JPH03189918A - Magnetic disk device, magnetic head and its positioning control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic disk device and a magnetic head that record magnetization directions between adjacent tracks with an azimuth to each other in order to achieve narrow tracks and high track density. and its positioning control method.

[Prior art] Magnetic disk media are made by coating both sides of a thin aluminum disk with a film of magnetic oxide (gamma iron oxide, etc.), or by plating an alloy of N1-Go with Kkeru-cobalt). , information is written by being magnetized in dots on this magnetic surface. The narrow concentric bands on which information is recorded are called tracks, but in reality, the entire surface is uniformly painted or plated, and the tracks are only formed by the written information itself. Therefore,
Track width is determined by the width of the write head. Conventionally, the spacing between tracks was about 40 tracks/mm to 8°/mm, but narrower tracks and higher track density are now required.

Conventionally, as a method suitable for increasing the track density of a magnetic recording device, there is a recording track as described in, for example, Japanese Patent Laid-Open No. 16604/1983.

In this track, a magnetic material is applied only to the recording track. As shown in Fig. 15 (a) and (b), after applying the magnetic material to the entire surface of the magnetic disk medium, only the width of each magnetic track is coated. The magnetic material is scraped away at the track spacing, leaving behind. Note that (a) is a plan cross-sectional view, and (1
)) is a side sectional view. According to this method, crosstalk from adjacent tracks is reduced due to the presence of the grooves, and even if a head with a wide track width is used to write, the grooves convert the track into a narrow track, and writing is inevitably performed using the narrow track.

In addition, as another method, for example, JP-A-6112031
There is a recording track as described in Publication No. 4.

These tracks are written using an azimuth recording method, and as shown in FIG. 15(c), recording is performed with the magnetization directions of adjacent tracks set at an azimuth (angle) with respect to each other. That is, if the first magnetization direction is, for example, 30 degrees with respect to the track traveling direction, and the second magnetization direction is, for example, 130'', then odd-numbered tracks are in the 30-degree direction and even-numbered tracks are in the 130-degree direction. They are each magnetized in the direction of 0. In this way, crosstalk from adjacent tracks can be reduced.

Note that a method of recording magnetization directions with azimuths from each other has been commonly used in VTRs (image tape recording).

[Problem to be solved by the invention]

The above-mentioned azimuth recording method has a great effect in reducing crosstalk from adjacent tracks, and the track width can be increased by that amount. are affected to the same extent as non-recording methods. As described above, the conventional azimuth recording method still has problems when taking into account not only the cross-dog but also the performance of the overall recording operation such as positional deviation.

An object of the present invention is to solve such conventional problems and to provide a magnetic disk device, a magnetic head, and a positioning control method thereof that can always control the correct positioning of the magnetic head and thereby achieve high track density. It is about providing.

[Means to solve the problem]

