing characteristics of the magnetic layer 3 will be described. FIG.
3A is a diagram showing user data recorded on the first magnetic layer 2 and a reproduced signal waveform when reproduced. FIG. FIG. 2B is a diagram showing ECC data recorded on the second magnetic layer 3 and a reproduced signal waveform when reproduced. As is clear from these figures, the ECC recorded on the second magnetic layer 3
The data has a recording density that is approximately 1/10 of the recording density of the user data recorded on the first magnetic layer 2. However, the recording data of any data is recorded by the NRZI code. That is, the recording current is inverted in response to the data "1", a magnetic transition is formed on the disk 1, and a signal corresponding to the magnetic transition is generated.

FIG. 5C is a diagram showing the power spectrum of the reproduced signal. In the figure, 500 is the power spectrum of the reproduction signal from the second magnetic layer 3, and 501 is the power spectrum of the reproduction signal from the first magnetic layer 2. As shown in FIG. 3C, a reproduction signal spectrum of data mainly including the user data 36 recorded on the first magnetic layer 2 and a reproduction signal of data mainly including the ECC data 40 recorded on the second magnetic layer 3. The signal spectrum should not overlap as much as possible on the frequency axis.

Therefore, a reproduction signal of data mainly including the user data 36 recorded on the first magnetic layer 2 is modulated into recording and coded data that does not include low frequency components as much as possible. For example, RLL (Run Length Limited) in which “0” is not continuous for a certain length or more
It is modulated with a code. In the self-clock method for extracting the discrimination clock from the recording data itself, it is common for HDDs to use a code for limiting the run length of “0”, and as a specific example, 8/9 (0, 4 ) A coding method or the like is used. Here, m / n (d, k) is for converting m-bit user data into n-bit recording encoded data, and the minimum run length of “0” is d, “0”.
Is the maximum run length of k. In this case, the ratio between the maximum frequency fmax and the minimum frequency fmin of the signal with respect to the repeated data is 1/5. Note that, due to the self-clock, similar recording encoding modulation is performed on data mainly including the ECC data 40 recorded on the second magnetic layer 3. Also, the ECC recorded on the second magnetic layer 3
The reproduced signal of the data mainly including the data 40 is made to contain as little high-frequency components as possible so as not to overlap the reproduced signal spectrum of the data of the first magnetic layer 2. Specifically, it is desirable that the second magnetic layer 3 of the disk 1 is designed to have a lower recording resolution than the first magnetic layer 2. That is, the half value width of the isolated signal waveform reproduced from the magnetization transition corresponding to the data “1” is designed so that the signal from the second magnetic layer 3 is wider than the signal from the first magnetic layer 2. Is desirable. (Modification of the Present Embodiment) FIGS. 10 to 12 are diagrams related to a modification of the present embodiment.

Also in this modification, the first magnetic layer 2 is formed on the surface layer of the disc 1 as in the present embodiment.
The second magnetic layer 3 is formed in a deep layer. In the first magnetic layer 2, user data 36 having a relatively high frequency is recorded. Further, relatively low-frequency ECC data 40 is recorded on the second magnetic layer 3.

The head 84 includes a recording element 85 for recording data (see FIG. 3) mainly including the ECC data 40 on the second magnetic layer 3 and a user data 3 on the first magnetic layer 2.
And a recording element 86 for recording data (see FIG. 3) mainly including the recording element 6. Further, the head 84 reads the recording data (EC
A reproducing element 87 for reproducing the C data 40);
A reproducing head including a reproducing element 88 for reproducing recorded data (user data 36) from the magnetic layer 2 is provided.

Each recording element 85, 8 constituting the recording head
Numeral 6 indicates that in the same data track 8 on the disk 1, the radial position and the track width of the data track 30 corresponding to the first magnetic layer 2 and the data track 31 corresponding to the second magnetic layer 3 are substantially the same. It is provided so that it becomes. Also, a reproducing element 87 constituting a reproducing head
Are provided so that the center thereof and the center of the data track 31 are aligned. Similarly, the reproducing element 88 is provided so that the center thereof is aligned with the center of the data track 30.

