JPH0778321A - Magnetic disk device and servo information recording method of magnetic disk - Google Patents

Abstract

PURPOSE:To accurately trace the track which is formed from a writing gap, by a reading gap without being affected by an azimuth angle. CONSTITUTION:The recording servo information for accurately tracing the data track by the writing gap at the time of data recording and the reproducing servo information for accurately tracing the data track by the reading gap at the time of data reproduction are recorded in a disk 24 corresponding to each data track. By a positional signal reading control part 14, the information of head positional error is produced from the read-in recording servo information at the time of data recording or from the read-in reproducing servo information at the time of data reproduction. A VCM driving current is produced by a VCM positioning control part 13 in accordance with the information of head positional error, then a composite head 26 is positioned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk apparatus and a servo information recording method for a magnetic disk, and more particularly, a head in which a write gap and a read gap are separated from each other is provided in a rotary head positioning mechanism. The present invention relates to a sector servo type magnetic disk device and a servo information recording device.

In recent years, disk media and heads have been downsized, and the storage capacity has been increased and the transfer speed has been increased, and the magnetic recording bit area on the disk media has become smaller. Is a problem. Therefore, a head in which the write gap and the read gap are separated is considered.

In a magnetic disk device using a head in which a write gap and a read gap are separated from each other, it is required that data tracks can be accurately traced during data recording / reproduction.

[0004]

2. Description of the Related Art Conventionally, a magnetic disk device such as a hard disk device generally uses a head having a common write gap and read gap. For the head, for example, an inductive head is used.

In recent years, due to miniaturization of magnetic disk devices,
The disk medium and the head have been downsized, the storage capacity has been increased, and the transfer speed has been increased, and the magnetic recording bit area on the disk medium has been reduced. Therefore, the influence of disturbance such as medium noise has become a problem. Therefore, a composite head in which a write gap and a read gap are separately arranged in an integrated head has been considered.

FIG. 14 is an explanatory view of a composite head in which a write gap w and a read gap r are arranged separately. Many small magnetic disk devices have a rotary type head positioning mechanism that is rotationally driven by a voice coil motor or the like. As shown in FIG. 14 (A), the fulcrum 71
The composite head 2 near the tip of the arm 25 that rotates around the
6 is provided.

In the composite head 26, as shown in FIG. 14B, the write gap w and the read gap r are arranged in parallel at a predetermined interval.

Disk medium (hereinafter referred to as disk) 2
4 is a composite head 26 corresponding to each data track.
Is recorded on the data track. Based on the position error signal obtained by reading this servo information in the read gap r, data recording / reproduction is performed in a state where the read gap r is positioned on the data track defined by the servo information.

[0009]

In a magnetic disk device using a rotary head positioning mechanism, there is an azimuth angle (angle formed by the disk radial direction and the head). As the magnetic disk device becomes smaller, the rate of change of this azimuth angle for each track increases.

FIG. 14B is an explanatory diagram when the composite head 26 traces the track K ₁ on the inner circumference of the disk.
The azimuth angle is large enough to cause no problem. In this case, the track traced by the read gap r (read track) and the track traced by the write gap w (write track) match.

Therefore, in the state where the read gap r is positioned on the data track specified by the servo information, the write track formed by the write gap w matches the data track specified by the servo information. Therefore, during data reproduction, the formed write track can be correctly traced while the read gap r is positioned on the data track defined by the servo information.

FIG. 14C is an explanatory diagram when the composite head 26 traces the track K ₂ on the outer periphery of the disk.
Large azimuth angle. In this case, a read track and a write track are misaligned. In FIG. 14C, the write track indicated by the broken line is shifted upward from the read track indicated by the solid line due to the azimuth angle.

In this case, with the read gap r positioned on the data track defined by the servo information,
The write track formed with the write gap w is displaced from the data track defined by the servo information. Therefore, the read gap r
In the state where is positioned on the data track defined by the servo information, the read gap r deviates from the write track and accurate trace cannot be performed. In some cases, a part of the data track of the adjacent track may be read. Therefore, there arises a problem that the written data cannot be accurately read.

The present invention has been made in view of the above points, and has a composite head in which a write gap and a read gap are arranged separately, and the read gap is not affected by the azimuth angle. It is an object of the present invention to provide a magnetic disk device and a servo information recording method for a magnetic disk, which can accurately trace a track formed by the method.

[0015]

According to a first aspect of the present invention, a composite head in which a write gap and a read gap are arranged in parallel at a predetermined interval is provided at the tip of a rotary head positioning mechanism, and a magnetic disk is provided. In a magnetic disk device that reproduces the head positioning servo information recorded on the head to position the composite head on the data track and records and reproduces the data, the write gap accurately traces the data track during data recording. Recording servo information for positioning the composite head,
The reproducing servo information for positioning the composite head so that the read gap accurately traces the data track at the time of data reproduction, and the recording servo information for the distance corresponding to the azimuth angle of the composite head in each data track. A magnetic disk recorded with the track boundary of and the track boundary of the reproduction servo information separated from each other;
Head position error information generation means for generating head position error information from the read recording servo information at the time of data recording, and head position error information generating means for generating head position error information from the read reproducing servo information at the time of data reproduction; Head positioning control means for positioning the composite head based on the head position error information supplied from the error information generating means.

