JPH08297818A - Magnetic disk device - Google Patents

Abstract

PURPOSE: To compensate the manufacturing misalingment tolerance between a recording element and a reproducing element and to compensate the misalingment error between the recording element and the reproducing element with respect to a track due to the inclination of a slider at the time of performing a positioning by using a rotary actuator. CONSTITUTION: Address information used exclusively for recording operations are provided in ID blocks 32 and address information used exclusively for reproducing operations are provided togather with user data in data blocks 33. ID blocks are arranged to be shifted in a direction vertical to tracks from data blocks by the amount corresponding to the distance of the misalignment between the recording element and the reproducing element in a composite head. Since a correct position is performed by obtaining address information with sufficient readout probability at the time of recording and reproducing operations, the design of a magnetic disk device increased in track density is facilitated and the magnetic disk device is made high in performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device provided with a composite head in which a recording element and a reproducing element are separately provided, and more particularly, a manufacturing position of the recording and reproducing elements. A magnetic disk device in which the track density in the radial direction of the disk is increased by correcting the deviation tolerance and the positional deviation error with respect to the track between the recording and reproducing element due to the inclination of the slider when positioning using the rotary actuator. Regarding

[0002]

2. Description of the Related Art In a magnetic disk device, a head is moved in the radial direction of a rotating disk to perform reproduction and recording on a data block of a target sector. For this purpose, it is necessary to obtain the accurate position information of the head on the disk by some method. As a technique that has been widely adopted from the past, a pattern indicating a track number and a specific staggered pattern are written in advance on a magnetic disk, and a head is placed at a position where a target data block exists based on these two position information. There is a method to move. This position information is provided in the area of the servo block 81 in the schematic diagram showing the sector structure of the conventional example shown in FIG.

Further, as shown in FIG. 8, in order to surely record and reproduce data on a target data block, a gap 84 is provided immediately before each data block 83.
It is common to arrange the ID block 82 having the address information of the corresponding data block 83 via -2. Here, prior to the recording / reproducing operation with respect to the data block 83, the ID block 82 is reproduced and the address information is confirmed to finally determine whether or not the head 11 has moved to the target data block 83. Make a judgment. Up to now, the head positioning technique including the ID block described above has been adopted in many magnetic disk devices because it has high reliability in the reproduction operation and the recording operation with respect to the target sector. is there.

In recent years, in particular, in order to increase the recording density of a magnetic disk device, a technique using a head having high reproduction sensitivity is used. For example, a technique is widely known in which an MR element utilizing the magnetoresistive effect of an iron-nickel alloy is used as a reproducing head. Since the magnetoresistive effect element typified by the MR element cannot perform the recording operation, it is necessary to additionally use a recording head. As this recording head, an inductive head that uses a coil current to generate a magnetic field is used. Therefore, dedicated heads are used for recording and reproduction, respectively, and the positions of the elements of the heads for recording and reproduction are generally displaced. In a magnetic disk drive using a rotary type actuator as shown in FIG. 9, the deviation of the slider becomes large because the inclination of the slider with respect to the track direction becomes large at the position of the track near the outermost circumference or the track near the innermost circumference. Is especially noticeable. FIG. 10 shows an example in which the slider is tilted on the outermost track. The centers of the reproducing element and the recording element are displaced from each other in the direction perpendicular to the track direction. FIG. 11 shows an example of the state where the slider is tilted on the innermost track, but the center of the reproducing element and the center of the recording element deviate in the opposite direction from FIG.

As a conventional technique for correcting this deviation, for example, JP-A-63-142513 and JP-A-4-142513.
The method proposed in No. 232610 is mentioned. These are such that the positioning positions at the time of recording and at the time of reproducing are shifted by the amount of positional deviation of the head element for performing the above-mentioned reproduction and recording, or the deviation between the reproducing element and the recording element at the average tilt angle of the slider. This is a method in which the positions of both elements are provided so as to be 0 in advance, which is an effective technique for improving the track density.

[0006]

However, in the above-mentioned conventional technique, the reproduction operation of the ID block preceding the recording operation of the data block cannot be stably performed due to the deviation of the elements of the head for recording and reproducing. It was That is, as shown in FIG. 13 for explaining the head position in the conventional recording operation state, since the recording operation of the data block 83 is performed, the recording element 1 of the head is located at the center of the data track.
This is because the position of the reproducing element 120 of the head deviates from the center of the ID block 82 in the state where 21 is positioned. Therefore, it is necessary to position the recording element at the center of the data block 83 and record the data block 83 immediately after reproducing the ID block 82 by positioning the reproducing element at the center of the ID block 82. However, since it takes a very long time to perform the positioning accurately as compared with the data transfer rate, it is practically difficult to perform the positioning operation again in the gap portion between the ID block 82 and the data block 83. Since the reproduction error rate of the ID block due to the deviation between the recording element and the reproducing element is not within the allowable value especially at the track density exceeding 5 kTPI (track per inch),
This is a serious problem in designing a magnetic disk device.

To solve this problem, US Pat.
In the 2ID sector format method proposed in Japanese Patent No. 57149, a dedicated ID block for a recording operation and a dedicated ID block for a reproducing operation are overlapped, and the dedicated ID block for a recording operation is perpendicular to a track. This is a technique provided at a position offset in the direction by the distance between the recording element and the reproducing element. Although this method can effectively solve the problem of misalignment between the recording and reproducing elements of the head, the ID blocks which cannot be used by the user are redundantly provided, and therefore, the storage capacity of the disk is additionally consumed. There was a drawback that it would end up.

There is also proposed a technique for eliminating the above ID block, such as the sector format without ID shown in Japanese Patent Laid-Open No. 05-174498. The ID-less method generates information necessary for uniquely identifying a sector from track information embedded in a servo block and a numerical value obtained by counting the number of sectors passed from the beginning of the track. According to this method, since the reproducing operation of the ID block is not performed at all, there is no problem caused by the positional deviation between the recording and reproducing elements of the head. However, as generally used conventionally, it is not possible to confirm whether or not the head is correctly positioned in the target sector by the address information of the ID block, so that the reliability of the recording operation especially for the data block is lacking. There was a problem.