The recording element 85 of the head 84 is arranged on the inflow end side in the rotation direction of the disk 1 with respect to the position of the recording element 86. In this case, the reproducing elements 87 and 88
May be in any order.

When ECC data is recorded on the second magnetic layer 3, the recording magnetic field generated from the recording element 85 reaches the second magnetic layer 3, and data is recorded on the second magnetic layer 3.
In this case, the data of the DATA portion is also recorded on the first magnetic layer 2 closer to the head 4 than the second magnetic layer 3. Here, the recording element 86 is replaced with the recording element 85 as described above.
Is located closer to the outflow end of the disc than
If it is controlled so that the data recording operation by the recording element 86 is performed immediately after the data recording operation by the recording element 85, the ECC by the recording element 85 is added to the first magnetic layer 2.
The user data is overwritten and recorded (overwritten) by the recording element 86 on the data. Note that the recording magnetic field generated from the recording element 85 should reach the second magnetic layer 3 sufficiently, and the recording magnetic field generated from the recording element 86 should be the first magnetic layer.
The structure such as the gap length of the recording elements 85 and 86 and the layers of the first and second magnetic layers 2 and 3 are set so that the magnetic layer 2 can reach the magnetic layer 2 sufficiently but the second magnetic layer 3 does not have a magnetic influence. The design is performed in consideration of the thickness, the depth of the second magnetic layer 3, and the like.

As shown in FIG. 11 (FIG. 11B is a view of FIG. 11B as viewed from the surface facing the disk 1 with respect to FIG. 11A), a head 84 for an air bearing slider is used. A recording element 85 / reproducing element 87 and a reproducing element 88 / recording element 86 are formed on the base 120 in this order from the disk inflow end side. The recording element 85 and the reproducing element 87 share a core (recording / reproducing core 122) serving as a magnetic path. The reproducing element 88 and the recording element 86 share a core (recording / reproducing core 124) serving as a magnetic path.

The reproducing element 87 constitutes an MR (magnetoresistive effect) type or GMR type reproducing head.
MR film 125 whose resistance changes according to the amount of magnetic flux, and MR film
It comprises an electrode 126 for supplying a sense current for supplying a sense current to the film 125. The recording element 85 forms an electromagnetic induction type recording head, and includes a recording core 122 and a recording coil 121 for applying a recording current. The reproducing element 88 forms a similar MR (magnetoresistive effect) type or GMR type reproducing head, and supplies a sense current to the reproducing core 124, the MR film 127 whose resistance varies according to the amount of magnetic flux, and the MR film 127. And an electrode 128 for supplying a sense current. The recording element 86 forms an electromagnetic induction type recording head, and includes a recording core 124 and a recording coil 123 for applying a recording current.

Further, the gap between the recording / reproducing core 122 of the recording element 85 and the reproducing element 87 is not parallel to the gap between the recording / reproducing core 124 of the recording element 86 and the reproducing element 88, and has a certain angle. It is formed. Specifically, in the head 84 of this modification shown in FIG. 11, the gap between the recording / reproducing cores 124 of the recording element 86 and the reproducing element 88 is formed perpendicular to the tangential direction of the data track. The gap between the recording / reproducing cores 122 of the recording element 85 and the reproducing element 87 is formed not to be parallel to the gap of the recording / reproducing core 124 but to have a certain angle. The gap between the recording / reproducing core 124 of the recording element 86 and the recording / reproducing core 124 of the reproducing element 88 is not perpendicular to the tangential direction of the data track but at a certain angle. Recording / reproducing core 1 of recording element 85 and reproducing element 87
The gap of the recording / reproducing core 124 may be formed so as to have a certain angle instead of being parallel to the gap of the recording / reproducing core 124. That is, the recording / reproduction of the recording element 86 and the reproducing element 88
The gap between the reproducing core 124, the recording element 85 and the reproducing element 8
It is sufficient that the gap of the recording / reproducing core 122 is not parallel.