According to a second aspect of the invention, the magnetic disk is
The track boundary of the shared servo information which is shared at the time of recording and reproducing the data is made to coincide with the track boundary and the center of the track width of the recording servo information or the track boundary and the center of the track width of the reproducing servo information. The shared servo information is recorded.

According to a fourth aspect of the present invention, the write gap and the read gap separated into the first and second gaps are arranged in parallel at a predetermined interval at the center position of the core width corresponding to the data track width. A magnetic disk device in which a composite head is provided at the tip of a rotary head positioning mechanism and reproduces servo information for head positioning recorded on a magnetic disk to position the composite head on a data track for recording / reproducing data. In the servo information recording method of a magnetic disk for recording the servo information on the magnetic disk used for, by using a head position signal generated by a head position detecting means for generating a head position signal corresponding to the position of the composite head, When the data is recorded with the composite head positioned, the write gap keeps track of the data track. The recording servo information for positioning the composite head to trace the probability, recorded using one or both of the first and second gaps,
Positioning the composite head so that the read gap accurately traces the data track during data reproduction, with the composite head positioned based on the head position error information obtained by reading the recorded recording servo information. The reproducing servo information for reproducing is reproduced by using one of the first gap and the second gap so that the boundary between the first gap and the second gap forms a track boundary of the reproducing servo information. Record.

According to a fifth aspect of the present invention, a head position signal by the head position detecting means when the composite head is positioned based on the head position error information obtained by reading the recording servo information recorded on the magnetic disk. After the storage, the composite servo head is positioned so that the head position signal coincides with the stored head position signal when the reproduction servo information is recorded, and the reproduction servo information is recorded.

[0019]

According to the first aspect of the present invention, when the data is recorded, the read servo information is used to position the composite head so that the write gap accurately traces the data track. Servo information is used to position the composite head so that the read gap accurately traces the data track. Therefore, the read gap can accurately trace the data track formed by the write gap without being affected by the azimuth angle of the composite head, and the written data can be accurately read.

According to a second aspect of the present invention, the track boundary of the shared servo information shared at the time of recording and reproducing the data is made to coincide with the track boundary and the center of the track width of the recording servo information, or the reproduction servo information is recorded. Only one set of the shared servo information may be recorded so as to match the track boundary and the center of the track width. For this reason, it is possible to reduce the required area as compared with the case where the shared servo information is separately provided for data recording and data reproduction.

According to a fourth aspect of the present invention, in the state where the composite head is positioned by using the recorded recording servo information, the first head is used.
The boundary between the gap and the second gap can form the boundary of the reproducing servo track. Therefore, the first
In addition, in the write gap not separated into the second gap, the composite head can be positioned more precisely than in the case where only the head position signal by the head position detection means is used, and for reproducing with higher position accuracy. It is possible to record servo information.

According to a fifth aspect of the present invention, a head position signal when the composite head is positioned by using the recording servo information is stored, and when the head position signal is stored, at a time point after one magnetic disk or more, Using the stored head position signal, the reproducing servo information can be recorded in a state in which the composite head is positioned sufficiently before the recording position of the reproducing servo information. Therefore, when the recording position of the reproducing servo information is close to the recording position of the recording servo information, the reproducing servo information can be recorded more accurately.

[0023]

1 is a block diagram of a magnetic disk drive according to an embodiment of the present invention. The magnetic disk device 11 includes a disk enclosure 12 and a voice coil motor (VCM).
It comprises a positioning control unit 13, a position signal read control unit 14, a data read / write control unit 15, a disk rotation speed control unit 16, and a host controller 17. The disk enclosure 12 includes a magnetic disk medium 24, a motor 21,
It comprises an arm 25, a composite head 26, a voice coil motor (VCM) 23, and a write / read amplifier 22.

Servo information, which will be described later, is recorded on the disk 24. The position signal read control unit 14 detects servo information from the head output signal from the write / read amplifier 22, and obtains the track number obtained from the servo information,
Head position information such as head position error information is supplied to the VCM positioning control unit 13.

The VCM positioning control unit 13 instructs the head controller 17 to move the head to the target track,
Also, information such as designation of recording / reproducing of data is supplied.

The VCM positioning control unit 13 calculates the head position control amount based on the head position information according to the head movement command, and supplies the VCM drive current according to the head position control amount to the VCM 23. The VCM 23 drives the arm 25 with the VCM drive current to perform the seek operation of the composite head 26 and the follow-up operation to the designated track.

Further, the data read / write controller 15
Controls recording / reproducing of data in accordance with a command from the host controller 17.

Further, the disk rotation speed control section 16 controls the motor 21 so that the disk 24 rotates at a predetermined speed.

FIG. 2 is an explanatory view of the structure of the composite head 26. As shown in FIG. 2A, the composite head 26 is provided near the tip of the arm 25 that is rotationally driven. The composite head 26 is provided with a head portion 28 at the end of a slider 27. FIG. 2B is a partially enlarged view of the head portion 28. Note that, in FIG. 2B, the write head 31 is a cross-sectional display along the Z ₁ Z ₂ line.

The head section 28 comprises a write head 31 and a read head 35 which are separately arranged. Due to the rotation of the disk 24, the magnetization pattern formed on the track moves in the circumferential direction of the disk 24 with respect to the composite head 26, and the composite head 26 moves in the disk radial direction during seek operation of the composite head 26. .