Therefore, it is possible to reliably and stably perform the ID block reproducing operation preceding the data block reproducing operation and the recording operation, and to store a large amount of additional information that consumes a large amount of storage capacity of the disk. The development of new technology that was not needed was expected.

[0010]

In order to achieve the above object, the present invention provides first address information in an ID block, and second address information together with user data in a data block. The blocks are arranged so as to be vertically displaced from the center of the track by an amount approximately equal to the distance between the recording element and the reproducing element in the composite head. When the data block is recorded, the head reproducing element is positioned at the position of the ID block, and when the data block is reproducing, the head reproducing element is positioned at the position of the data block. In this case, the address information is surely read without displacement. This vertical shift distance is magnetically stored on the disk surface or electrically stored in the storage element on the circuit board.

Further, according to the present invention, when it is difficult to directly measure the displacement distance between the recording element and the reproducing element of the composite head, the servo pattern is recorded using the recording element. There is provided means for indirectly measuring the amount of positional deviation between the recording element and the reproducing element by positioning the servo pattern using the reproducing element. Further, according to the present invention, in order to arrange the servo block or ID block with high accuracy, the servo block or ID block is recorded in the servo write process of the manufacturing process of the magnetic disk device, or the servo block is formed by the uneven pattern on the disk. Alternatively, it forms an ID block. Further, the present invention comprises a giant magnetoresistive effect element and has a track density of 10 kTPI or more, or an impact resistance of 500 G or more during operation, so that it can be used as a portable image storage device. Is provided.

Further, when recording a data block, I
After confirming whether the address information obtained from the D block and the address information of the target data block match, the data block is recorded together with the address information and the user data, so that the target sector can be reliably recorded. The data is recorded in. Further, at the time of reproducing the data block, it is possible to confirm whether the address information included in the reproduction data matches the address information of the target data block after the process of reproducing the data block or after the reproduction of the data block is completed. ,
The data is surely reproduced from the target sector.

Further, since the ID block information is not required during the reproducing operation, the ID address mark portion and the data address mark portion are formed by using different codes, and the detection of the data address mark is immediately waited for after the head seek. By doing so, it is possible to prevent the ID block from being forcibly reproduced in the position-shifted state and prevent the ID read error from occurring. Further, while the reproducing element of the head is passing through the area of the ID block, the operation of the reproducing amplifier or the data discriminating circuit is stopped, or
A magnetic disk device that has low power consumption and excellent access performance by means for suppressing the output of an error signal or forcibly performing a data block reproducing operation when an ID error signal is output Is.

Further, after the judgment or correction of the data read error is completed by the error check code added to the data block, it is confirmed whether or not the address information contained in the reproduced data and the address information of the target data block match. For this purpose, a semiconductor memory having a capacity capable of storing two or more data blocks is provided, and the reproduction data of the data block is temporarily transferred to the semiconductor memory so that the reproduction operation can be performed to confirm the address information. There is no need to insert a processing waiting time. Alternatively, by inserting an error check code for determining a read error of the address information in the middle of the data block, it is possible to check the address information without waiting for the end of reproduction of the data block, thus increasing the processing speed. And a magnetic disk device.

[0015]

According to the present invention, at the time of recording a data block, by positioning the recording element in the data block, the positions of the ID block and the reproducing element of the head can be made to coincide with each other. It is possible to obtain the address information of the sector to be processed with sufficient S / N and reliability. Further, when reproducing the data block, the head reproducing element is positioned in the data block to reproduce the data block, thereby obtaining the address information of the corresponding sector with sufficient S / N and reliability. You can also By the above operation, in both recording and playback operation,
Since the false detection rate of ID information can be reduced, it is easy to design a magnetic disk having a high track density, and it is possible to dramatically increase the storage capacity as compared with a conventional magnetic disk device. Further, since it is possible to reduce the accuracy required for following vibration and settling vibration, the servo mechanism can be easily designed, and the access performance of the magnetic disk device can be improved. Further, there is also an effect that the safety is enhanced against vibrations applied from the outside during operation. In particular, the effect of the present invention is high in a disk device having a track density of 10 kTPI or more.

In carrying out the present invention, the data that must be added to the format of the prior art is the ID information in the data block. Since this is about 10 bytes, which is a sufficient amount of information, the ID information is added. By doing so, the consumption of extra disk capacity can be suppressed to 2% or less. Further, according to the present invention, by correcting the center misalignment distance between the recording element and the reproducing element due to the head processing error, it is possible to increase the yield in manufacturing the head, and it is possible to remarkably improve the productivity. is there. Further, since the error check code added to the ID information in the ID block is different from the error check code added to the ID information in the data block and the number of bits is used, the reliability of the write operation can be particularly improved. It is also possible to provide a portable magnetic disk device for personal use having a shock resistance of 500 G or more.

[0017]

【Example】

<Embodiment 1> An embodiment of the magnetic disk device of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a schematic configuration of the present device, and FIG. 2 is a plan view of a part of the present device when viewed from above. The magnetic disk device of this embodiment includes an inductive type element as a recording element, a recording / reproducing separation head 11 using a magnetoresistive element as a reproducing element, and a rotary actuator 12, and The data surface servo is performed using the position information embedded on the data surface of the disk 13. CPU (central control unit) when recording or reproducing
Power is applied to the voice coil motor 14 in accordance with a command from the recording / playback separation type head 11 on the target track 15 via the rotary type actuator 12. After that, the address of the target sector is searched for via the recording / reproducing circuit, and recording or reproducing of the data portion is executed.

In the present invention, in order to correct the positional deviation between the recording and reproducing elements of the head, the following sector format is constructed. FIG. 3 is a schematic diagram showing a configuration example of four sectors in four adjacent tracks 15 formed on the disc. A plurality of different sectors are provided before and after each sector, and one track has a structure having a plurality of sectors. 1
One sector can store 512 bytes, which is the minimum unit for storing information.

One sector includes a servo block 31 and
It is composed of an ID block 32 and a data block 33. A gap region 34 is provided between each block and the next sector as a gap for absorbing the processing time of the controller and the rotation fluctuation of the disk. The above-described blocks are separated from each other by the gap region 34, and the length of the gap region 34 may be several bytes or more. The structure of each block will be described below in detail.