In order to achieve the above object, the magnetic disk positioning control system of the present invention provides (a) recording and reproducing signals using a separate recording and reproducing head that gives an azimuth angle to signals between adjacent tracks and separates recording and reproducing functions; A feature of the present invention is that, at the same time as recording and reproducing information, a signal is reproduced by a reproducing head to control the positioning of the head. (b) Recording/reproducing data is recorded in the upper layer of the magnetic disk recording medium, and positioning signal data is recorded in the lower layer disposed below the upper layer, and the recording data of the target track and the positioning signal data of both adjacent tracks are recorded. Another feature is that the pattern is recorded with the same azimuth angle. In addition, (c) the reproducing head is formed from two reproducing head elements, and the target]
Another feature is that positioning control is performed so that the signal amplitudes of the positioning signal data read from both tracks adjacent to the rack are equal. (iv) The reproducing head is formed with one element, and the positioning signal data recorded on the magnetic disk recording medium is made into a signal called a dibit pattern in which the signals from the left and right adjacent tracks can be separated. Another feature is that positioning control is performed so that the amplitudes of the positioning signal data read from the left and right adjacent tracks are equal. In addition, (e) the recording frequency of the recording/reproduction 9- raw data reproduced by the reproduction head is set higher than the recording frequency of the positioning signal data reproduced by the reproduction head, and the two types of data are separated and detected by frequency separation. There is also a characteristic of doing so. (f) When using a magnetic head that includes a reproducing head and a recording head consisting of two reproducing head elements, and storing only recorded and reproduced data on a magnetic disk recording medium, it is possible to track the target track. 2. Reading the recorded and reproduced data from both tracks adjacent to 2.
Another feature is that positioning is controlled so that the signal amplitudes of the individual reproducing elements are equal. Furthermore, the magnetic disk device of the present invention uses a recording/reproducing separation head in which signals between adjacent tracks have an azimuth angle and recording and reproducing functions are separated, and reproduces signals from two reproducing head elements. A recording and reproducing circuit that detects the peak and amplifying the reproduced signals from the two read head elements, extracting only the low frequency signals with a low pass filter, 1
The present invention is characterized in that it includes a positioning circuit that detects a pair of peaks, extracts an envelope signal from an adjacent track, and performs positioning control so that the difference in amplitude between the two becomes zero. Furthermore, the magnetic head of the present invention has
(H) A feature is that the track width of the reproducing head of the recording/reproducing separated head in which the recording and reproducing functions are separated is set to be equal to or greater than the track pitch and equal to or less than twice the track pitch. Another feature is that the magnetic head has an azimuth angle added to the rear end surface where the spacing between the air bearing surfaces on both sides of the head slider is minimum, and a head is mounted in which recording and reproducing head elements are formed.

Another feature is that the center distance between the heads having left and right azimuth angles on the magnetic head is set to an odd multiple of the track pitch.

[For production]

In the present invention, a method of performing positioning while reproducing positioning information in parallel with recording and reproducing operations using a separate recording/reproducing head in which an azimuth angle is provided between adjacent tracks;
That is, a data track servo method is executed. That is, a magnetic head slider is equipped with a pair of heads having an azimuth angle to each other, and by selecting a head to be used for each track, a signal having an azimuth angle is recorded between adjacent tracks. Each magnetic head is a separate recording/reproducing head that includes a recording head element and a reproducing head element, and is capable of constant reproducing operation.

This head is one in which the total track width of the reproducing head is equal to or larger than the track pitch and narrower than twice the track pitch. Further, in order to execute the data track servo method, a read signal from a reproducing head having a center tap divided into two at the center is used.

When only recording/reproduction data is recorded on a magnetic disk medium, the recording/reproduction data on the same track is separated and reproduced by left and right reproduction head elements.

Further, when the magnetic disk medium is a two-layer film, record data is recorded on the upper film, positioning signal data is recorded on the lower film, and the positioning signal data from the adjacent left and right tracks is reproduced by the reproducing head. The positioning signal is obtained from the difference in amplitude of the signals from these two read head elements 2, and by controlling the positioning signal to be zero, highly accurate positioning can be performed.

[Example] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view of a magnetic head and a recording pattern on a magnetic disk surface, showing a first embodiment of the present invention.

FIG. 1 shows a magnetic head for recording and reproducing positioning signal data, recording and reproducing data, and a plane of a magnetic disk. That is, ■ is the magnetic disk plane, 2 is the magnetization reversal pattern of recording/reproducing data on the magnetic disk surface,
3 is a positioning signal data magnetization reversal pattern, 4 is a reproducing head, 5 is a recording head, and 6 is a reproducing head element.

Here, the magnetic disk recording medium is composed of two layers, an upper layer and a lower layer, in which the magnetization reversal pattern 3 of positioning signal data is recorded in the lower layer, and the magnetization reversal pattern 3 of recording/reproducing data is recorded in the upper layer. Reversal pattern 2 is recorded. In FIG. 1, the recording/reproducing data 2 in the upper layer is shown by a solid line, and the positioning signal data 3 in the lower layer is shown by a dotted line. Three tracks A, B, and C are shown on the magnetic disk medium. Positioning signal data 3 and recording/reproducing data 2 on the same track are recorded at a predetermined azimuth angle with respect to data on an adjacent track. As a result, the reproduced signals of the respective data do not interfere with each other between adjacent tracks.