The write head 31 comprises a core 33 and a coil 32, and a write gap w is formed at the tip of the core. The size of the write gap w in the disk radial direction (core width of the gap w) determines the width of the write track. When recording data, a magnetization pattern corresponding to the data is recorded on the moving track.

An MR element is used for the read head 35, and a read gap r is formed at the tip of the MR element. The size of the read gap r in the disk radial direction (core width of the gap r) determines the width of the read track. When the data recorded on the track is read at the read gap r, a sense current corresponding to the magnetic field change is obtained via the terminal 36.

Next, the disk 2 of the magnetic disk device 11
The servo information recorded in No. 4 will be described. Figure 3
Shows an explanatory diagram of servo information recorded on the disk 24 and head positioning. In FIG. 3, the data track n-
The part of 1, n, n + 1 is described.

The magnetic disk device 11 uses a sector servo system, and each sector is composed of a servo area and a data area located after the servo area. The servo information is recorded in the servo area of each sector.

The servo information is recorded in each of the shared section 41, the recording servo information section 42, and the reproduction servo information section 43.
The shared portion 41 is located after a predetermined data length from the beginning of the sector.

In the shared portion 41, data track numbers, sector numbers, etc. (code information) that can be shared during data recording and data reproduction are recorded. The sector number is not always necessary. The recording servo information 42, recording servo information W _S for data recording on the write gap w positions the composite head 26 to accurately trace the data tracks are recorded. In the reproduction servo information section 43, reproduction servo information R _S for positioning the composite head 26 so that the read gap r accurately traces the data track during data reproduction is recorded.

FIG. 3 shows a write track by a write gap w and a read gap r by the azimuth angle.
It shows the case where the read track is deviated by.

The boundary L _D of each data track is shown by a broken line. The track boundary L _R of the reproduction servo information R _S is located at the center of the data track width (shown by a broken line),
The center of the track width of the reproduction servo information R _S coincides with the boundary L _{D of the} data track.

The relationship between the track position of the recording servo information W _{S and} the track position of the reproducing servo information R _S changes depending on the azimuth angle. In the track where the azimuth angle is small enough to be ignored, the track position of the recording servo information W _S matches the track position of the reproducing servo information R _S. In Figure 3,
Due to the azimuth angle, the track boundary L _W of the recording servo information W _S is located slightly below the track boundary L _R of the reproduction servo information R _S (that is, the data track center position), and the track boundary L W of the recording servo information W _S is The center of the track width is located slightly below the boundary L _{D of the} data track.

In FIG. 3, the shared section 41 and the recording servo information section 4 are shown.
2. The vertical solid line in each track of the reproduction servo information section 43 indicates the position where the magnetization direction is reversed. Common part 4
In 1, the data track number and the like are recorded as a magnetization pattern. The reproduced code is different between the magnetization pattern over the entire width of the data track and the magnetization pattern of about half the width of the data track. A gray code is usually used for the data track number.

It should be noted, track boundary of the magnetization pattern of the common portion 41, track boundary L _R playback servo information R _S, or are allowed to coincide with the center of the track width of the reproducing servo information R _S.

FIG. 4 is an explanatory diagram of a signal obtained by reading the recording servo information W _S and the reproducing servo information R _S. As shown in FIGS. 3 and 4, in the recording servo information section 42, the magnetization patterns W _S1 and W _S2 are recorded as the recording servo information W _S.
Alternate positions for adjacent recording servo tracks,
It is recorded.

In each data track, when the recording servo information W _S is read, signals are reproduced in the reading gap r in the order of the magnetization patterns W _S1 and W _S2 . The magnetization patterns W _S1 and W _{S2 at} this time are the magnetization patterns recorded on the recording servo tracks vertically adjacent to each other with the boundary L _W interposed therebetween.

Reference symbol v _{W in} FIG. 4 shows the reproduction signals of the magnetization patterns W _S1 and W _S2 when the read gap r is at the position in the figure. In FIG. 4, the read gap r is slightly above the boundary position L _W of the recording servo track, and the magnetization pattern W _S2 has a larger area overlapping the read gap r. Therefore, the reproduction signal v _W has a larger amplitude for the magnetization pattern W _S2 than for the magnetization pattern W _S1 .

When positioning the read gap r,
Amplitude to the amplitude and the magnetization pattern W _S2 for magnetization pattern W _S2 is set to be equal. As a result, the center position of the core width of the read gap r is aligned with the boundary L _W of the recording servo track.

Similarly to the recording servo information W _S , FIG.
As shown in FIG. 5, magnetization patterns R _S1 and R _S2 are recorded in the reproduction servo information section 43 as reproduction servo information R _S at alternate positions for adjacent reproduction servo tracks.

When reading the reproduction servo information R _S in each data track, signals are reproduced in the order of the magnetization patterns R _S1 and R _{S2 in} the read gap r.

Reference symbol v _{R in} FIG. 4 shows a reproduction signal of the magnetization patterns R _S1 and R _S2 when the read gap r is at the position in the figure. In FIG. 4, the read gap r is slightly above the boundary position L _R of the reproduction servo track. Therefore, the reproduction signal v _R has a larger amplitude for the magnetization pattern R _S2 than for the magnetization pattern R _S1 .

When positioning the read gap r,
The read gap r is set so that the amplitude with respect to the magnetization pattern R _S2 and the amplitude with respect to the magnetization pattern R _S2 become equal.
The center position of the core width of is the boundary L _{R of the} reproducing servo track.
Is adapted to.

