KR20010041116A - Magnetic disc device - Google Patents

Abstract

The recording element requires a constant cross-sectional area for the purpose of passing a magnetic flux for inverting the magnetization of the magnetic layer of the magnetic disk. However, if the cross-sectional shape of the magnetic pole has a large aspect ratio, the magnetic pole does not effectively pass the magnetic flux. This phenomenon becomes the lower limit of the track width dimension of the magnetic pole and the track density cannot be increased. The present invention sets such a limit by making the recording field width wider than the track pitch to secure the recording magnetic strength sufficient to reverse the magnetization of the magnetic layer, and recording without making the recording heads having the recording elements overlap. A large-capacity magnetic disk device with a smaller track width than the recording element width is realized.

Description

Magnetic Disk Device {MAGNETIC DISC DEVICE}

In the magnetic disk apparatus, the head is moved in the radial direction with respect to the rotating disk to accurately position the target data track, thereby magnetically recording and reproducing the information.

3 is a cross-sectional view illustrating a schematic configuration of a typical magnetic disk device. In this example, eight heads 11 are supported by one rotary actuator 13 driven by the voice coil motor 14. Each of the eight heads 11 records and reproduces each of both surfaces of the four disks 12.

The top view which shows schematic structure of this apparatus is shown in FIG. The rotary actuator 13 is driven by the voice coil motor to move the head 11 in the radial direction of the rotating disk 12.

Moreover, the schematic diagram which looked at a part of this apparatus from the upper surface is shown in FIG. On the magnetic disk 12, special magnetization information for indicating the positional information of the head is recorded before shipment from the factory. Based on this positional information, the CPU (central control unit) determines the electric power supplied to the voice coil motor, and performs accurate positioning of the head 11 with respect to the target track 15 via the rotary actuator 13. In addition, although the track 15 is indicated by the solid line in FIG. 5, the track is formed by magnetic information and is not really optically recognizable.

Next, FIG. 6 shows a schematic view of the head of the magnetic disk apparatus as viewed from above. The head 11 has a structure called a composite head or a separate recording / reproducing head in which a magnetoresistive type reproduction element 61 and an inductive recording element 62 are stacked on the same slider. . The technique using the MR element using the magnetoresistive effect of iron-nickel alloy is widely known as the regeneration element 61. As shown in FIG. Moreover, the practical use of the GMR element which sandwiched iron-nickel alloy with the nonmagnetic material is also considered. Since the MR element has excellent characteristics in the reproduction sensitivity of the recording information of short wavelength, it is an effective technique for increasing the recording density of the magnetic disk device. Since the magnetoresistive element represented by this MR element cannot perform the recording operation, an inductive element formed by etching a thin film to form a fine magnetic pole or coil is used as the recording element 62. The operation principle of the inductive element is the same as that of a tape recorder which is widely used in the related art. Most of the magnetic disk devices announced in recent years employ this composite head. In addition, although the reproduction element 61 and the recording element 62 are shown with the rectangular symbol in FIG. 6, it is for the purpose of visually explaining the width | variety and the position of an element for convenience, and differs from the optical shape of an actual element. This is also the same in the subsequent drawings for explaining the width and position of the device.

The magnetic disk device is characterized by being able to arbitrarily rewrite the information once stored. By overwriting the new magnetization information on the data track on which the old magnetization information is recorded, most components of the old magnetization information are masked. This recording method is called a direct overwrite recording method and is used in all magnetic disk apparatuses because high performance performance can be realized because no erase process is required.

In the magnetic disk device using the direct overwrite recording method, the width of the recording element 62 is made narrower than the track pitch as shown in FIG. 6 so as not to delete adjacent data tracks, thereby ensuring the reproducibility of the magnetic disk device. . This is because the head magnetic field at the time of recording has spread in the track width direction, and regions where old magnetization information is erased are formed on both sides of the recording track. The recording width including the areas on both sides of the erase is called an erase width. In addition, the width of the reproducing element 61 can secure the signal S / N as disclosed in Japanese Patent Laid-Open No. 59-168905 in consideration of the positioning error of the head between recording and reproduction. It is preferable to make the width narrower than the recording width in the range which exists. By setting the appropriate recording element width and reproduction element width for the track pitch, it is possible to avoid the risk of data loss by erasing adjacent tracks during recording. In addition, it is possible to realize a magnetic disk device having a low retry frequency at the time of reproduction which deteriorates performance performance and obtaining an excellent bit error rate with sufficient signal S / N.