FIG. 12B shows the power spectrum 123 of a reproduced signal when the data mainly including the user data 36 is reproduced from the first magnetic layer 2 by the reproducing element 87 in the head 84 of the present modified example. As shown, it is suppressed to a low level. This is because the recording bit of the data recorded on the first magnetic layer 2 has a certain angle with respect to the gap of the reproducing element 87 of the head 84, so that the signal level is reduced due to azimuth loss. Also,
Similarly, since the recording bit of the data recorded on the second magnetic layer 3 has a certain angle with respect to the gap of the reproducing element 88 of the head 84, the signal level is reduced due to the amajith loss. Accordingly, the gap between the recording / reproducing core 124 of the recording element 86 and the reproducing element 88 and the recording element 85 and the reproducing element 87
The angle of the gap of the recording / reproducing core 122 is desirably designed so that the azimuth loss is maximized. In FIG. 12B, the power spectrum 122 of the reproduced signal is a power spectrum when the data mainly including the ECC data 40 is reproduced from the second magnetic layer 3 by the reproducing element 87. In FIG. 12A, the power spectrum 120 of the reproduction signal is a power spectrum when data mainly including the ECC data 40 is reproduced from the second magnetic layer 3 by the reproduction element 88. Further, the power spectrum 121 indicates that the reproducing element 88
Is a power spectrum when data mainly including the user data 36 is reproduced from the first magnetic layer 2.

The data recording / reproducing circuit of this modification is similar to that of FIG.
As shown in FIG. 3, a recording system including recording current drivers (write amplifier circuits) 89 and 90, a reproduction amplifier 91,
And a data controller 109 for controlling data input / output.

The recording current driver 90 controls the EC transmitted from the data controller 109 in synchronization with the clock F2.
The recording data W2 mainly composed of the C data 40 (data 38 to 41 of the second magnetic layer 3 shown in FIG. 3) is converted into a recording current and output to the recording element 85. On the other hand, the recording current driver 89
Converts the recording data W1 (data 34 to 37 of the first magnetic layer 2 shown in FIG. 3) mainly including the user data 36 transmitted from the data controller 109 in synchronization with the clock F1 into a recording current, 86.

On the other hand, as a reproducing system, a reproducing amplifier 91
Amplifies the reproduced signal read from the first magnetic layer 2 by the reproducing element 88 and outputs the amplified signal to the LPF 93 via the HPF 110. Note that the HPF 110 may be omitted. Here, the HPF 110, the LPF 93, the equalizing circuit 94, the peak detecting circuit 95, the data discriminating circuit 96, and the PLL circuit 9
7 indicates the user data 36 from the first magnetic layer 2 of the disk 1.
And a playback signal processing circuit for outputting the playback signal to the data controller 29. In other words, the reproduced signal output from the HPF 110 passes through the LPF 93 for band limitation (removal of noise) to a required band and the equalizing circuit 94 for equalizing a desired waveform with a minimum peak detection error. The signal is sent to the detection circuit 95. The peak detection signal detected by the peak detection circuit 95 is output to the data discrimination circuit 9
6 and the PLL circuit 97. The PLL circuit 97 generates a discrimination clock and supplies it to the data discrimination circuit 96. The data discrimination circuit 96 outputs a binary (“0”) from the reproduced signal.
Alternatively, the reproduced data R1 mainly including the user data 36 substantially synchronized with the frequency of the clock F1 is detected and sent to the data controller 109.

On the other hand, the reproduction amplifier 92 amplifies the reproduction signal read from the second magnetic layer 3 by the reproduction element 87,
Output to PF99. The LPF 99 is for removing a reproduction signal (user data of a high-frequency signal) from the first magnetic layer 2. Here, the LPF 99, the equalizing circuit 10
0, the peak detection circuit 101, the data discrimination circuit 102, and the PLL circuit 103 reproduce the ECC data 40 from the second magnetic layer 3 of the disk 1 and
09 to form a reproduced signal processing circuit. LP
An equalization circuit 100 for equalizing a reproduced signal output from the F99 to a desired waveform that minimizes a peak detection error.
To the peak detection circuit 101 via The peak detection signal detected by the peak detection circuit 101 is sent to the data discrimination circuit 102 and the PLL circuit 103. The PLL circuit 103 generates a discrimination clock, and outputs the data discrimination circuit 1
02. The data discrimination circuit 102 discriminates the reproduced signal into binary data (“0” or “1”), detects the reproduced data R2 mainly including the ECC data 40 substantially synchronized with the frequency of the clock F2, and detects the reproduced data R2. To send to.