The structure and role of the servo block 31 is as follows.
This is basically the same as the servo block 81 in the schematic diagram showing the conventional sector structure shown in FIG. In FIG.
The configuration of the servo block 31 is schematically shown. The servo block 31 includes a gain zone section 40 and a marker section 4
1, gray code section 42, servo burst section 43, PA
And a D section 44. Gain zone section 40
Is an area for generating the servo clock and adjusting the gain of the read amplifier. The marker section 41 is an area for establishing synchronization when reading the subsequent information and for generating an index pulse and a sector pulse. The gray code section 42 is an area in which the track number is represented by a gray code. The servo burst section 43 is formed of a staggered pattern, and head position information is generated by comparing the reproduction signal amplitudes of the four areas 43-1 to 43-4.

Here, an example is shown in which the width of the servo burst portion 43 matches the track pitch (track interval). However, from the viewpoint of positioning accuracy, the width of the servo burst portion 43 should be narrower than the track pitch. Is preferred. For example, if it is set to about 70% of the track pitch, the positioning error due to the non-linearity of the off-track characteristics of the head can be minimized, which is particularly preferable.

The ID block 32 is the data block 33.
This is provided in order to confirm whether or not the recording element of the head is correctly positioned in the target sector by performing the reproduction before the operation of recording. ID block 3 in FIG.
2 schematically shows the configuration of No. 2. Unlike the function of the ID block 82 in the conventional sector shown in FIG. 8, the function of the ID block 32 functions as ID information dedicated to the recording operation of the data block 33 and is used in the reproducing operation of the data block 33. Absent. Further, the position where the ID block 32 is placed is provided so as to be shifted from the center position of the track in the direction perpendicular to the track direction, and the distance of this deviation differs depending on each track position. Specifically, the optimum distance is the same as the amount of center deviation between the recording element and the reproducing element of the head that occurs when performing the positioning operation using the rotary actuator. The structure of this ID block 32 is basically the same as that of the conventional ID block 82 shown in FIG.
It is composed of a CO (voltage control oscillator) sync section 50, an ID address mark section 51, an ID data section 52, a CRC section 53, and a PAD section 54. The VCO sink unit 50 is a region for pulling in the oscillation frequency of the VCO to establish clock synchronization and adjust the gain of the read amplifier. ID address mark part 5
Reference numeral 1 denotes a start position of subsequent information, and is an area in which a specific bit pattern is formed for synchronizing reproduction. I
The D data section 52 includes the cylinder number of the corresponding sector,
It is composed of a head number, a flag which is additional information such as a sector number and a defective sector. The CRC unit 53 is
This is an area added to detect whether an error has occurred in the reading of the ID block 32. The PAD section 54 is an area added for stably performing the read operation up to the CRC section.

The data block 33 is an area for storing user data, and occupies a larger area on the disk than the servo block 31 and the ID block 32. FIG. 6 schematically shows the configuration of the data block 33.
The function of the data block 33 has, in addition to the function of the conventional data block 83 shown in FIG. 8, a function of confirming whether or not the read operation to the target sector is correctly performed. This is a function added to prevent the ID block from being reproduced during the data block reproducing operation.
Functions as information. Therefore, ID information for uniquely identifying a sector is added to the structure of the data block 83 of the conventional example. As this information, ID
A data string substantially equivalent to the ID data part 52 of the block 32 is used. When recording the data block 33, the ID data portion 62 and the data portion 63 are continuously written. The data block 33 includes a VCO sync unit 60, a data address mark unit 61, an ID data unit 62, a data unit 63, an ECC unit 64, and a PAD.
And a part 65. The VCO sink unit 60
A data address mark portion 61 and an ID data portion 62
, The ECC unit 64, and the PAD unit 65 respectively include the VCO sync unit 50 and the ICO unit 50 of the ID block 32 described above.
D address mark portion 51, ID data portion 52, CR
It is equivalent to the function performed by the C section 53 and the PAD section 54.
The data portion 63 is 512 bytes of the data stored in the magnetic disk device by the user.

Next, the positional relationship between the head and the track when the recording operation is performed on the sector of the present invention will be described with reference to FIG. During the recording operation, the recording element 1 of the head
The head is positioned so that 21 coincides with the center of the data block 33. Since the ID block 32 is provided in advance by being displaced from the center of the track by an amount corresponding to the distance between the recording element and the reproducing element,
The reproducing element 120 of the head at this position coincides with the center of the ID block 32. Due to this positional relationship, the ID block 3 preceding the recording operation for the data block 33
It is possible to perform the reproduction of No. 2 in a state where there is no displacement of the head position, and it is possible to confirm the address information without fail. Furthermore, after reproducing the ID block 32, the data block can be immediately recorded without correcting the position of the head.

FIG. 14 is a diagram for explaining the positional relationship between the head and the track when the reproducing operation is performed on the sector of the present invention. During the reproducing operation, the reproducing element 12 of the head
The head is positioned so that 0 coincides with the center of the data block 33. In this positional relationship, the reproducing element 120 of the head is displaced from the center of the ID block 32. However, the information of the ID block 32 is not required during the reproducing operation of the present invention, and I in the displaced state.
It is possible to eliminate the step of reproducing the D block 32. Since the address information necessary for confirming the target sector is included in the data block 33, it can be reproduced without the head position deviation.

By adopting the format of the present invention, the address information can be reproduced without any positional deviation even when the head positioning position is changed between recording and reproduction. The occurrence of address detection errors can be greatly reduced, and a high-performance magnetic disk device can be realized.

The format of the present invention is US Pat.
No. 7149, which has ID information duplicated and has 2
Compared with the ID format, it has a great advantage in the usage efficiency of the disk area. In the 2ID format, the VCO sync section, the CRC section, and the PAD are provided for both the recording-only ID block and the reproduction-only ID block.
Since a part and a gap region are required, an extra capacity of about 50 bytes per sector is required. In the present invention, by processing the read ID together with the data block, the above area is not necessary at all, and it is only necessary to add a capacity of 10 bytes or less per sector.

As described in the above embodiments, the present invention provides a method for greatly reducing the displacement distance of the above elements in a magnetic disk device provided with a composite head in which recording and reproducing elements are provided separately. Although provided, it can be widely applied to a storage device for information having a sector format by using a composite head. For example,
The present invention can be easily applied to information storage devices such as magneto-optical disk devices, magnetic tape devices, and magneto-optical tape devices.