In this case, when positioning the head on the B track, positioning is performed using the positioning signal data of the adjacent tracks A and C, and when positioning the head on the C track, the head is positioned using the positioning signal data of the adjacent tracks B and D (not shown). Positioning is performed using positioning signal data. Therefore, the azimuth angle of the recording/reproduction data 2 (solid line) of track B and the azimuth angle of the positioning signal data 3 (dotted line) of the tracks A and (,) on both sides thereof are the same angle.

Similarly, the azimuth angles of the recording/reproducing data 2 of the C track and the adjacent B and Dh track positioning signal data 3 are equal.

As shown in FIG. 1, the magnetic head of the present invention uses a composite head consisting of a recording head element 5 and a reproducing head element 4. The reproducing head element 4 is composed of two divided reproducing head elements 6-1 and 6-2. Both reproducing head elements 6-1. , 6-2 each cover nearly half of the trucks on both sides and half of its own truck. Therefore, the track widths covered by both ends of the plurality of head elements constituting the reproducing magnetic head are A, B, and C.
wider than each track pitch, 2 of the track pitch.
The value is chosen to be narrower than double. At the current position in FIG. 1, the recorded and reproduced data 2 is read from the positioned track B. The positioning signal data 3 is read out from adjacent left and right tracks A and C by the read head elements 6-1 and 6-2, respectively, due to the azimuth angle relationship.

Note that the positioning signal data 3 on the magnetic disk medium is
In order to make it easier to distinguish the positioning signal data 3 from the positioning signal data 3 from the adjacent tracks A and C, it is desirable that the two be recorded with a phase shift of 15-.

Here, the positioning signal data 3 recorded in A and C are shifted and recorded so that they appear alternately.

3(a) and 3(b) are plan and side views of the magnetic head of the present invention, FIG. 4 is a sectional view of the magnetic head and magnetic disk of the present invention, and FIG. 6 is a frequency band diagram of data signals and servo signals in the figure;
The figure is a reproduction waveform diagram of a positioning data signal reproduced by the magnetic head of the present invention.

In Figures 3 and 4, ■ is a magnetic disk disk;
4 is a reproducing head element, 5 is a recording head element, 8 is a magnetic head composed of recording and reproducing head elements, 16 is an upper data storage layer, and 17 is a lower servo signal storage layer.

As shown in FIG. 3(a), when viewed from the bottom surface of the magnetic head 8, it consists of a central portion of the slider and both side portions having air bearing surfaces. When viewed from the side in FIG. 3(b), the recording head element 65 and the reproducing head element 4 are attached to the leading edge of the slider, and the magnetic disk 1
The head 8 floats with a constant spacing provided between the head 8 and the surface of the head 8 . As shown in FIG. 4, the reproducing head element 4 is arranged so as to be able to reproduce the signals in the servo signal storage layers 17 of both tracks adjacent to the recording head element 5, and the recording head element 5 Data is recorded on the data storage layer 16 of the track sandwiched between the tracks and is reproduced again. Here, tracks N-1 (EVEN), N
Three tracks are involved: (ODD) and N+I (ODD). As shown in FIG.
Obtain EN20 and 0DD21. The reason why the peak positions are different is that the servo signals are recorded with a shifted phase. Therefore, the position where the amplitudes of both servo signals are equal is the position where the recording head element 5 is correctly positioned.

Further, in order to distinguish between the servo signal and the recorded/reproduced data, the servo signal frequency range 18 is set to be significantly lower than the data signal frequency range 19 by 17- as shown in FIG. This makes it possible to reliably separate both signals 18 and 19 using a filter technique that separates signal bands.

FIG. 2 is a configuration diagram of a magnetic disk device showing an embodiment of the present invention, and FIG. 8 is a diagram showing the configuration of a magnetic disk device that is reproduced from the positioning signal data pattern and LU positioning signal data in FIG. 1 (first embodiment). FIG. 3 is a diagram of an envelope signal waveform.

In FIG. 2, 1 is a magnetic disk, 8 is a magnetic head,
9 is a magnetic disk device, 10 is a positioning mechanism system, 11 is a recording/reproducing circuit, 12 is a positioning circuit, 13 is a control circuit,
14 is a disk drive motor, and 15 is an interface with a host device.

