JPH09251736A - Magnetic disk and magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disk device capable of increasing the recording capacity of a magnetic disk by simultaneously detecting amplitude information and phase information regarding a magnetic head signal. SOLUTION: When a current is supplied to a voice coil 5, an arm 4 is rotated around a vertical shaft 4a based on a force produced by the magnetic fields of magnets 7a and 7b and a current flowing to the voice coil 5. Thus, a head slider 6 attached to the other end of the arm 4 is moved in the radial direction of a magnetic disk 3. Thus, a magnetic head 8 mounted on the head slider 6 performs a seeking operation for a magnetic disk 3 and performs data recording/reproducing for a specified data track. In this way, since a servo zone and a data zone are formed along the moving locus of the magnetic head 8 when it is moved in the direction of the inner or the outer peripheral direction, a time interval is maintained during the seeking operation and unlocking of a PLL circuit or azimuth losses are suppressed for producing clocks.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk on which information such as data and programs is recorded and reproduced by a magnetic head mounted on a flying head slider, and a magnetic disk device equipped with the magnetic disk. Is.

[0002]

2. Description of the Related Art For example, in a computer system, a hard disk device is used as a magnetic disk device. In recent years, the recording capacity of hard disk devices has been increased, and for example, hard disk devices incorporating a pre-embossed magnetic disk have been developed. In this pre-embossed magnetic disk, a data recording area (hereinafter, referred to as a data zone) and a control signal recording area (hereinafter, referred to as a servo zone), each of which has an uneven portion, are radially formed.

That is, in the data zone, concentric circular data tracks for recording data and the like are formed as convex portions, and guard bands for separating adjacent data tracks are concave portions. Is formed. Further, in the servo zone, a gray code for specifying a data track, a clock mark that serves as a reference when generating a servo clock, and a fine pattern for obtaining track position information are formed. It may be formed by a convex portion or a concave portion.

Here, as the fine pattern,
An amplitude detection type pattern that detects the amplitude of the magnetization reversal and converts it into a position error signal is used. FIG. 12 is a plan view showing an example of a fine pattern formed on a conventional pre-embossed magnetic disk. This fine pattern is a burst pattern in which a reproduction signal of a constant frequency can be obtained by the magnetic head, and a plurality of rectangular embosses (four in this example) are arranged in parallel at regular intervals. The X pattern, the Y pattern, the A pattern, and the B pattern are arranged in this order.

Patterns A and B are on / off track confirmation patterns for confirming whether or not the magnetic head is correctly positioned on the data track. Amplitude and B of the signal by the A pattern reproduced by the magnetic head
The A pattern and the B pattern are arranged so that the position of the magnetic head is just on track when the signals of the patterns have the same amplitude. That is, the A pattern is arranged on one side of the center line of the data track, the B pattern is arranged on the other side, and the short side of each emboss of the A pattern and the B pattern is placed on the center line of the data track. It is located in.

However, since the A pattern and the B pattern have only amplitude information, it can be confirmed that the magnetic head is on-track or off-track.
It is impossible to determine which of the even and odd data tracks is located. Therefore, the X pattern and the Y pattern are provided to enable the even / odd track discrimination. The X pattern and the Y pattern are arranged so that there is a detection time difference between the signal amplitude of the X pattern reproduced by the magnetic head and the signal amplitude of the Y pattern. That is, the X pattern and the Y pattern are offset from each other on the center line of the data track, and the centers of the long sides of the embosses of the X pattern and the Y pattern are placed on the center line of the data track.

According to the magnetic disk having the fine pattern having such a structure, the signal waveform reproduced by the magnetic head is as shown in FIG. That is, the same figure (A)
Is a signal waveform when the magnetic head passes along the line AA shown in FIG. 12, and first, the amplitude v when the X pattern passes.
The signal waveform of 1 appears for a predetermined time, then the signal waveform of amplitude 0 when passing no pattern appears for a predetermined time, and finally the signal waveform of amplitude v2 when passing the A pattern and B pattern appears for a predetermined time. FIG. 12B shows a signal waveform when the magnetic head passes along the line BB shown in FIG. 12. First, a signal waveform with an amplitude of 0 when passing no pattern appears for a predetermined time, and then,
The signal waveform of the amplitude v1 when passing the B pattern appears for a predetermined time, and finally the amplitude v2 when passing the A pattern and the B pattern.
Signal waveform appears for a predetermined time.