The magnetoresistive effect element represented by this MR element is an effective technique for increasing the recording density in the rotational direction of the magnetic disk or increasing the track density in contact with the radial direction of the magnetic disk by having excellent characteristics in reproduction sensitivity.

However, since the inductive element serving as the recording element must pass a magnetic flux necessary for inverting the magnetization of the magnetic layer of the magnetic disk, its cross-sectional area cannot be reduced. For this reason, if the track width is reduced, the magnetic pole thickness tends to be large. For example, a magnetic pole of an inductive element having a track width of 1.5 mu m in the width direction requires a structure thicker than 3 mu m. For this reason, it is a big problem to keep tolerance of track width direction small enough.

In addition, when the aspect ratio defined by the height / width of the cross section of the magnetic pole becomes extremely large, the structural magnetic resistance becomes large and it is difficult to match the magnetic anisotropy of the magnetic pole in one direction. The poles do not effectively pass the magnetic flux. If the magnetic field intensity emitted from the recording gap of the magnetic pole is weakened, the property of overwriting the previously recorded magnetization information is deteriorated, the transition length of the recorded magnetization becomes long, the resolution decreases, and the noise component of the medium is large. This makes it difficult to secure the necessary signal S / N as the magnetic disk device.

As a technique that does not lower the magnetic resistance of the magnetic pole even when the track width of the magnetic pole is reduced, a method of reducing the required cross-sectional area of the magnetic pole by using a material having a high saturation magnetic flux density as the magnetic pole material and reducing the cross-sectional shape of the magnetic pole tip only. The method is invented. However, a technique for producing a magnetic material that greatly exceeds the saturation magnetic flux density of a NiFe alloy having a high Fe concentration in development has not been established, and a complicated and long tact process is required to reduce only the cross-sectional shape of the tip portion. Since it is necessary, there exists a fault that manufacturing cost becomes high.

In the prior art, there is a lower limit on the dimension of the magnetic pole in the track width direction, and in particular, a sufficient signal S / N cannot be secured at a track width of 0.7 mu m or less. In order to solve such a problem, the technique disclosed in Japanese Patent Laid-Open No. 7-192226 proposes a magnetic disk apparatus having a magnetic pole track width larger than the track pitch. In this technique, there is a possibility of realizing a high track density magnetic disk apparatus that exceeds the lower limit of the track width of magnetic poles. On the contrary, it is necessary to make the track width of the playhead extremely small compared to the track pitch. Since only a small reproduction output can be obtained in a reproduction head having a small track width dimension, there is a problem that a technique for improving the reproduction head is required in order to increase the track density using this technique.

Therefore, a technique of improving the recording density of a magnetic disk device by using a wide magnetic pole recording element having a sufficient magnetic field strength and a wide reproduction width reproducing element having a sufficient reproduction sensitivity, and at the same time narrowing the width of the data track Development is desired.

(Initiation of invention)

The above problem can be solved by using a recording technique in which the recording track width formed by the recording element is larger than the track pitch and recording is performed in order without overlapping one track in the radial direction of the magnetic disk.

It is also possible to solve the problem by using a technique of recording in order without erasing the track width formed by the recording element by an integral multiple of the track pitch and not overlapping one track in the radial direction of the magnetic disk.

In addition, it is possible to solve the problem by using a technique of making the recording width of the recording element at least twice as large as that of the playback element, and recording in order without overlapping one track in the radial direction of the magnetic disk.

At this time, by using a technique of providing a slip destination data table and exchanging physical addresses, the above-mentioned problem can be solved and the performance performance of the magnetic disk device using the present technique can be improved. In addition, by implementing defragmentation processing of the slip destination data table in response to instruction requests from the user or interrupt requests of the microprograms, performance performance at the beginning of use can be maintained for a long time.

At this time, by dividing the track pitch into a plurality of zones having different track pitches for each zone, one magnetic disk device can share an area that exhibits the same performance performance as a conventional magnetic disk device and an area whose recording density is more than double. Can be. In addition, the user can arbitrarily set the boundaries of a plurality of regions having different track pitches, so that the performance can be optimized to increase the performance in accordance with individual applications. In addition, by having a function of storing file allocation data that the operation system manages a file in a wide area of the track pitch, it is possible to increase the performance performance of the disk I / O of the operation system.