<Embodiment 2> In the conventional magnetic disk device, in both recording and reproducing operations, in order to determine that the head has moved to a target sector, an ID block previously recorded on the disk is recorded. 82 is reproduced, the address information contained in this ID block 82 is compared with the address information of the target sector, and the coincidence is confirmed. In the magnetic disk device of the present invention, in the above-mentioned address information confirmation operation, data recorded at different locations on the disk are used for the recording operation and the reproducing operation. That is, in the recording operation, the address information is generated from the reproduction data of the ID block 32, and in the reproducing operation, the address information is generated from the reproduction data of the data block 33. The processing flow of the recording operation for one sector in the magnetic disk device of the present invention will be described with reference to the flowchart of FIG. The controller seeks the head 11 based on the position information of the servo block 31.
After performing 3), the reproducing operation of the ID block 32 is started and the detection of the ID address mark portion 51 is awaited (step
p4). Playback operation of the ID block 32 (step
After p5) is completed and the error check is performed by the CRC unit 53 of the ID block 32 (step 6), I
It is confirmed whether the information in the D data section 52 matches the address information of the target sector (step 7). If a match is confirmed here, the recording operation of the data block 33 is started. In the following order, the VCO sink unit 60 (ste
p8), the data address mark portion 61 (step 9),
ID data portion 62 (step 10), data portion 63 (s
step 11), ECC section 64 (step 12), PAD
Recording is performed with the part 65 (step 13), and the recording of one sector is completed.

Next, the processing flow of the reproducing operation for a certain sector will be described. After performing the seek (step 3) of the head 11, the controller immediately shifts to the reproducing operation of the data block 33. That is, I
The detection of the D address mark portion 51 is not waited for, but the detection of the data address mark portion 61 is waited (step 4). After the reproduction operation (step 5) of the data block 33 is completed and the error check by the ECC section 64 of the data block is executed (step 6), the ID data section 6
It is confirmed whether the information of No. 2 matches the address information of the target sector (step 7), and the reproduction of one sector is completed.

As described above, the recording operation and the reproducing operation are both performed at 2
By selectively using the three different address information, it becomes possible to detect the address information independently during the recording operation and the reproducing operation. Even if the information of the ID block of a certain sector is lost for some reason, since the address information is included in the data block, it is determined whether the reproduced data is obtained from the target sector. The data in this sector can be reproduced by the same processing as the normal operation. In addition, the information of the data block of a certain sector is lost for some reason,
Even if the ID block is once registered as a defective sector, if the ID block can be correctly reproduced, the data block can be recorded and restored to be used as a normal sector. Further, by using different code systems for the error check codes related to the two address information or using error check bit strings of different lengths, the error rate at the time of detecting the address information during the recording operation and the reproducing operation can be improved. Can be designed independently. For example, by strengthening the error detection during the recording operation, it is possible to design the recording operation with higher reliability.

As described above, this embodiment can perform data processing almost equivalent to the data processing method of the conventional format shown in FIG. 8, so that the conventional hard disk controller and address The present invention can be implemented at a low cost because it can be realized without significantly changing the mark detection circuit and the like.

Further, this embodiment can realize a magnetic disk device having a high performance especially when combined with the first embodiment. In this case, even if the positioning position is changed between the recording operation and the reproducing operation, the address information can always be obtained from the reproduction signal having no positional deviation, and the recording density in the track direction is increased to increase the storage capacity. It is possible to realize a high-performance magnetic disk device having a large size.

<Embodiment 3> An embodiment of a system in which the present invention is applied to a magnetic disk device will be described with reference to FIG. The reproduced data read from the magnetic disk 13 by the magnetic head 11 is amplified by the head amplifier 170, the waveform is shaped by the equalizer 171, and then converted into a digital signal by the peak detection circuit 172. This digital signal includes a signal from the VCO sync section for synchronizing clocks, and detects an address mark section that is a specific bit pattern in order to determine the start section of the data that follows. There is a need. In the conventional magnetic disk device, the ID address mark portion is similarly detected in both the recording and reproducing operations, and the ID data portion following this is reproduced.

The magnetic disk apparatus of the present invention is characterized in that the ID address mark detector 175 detects the ID address mark portion 51 during the recording operation, and the subsequent ID data portion 52 is reproduced. During the reproducing operation, the data address mark detector 61 176 detects the data address mark portion 61, and the data portion 62 following this is reproduced. In this way, by using two different address mark portions for the recording operation and the reproducing operation, it is possible to detect the address mark portion independently during the recording operation and during the reproducing operation. In the conventional device, the reproducing process of the data block 83 could not proceed until the head was accurately positioned with respect to the ID block 82 after the seek and the ID address mark portion was successfully detected. By applying the present invention,
Even if the ID address mark portion 51 cannot be detected after the seek due to the displacement of the head or the like, the reproduction process of the data block 33 can be executed, so that the performance of the device can be improved. Further, since the ID address mark portion 51 and the data address mark portion 61 can be detected independently during the recording operation and the reproducing operation, the positional relationship between these two address mark portions can be freely designed. Becomes This effect is particularly preferable when combined with the first embodiment, and even if the operation of changing the positioning position between the recording operation and the reproducing operation is performed, the address mark portion is always detected from the reproduction signal having no positional deviation. It is possible to realize a high-performance magnetic disk device in which the recording density in the track direction is increased and the storage capacity is increased.

<Embodiment 4> In the present embodiment, in the magnetic disk drive having the means for shifting the head positioning target in the recording and reproducing operations described in Embodiment 1, the above-described recording and reproducing operations are performed. A magnetic disk device having means for pre-recording data on the head position deviation amount (correction amount) in a boot track on the disk, reading the data when the magnetic disk device is powered on, and using it for subsequent seek operations. Explain.