[0050] With respect to record servo track is, when the center of the read gap r coincides with the boundary L _W of record servo track, as the write gap w to accurately trace the data track, boundary L _W of record servo track , Is formed at a position corresponding to the azimuth angle in each data track.

At the time of data recording, recording servo information W_STo
Playback signal v obtained by reading at the reading gap r_WOr
From the center of the read gap r to the recording servo track
Border L _WTo position. Positioned in this way
To record data in the data area with the write gap w
It As described above, the boundary L of the recording servo track_Wposition
Since it is determined according to the azimuth angle,
Indicates that the write track due to the write gap w is positive.
It exactly matches the data track. P in FIG._WIs the de
Write gap w and read gap when recording data
The positional relationship of r is shown.

During data reproduction, reproduction servo information R_STo
Playback signal v obtained by reading at the reading gap r_ROr
The center of the read gap r
Border L _RPosition at (ie center of data track)
It With this positioning, read gap
The data in the data area is reproduced with r. At this time, read
The gap r accurately traces the data track.
P in FIG._RIs the write gap w at the time of data reproduction.
The positional relationship of the read gap r is shown.

The track boundary of the magnetization pattern of the shared portion 41 is made to coincide with the track boundary L _R of the reproduction servo information R _S.

Necessary servo information can be read from the single shared portion 41 during both data recording and data reproduction.
Therefore, it is not necessary to separately record the code information such as the data track number for recording the data and for reproducing the data, and an extra storage area is not required.

The track boundary of the magnetization pattern of the shared portion 41 may be formed so as to coincide with the track boundary L _W of the recording servo information W _S. In this case, the recording servo information W _S is used to position the center of the read gap r at the boundary L _W of the recording servo track, and the servo information of the shared portion 41 is read.

As described above, in the magnetic disk device 11 of this embodiment, the data track on which the data is recorded by the write gap w can be accurately traced by the read gap r without being affected by the azimuth angle. The written data can be accurately read.

Further, since the read gap r can trace the data track accurately, it is not necessary to make the width of the write gap w significantly larger than the width of the read gap r as a measure against the azimuth angle, and further increase in density can be achieved. It is possible to reduce the size of the device.

In the example of FIG. 3, the recording servo information W _S
The magnetization patterns W _S1 , W _{S2 of} No. ₂ and the magnetization patterns W _S1 , W _S2 , R _S1 , R _S2 of the reproduction servo information R _S use patterns for one signal cycle, but when the noise level is high,
The influence of noise may be prevented as a pattern for a plurality of signal periods.

FIG. 5 is an explanatory diagram of head positioning when the write gap is divided into two write gaps w1 and w2 at the center position of the core width corresponding to the data track width. The servo information is exactly the same as in the case of the write gap w in which the gap is not divided into two (FIG. 3).

Positioning of the head during data recording and data reproduction is performed by using both gaps w1 and w2.
This can be done in exactly the same way as when the gaps in FIG. 3 are not separated.

Next, in the magnetic disk device 11, the head position is controlled by reading the servo information, as shown in FIG.
Position signal read controller 14 and VCM positioning controller 1
3 will be described.

FIG. 6 shows the position signal read controller 14 and VC.
The block diagram of the M positioning control part 13 is shown. The position signal read control unit 14 is provided with a position information demodulation circuit 51 that generates position information such as a data track number and head position error information from the head output signal.

The VCM positioning control section 13 calculates the head position control amount based on the position information supplied from the position information demodulation circuit 51 and generates the VCM drive signal, and the VCM control circuit 52 and the VCM control circuit 52. VC supplied from
Amplify M drive signal to generate VCM drive current
It is composed of a power amplifier 53 which is supplied to 23.

The VCM positioning control section 13 supplies a data read / write switching signal to the position information demodulation circuit 51 in accordance with the data recording or reproduction designation from the host controller 17. The position information demodulation circuit 51 generates head position error information based on the recording servo information W _S when data recording is specified by the data read / write switching signal, and reproduces when data reproduction is specified. Head position error information is generated based on the servo information R _S.

FIG. 7 shows a block diagram of the position information demodulation circuit 51. The position information demodulation circuit 51 includes the gate signal generation circuit 5
6, a code information demodulation circuit 55, a selection circuit 57, a position error demodulation circuit 58, and a position information generation circuit 59.

The gate signal generation circuit 56 generates a gate signal for detecting each servo information in the servo area of each sector. A gate signal for detecting the servo information of the shared area 41 in the servo area is supplied to the code information demodulation circuit 55. Further, the gate signal for the recording servo information W _S and the gate signal for the reproducing servo information R _{S of} the servo area are supplied to the selection circuit 57.

When data recording is designated by the data read / write switching signal, the selection circuit 57 supplies the recording servo information W _S gate signal to the position error demodulation circuit 58. When data reproduction is designated, the reproduction servo information R _S gate signal is supplied to the position error demodulation circuit 58.

The position error demodulation circuit 58 uses the gate signal supplied from the selection circuit 57 to write servo information W _S.
Alternatively, the reproduction servo information R _S is detected, and the position error information is generated based on the detected signal.

The code information demodulation circuit 55 demodulates the code information (servo information) such as the data track number recorded in the shared portion 41 and supplies it to the position information generation circuit 59.

The position information generation circuit 59 outputs the code information such as the track number supplied from the code information demodulation circuit 55 and the position error information supplied from the position error demodulation circuit 58 as position information.