The present invention relates to a magnetic disk device for recording and reproducing magnetic information on a magnetic disk using a composite head.

Fig. 1 is a view for explaining the relationship between the track pitch and the width of the recording and reproducing element in the first embodiment of the magnetic disk apparatus of the present invention.

Fig. 2 is a diagram for explaining the relationship between the track pitch and the width of the recording and reproducing element in the embodiment of the conventional magnetic disk apparatus.

3 is a cross-sectional view illustrating an example of a schematic configuration of a magnetic disk device.

4 is a plan view for explaining an example of a schematic configuration of a magnetic disk device.

5 is a schematic view of a part of the magnetic disk apparatus seen from above.

6 is a schematic view showing the head portion of the magnetic disk apparatus viewed from above.

Fig. 7 is a diagram for explaining the relationship between the track pitch and the width of the recording and reproducing element in the second embodiment of the magnetic disk apparatus of the present invention.

8 is a diagram illustrating a relationship between the overwrite characteristic and the recording element width.

Fig. 9 is a view for explaining the geometrical relationship between the playback element width and the recording element width in the third embodiment of the magnetic disk device of the present invention.

Fig. 10 is a diagram for explaining the relationship between the effective recording track width, the actual enzyme track width, and the recording element width.

Fig. 11 is a diagram for explaining the relationship between the recording and erasing track width and track pitch in the fourth embodiment of the magnetic disk apparatus of the present invention.

Fig. 12 is a view for explaining a process in which magnetization information is added and contents of a slip destination data table when new data is recorded in the magnetic disk device of the present invention.

FIG. 13 is a view for explaining a process in which magnetization information is added and contents of the slip destination data table when recording overwrite data in the magnetic disk device of the present invention.

Fig. 14 is a view for explaining the defragmentation processing step of the slip destination data table of the magnetic disk device of the present invention.

FIG. 15 is a view for explaining that in one embodiment of the magnetic disk apparatus of the present invention, the zone area on the outer circumferential side of the magnetic disk is set to an area where the track pitch is wider than the recording element width.

Fig. 16 is a diagram for explaining the relationship between the track pitch and the width of the recording and reproducing element in the region where the track pitch is widened in one embodiment of the magnetic disk apparatus of the present invention.

FIG. 17 is a view for explaining that in one embodiment of the magnetic disk apparatus of the present invention, a portion of each zone of the magnetic disk is set to an area where the track pitch is larger than the recording element width.

(The best mode for carrying out the invention)

<Example 1>

The basic configuration of the magnetic disk device of the present invention is almost the same as that described in the matters of the prior art using Figs. 3, 4 and 5. Embodiments and features of the present invention will be described with reference to FIG. 1 showing an example of the present invention and FIG. 2 showing an example of the prior art, in relation to the width of the recording and reproducing element and the track pitch. 1 and 2, the head records and reproduces the magnetization information while moving from the left to the right in the drawing relative to the disc. In the figure, the pattern on the left side of the recording element 62 or the recording element 64 corresponds to newly recorded magnetization information and is indicated by the track 71 recorded this time. On the other hand, the pattern on the right side of the recording element 62 or the recording element 64 is magnetization information that is erased by overwriting, and is indicated by a track 73 that can be destroyed in the transfer diagram. Since the track 74 which is not affected is out of the traveling area of the recording element 62 or the recording element 64, the previous magnetization information is maintained as it is.

In the present invention shown in Fig. 1, the track pitch is about half that of the conventional art shown in Fig. 2, and about twice the data per unit area can be stored. The reproduction element 62 of the present invention is narrower than the track pitch so as not to reproduce the magnetization information of the adjacent track. For this reason, the reproducing element 62 of the present invention is about half the width of the reproducing element 61 of the prior art. On the other hand, by making the structure larger than the recording element 64 and track pitch of this invention, it can be set as the same width as the recording element 62 of the prior art. As a result, the recording element 64 can generate a recording magnetic field of sufficient strength, and the magnetic disk device of the present invention can realize good overwrite characteristics and a high signal S / N ratio.