The data of the head position deviation amount at the time of recording and at the time of reproducing has an optimum value which is different for each device, each head and each track due to manufacturing tolerances and the like. It is difficult to calculate accurately from the angle) and the distance between the recording element and the reproducing element of the head. In order to improve the positioning accuracy and realize a device with a high track density, it is preferable to have a function of actually measuring the positional deviation amount by some method before shipping the device and storing it in the device itself. In this case, in a magnetic disk manufactured as a prototype according to the first embodiment, when one track is recorded and the track is reproduced, the error rate at the time of data read is 1.
It became larger than 0 minus 6. On the other hand, when the present invention is applied and the same operation as described above is performed based on the data of the positional deviation amount stored on the disk surface, the error rate becomes a value smaller than 10 −9. The error rate was satisfied according to the specifications of the device.

As a method of storing offset data different from the above example, a nonvolatile memory of some kind (for example, PROM) provided on the circuit board of the magnetic disk device is used.
Or an EEPROM or a dielectric memory). In this case, the effect on the positioning accuracy of the device is the same no matter what the storing means. In the method of recording the data of the amount of positional deviation of the head on the disk surface, the circuit board of the disk device can be detached from the mechanical section and the repair work can be performed. In addition, the data of the amount of positional deviation of the head is stored in the non-volatile memory on the circuit board.
In this method, the time required to read the boot track at the time of booting the device can be shortened, so that there is an effect that the response at the time of booting the magnetic disk device is excellent.

<Embodiment 5> In the present embodiment, in the magnetic disk device equipped with the means for shifting the head positioning target in the recording and reproducing operations described in Embodiment 1, the above-described recording and reproducing operations are performed. A magnetic disk device including means for actually measuring the data of the positional deviation amount (offset amount) of the head in the manufacturing process of the device will be described. By performing a seek operation and a following operation on the basis of the offset data, it is possible to reduce the distance of the positional deviation of the head from the track center, or to remove it to a negligible extent.

For this purpose, it is necessary to determine the offset data of the head positioning target before the seek operation. In order to easily realize this, an approximate value is calculated based on the design value of the deviation between the recording element and the reproducing element of the head and the data of the yaw angle (angle of inclination with respect to the track) of the slider. be able to. However, in order to efficiently absorb the error in the element position in manufacturing individual heads and the error in the processing of the positional relationship with the actuator and spindle motor, the optimum value of the offset data should be set for each head of each device. It is desirable to make an actual measurement for each and decide.

Although various processes can be considered as a method of actual measurement, as one embodiment, a servo write process of a magnetic disk drive manufacturing line can be used.
Specifically, after the servo pattern is recorded by using the recording element of the head incorporated in the product, the reproducing element of the same head is used to follow the pattern, and this position is set to the first position. Head position. A second servo pattern for measurement is recorded with this first head position as a reference, and a position following the second servo pattern is defined as a second head position. The difference between the first and second head positions becomes offset data at the measured track position. This time, Example 1
Data blocks 33 were recorded on a magnetic disk manufactured as a prototype based on
The distance between the center of 3 and the center of the track shown in the servo block 31 in the radial direction was measured by the Bitter method. First, when a data block was recorded on the basis of the offset data obtained by calculation, the distance of the track deviation was about 0.5 μm in a wide place. On the other hand, when the present invention is applied and the same operation as described above is performed based on the offset data actually measured using the servo write process, the track deviation distance is 0.1 μm or less even in a wide place. . In particular, in the case of a head that requires a sense current during reproduction, as represented by an MR head, the optical center of the reproducing element and the center of magnetic sensitivity when reproducing magnetic information are It is generally different. In order to correct the effect of this center deviation, it is preferable to apply the present invention and actually measure the pattern produced using the recording element of each head using the reproducing element of this head itself.

By performing this measurement on several tracks from the outer circumference to the inner circumference of the disk, offset data capable of sufficiently correcting various errors can be obtained. This measurement does not necessarily have to be done for every track. The amount of misalignment of each of the other tracks can also be obtained by function approximation based on the measured values of a small number of tracks.

Many means different from the above embodiment can be considered as a method of measuring the offset data, but the present invention measures the offset data by using the recording element and the reproducing element of each head itself. However, the present invention is not limited to the embodiment using the servo write process described above.

<Embodiment 6> In this embodiment, the ID block 32 described in Embodiment 1 is replaced by the data block 3.
In a magnetic disk device provided offset from the center of the disk 3 in the radial direction of the disk, a magnetic disk device provided with means for recording the ID block 32 or the data block 33 in a servo write process in the manufacturing process of the device. Explain. Further, as a second embodiment, a magnetic disk device equipped with means for recording the ID block 32 or the data block 33 in advance by the unevenness of the disk will be described.

The optimum value of the offset amount is different for each device, each head, and each track. In particular, in a magnetic disk device having a track pitch of 2 μm or less, in order to satisfy the error rate specification of the device,
ID block 32 and data block 3 with extremely high accuracy
It is necessary to set the offset distance with respect to 3. In order to achieve this purpose, for example, after the device is assembled, the head is positioned based on the position information of the servo block 31 and the ID block 32 can be automatically recorded for each track. In a magnetic disk device having a high track density, it is difficult to ensure the accuracy of the offset distance, and the ID read error may reduce the throughput of the device.

Therefore, in this embodiment, the ID block 32 is written together with the servo block 31 in the servo write process at the stage of mounting the magnetic disk 13 on the magnetic disk device 16 in the magnetic disk device manufacturing line. , It became possible to perform a more favorable placement. Since this embodiment uses the existing manufacturing equipment, it can be relatively easily incorporated into the manufacturing process of the product. Alternatively, in order to form a pattern with higher accuracy, the magnetic disk may be recorded on the magnetic disk by using a high-precision information recording device equipped with an air spindle, an air slider or the like.

Further, as a second embodiment, by using the photolithography technique widely used in the manufacture of semiconductors, the resist agent applied to the disk is exposed by using a mask produced with high precision, and the servo block 31 is exposed. By forming irregularities on the disk, it was possible to realize a highly accurate servo pattern. At this time, ID
The block 32 is also exposed at the same time and is formed in advance by the unevenness of the disk, so that the ID block 3
We were able to dramatically improve the accuracy of the offset distance of 2. This embodiment is particularly suitable for a thin magnetic disk device containing one magnetic disk.

<Embodiment 7> In this embodiment, a giant magnetoresistive effect element having a multi-layered magnetic film to increase the rate of change in magnetoresistance is used as an element for reproducing the head, and the density in the track radial direction is used. 10kTPI (track, par,
The description will be made on the magnetic disk device having a size of inch or more.