Next, a processing procedure of head positioning control in the magnetic disk device 11 will be described. Figure 8
Shows a flow chart of head positioning control performed by the VCM control circuit 52 at the time of recording / reproducing data.

When the magnetic disk device 11 starts its operation, the VCM control circuit 52 carries out a standby process while it does not receive a move command from the host controller 17 (step 101). In step 102, the host controller 17
It is determined whether or not a move command is received from. If it is determined that the move command is received, the process proceeds to step 103.

In steps 103 to 106, the composite head 26 is moved to the target track. In step 103, the data track number of the code information recorded in the shared section 41 is read from the position information supplied from the position information demodulation circuit 51.

In step 104, the position information demodulation circuit 5
Read the position error information from the position information supplied from 1.
Mu. As shown in FIG. 3, the track boundary of the shared portion 41
Is aligned with the boundary of the playback servo track,
Data write / read supplied to the position information demodulation circuit 51
Playback servo information R _S
Let's select. As a result, the reproduction servo information R_STo
The position error information based on it is read.

In step 105, it is determined whether the data track number read in step 103 matches the target track number. If the read data track number matches the target track number, it is determined that the data track number has entered the target track, and the moving process of the composite head 26 is terminated and the process proceeds to step 107.

If the data track number does not match the target track, the process proceeds to step 106. In step 106, the head movement control amount is calculated from the difference between the current data track number and the target track number read in step 103 and the position error information read in step 104. A VCM drive signal corresponding to the calculated head movement control amount is generated and supplied to the power amplifier 53. As a result, the composite head 26 is driven at a predetermined speed according to the distance between the target track and the current track. Step 106
After that, the process returns to step 103 to continue the head moving process.

In steps 107 to 112, head positioning processing is performed when recording or reproducing data in the target track. In step 107, it is determined whether the data processing mode is the data writing mode or the data reading mode based on the mode designation information from the upper controller 17. If in the data write mode, the data write / read switching signal is set to the write side in step 108, and the position information demodulation circuit 5
1 causes the recording servo information W _S to be selected. In the data read mode, in step 109, the data write / read switching signal is set to the read side,
The position information demodulation circuit 51 is caused to select the reproduction servo information R _S.

In step 110, the position information demodulation circuit 5
The position error information is read from the position information supplied from 1. This position error information is for any one sector in the data track. In the data write mode, the position error information is the position error information based on the read recording servo information W _S , and in the data read mode, the position error information is the read reproduction servo information R _S. It is the position error information based on it.

In step 111, the head positioning control amount is calculated based on the position error information of the current sector read in step 110. A VCM drive signal corresponding to the calculated value of the head positioning control amount is generated and supplied to the power amplifier 53.

As a result, in the data write mode,
Based on the read recording servo information W _S , the composite head 26 is positioned so that the write gap w accurately traces the data track. In the data read mode, the composite head 26 is positioned so that the read gap r accurately traces the data track based on the read reproduction servo information R _S.

After the composite head 26 is positioned in step 111, the data read / write controller 15 writes or reproduces data in the data area of the current sector.

In step 112, it is judged from the data processing end information from the upper controller 17 whether or not the writing or reading of data in the current data track is completed.

If the writing or reading of data has not been completed, the process returns to step 110 to perform head positioning control in the next sector. When the writing or reading of data is completed, the process returns to step 101 and waits for the next head movement command.

Next, a servo information recording device for recording servo information on the disk 24 will be described. FIG. 9 shows a configuration diagram of the servo information recording device 61. The servo information recording device 61 includes a disk enclosure 12, a voice coil motor (VCM) positioning controller 63, a position signal read / write controller 64, a disk rotation speed controller 16,
It is composed of a control controller 65 and an external length measuring unit 66. The external length measurement unit 66 includes a laser length measurement system 67, an interferometer 68, and a reflection mirror 69.

The disk enclosure 12 is a part to be mounted on the magnetic disk device 11 of FIG. 1 after recording the servo information.

The position signal read / write controller 64 supplies the servo information supplied from the controller 65 to the write / read amplifier 22. As a result, the write head of the composite head 26 records the servo information on the disk.

Further, the position signal read / write controller 64
In accordance with instructions from the control controller 65, generates head position error information from the recorded servo information W _S read via the read head and the write / read amplifier 22 and supplies it to the control controller 65.

The VCM positioning control section 63 controls the position of the composite head 26 based on the head position control information supplied from the control controller 65. The laser length measurement system 67 irradiates the reflection mirror 69 with a laser beam via the interferometer 68. The reflected light at this time is detected to measure the rotation angle of the arm 25. A head position signal indicating the position of the composite head 26 is generated from the measured rotation angle and supplied to the control controller 65.

The control controller 65 includes the external length measuring unit 6
The head position control information is generated using the head position signal supplied from No. 6 or the position error information supplied from the position signal read / write control unit 64, and is supplied to the VCM positioning control unit 63.

The VCM positioning control unit 63 calculates the head position control amount based on the head position control information supplied from the control controller 65, and supplies the VCM drive current according to the head position control amount to the VCM 23. VCM
23 rotates the arm 25 by the VCM drive current,
Position the composite head 26.

Further, the disk rotation speed control section 16 controls the motor 21 so that the disk 24 rotates at a predetermined speed.