By rotating the disk drive motor 14, a plurality of stacked magnetic disk disks 1 are rotated, and then by operating the positioning mechanism 10 including a voice coil motor etc., the magnetic head 8 is moved to the magnetic disk disk 1. move it along. Recording and reproducing data 2 and positioning signal data 3 are respectively recorded on the magnetic disk 1.

Further, as the magnetic head 8, a separate recording/reproducing head is used. The positioning circuit 12 positions the magnetic head 8 on the track to be accessed based on the servo signal read by the reproducing head element 4 of the magnetic head 8. Data recorded or reproduced by the recording/reproducing head element 5 of the magnetic head 8 is transferred from or to the recording/reproducing circuit 11, and is also transferred to/from the host device via the control circuit 13. be done.

In the upper part of FIG. 8, a positioning signal data pattern is shown, and the positioning signal is recorded by being magnetized in the direction of the arrow. Now, in order to position the magnetic head 8 on the L U - E V E N track, the reproducing head element 4
When the servo signal is extracted from the positioning circuit 1 in Fig. 2,
2 is an envelope signal (position signal) 41.4 shown in the lower part of FIG. 8 from the separated positioning signal data.
2 is played. By counting the beeb values of the position signals 41 and 42, the number of tracks to which the magnetic head 8 has moved can be determined. The envelope signal 41 is the reproduction signal from the left side reproduction head element 4, and the signal 42 is the reproduction signal from the right reproduction head element 4, and within the range indicated by the solid line, the amplitude of both signals is equal to the other signal indicated by the dotted line. If it is positioned at the new position (1), it will be correctly positioned on the RU-EVEN1 rack. Here, LU
-The signal obtained from the EVEN region is shown as a solid line, and the LU-OD
Signals obtained from region D are indicated by dotted lines. In this figure, EVEN and O
Since the envelope signals obtained from the DD areas are equal, by controlling the difference in the envelope signals from these areas to zero, it is possible to accurately position the track at the center of the target track indicated by the arrow. In addition,
The LU area existing between the RUs can also be positioned in the same way using the other azimuth angle head.

FIG. 7 is a configuration diagram of a recording/reproducing circuit and a positioning circuit system according to the present invention.

In FIG. 7, 11 is a recording/reproducing circuit, and 1220 is a positioning circuit. The recording and reproducing circuit 11 includes a recording amplifier 35, a reproducing amplifier 22, an adding circuit 3o, a high pass filter 23, a peak detecting circuit 24, and a discrimination circuit 25. Further, the positioning circuit (2) is composed of a low-pass filter 27, an envelope signal generation circuit 43, a position signal reproducing circuit 31, and a positioning system control circuit 32.

Input terminal 36 to recording amplifier 35 and reproduction system circuit 44
The output terminal 26 from is connected to the control circuit 13 of FIG. In addition, the input/output terminal 33 of the positioning system control circuit 32
．． 34 is also connected to the control circuit 13 shown in FIG. The envelope signal generation circuit 43 uses a pair of peak detection circuit 28, envelope circuit 29, and PLL circuit 45 to generate envelope signals 41 and 42 from adjacent tracks A and C as described above. Furthermore, in the position signal reproducing circuit 31, the difference in amplitude between the two is determined,
The positioning system control circuit 32 controls the positioning system so that the difference becomes zero. This enables highly accurate positioning at the same time as recording and reproducing.

21 FIG. 9 is a relationship diagram between a magnetic disk and a magnetic head showing a second embodiment of the present invention, and FIG. 10 is a positioning signal data reproduction waveform diagram in FIG. 9.