In the magnetic disk device described in the first embodiment, the MR element utilizing the magnetoresistive effect of permalloy, which is an iron-nickel alloy, is used as the reproducing element of the head. 10 for this magnetic disk unit
When a pattern having a track density exceeding kTPI is formed, the reproduction signal of the offset ID block becomes weak, and the data error rate is 10 minus 7.
It became larger than the power of two and did not meet the design specifications of the device. Therefore, in this embodiment, the track density is set to 11 kTPI.
In the magnetic disk device set to, the magnetic film has a multi-layered structure to increase the rate of change of the magnetic resistance and to improve the sensitivity during reproduction to MR.
A head that is approximately 6 times the size of the device was used. When the reproducing operation of the ID block was performed by this device, a sufficiently large reproduced signal could be obtained, the address information could be correctly detected, and the device design specifications were satisfied. Further, by setting the track density to 10 kTPI or more, the storage capacity of the device using the disk having a diameter of 1.8 inches could be 500 Mbytes or more. This magnetic disk device can record a moving image for about 1 hour by using an MPEG2 image compression code, and can be applied as a portable image storage device.

<Embodiment 8> In this embodiment, the ID block 32 described in Embodiment 1 is replaced by the data block 3.
In the magnetic disk device provided with an offset in the radial direction of the disk from the center of No. 3, a magnetic disk device having impact resistance of 500 G or more during operation will be described.

The reliability of the magnetic disk device can be greatly improved by improving the shock resistance during operation. In particular, the phenomenon that the head position deviates from the target data track and the data on the adjacent track is overwritten due to an external shock during the recording operation, makes the reliability of the magnetic disk device extremely extreme. It is one of the major causes of deterioration.

In the conventional magnetic disk apparatus, after performing a head seek when performing a recording operation, a waiting time is inserted so that the settling vibration of the head is sufficiently attenuated. Further, in the ID-free format method proposed in Japanese Patent Laid-Open No. 05-174498, in which the ID block is omitted, the means for confirming that the head is positioned in the target sector is a processing method using the conventional format shown in FIG. Therefore, there is a possibility that the waiting time inserted in this recording operation becomes long.

By adopting the format of the present invention, the ID information in the ID block 32 is confirmed prior to the recording operation, and the impact resistance during operation is set to 500 G or more, thereby providing a margin for the positioning accuracy. I was able to take it. As a result, the seek time can be shortened without requiring extra time for estimating the margin for waiting for the damping of the settling vibration. For the above reasons, it was possible to provide a magnetic disk device having more data reliability and access performance than the device using the conventional format example shown in FIG.

Particularly, in the magnetic disk device having the track density of 10 kTPI or more, which is explained in the seventh embodiment,
Since the positional deviation distance between the recording element and the reproducing element of the head becomes large with respect to the track pitch, it is possible to provide a higher performance magnetic disk drive by combining this embodiment with this embodiment.

<Embodiment 9> In this embodiment, the magnetic disk device described in Embodiment 3 is used to judge the end of the head seek by reproducing the ID block 32 and the data block 33 during recording and reproducing, respectively. In the following, a magnetic disk device in which the ID address mark portion 51 and the data address mark portion 61 are formed by using different codes will be described.

In the magnetic disk device of the present invention, the data of the data block 33 is required for the reproducing operation, whereas the data of the ID block 32 is unnecessary.
On the contrary, the data in the data block 33 is unnecessary while the data in the ID block 32 is required in the recording operation. As a result, misalignment relating to the arrangement of the ID block 32 and the data block 33 is allowed, and basically the ID block 32 cannot be correctly reproduced at the head position during the reproducing operation. However, if the skew angle of the slider reaches a certain condition depending on the angle of the actuator, both the ID block 32 and the data block 33 may be correctly reproduced. In this case, a means for determining whether the reproduced data is the ID block 32 or the data block 33 is required. According to the present invention, the address mark portions 51 and 52 added to the ID block 32 and the data block 33 are formed of different bit strings, so that the ID block 32 can be read only by referring to the address mark portion in the reproduced data string. It is possible to determine whether the data block 33. Conventional 2
When two address mark parts are formed by the same bit string, the reproduced data is the ID block 32 or the data block 3.
In order to determine whether it is 3, a process for managing the timing is involved.

In the magnetic disk device of this embodiment, a program on the CPU is used for a part of the above processing. First, the data reproduced from the disc is once transferred to the cache memory by the hardware. The CPU refers to the data string on the cache memory according to the built-in program and reads the data corresponding to the address mark portion. By comparing this with a bit string of an address mark prepared in advance, it is determined whether the reproduced data on the cache memory is an ID block or a data block.

It is also possible to consider a second embodiment in which the series of processes described above is performed by hardware. in this case,
By inputting the reproduced serial data to the shift register and forming a circuit for activating the AMF (address mark found) signal when the bit string of the address mark portion prepared in advance is matched, a circuit equivalent to that of the previous embodiment is obtained. Processing can be realized. In this second embodiment, C
By reducing the load on the PU and performing high-speed processing,
A more preferable magnetic disk device can be provided.

<Embodiment 10> In this embodiment, the magnetic disk device described in Embodiment 3 is used to judge the end of the head seek by reproducing the ID block 32 and the data block 33 during recording and reproduction, respectively. In the area of ID block 32, a magnetic disk device that suspends a part of the reproducing circuit will be described.

The magnetic disk device of the present invention is characterized in that the data of the data block 33 is required for the reproducing operation, whereas the data of the ID block 32 is not required at all. Therefore, during the time when the reproducing element of the head passes through the area of the ID block 32, the operation of a part of the reproducing circuit can be stopped and the average power consumption of the device can be reduced by several percent.

This time, a magnetic disk device equipped with a disk having a diameter of 2.5 inches was prototyped and the average power consumption of the device was measured. First, when the reproducing operation was continuously performed as in the conventional example, the average power consumption of the device was about 2.08 watts. Next, the present invention is adopted, and as described above, in the reproducing operation, the ID data section 3
In No. 2, when the regeneration circuit was stopped, the average power consumption of the device was about 1.97 watts. For this reason, it is possible to provide a magnetic disk device with less supplied energy, and it is possible to extend the continuous use time of a portable information device that is battery-powered.