Next, in the servo information recording device 61,
A procedure for recording servo information will be described. Here, in the composite head 26, the write gaps are the gaps w1 and w.
It will be described in the case of being separated into two. Among the servo information, first, record the record servo information W _S.

[0093] When recording the recording servo information W _S is in a state of positioning the composite head 26 by using the head position signal supplied from the external measuring unit 66, recording servo information W _S
To record.

FIG. 10 is an explanatory diagram for recording the recording servo information W _S using both the gaps w1 and w2. FIG. 10 shows a procedure for forming a recording servo track for the data tracks n-1 and n. In the figure,
The shaded area indicates the locus drawn by the write gaps w1 and w2.

First, as shown in FIG. 10A, the gap w2 is calculated by using the head position signal from the external length measuring unit 66.
The composite head 26 is positioned so that the upper end of the position is at a position where the boundary L _W of the recording servo track in the data track n-1 should be formed. Recording servo track boundary L _W
The position is calculated and determined in advance according to the azimuth angle.
In this state, the upper side of the magnetization pattern W _S2 is recorded.
As a result, the boundary L _W of the recording servo track is formed at the upper end of the gap w2 at a predetermined position near the center of the data track n-1.

Next, as shown in FIG. 10B, under the magnetization pattern W _S2 in a state where the composite head 26 is positioned at the lower position by the half width of the recording servo track by using the head position signal. Recording side. At this time, FIG.
Since the recording is performed so as to overlap the portion recorded at the position (A), no gap is generated in the recording portion.

Next, as shown in FIG. 10C, the composite head 26 is positioned using the head position signal from the position of FIG. 10B to a position lower by half the width of the recording servo track. In this state, the upper side of the magnetization pattern W _S1 is recorded. As a result, the boundary L _W of the recording servo track is formed at the upper end of the gap w2 at a predetermined position near the center of the data track n. At this time, FIG. 10 (B)
Since the recording is performed so as to overlap the portion recorded at the position, there is no gap in the recording portion.

The case where the write head is not divided into two cores is exactly the same as the case described with reference to FIG.

FIG. 11 shows an explanatory diagram for recording the recording servo information W _S using only the gap w1. Figure 1
1 shows a procedure for forming a recording servo track for the data tracks n-1 and n. In the figure, the shaded area indicates the locus drawn by the write gap w1.

First, as shown in FIG. 11A, the gap w1 is calculated by using the head position signal from the external length measuring unit 66.
The composite head 26 is positioned so that the upper end of the position is at a position where the boundary L _W of the recording servo track in the data track n-1 should be formed. In this state, the magnetization pattern W _S2
The upper side of is recorded. As a result, the data track n
A boundary L _W of the recording servo track is formed at a predetermined position near the center of −1 at the upper end of the gap w1.

Next, as shown in FIG. 11B, the magnetization pattern W _S2 is recorded while the composite head 26 is positioned at a slightly lower position by using the head position signal. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 11A, no gap is generated in the recording portion.

Next, as shown in FIG. 11C, the head position signal is used to position the composite head 26 from the position shown in FIG. 11A to the lower position by the half width of the recording servo track. In this state, the lower side of the magnetization pattern W _S2 is recorded. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 11B, no gap is generated in the recording portion.

Next, as shown in FIG. 11D, the magnetization pattern W _S2 is recorded with the composite head 26 positioned slightly below using the head position signal. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 11C, no gap is generated in the recording portion.

Next, as shown in FIG. 11 (E), the head position signal is used to position the composite head 26 from the position in FIG. 11 (C) to a position lower by half the width of the recording servo track. In this state, the upper side of the magnetization pattern W _S1 is recorded. As a result, the boundary L _W of the recording servo track is formed at the upper end of the gap w1 at a predetermined position near the center of the data track n. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 11D, no gap is generated in the recording portion.

Next, the recording procedure of the reproduction servo information R _S , which is performed after the recording of the recording servo information W _S is completed, will be described. When recording the reproduction servo information R _S , the position error information generated by the position signal read / write control unit 64 based on the recording servo information W _S read in the read gap r and the external length measurement unit 66 are supplied. The reproduced servo information R _S is recorded while the composite head 26 is positioned using the head position signal.

FIG. 12 is an explanatory diagram for recording the reproduction servo information R _S by using only the gap w1. Figure 1
2 shows a procedure for forming a reproduction servo track for the data tracks n-1 and n. In the figure, the shaded area indicates the locus drawn by the write gap w1.

First, as shown in FIG.
Recorded servo information W_SUsing the position error information by
The center of the read gap r is the boundary of the recording servo track.
World L _WPosition the composite head 26 so that
It

At the time of recording the recording servo information W _S , the boundary L _W of the recording servo track is equal to the deviation between the write gaps w1 and w2 and the read gap r due to the azimuth angle.
It is recorded at a position deviated from the center of the data track width. Therefore, when the center of the read gap r coincides with the boundary L _W of the recording servo track, the upper end of the gap w1 (the boundary between the gap w1 and the gap w2) is the boundary L of the reproducing servo track in the data track n-1.
It coincides with _R (center of data track n-1).

In this state, the upper side of the magnetization pattern R _S2 is recorded. As a result, the boundary L _R of the reproduction servo track at the center of the data track n−1 is formed at the upper end of the gap w1.

Next, as shown in FIG. 12B, the head position signal is used to position the composite head 26 at a position slightly lower than the position shown in FIG. It records R _S2 . At this time, FIG. 12 (A)
Since the recording is performed so as to overlap the portion recorded at the position, there is no gap in the recording portion.