In the first embodiment, the reproducing head element 4 was composed of two elements on the left and right, but in the second embodiment, as shown in FIG. 9, one reproducing head element 4 was used. There is. In this method, the relationship between the positioning signal pattern 3 and the reproducing head element 4 is designed so that it covers the track B to be positioned and its adjacent tracks A and C1, as shown in FIG. The positioning signal pattern is recorded as a dibit pattern as shown in FIG.
The magnetization directions recorded in U-ODD and LU-EVEN are the same. The tip of the magnetization direction arrow is the north pole, and the rear end is the south pole. Note that the azimuth angle is recorded so as to be the same for every other track. When the positioning signal data 3 of the dibit signal pattern is read out by the reproducing head element 4, a waveform as shown in FIG. 10(a) is output. The signal 20 indicated by the solid line 2- is the signal of the adjacent track C on the right, and the signal 2 indicated by the dotted line
1 is the signal of the left adjacent track A. In this method,
Although it is necessary to separate the positioning signal data from the adjacent left and right tracks A and C, separation is made possible by using a dibit pattern conventionally used when using a servo motor. That is, as shown in FIG. 10(a), E V lζN and OD D can be separated, and when comparing the amplitudes of the solid line signal 20 and the dotted line signal 21, the dotted line signal 21 is larger than the signal 20. be. When the amplitudes of the solid line signal 20 and the dotted line signal 21 are averaged, the level shown in FIG. 10(b) is obtained, and the dotted line O
The DD signal is larger than the EVEN signal indicated by the solid line. By controlling the position of the magnetic head 8 so that these two signals are equal, the magnetic head 8 can be correctly positioned on the RU-ODD track. In addition,
In order to properly reproduce the dibit pattern, a wide servo signal frequency band is required, so it is essential that the recording and reproduction signal frequency be high, and therefore this method is particularly suitable for high-density recording magnetic disk drives. .

FIG. 11 is a configuration diagram of a recording/reproducing circuit and a positioning circuit showing a second embodiment of the present invention.

In the second embodiment, since the reproducing head consists of one element compared to the first embodiment, the number of circuits can be reduced compared to the circuit configuration shown in FIG. That is, the addition circuit 30 of the reproduction circuit 44 is not required, and only one each of the low-pass filter 27, the VIG detection circuit 28, and the envelope circuit 29 of the positioning circuit 12 is required. 42 is P L
It is an L circuit. Other than the above, the configuration of FIG. 11 is the same as that of FIG. 7.

FIG. 12 is a relationship diagram between a magnetic disk and a magnetic head showing a third embodiment of the present invention.

The third embodiment differs from the first and second embodiments in that the magnetic disk 1 is a single layer, and as shown in FIG. Only data 2 is recorded. The overall configuration of the magnetic disk device is the same as that of the first embodiment shown in FIGS. 1 and 7, but the reproduction methods for recording and reproducing data and positioning signal data are different. That is, the arrangement of the magnetic head consisting of the recording head element 5 and the reproducing head element 4 consisting of left and right elements 6-1, 6-2 is also the same as in FIG.

Both the recording head element 5 and the reproducing head element 4 reproduce the recording/reproducing pattern on the magnetic disk medium.

FIG. 13 is a reproduction waveform diagram of a positioning data signal reproduced by the head of FIG. 12, and FIG. 14 is a block diagram of a recording/reproducing circuit and a positioning circuit system.

In a single layer of a magnetic disk medium, data magnetized in every other track at the same azimuth angle and in a different azimuth angle direction from adjacent tracks is recorded. 2 is a recording/reproducing data pattern.

Signals 46 and 47 reproduced from the two reproduction head elements 6-1 and 6-2 are each amplified by two reproduction amplifiers 22 and then input to the reproduction system circuit 44 and the positioning circuit 12. For the recording/reproduction data signal, an adder circuit 30 creates a sum signal of the outputs of the two heads 5 elements, and a peak detection circuit 24 and a discrimination circuit 25 provide a reproduction data pulse at an output terminal 26.

The recording/reproducing pattern is recorded by two reproducing head elements 6-], 6-
2, the solid and dotted signals shown in FIG. 13 are obtained. The solid line signal 47 is the reproduction signal of the head element 6-1, and the dotted line signal 46 is the reproduction signal of the head element 6-2.

For positioning signals, two reproducing head elements 6-
Signal 35.3 shown in Figure 13 reproduced from 1.6-2
6 is input to the envelope signal generation circuit 43 via the reproduction amplifier 22, and envelope signals corresponding to the signals 35 and 36 are respectively generated.

These envelope signals pass through a position signal reproducing circuit 31 and a positioning system control circuit 32, and are outputted to an output terminal 33 by V.
A CM drive signal is obtained. The positioning system control circuit 32 is
An output is given to control the position of the magnetic head so that the amplitudes of the head element reproduction signals 46 and 47 shown in FIG. 13 are equal.