<Embodiment 11> In this embodiment, the magnetic disk device described in Embodiment 3 is used to judge the end of head seek by reproducing the ID block 32 and the data block 33 during recording and reproduction, respectively. In the following, a magnetic disk device provided with a semiconductor memory for temporarily storing reproduced information will be described.

According to the present invention, in the recording operation and the reproducing operation,
By changing the means for determining that the head has been positioned in the target sector, a positional deviation relating to the arrangement of the ID block 32 and the data block 33 is allowed and a high performance magnetic disk device is provided. In particular, at the time of the reproducing operation, by confirming that the address information of the target sector and the address information contained in the reproduced data block 33 match, it is determined whether or not the correct reproduction is performed from the target sector. At this time, the reproduced data includes the ID data portion 62 and the data portion 63 continuously, and the error correction is performed by one ECC portion 64. It is desirable from the viewpoint of the reliability of the information of the ID data section 62 to confirm the information of the ID data section 62 after the error correction by the ECC section 64 is completed. However, since the ECC unit 64 is provided at the end of the data block, the error correction by the ECC unit 64 is completed, and the completion of the seek operation can be confirmed by 1
It is almost equal to the timing when the reproduction of one sector ends.
The delay in confirming the completion of the seek operation causes the access performance of the device to deteriorate.

By adopting the present embodiment and providing the semiconductor memory for temporarily storing the reproduction data, the access performance of the apparatus is deteriorated even if the completion of the seek operation is confirmed after the reproduction of one sector is completed. Can be prevented.

<Embodiment 12> In this embodiment, the magnetic disk device described in Embodiment 3 is used to judge the end of head seek by reproducing the ID block 32 and the data block 33 during recording and reproducing, respectively. In FIG. 3, a magnetic disk device having two error check units for error correction in a data block will be described with reference to the drawings.

In the magnetic disk drive shown in the third embodiment,
After the reproduction of the data block 33 is completed, the address information of the ID data section 62 is confirmed, and the completion of the seek operation is determined. From the viewpoint of the performance of the magnetic disk device, it is preferable to confirm the address information at the earliest possible timing. For this purpose, in this embodiment, as shown in FIG. 7, in addition to the ECC unit 72 corresponding to the conventional error check code, a CRC unit 71 is provided as a second error check unit related to the ID data unit 62. The structure of the data block 33 at this time has two error correction codes as shown in FIG. 7, and each error correction code is an error correction code called ECC or CRC as in the above example. It is not necessary to use the same system, and each device can be designed independently.

With this configuration, the ID data section 62 and the CRC section 7 can be provided without waiting for the end of reproduction of the data block 33.
It becomes possible to confirm the address information of the ID data portion 62 at the time when the reproduction of No. 1 is performed and to determine the completion of the seek operation. Since it is possible to confirm the ID information before the error check by the ECC unit 72, it is possible to speed up the reproduction process and provide a high-performance magnetic disk device with excellent access performance.

Further, since the ID data section 62 has a dedicated error correction code, the ID data section 62
Can independently detect and correct errors. Therefore, the error correction capability can be set to a level different from that of the data section 63. In particular, by adjusting the bit length of the CRC section 71 to enhance the error correction capability, the address information of the ID data section 62 can be reliably obtained, and a more reliable magnetic disk device can be provided. .

<Embodiment 13> In this embodiment, as described in Embodiment 3, IDs are recorded and recorded respectively.
In a magnetic disk device that reproduces the block 32 and the data block 33 to determine the end of head seek, the output of the ID error signal during reproduction is fixed to OFF, or the output of the ID error signal is ignored and the data block is ignored. A magnetic disk device for reproducing the data will be described.

A major characteristic of the magnetic disk drive adopting the format of the present invention is that the reproduction of the ID block 32 is not required in the processing during the reproducing operation.
When reproduction processing is performed by employing the present invention, in many situations, as shown in FIG. 14, the head reproduction element 120 is used.
Position is off-tracked from the ID block 32. In this positional relationship, as in the conventional magnetic disk device, I
When the reproduction process is executed for the D block 32, the VCO
ID address mark portion 5 that cannot be detected by the sync portion 50
1 is not detected, the error correction by the CRC unit 53 is impossible, the information of the ID data unit 52 does not match the address information of the target sector, and the like, the ID read error signal is output and the process proceeds to the retry process. Probability is high.

In order to prevent this phenomenon, in the magnetic disk device of this embodiment, the ID read error signal is fixed to OFF during the reproducing operation. As a result, the controller can continue the reproducing operation of the data block 33, and an extra retry process does not occur, so that the access performance of the magnetic disk device is improved. Further, in the processing of the controller when the head is in the area of the ID block 32, it is not necessary to rewrite the microprogram of the conventional controller, and this embodiment can be easily introduced into the product.

As a second embodiment for solving this object, even if an ID read error signal is output during the reproducing operation, the ID read error signal is ignored and the reproducing operation is continued. You can think of a way. In this case, the controller microprogram
This can be realized by rewriting so that the ID read error signal is not taken in during the reproducing operation. This second
In this embodiment, since it is not necessary to change the circuit part, it can be easily introduced into the product. Further, since the retry process due to the occurrence of the ID read error can be suppressed, it is possible to provide the magnetic disk device having the improved access performance in the reproducing process.

[0073]

As described above, according to the present invention, in a disk device using a composite head in which a recording element and a reproducing element are separated, by providing dedicated ID information at the time of recording operation and at the time of reproducing operation respectively, It is possible to correct the positional deviation tolerance between the reproducing element and the reproducing element, and the positional deviation error between the recording and reproducing element due to the inclination of the slider when positioning is performed using the rotary actuator. Higher performance of the device can be realized.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a cross-sectional structure of a magnetic disk device of the present invention.

FIG. 2 is a plan view of a part of the magnetic disk device of the present invention seen from above.

FIG. 3 is a schematic diagram showing an example of a sector structure of the present invention.

FIG. 4 is a schematic diagram showing an example of a structure of a servo block according to the present invention.

FIG. 5 is a schematic diagram showing an example of the structure of an ID block according to the present invention.

FIG. 6 is a schematic diagram showing an example of the structure of a data block in the present invention.