In the magnetic disk apparatus of the present invention, since the composite head including the recording element 64 wider than the track pitch is provided, the magnetizing information of adjacent tracks can be shaped to a width equal to or less than the track pitch in addition to the recording operation. have. That is, during recording, following control is performed at the head position as shown in FIG. Of the tracks 72 recorded previously, an area on one side that interferes with the tracks 71 recorded at this time is overwritten and erased, so that the data track 72 having a width sufficient for reproducing the magnetization information in the reproduction element 62 is deleted. Can be formed. By recording while maintaining this positional relationship, interference with the adjacent track 74 on the reverse side can be avoided.

In addition, in the present invention shown in FIG. 1, the width of the reproduction element 62 is made narrower than the track pitch. However, in the future, if the technique of separating magnetization information from adjacent tracks by signal processing is advanced, the width of the playback element 62 is wider than the track pitch. It is possible to. In addition, based on the coating method of adjacent tracks, it is also possible to actively reproduce two data tracks simultaneously and improve the transmission speed.

Next, as a second embodiment of the present invention, the relationship between the width of the recording and reproducing element and the track pitch is shown in FIG. The composite head of this magnetic disk apparatus is provided with a recording element 66 corresponding to about three times the track pitch as shown in FIG. For this reason, the pattern that is overwritten and erased in accordance with the recording of the new magnetization information becomes the width of two tracks as indicated by the trackable track 73. By using the recording element 66 which is about three times the width of the track pitch as in this embodiment, a narrower track pitch magnetic disk device can be realized. Further, in order to realize a higher track density magnetic disk device, it is also possible to increase the ratio of the recording element width to the track pitch to 4, 5, 6.

In any of the embodiments described above, it is possible to correctly form a data track corresponding to a narrow track pitch by writing in one direction in the radial direction of the disc. According to the present invention, it is possible to provide a low cost and large capacity magnetic disk device which is particularly suitable for the storage of images having a high demand for serial transmission of data. By providing a dummy track in accordance with the unit of image transfer in the magnetic disk apparatus of the present invention, the performance performance can be significantly improved. For example, by increasing the block capacity, which is a unit of transfer, to about 10 seconds of the size of an image, a magnetic disk device having random access performance similar to that of a conventional magnetic disk device while suppressing a decrease in format efficiency due to dummy tracks is provided. It can be realized. In addition, by making the unit of transmission a variable block and corresponding to the seam of the image in which the size of the block is recorded, the decrease in the format efficiency due to the dummy track can be made small enough to be negligible.

As a method of making the recording element wider than the track pitch, a technique of using a recording element wider than the track pitch in forming the servo pattern to form a wider servo pattern is disclosed in Japanese Patent Laid-Open No. 1-94574. It is disclosed in Japanese Patent Laid-Open No. 5-298840. Further, as a method of using the recording elements without overlapping, a technique of erasing the magnetization information of a magnetic disk without overlapping at a narrow pitch is disclosed in Japanese Patent Laid-Open No. 63-32705. In addition, as a method in which the device width is wider than the track pitch, a technique for making a width of an element corresponding to a lower mode among a plurality of devices wider than the track pitch of the upper mode is used for a two-mode floppy device. -258209 and Japanese Patent Laid-Open No. 5-28427. None of the techniques described here have a configuration in which the data track recording element is wider than the track pitch, and does not use a method of overwriting a nearby data track. For this reason, since the track pitch cannot be made smaller than the magnetic pole width of the recording element, it is fundamentally different from the technique of the present invention.

<Example 2>

In order to make the magnetic disk device of the present invention have a performance performance suitable for more uses, a slip destination data table is provided, and exchange processing can be performed for each sector unit or track unit. A process of writing new data is shown in FIG. 12 and a process of recording overwrite data is shown in FIG. 13 regarding the process of forming magnetization information on the disk and the process of updating the slip destination data table.

FIG. 12 shows a magnetization state in which information has been recorded in advance to the track 101 and the track 102 of the disc, and no valid data has been recorded after the track 103. The final pointer points to the track 102. The value of the sleep (swap) destination data table is initialized to 0, indicating that no track has been exchanged. Here, when recording new data, following the values of the last pointer (track number last recorded last time), follow-up is performed at the position where the recording element 64 is applied to the track 103 and the track 104. In the meantime, the magnetization information is recorded. At the end of recording, the value of the last pointer is updated from 102 to 103.