In the third embodiment, the case where the recording/reproduction data is recorded on a single layer is shown, but when recording data, positioning is performed while reading, and since the reading position is the center, the magnetic head If it shifts, the center will also shift. As described above, if positional deviation occurs during data recording, the track center deviation may accumulate and cause a large positioning error. Therefore, it is desirable to use the well-known sector servo or index servo in combination to embed positioning signal data in the recording/reproduction data, thereby preventing cumulative errors.

That is, as shown in FIG. 12(b), a position signal is embedded at every certain angle on the circumference. All you have to do is read the position signal during playback and return it to the correct position.

The magnetic head 8 used in this embodiment needs to include a pair of head elements that have an azimuth angle to each other.

To this end, as shown in FIG.
The rear ends of the pair of air bearing surfaces are processed to have an azimuth angle, and a reproducing head element 4 and a recording head element 5 are formed on each end face.

27 The azimuth angle is preferably about 5 degrees to 40 degrees. The relationship between the magnetic head 8 in the first and second embodiments and the magnetic disk 1 viewed from the rear end of the head is shown in FIG. The recording head element 5 is positioned at a target track on the data recording layer 16 in the upper layer of the magnetic disk, and records and reproduces data from the target track as well as adjacent servo signal (positioning signal data) storage layer 17 in the lower layer of the magnetic disk. Positioning signals are also read from the track at the same time.

In this embodiment, the interval between the left and right reproducing head elements 4 is selected to be an odd multiple of the track pitch, and head selection and positioning control are performed in consideration of this interval.

The head 8 used in the second embodiment has the first and third heads.
This embodiment is the same as that of the embodiment, except that the reproducing head element 4 is a well-known head without a center tap.

The reproducing magnetic head used in the present invention may be an inductive head in which a wire is wound around the tip of a slider, or an MR head 8 in which Permalloy utilizes the magnetoresistive effect in which the resistance changes depending on the magnetic field.

〔Effect of the invention〕

As explained above, according to the present invention, positioning signals can be reproduced in parallel with recording and reproducing operations, so positioning control is always possible, and as a result, high track density can be achieved. .

[Brief explanation of drawings]

FIG. 1 is a relationship diagram between a magnetic disk and a magnetic head showing a first embodiment of the present invention, FIG. 2 is a configuration diagram of a magnetic disk device to which the present invention is applied, and FIGS. 5 and 6 are frequency band diagrams of servo and data signals and reproduction waveform diagrams of positioning signal data in FIG. 1, and FIG. FIG. 8 is a block diagram of the recording/reproducing circuit and the positioning circuit in the embodiment of FIG. 8, a positioning signal pattern and envelope signal waveform diagram in the embodiment of FIG. 29 Reproduction waveform diagram of inspection and positioning data signals showing an example of the relationship between a magnetic disk and a magnetic head, FIG. 11 is a configuration diagram of a recording/reproduction circuit and a positioning circuit in the second embodiment, and FIG. 13 is a diagram showing the relationship between the magnetic disk and the magnetic head showing the embodiment 3, FIG. 13 is a reproduction waveform diagram of the positioning data signal in FIG. 12, and FIG.
FIG. 15 is a block diagram of the recording/reproducing and positioning circuit in this embodiment, and FIG. 15 is a diagram showing various conventional methods for increasing track density. 1: Magnetic disk, 2: Recording/reproducing data magnetization reversal pattern, 3: Positioning signal data magnetization reversal pattern, 4: Reproducing head element, 5: Recording head element, 6-1.6-2:
Left and right separation element of read head element, 8: Magnetic head, 9:
magnetic disk device, IO: positioning mechanism system, ll: recording/reproducing circuit, 12: positioning circuit, 13: control circuit, ]4
: Disk drive motor, J5; Interface with host, 16: Data storage layer, 17. Servo signal storage layer, 18
+servo signal frequency domain, 19: recording and reproduction data signal frequency domain, 35: recording amplifier, 36: 30- recording data input terminal, 22: reproduction amplifier, 23 bypass filter, 24 peak detection circuit, 25: discrimination circuit ,3
0. Addition circuit, 26: Reproduction data pulse, 27: Low-pass filter, 28: Beak detection circuit, 29: Envelope circuit, 31: Position signal reproduction circuit, 32: Positioning system control circuit, 33: VCM drive signal output terminal, 34: Servo control signal output terminal, 37: AGC control signal generation circuit, 4
0: Differential amplifier, 41, 42: Envelope signal, 43
: Envelope signal generation circuit, 44: Reproduction circuit, 45
:PLL circuit. Figure δ Figure 1 Figure (Part 1) (a) ] =121 Figure (Part 2) (b)