The data controller 109 is connected to a host computer (not shown), and encodes the recording data transferred from the host computer.
Outputs 1. In the data controller 109,
The user data 36 and the ECC data 40 reproduced by the reproducing system are input, and the ECC processing (error detection and correction processing) for the user data 36 is executed using the ECC data 40, and the normally decoded user Transfer the data (recorded data) to the host computer.

In the sector format of the present embodiment, the case where user data and ECC data are divided and stored in each of the two recording areas has been described, but the present invention is not limited to this. That is, as shown in FIG. 4, for example, in a servo area (servo sector in which servo data for positioning control of the head 4 is recorded) on the disk, the first
The present invention can also be applied to a system in which servo burst data is recorded on the magnetic layer 2 and a cylinder code (track address) is recorded on the second magnetic layer 3. However, naturally, the first signal is read from the servo signal read from the servo area by the read head.
A reproduction system for discriminating between the servo burst data of the magnetic layer 2 and the cylinder code of the second magnetic layer 3 and reproducing each of them is required.

[0048]

As described above in detail, according to the present invention, user data and ECC data are divided into respective data recording areas by a method utilizing a data recording area consisting of a surface layer and a deep layer of a disk. And store. Therefore, the recording area of the user data can be increased, and the amount of ECC data can be increased. Thus, it is possible to avoid a situation in which the amount of user data decreases in inverse proportion to the increase in the amount of ECC data. In other words, enough ECC
Since the ECC function having a high data amount and a high error correction capability can be realized and the reliability of user data can be ensured, a high-reliability and large-capacity disk storage device can be provided as a result. Further, ECC data can be arbitrarily changed without changing the sector format on the conventional disk.

[Brief description of the drawings]

FIG. 1 is an exemplary view showing a configuration of a magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the disk of the embodiment.

FIG. 3 is an exemplary view showing a sector format of the disk of the embodiment;

FIG. 4 is an exemplary view showing a format of a disc according to a modification of the embodiment.

FIG. 5 is a view showing a reproduced signal waveform and a power spectrum related to the embodiment.

FIG. 6 is a diagram showing a head structure of the embodiment.

FIG. 7 is a diagram showing a head structure of the embodiment.

FIG. 8 is a diagram showing a head structure of the embodiment.

FIG. 9 is a diagram showing a head structure of the embodiment.

FIG. 10 is an exemplary view showing the configuration of a magnetic disk device according to a modification of the embodiment.

FIG. 11 is a view showing a head structure related to the modification.

FIG. 12 is a diagram showing a power spectrum of a reproduction signal related to the modification.

FIG. 13 is a view for explaining a data format on a conventional disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 2 ... 1st magnetic layer (1st recording area) 3 ... 2nd magnetic layer (2nd recording area) 4 ... Head 5,85 ... Recording element (2nd recording area) 6,86 ... Recording Element (first recording area) 7, 87, 88 Reproduction element (MR element) 8 Data track 9, 10, 89, 90 Recording current driver 11, 91, 92 Reproduction amplifier 12, 110 HPF 13, 19, 93, 99 ... LPF 14, 20, 94, 100 ... equalizing circuit 15, 21, 95, 101 ... peak detecting circuit 16, 22, 96, 102 ... data discriminating circuit 17, 23, 97, 103 ... PLL circuit 29,109… Data controller

Claims (11)