FIG. 13 shows a magnetization state in which information is recorded in advance from the track 101 to the track 103 of the disc, and no valid data is recorded after the track 104. The final pointer points to the track 103. Here, when overwriting the new data for the track 102, the magnetization information is recorded while following the position of the recording element 64 across the track 104 and the track 105 in accordance with the value of the last pointer. Is done. At the end of recording, the value of the last pointer is updated from 103 to 104, the value of track number 102 in the slip destination data table is updated from 0 to 2, and the value of track number 104 is avoided from zero. Record the value X of the reference flag. When the track 102 is to be played back later, the track 104 obtained by adding 2 to 102 is reproduced correctly by first referring to the item 2 of the track number 102 in the slip destination data table. can do.

In the magnetic disk apparatus provided with the slip destination data table in the present invention, it is possible to perform an arbitrary number of overwrite processes for any track, and exhibit almost the same random access performance as the conventional magnetic disk apparatus. In this embodiment, the slip destination data table is provided in track units to reduce the load on the hardware and the controller. In order to utilize the area of the disk more efficiently, it is also possible to install the slip destination data table in units of sectors and perform advanced replacement processing.

In the magnetic disk apparatus provided with the slip destination data table of the present invention, by periodically defragmenting the contents of the slip destination data table, a track or sector where replacement processing is performed so that access is not performed can be used again. Can be resurrected. Here, description will be given for the magnetization state as shown in FIG. 13 in which the track 102 is replaced with the track 104. An update process of the slip destination data table according to the defragmentation process at this time is shown in FIG.

First, in step 1, data of the track 103 is reproduced, and the reproduced information is recorded over the track 102 and the track 103. The value of the slip destination data table updates the value of the track number 103 from 0 to -1. Subsequently, when the track 103 is reproduced, since the item in the slip destination data table is -1, the track 102 obtained by adding -1 to 103 is reproduced. Next, in step 2, the data of the track 104 is reproduced, and the value of the slip destination data table for recording the reproduced information over the track 103 and the track 104 is determined by the track number 102 of the reference source. Update the value from 2 to 1. Subsequently, when the track 102 is played back, since the item in the slip destination data table is 1, the track 103 obtained by adding 1 to 102 is played. Finally, in step 3, the value of the last pointer is updated from 104 to 103, the value of the track number 104 of the slip destination data table is updated from X to 0 of the referenced flag, and the defragmentation process ends. . By this process, the track 104 is newly revived as a usable track.

The timing for defragmentation may be any time in accordance with an instruction from the user at a time interval set by the user in advance. The normal defragmentation process is performed at a time when there is no access request from the user for a predetermined time or more, but the magnetic disk apparatus of the present invention can respond to an access request from the user even during processing.

<Example 3>

In order to further improve the performance performance of the magnetic disk apparatus of the present invention, a disk area is described as an example in which a disk having four zones in which the number of sectors in the track differs from zone 153 to zone 156 in FIG. Do it. On the outer circumferential side of the disk, the zone 153 is provided with 360 sectors in one track, 324 in the zone 154, 288 in the zone 155 and 252 in the zone 156. In the respect system, since adjacent sectors of outer and inner tracks have different sector arrangements of tracks, dummy tracks are provided to avoid mutual interference.

From the three zones 154 on the inner circumferential side of the disc to the zone 156, the narrow track is arranged so that the width of the recording element 64 and the reproduction element 62 as shown in FIG. 1 is related to the track pitch. The pitch area 152 is set. On the other hand, in the zone 153 on the outer circumferential side, the optical track pitch area 151 so as to have a relationship between the track pitch and the width of the recording element 68 and the reproduction element 67 as shown in FIG. Set to). By setting it as such, the zone 153 can directly overwrite and replace data without performing an exchange process using the slip destination data table. In this zone 153, by arranging data that may be replaced frequently, it is possible to prevent a decrease in recording efficiency due to repeated exchange processing. For example, a file allocation table for managing a file by an operation system, a RAM disk file, a system swap file, or the like is data that may be frequently replaced. In this manner, the process of preferentially reassigning specific data to the zone 153 can be realized by an application higher than the operation system.

In addition, the boundary between the optical track pitch area 151 and the narrow track pitch area 152 is a function which is realized by a microprogram in the magnetic disk device, not assigned to a special device such as a servo track writer before shipment from the factory. . After the magnetic disc is shipped from the factory, the user can arbitrarily change the function, thereby optimizing the magnetic disc apparatus having the best performance in the individual use environment.