With respect to these reproduction signals, a timing signal for specifying each pattern is output from the timing control circuit which constitutes the magnetic disk device. And
According to the timing signal, as shown in FIGS. 14A and 14B, each reproduction signal is full-wave rectified and integrated to output voltages Vx, Vy, Va, Vb corresponding to the amplitude of each reproduction signal. . Then, the even-odd track determination is performed by the voltages Vx and Vy, the on-track confirmation is performed by the voltages Va and Vb, and the tracking is controlled. That is, the voltage V
When x has a predetermined value and the voltage Vy is 0, it is determined that the track is an odd number, the voltage Vx is 0, and the voltage Vy is 0.
Has a predetermined value, it is determined that the track is an even number. Further, when the voltage Va is higher than the voltage Vb, it is confirmed that the track is off-tracked to the A pattern side, and the voltage Vb
Is larger than the voltage Va, it is confirmed that the B pattern side is off-track, and when the voltage Va and the voltage Vb are equal, it is confirmed that the track is on-track.

[0009]

In the fine pattern provided on the above-mentioned conventional magnetic disk, four patterns of X pattern, Y pattern, A pattern and B pattern are required, so that the data track becomes short. ,
There is a drawback that the recording capacity becomes small.

In view of the above points, an object of the present invention is to provide a magnetic disk capable of increasing the recording capacity of the magnetic disk and a magnetic disk device equipped with the magnetic disk.

[0011]

According to the present invention, the above object is a magnetic disk in which information is recorded and reproduced by a magnetic head mounted on a flying type head slider, and a data recording area and a control signal are provided. This is achieved by providing a pattern in the magnetic recording disk radially divided into recording areas so that the amplitude information and the phase information of the signal obtained from the magnetic head can be detected at the same time in the control signal recording area.

According to the above-mentioned structure, since the two-phase pattern can detect not only the amplitude but also the time difference at the same time, the area occupied by the pattern can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiments described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. It is not limited to these forms unless otherwise stated.

FIG. 1 is a perspective view showing a structural example of a hard disk device which is an embodiment of a magnetic disk device of the present invention. In this hard disk device 1, a spindle motor 9 is provided on the back side of a flat surface of a housing 2 made of an aluminum alloy or the like, and a pre-embossed magnetic disk that is rotationally driven by the spindle motor 9 at a constant angular velocity. A disc 3 is provided. Further, an arm 4 is attached to the housing 2 so as to be swingable around a vertical axis 4a. A voice coil 5 is attached to one end of the arm 4, and a head slider 6 is attached to the other end of the arm 4. A magnet 7 is provided on the housing 2 so as to sandwich the voice coil 5.
a and 7b are attached. A voice coil motor 7 is formed by the voice coil 5 and the magnets 7a and 7b.

In such a configuration, the voice coil 5
When an electric current is supplied from the outside to the arm 4, the arm 4 rotates around the vertical axis 4a based on the force generated by the magnetic fields of the magnets 7a and 7b and the electric current flowing through the voice coil 5. Thereby, the head slider 6 attached to the other end of the arm 4 moves substantially in the radial direction of the magnetic disk 3. Therefore, the magnetic head 8 mounted on the head slider 6 performs a seek operation on the magnetic disk 3 to record and reproduce data on a predetermined data track of the magnetic disk 3.

FIG. 2 is a plan view showing an embodiment of a magnetic disk of the present invention, FIG. 3 (A) is a sectional view in the radial direction,
FIG. 2B is a sectional structural view in the circumferential direction. A data recording area (data zone) and a control signal recording area (servo zone) formed of concavo-convex portions are radially formed on a substrate 31 made of synthetic resin, glass, aluminum or the like of the pre-embossed magnetic disk 3. The magnetic film 32 is formed on the surface thereof.

That is, the data zone is concentric and is formed so that the data track DT for recording data or the like is formed as a convex portion and is adjacent to the data track D.
A guard band GB for dividing T is formed as a recess. Further, in the servo zone, a gray code for specifying the data track DT, a clock mark serving as a reference of the servo clock, and a servo pattern such as a fine pattern for obtaining track position information are formed.