[Claims] 1. A disk storage device configured to execute recording and reproduction of data on a disk storage medium by a head, wherein a first recording provided on a surface layer for recording data as the disk storage medium. A disc having an area and a second recording area provided in a depth direction from the surface layer in the thickness direction; and data of recording frequencies different from each other in the first recording area and the second recording area as the head. Head means having a recording head for recording information and a reproducing head for reproducing each recording data from each of the first recording area and the second recording area; and the first recording area and the second recording area. Recording signal processing means for transmitting each recording signal for recording data of a recording frequency corresponding to each of the recording areas to the recording head. And reproduction signal processing means for separating and reproducing different recording data from a reproduction signal read by the reproduction head from each of the first recording area and the second recording area. Characterized disk storage device. 2. The data recording apparatus according to claim 1, wherein data having a relatively high recording frequency is recorded in said first recording area of said disk, and data having a relatively low recording frequency is recorded in said second recording area. 2. The disk storage device according to claim 1, wherein: 3. The user data used by a host computer is recorded in the first recording area of the disc,
2. The disk storage device according to claim 1, wherein data for error detection and correction to be used for error detection and correction when reproducing the user data is recorded in the second recording area. 4. A servo burst data included in servo data for controlling positioning of said head means at a designated position on said disk storage medium is recorded in said first recording area of said disk. 2. The disk storage device according to claim 1, wherein a cylinder code included in said servo data is recorded in said recording area. 5. An electromagnetic induction type first recording head for recording data in the first recording area, and an electromagnetic induction type recording head for recording data in the second recording area. 2. The disk storage device according to claim 1, further comprising a second recording head, and a magnetoresistive (MR) head as the reproducing head. 6. An electromagnetic induction type first recording head for recording data in the first recording area, and an electromagnetic induction type recording head for recording data in the second recording area. And a magnetoresistive (MR) head as the reproducing head, wherein the recording gap of the first recording head and the reproducing gap of the reproducing head are parallel to each other. 2. The disk storage device according to claim 1, wherein the recording gap of the second recording head is formed at a certain angle with each of the recording gap of the first recording head and the reproduction gap. . 7. The head unit has an electromagnetic induction type first recording head for recording data in the first recording area, and a reproduction gap parallel to a recording gap of the first recording head. A first reproducing head of a magnetoresistive effect type (MR type), a second recording head of an electromagnetic induction type for recording data in the second recording area, and a recording gap of the second recording head. A second magneto-resistive (MR) reproducing head having a parallel reproducing gap; a recording gap of the first recording head, a reproducing gap of the first reproducing head, and a second reproducing head; 2. The disk storage device according to claim 1, wherein a recording gap of the recording head and a reproducing gap of the second reproducing head are formed at a fixed angle. 8. The head unit has a single reproducing head, and is configured to simultaneously read out respective recording data recorded in each of the first recording area and the second recording area. The disk storage device according to any one of claims 1, 5, and 6, wherein 9. The head unit according to claim 2, wherein the second recording head is disposed on an inflow end side in a rotation direction of the disk with respect to the first recording head. 7. The data recording apparatus according to claim 5, wherein the data recording operation is performed by the first recording head immediately after the data recording operation.
The disk storage device according to claim 7. 10. A data recording / reproducing apparatus applied to a disk storage device configured to execute recording / reproducing of data on / from a disk storage medium by a head, wherein the disk storage medium has a surface layer for recording data. A disk having a first recording area provided in the first recording area and a second recording area provided in a depth direction from the surface layer in the thickness direction, wherein the head includes the first recording area and the second recording area. First and second recording heads for recording data having mutually different recording frequencies, and a reproducing head for simultaneously reproducing each recording data from each of the first recording area and the second recording area. And generating a recording signal corresponding to data of a relatively high frequency to be recorded in the first recording area. A recording signal processing circuit for generating a recording signal corresponding to relatively low-frequency data to be recorded in the second recording area and transmitting the recording signal to the second recording head; From the read signal read by the second
A first reproduction signal processing for filtering out the recording data recorded in the first recording area from the reproduction signal and reproducing the decoding data from the reproduction signal by having a filter means for removing low-frequency data recorded in the recording area And a first signal from the read signal read by the read head.
A second reproducing signal processing for filtering out the recording data recorded in the second recording area from the reproduction signal and reproducing the decoded data from the reproduction signal, comprising a filter means for removing high-frequency data recorded in the recording area A data recording / reproducing apparatus, comprising: a circuit; 11. The first recording area of the disc records user data used by a host computer, and the second recording area is used for error detection and correction processing when reproducing the user data. The first reproduction signal processing circuit reproduces the user data from the reproduction signal read by the reproduction head, and the second reproduction signal processing circuit reproduces the user data from the reproduction signal read by the reproduction head. 11. The data recording / reproducing apparatus according to claim 10, wherein the data for error detection and correction is reproduced from the read reproduction signal.