As a second embodiment in which the area of the disc is divided into several areas having different track pitches, an area of a part of each zone can be allocated to a wide area of track pitch. The disk shown in FIG. 17 has four zones in which the number of sectors in the track from zone 153 to zone 156 is different, similar to the disk of FIG. 15. In the zone 156 on the inner circumference side, all of the 252 sectors are allocated to the narrow track pitch area 162. From three zones 153 on the outer peripheral side of the disc to the zone 155, an area of 252 sectors from the top is allocated to the narrow track pitch area 162, and the remaining sectors are allocated to the optical track pitch area 161. have. By this setting, the number of sectors in one track of the narrow track pitch area 162 can be the same number from the outer circumference to the zone of the inner circumference. Thus, the slip destination data table can be provided in track units to reduce the load on the hardware and the controller.

<Example 4>

The effective recording track width can be defined as the half width of the magnetization pattern actually recorded on the disc. The actual enzyme track width can be defined as the half width of the base track that is erased by overwriting the magnetization pattern actually recorded on the disk. Compared to a head having a recording element width of about 1.6 mu m, trimming was performed by ion milling technology to narrow the width to about 1.4 mu m, 1.1 mu m, and 0.9 mu m. In this head, the results of the effective recording track width and the actual enzyme track width are shown in the graph of FIG. 10 with the width of the geometry of the recording element of each head as the horizontal axis. The actual enzyme track width was wider than the effective recording track width, and the difference was found to be almost constant at about 0.5 탆 regardless of the geometry width of the recording element. This suggests that even if the geometry width of the recording element is made narrow, the real enzyme track width remains constant.

As shown in Fig. 11, the magnetic disk apparatus of the present invention includes a head having a configuration in which the track pitch is approximately half the width of the actual enzyme track. In the conventional magnetic disk apparatus, in order to make the actual enzyme track width equal to the track pitch, it is necessary to make the geometry width of the recording element extremely narrow. The magnetic disk apparatus of the present invention can be provided with a recording element 69 having a width for generating sufficient recording magnetic strength, and can realize good overwrite characteristics and high signal SN. A technique for setting the magnetic disk device in the sequential recording described in Example 1, the exchange processing using the slip destination data table described in Example 2, or the plurality of track pitch areas described in Example 3; By applying this, it is possible to provide a large capacity magnetic disk device with more excellent performance performance.

<Example 5>

The magnetic disk apparatus employs a direct overwrite recording method for overwriting new magnetization information on a data track on which old magnetization information is recorded. Since the old magnetized information can be masked without requiring an erase process, high performance performance can be realized. However, since the components of the old magnetization information remaining slightly are the same as the clock frequency of the new magnetization information, it is difficult to separate them, which is a direct factor that degrades the signal SN as a noise component. The signal intensity ratio of the old magnetization information before and after overwriting of the new magnetization information is called the overwrite characteristic. The smaller the overwrite characteristic is, the smaller the noise component is, and a good signal SN can be obtained. One target of the overwrite characteristic needed to obtain sufficient signal SN is about -30 dB.

This time, a trimming process was performed in which the width of the recording element was narrowed to about 1.4 µm and 1.1 µm to 0.9 µm in width by the ion milling technique, compared to a head having a width of about 1.6 µm. The result of measuring the overwrite characteristic in this head is shown in the graph of FIG. 8 with the horizontal axis as the geometric width of the recording element of each head. The overwrite characteristic was found to deteriorate as the geometry width of the recording element became smaller. At this time, the geometry width of the recording element of the head showing the overwrite characteristic of -30 dB or less was only the head larger than twice the geometry width of the reproduction element.

As shown in Fig. 9, the magnetic disk apparatus of the present invention includes a head having a configuration in which the geometry width of the recording element 68 is twice or more the geometry width of the reproduction element 67. In the conventional magnetic disk apparatus, the geometry width of the recording element is set to about 1.2 to 1.5 times the geometry width of the reproduction element. The effective reproducing track width is almost equal to the geometric width of the reproducing element, but as the effective reproducing width is narrower than the track pitch, it is necessary to make the geometry width of the recording element extremely narrow. The magnetic disk apparatus of the present invention can be provided with a recording element 68 having a width capable of generating sufficient recording magnetic strength, and can realize good overwrite characteristics and high signal SN. In this magnetic disk device, an exchange process using the sequential recording described in Example 1, the slip destination data table described in Example 2, or a plurality of track pitch areas described in Example 3 are set. By applying the technology, it is possible to provide a large capacity magnetic disk device with more excellent performance performance.