Next, as shown in FIG. 12C, the head position signal is used to position the composite head 26 from the position of FIG. 12A to a position lower by half the width of the reproducing servo track. In this state, the lower side of the magnetization pattern R _S2 is recorded. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 12B, no gap is generated in the recording portion.

Next, as shown in FIG. 12D, the composite head 26 is positioned slightly lower than the position shown in FIG. It records R _S2 . At this time, FIG. 12 (C)
Since the recording is performed so as to overlap the portion recorded at the position, there is no gap in the recording portion.

Then, as shown in FIG.
Recorded servo information W_SUsing the position error information by
The center of the read gap r is the boundary of the recording servo track.
World L _WPosition the composite head 26 so that
It As a result, as in FIG. 12A, the gap w1
Playback servo track whose top edge is within data track n
Boundary L_RMatches

In this state, the upper side of the magnetization pattern R _S1 is recorded. As a result, the boundary L _R of the reproducing servo track near the center of the data track n is formed at the upper end of the gap w1. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 12D, no gap is generated in the recording portion.

As described above, the recorded recording servo information W
_With the composite head 26 positioned using _S , the boundary L _R of the reproducing servo track can be formed at the gap w1. Therefore, in the write gap which is not divided into the gaps w1 and w2, it is possible to perform more precise positioning as compared with the case where only the head position signal of the external length measuring unit 66 is used, and the reproducing servo with higher position accuracy is provided. The information R _S can be recorded.

When the order of the tracks for recording the reproduction servo information R _S is in the ascending order of the data track numbers, the gap w2 is used to similarly reproduce the reproduction servo information R _S.
S can be recorded.

Further, the head position signal when the center of the gap r is positioned at the boundary L _W of the recording servo track using the recording servo information W _S is stored in the control controller 65, and this head position signal is stored. It is also possible to adopt a system in which the reproduced servo information R _S is recorded in a state in which the gap r is positioned using the stored head position signal at a time point after one round of the disk or more from the time point.

[0118] In this manner, the recording position of the reproduction servo information R _S is, when approximated to a recording position of the recording servo information in sufficient front of the recording position of the reproduction servo information R _S,
The gap r can be positioned by using the stored head position signal, and the reproduced servo information R _S can be recorded more accurately.

FIG. 13 is an explanatory diagram for recording the reproduction servo information R _S using both the gap w1 and the gap w2. FIG. 13 shows a procedure for forming a reproduction servo track for the data tracks n-1 and n.
In the figure, the shaded area indicates the locus drawn by the write gaps w1 and w2.

First, the position error information based on the read recording servo information W _S is used to make the center of the read gap r coincident with the boundary L _W of the recording servo track in the data track n−1. Position 26.

At this time, the upper end of the gap w2 coincides with the upper boundary of the data track n-1. From this state, by using the head position signal of the external length measuring unit 66, as shown in FIG.
As shown in FIG. 3 (A), the composite head 26 is positioned at the lower position by the half width of the reproducing servo track. Thus, matching the boundary L _R playback servo track in which the upper end of the gap w2 is within a data track n-1.

With the composite head 26 positioned as described above, the upper side of the magnetization pattern R _S2 is recorded. As a result, the boundary L _R of the reproducing servo track at the center of the data track n−1 is formed at the upper end of the gap w2.

Next, as shown in FIG. 13B, using the position error information based on the read recording servo information W _S ,
The composite head 26 is positioned so that the center of the read gap r coincides with the boundary L _W of the recording servo track in the data track n.

In this state, the lower side of the magnetization pattern R _S2 is recorded. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 13A, no gap is generated in the recording portion.

Next, as shown in FIG. 13C, the composite head 26 is positioned at a position lower than the position of FIG. 13B by a half width of the reproducing servo track by using the head position signal. In this state, the upper side of the magnetization pattern R _S1 is recorded. As a result, the boundary L _R of the reproducing servo track at the center of the data track n is formed at the upper end of the gap w2. At this time, since the recording is performed so as to overlap the portion recorded at the position of FIG. 13B, no gap is generated in the recording portion.

If the write gap is not divided into two gaps, the reproduction servo information R _S can be recorded in exactly the same manner as described with reference to FIG.

[0127]

As described above, according to the invention of claim 1,
At the time of data recording, the read head servo information is used to position the composite head so that the write gap accurately traces the data track, and at the time of data playback, the read servo information is used to read the read gap. Since the composite head is positioned to trace the track accurately, the read gap can accurately trace the data track formed by the write gap without being affected by the azimuth angle of the composite head. Has a feature that can be accurately read.

According to the second aspect of the invention, the track boundary of the shared servo information which is shared at the time of recording and reproducing the data,
Only one set of the shared servo information may be recorded so as to match the track boundary and the center of the track width of the recording servo information or the track boundary and the center of the track width of the reproducing servo information. Therefore, the required area can be made smaller than in the case where shared servo information is separately provided for data recording and data reproduction.

According to the invention of claim 4, in the state where the composite head is positioned by using the recorded recording servo information,
Since the boundary of the reproducing servo track can be formed at the boundary between the first gap and the second gap, the head position detected by the head position detecting means is the write gap that is not divided into the first and second gaps. Compared with the case of using only the signal, the composite head can be positioned more precisely, and the reproducing servo information with higher position accuracy can be recorded.