FIG. 7 is a schematic diagram showing an example of the structure of a data block according to the present invention.

FIG. 8 is a schematic diagram showing a sector structure of a conventional example.

FIG. 9 is a diagram illustrating that the slider tilts depending on the position of the actuator.

FIG. 10 is a view for explaining the inclination of the slider at the outermost track position.

FIG. 11 is a view for explaining the inclination of the slider at the innermost track position.

FIG. 12 is a diagram illustrating a head position during a recording operation according to the present invention.

FIG. 13 is a diagram illustrating a head position during a recording operation in a conventional example.

FIG. 14 is a diagram illustrating a head position during a reproducing operation according to the present invention.

FIG. 15 is a diagram illustrating a head position during a reproducing operation in a conventional example.

FIG. 16 is a flowchart illustrating the flow of recording and reproducing operations.

FIG. 17 is a block diagram showing an example of a circuit configuration according to the present invention.

[Explanation of symbols]

11 ... Recording / playback separation type head, 12 ... Rotary type actuator, 13 ... Magnetic disk, 14 ... Voice coil motor, 31 ... Servo block, 32 ... ID block, 33
... data block, 51 ... ID address mark part, 52
... ID data part, 61 ... Data address mark part, 62
... ID data section, 91 ... Slider, 120 ... Reproducing element, 121 ... Recording element.

Front page continuation (72) Inventor Mikio Suzuki 1-280, Higashi Koikeku, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor, Rinjiro Tsuchiya 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi, Ltd. Chuo Inside the research institute (72) Inventor Masuo Umemoto 1-280, Higashi Koikekubo, Kokubunji, Tokyo Inside Hitachi Central Research Laboratory (72) Inventor Takashi Kawabe 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi Central Research Institute (72) ) Inventor Katsuro Watanabe 1-280, Higashi Koikekubo, Kokubunji, Tokyo, Central Research Laboratory, Hitachi, Ltd. (72) Inventor Atsushi Saito 1-280, Higashi Koikeku, Kokubunji, Tokyo (72) Inventor, Wakabayashi Koichiro 1-280, Higashi Koigokubo, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kiyoshi Matsumoto 1-280 Higashi Koigokubo, Kokubunji, Tokyo Stock Association Hitachi Central Research Laboratory

Claims (16)

[Claims] 1. In a magnetic disk device having a composite head in which a recording element and a reproducing element are provided separately, and a disk having a plurality of tracks formed, recording is performed in an ID block on the disk. The address information dedicated to the operation is provided, at least the address information dedicated to the reproducing operation is provided in the data block, and the ID block is equal to the displacement distance between the recording element and the reproducing element in the composite head. A magnetic disk device characterized in that it is arranged so as to be displaced from a data block in a direction perpendicular to a track. 2. A magnetic disk device comprising a composite head in which a recording element and a reproducing element are separately provided, and a plurality of tracks are formed on the disk, wherein the plurality of tracks are arranged in a plurality of sectors. Each of the plurality of sectors has an ID block and a data block, and each of the ID block and the data block includes address information of a corresponding sector.
The ID block is displaced from the data block in the direction perpendicular to the track direction by an amount substantially equal to the distance between the recording element and the reproduction element in the direction perpendicular to the track direction. A magnetic disk device characterized by the above. 3. The head is positioned so that the recording element coincides substantially with the center of the data block during the recording operation of the data block, and the reproducing element operates during the reproducing operation of the data block. The magnetic disk drive according to claim 2, wherein the head is positioned so as to substantially coincide with the center of the block. 4. Data of the distance of deviation between the recording element and the reproducing element in the direction perpendicular to the track direction is magnetically stored on the disk surface, or built in the disk device. 4. The magnetic disk drive according to claim 3, wherein the head is positioned based on the data of the displacement distance by electrically storing it in the stored storage element. 5. A step of determining a distance between the ID block and the data track in a direction perpendicular to a track direction, a head incorporated in a product is used to record a pattern on a disk incorporated in the product. 4. The magnetic disk drive according to claim 3, further comprising: a step of performing the positioning and a step of performing positioning with respect to the pattern using a head incorporated in the product. 6. The servo block or ID block is provided for each track, or for each predetermined track,
The magnetic disk device according to claim 1, wherein the recording is performed in a servo write process in a magnetic disk device manufacturing line. 7. The magnetic disk drive according to claim 2, wherein the servo block or ID block is recorded in advance by the unevenness of the disk, and the pattern of the unevenness is magnetically or optically read. . 8. A composite head in which a recording element and a reproducing element are separately provided, and a giant magnetoresistive effect element portion composed of at least two magnetic laminated films is provided as the reproducing element. 3. The magnetic disk device according to claim 2, wherein a plurality of tracks formed on the disk have a track-direction density of 10 KTPI or more. 9. The magnetic disk drive according to claim 2, wherein the shock resistance during operation is 500 G or more. 10. A magnetic disk having a plurality of tracks formed on a disk, the plurality of tracks being divided into a plurality of sectors, each of the plurality of sectors having an ID block and a data block. A magnetic disk device, wherein the disk device includes means for waiting for detection of the ID block after head seek in a recording operation and waiting for detection of the data block after head seek in a reproducing operation. 11. An ID address mark portion indicating a data start position of the ID block and a data address mark portion indicating a data start position of the data block are formed by using different codes. The magnetic disk device according to claim 10. 12. In the operation of reproducing the data block, at least part of the operation of the reproducing circuit is suspended to reduce the power consumption while the reproducing element of the head passes through the area of the ID block. The magnetic disk device according to claim 10, further comprising: 13. A semiconductor memory having a capacity capable of storing two or more of the data blocks, wherein information reproduced from the data block is transferred to the semiconductor memory. The magnetic disk device described. 14. A data string for error correction included in the data block, comprising a first error check section associated with an ID data section and a second error check section associated with a data section. The magnetic disk device according to claim 10. 15. The magnetic disk drive according to claim 10, wherein the output of the ID error signal is fixed to OFF in the operation of reproducing the data block. 16. The reproducing operation according to claim 10, wherein when an ID error signal is output in the operation of reproducing the data block, the reproducing operation is continuously performed to forcibly reproduce the data block. Magnetic disk device.