According to the present invention, in the disk apparatus using the composite head in which the recording element and the reproduction element are separated, the track pitch is smaller than the recording track width formed by the recording element, whereby the recording magnetic field strength decreases due to the narrowing of the recording element width. In this way, a large-capacity magnetic disk device with increased track density can be realized.

In addition, by providing the sleep destination data table, it is possible to realize a magnetic disk device having a random access capability capable of rewriting arbitrary data.

In addition, by providing a track pitch of a part of the disk and providing an area in which data can be directly replaced, a magnetic disk device excellent in performance performance with low controller overhead can be realized.

Claims (19)

The recording track width formed by the recording element of the magnetic disk apparatus using a hybrid head having a recording element for recording magnetization information on a magnetic disk and a reproducing element for converting magnetization information of the magnetic disk into an electrical signal has a track pitch. A magnetic disk apparatus having a larger head, and having a means for recording the magnetic disk without recording in the radial direction of the magnetic disk when recording the magnetization information. The method of claim 1, And recording means in order to record the magnetization information on the magnetic disk in such a manner that the recording means does not overlap one track in the radial direction of the magnetic disk. The method of claim 1, And a head having a geometric width of the recording element at least twice the geometric width of the reproduction element. The method of claim 1, The recording track width formed by the recording element is larger than the track pitch, and the recording track width formed by the recording element is smaller than twice the track pitch, and the erase track width formed by the recording element is almost the track pitch. A magnetic disk apparatus comprising a double head. The method of claim 1, And a sleep destination data table for managing exchange destinations of physical addresses on the magnetic disk, and when the previously recorded information is replaced with new information, the sleep destination data table is searched and updated. Magnetic disk device. The method of claim 1, And the magnetic disk is divided into a plurality of areas having different track pitches. The method of claim 6, The magnetic disk is divided into a plurality of zones having a sector number in one track for each radius of the magnetic disk, and at least one zone of the zone is further divided into a plurality of regions having different track pitches. Disk device. The method according to claim 6 or 7, And a function of setting a boundary between a plurality of areas having different track pitches by the user after shipment from the factory. The method according to claim 6 or 7, And a file storing data allocation data for managing a file by an operation system in a plurality of areas having different track pitches. In the magnetic disk apparatus using a hybrid head having a recording element for recording magnetization information on a magnetic disk and a reproducing element for converting the magnetization information of the magnetic disk into an electrical signal, an erase track width formed by the recording element is track pitch. And a means for performing recording while recording the magnetization information on the magnetic disk so as not to overlap in the radial direction of the magnetic disk. The method of claim 10, And recording means in order to record the magnetization information on the magnetic disk so that the recording means does not overlap by one track in the radial direction of the magnetic disk. The method of claim 10, And a head having a geometric width of the recording element at least twice the geometric width of the reproduction element. The method of claim 10, The recording track width formed by the recording element is larger than the track pitch, and the recording track width formed by the recording element is smaller than twice the track pitch, and the erase track width formed by the recording element is almost the track pitch. A magnetic disk apparatus comprising a double head. The method of claim 10, And a sleep destination data table for managing the exchange destination of physical addresses on a magnetic disk, wherein when the previously recorded information is replaced with new information, the sleep destination data table is searched and updated. The method of claim 14, And a function for executing defragmentation processing of the sleep destination data table in response to an instruction request from a user or an interrupt request of a micro program started by a timer. The method of claim 10, And the magnetic disk is divided into a plurality of areas having different track pitches. The method of claim 16, The magnetic disk is divided into a plurality of zones in which the number of sectors in one track is different for each radius of the magnetic disk, and at least one zone of the zone further divides the track pitch into a plurality of regions. Device. The method according to claim 16 or 17, And a function of setting a boundary between a plurality of areas having different track pitches by the user after shipment from the factory. The method according to claim 16 or 17, And a function of storing, in a plurality of areas with different track pitches, file allocation data for managing a file by an operation system.