According to the fifth aspect of the present invention, the head position signal when the composite head is positioned using the recording servo information is stored, and the time after the time when the head position signal is stored is one magnetic disk or more. With the head position signal stored, the reproducing servo information can be recorded with the composite head positioned sufficiently before the recording position of the reproducing servo information. However, when the position is close to the recording position of the recording servo information, the reproducing servo information can be recorded more accurately.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetic disk device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a composite head structure.

FIG. 3 is an explanatory diagram of servo information recorded on a disk and head positioning.

FIG. 4 is an explanatory diagram of signals obtained from recording servo information and reproducing servo information.

FIG. 5 is an explanatory diagram of head positioning in the case of a separated write gap.

FIG. 6 is a configuration diagram of a position signal read control unit and a VCM positioning control unit.

FIG. 7 is a configuration diagram of a position information demodulation circuit.

FIG. 8 is a flowchart of head positioning control.

FIG. 9 is a configuration diagram of a servo information recording device.

FIG. 10 is an explanatory diagram for recording recording servo information using gaps w1 and w2.

FIG. 11 is an explanatory diagram for recording recording servo information using a gap w1.

FIG. 12 is an explanatory diagram for recording reproduction servo information using a gap w1.

FIG. 13 is an explanatory diagram when recording reproduction servo information using gaps w1 and w2.

FIG. 14 is an explanatory diagram of a composite head.

[Explanation of symbols]

 11 magnetic disk device 12 disk enclosure 13 VCM positioning control unit 14 position signal read control unit 15 data read / write control unit 16 disk rotation speed control unit 17 host controller 21 motor 22 write / read amplifier 23 VCM 24 magnetic disk 25 arm 26 Complex head 41 Common part 42 Recording servo information part 43 Reproduction servo information part 51 Position information demodulation circuit 52 VCM control circuit 53 Power amplifier 55 Code information demodulation circuit 56 Gate signal generation circuit 57 Selection circuit 58 Position error demodulation circuit 59 Position information generation circuit 59 61 Servo Information Recording Device 63 VCM Positioning Control Unit 64 Position Signal Read / Write Control Unit 65 Control Controller 66 External Length Measuring Unit 67 Laser Length Measuring System 68 Interferometer 69 Reflection Model Over r read gap w write gap w1, w2 write gap

Claims (5)

[Claims] 1. A composite head (26) in which a write gap (w) and a read gap (r) are separated in parallel at a predetermined interval is provided at the tip of a rotary head positioning mechanism (25), and a magnetic head is provided. In a magnetic disk device for recording / reproducing data by reproducing servo information for head positioning recorded on a disk (24) and positioning a composite head (26) on a data track, a write gap (w) at the time of data recording Said composite head (26) so that it traces the data track exactly
Recording servo information for positioning the data track and reproducing servo information for positioning the composite head (26) so that the read gap (r) accurately traces the data track during data reproduction. In the magnetic disk (24) recorded with the track boundary of the recording servo information and the track boundary of the reproducing servo information separated by a distance corresponding to the azimuth angle of the composite head (26), Head position error information generating means (14) for generating head position error information from the read recording servo information and generating head position error information from the read reproducing servo information during data reproduction, and the head position error information. Based on the head position error information supplied from the information generating means (14), the composite head (
And a head positioning control means (13) for positioning 6). 2. The magnetic disk (24), the track boundary of the shared servo information to be shared at the time of recording and reproducing data is made to coincide with the track boundary and the center of the track width of the servo information for recording, or for the reproduction. 2. The magnetic disk device according to claim 1, wherein the shared servo information is recorded so as to match the track boundary and the center of the track width of the servo information. 3. The magnetic according to claim 1, wherein the write gap is separated into a first gap and a second gap (w1, w2) at a center position of a core width corresponding to a data track width. Disk device. 4. A write gap and a read gap (r), which are separated into first and second gaps (w1, w2) at a center position of a core width corresponding to a data track width, are separated in parallel at a predetermined interval. Arranged combined heads (26)
Is provided at the tip of the rotary type head positioning mechanism (25), and the servo information for head positioning recorded on the magnetic disk (24) is reproduced to position the composite head (26) on a data track to transfer data. In a servo information recording method of a magnetic disk for recording the servo information on the magnetic disk (24) used in a magnetic disk device for recording and reproducing, a head for generating a head position signal corresponding to the position of the composite head (26). The head position signal generated by the position detecting means (66) is used to position the composite head (26) so that the write gaps (w1, w2) accurately trace the data track during data recording. The recording servo information for positioning the composite head (26) is transferred to the first and second gaps (w).
1, w2) is used for recording, and the composite head (26) is positioned based on the head position error information obtained by reading the recorded recording servo information. The reproducing servo information for positioning the composite head (26) so that the read gap (r) traces the data track accurately is provided as a boundary between the first gap (w1) and the second gap (w2). A servo information recording method for a magnetic disk, wherein recording is performed using one of the first or second gaps (w1, w2) so that a portion forms a track boundary of the reproduction servo information. 5. A head position detecting means (66) for positioning the composite head (26) based on head position error information obtained by reading the recording servo information recorded on the magnetic disk (24). After storing the head position signal, when recording the reproduction servo information, the composite head (26) is positioned so that the head position signal matches the stored head position signal, and the reproduction servo information is recorded. The servo information recording method for a magnetic disk according to claim 4, wherein