Claims (1)

[Claims] 1. Positioning a magnetic head controlled by a positioning mechanism on an arbitrary track of a magnetic disk recording medium,
In magnetic disk drives that record and reproduce data, signals between adjacent tracks have an azimuth angle, and recording and reproduction signals are recorded and reproduced using a recording and reproduction separation head that separates the recording and reproduction functions.At the same time, the reproduction head A positioning control method for a magnetic disk, characterized in that the positioning of the head is controlled by reproducing a signal. 2. In the magnetic disk positioning control method according to claim 1, recording/reproducing data is recorded on an upper layer of the magnetic disk recording medium, and positioning signal data is recorded on a lower layer disposed below the upper layer, and the target track is A positioning control method for a magnetic disk, characterized in that recording data is recorded with the same azimuth angle of the positioning signal data patterns of both adjacent tracks. 3. In the magnetic disk positioning control method according to claim 2, the reproducing head is formed from two reproducing head elements, and the signal amplitude of the positioning signal data read from both tracks adjacent to the target track is made equal. A magnetic disk positioning control method characterized by performing positioning control. 4. In the magnetic disk positioning control system according to claim 2, the reproducing head is formed of one element, and the positioning signal data recorded on the magnetic disk recording medium is controlled by signals from adjacent left and right tracks. A positioning control method for a magnetic disk, characterized in that positioning control is performed so that the amplitudes of positioning signal data read from left and right adjacent tracks are equal, using separable signals. 5. In the magnetic disk positioning control method according to claim 2, 3 or 4, the recording frequency of the recording and reproduction data reproduced by the recording head is higher than the recording frequency of the positioning signal data reproduced by the reproduction head. , a magnetic disk positioning control method characterized by separating and detecting two types of data by frequency separation. 6. In the magnetic disk positioning control method according to claim 1, the magnetic head is a magnetic head including a read head and a write head each consisting of two read head elements, and the magnetic disk is placed on a magnetic disk recording medium. A positioning control method for a magnetic disk, characterized in that, when only recording and reproduction data is stored, positioning is controlled so that the signal amplitudes of two reproduction elements that read the recording and reproduction data from a target track are equal. 7. In a magnetic disk device that records and plays data by positioning a magnetic head controlled by a positioning mechanism on any track of a magnetic disk, recording and playback functions are achieved by giving an azimuth angle to signals between adjacent tracks. A recording and reproducing circuit that uses a separate recording and reproducing head that separates the two reproducing head elements, amplifies and adds the reproduced signals from the two reproducing head elements, extracts only the high frequency signal with a high-pass filter, and detects the peak; Amplify each reproduced signal from the head element, extract only the low frequency signal with a low-pass filter, detect a pair of peaks, extract the envelope signal from the adjacent track, and position the two so that the difference in amplitude is zero. A magnetic disk device comprising a positioning circuit for controlling the magnetic disk. 8. A reproducing head of a separate recording/reproducing head in which recording and reproducing functions are separated in a magnetic disk device that records and reproduces data by positioning a magnetic head controlled by a positioning mechanism on an arbitrary track of a magnetic disk. A magnetic head characterized in that the track width is set to be greater than or equal to the track pitch and less than or equal to twice the track pitch. 9. The magnetic head according to claim 8, wherein a head is mounted in which an azimuth angle is added to each rear end surface where the spacing of the air bearing surfaces on both sides of the head slider of the magnetic head is minimized, and recording and reproducing head elements are formed. A magnetic head characterized by: 10. The magnetic head according to claim 8 or 9,
A magnetic head characterized in that the center distance between the heads having left and right azimuth angles on the magnetic head is an odd multiple of the track pitch.