According to such a magnetic disk 3, since the servo zone and the data zone are formed along the movement trajectory when the magnetic head 8 moves in the inner peripheral side direction or the outer peripheral side direction, the seek operation is performed. It is possible to maintain the isochronous property during operation, and to generate a PL for clock generation.
The lock release of the L circuit can be suppressed. In addition, azimuth loss can be suppressed.

The above-mentioned magnetic disk 3 can be manufactured by using optical technology, and the manufacturing method is shown in FIGS.
Will be described. First, the surface of the glass master 41 is coated with, for example, a photoresist 42. The glass master 41 coated with the photoresist 42 is mounted on a turntable 43 and rotated. For example, only a portion of the photoresist 42 which forms a concave portion is irradiated with a laser beam 44 to perform pattern cutting. After irradiating the laser beam 44, the photoresist 42 is developed to form a photoresist 4
The exposed portion 2 is removed. The surface of the glass master 41 from which the exposed portions of the photoresist 42 have been removed is plated with nickel 45. The nickel 45 is transferred to the glass master 4
The stamper 46 is peeled off from the stamper 1.

Next, the substrate 31 is formed using the stamper 46. Then, a magnetic film 32 is formed on the surface of the substrate 31 by sputtering or the like to form the magnetic disk 3. Then, the magnetic disk 3 is set in the magnetizing device 47 and magnetized by the magnetizing magnetic head 48.

FIG. 6 is a plan view showing an example of a fine pattern formed in the embodiment of the magnetic disk shown in FIG. This fine pattern has at least one trapezoidal emboss with a predetermined interval (four in this example).
The A pattern and the B pattern having a parallel configuration are arranged in this order. The A pattern and the B pattern are on-track confirmation patterns for confirming whether or not the magnetic head 8 is correctly positioned on the data track DT (just on track), and on any of the even and odd data tracks DT. It is an even-odd track discrimination pattern for discriminating whether or not it is located at.

The amplitude of the A pattern detected by the magnetic head 8 is equal to the amplitude of the B pattern, and the A pattern and the B pattern are detected.
The position of the magnetic head 8 is just on-track when the peak intervals of the amplitude of the pattern are equal, and
The A pattern and the B pattern are arranged such that when the amplitude peak interval of the A pattern is smaller than the amplitude peak interval of the B pattern, it becomes an odd data track DT, and when it is large, it becomes an even data track DT. That is, the A pattern is arranged on one side of the center line of the data track DT, the B pattern is arranged on the other side, and the upper side of each emboss of the A pattern and the B pattern (short side) is arranged on the center line of the data track DT. Sides) or lower sides (long sides) are arranged so as to ride on each other, and the oblique side of each emboss is arranged in a range corresponding to one track pitch.

According to the magnetic disk 3 having the fine pattern having such a structure, the signal waveform reproduced by the magnetic head 8 is as shown in FIG. That is, FIG. 6A is a signal waveform when the magnetic head 8 passes along the line AA shown in FIG. 6, and first, the amplitude when passing through the A pattern is va and the peak interval is 2.T1. Signal waveform appears for a predetermined time, and then a signal waveform with an amplitude of vb when passing through the B pattern and a peak interval of 2 · T1 appears for a predetermined time. FIG. 6B is a signal waveform when the magnetic head 8 passes along the line BB shown in FIG. 6. First, a signal having an amplitude of va when passing through the pattern A and a peak interval of 2 · T2. A waveform appears for a predetermined time, and then a signal waveform with an amplitude of vb when passing through the B pattern and a peak interval of 2 · T2 appears for a predetermined time.

For these reproduced signals, as shown in FIG.
Peak detection as shown in (B) is performed, and the first pulse signal corresponding to the edge of each pattern is output. Then, for example, a D flip-flop or the like outputs a second pulse signal having a pulse width from the leading edge of the first pulse signal to the trailing edge thereof. Then, for example, an analog integrator or the like outputs an integrated signal corresponding to the pulse area of the second pulse signal. Since the second pulse signal is a logic level signal, the voltage is constant at V1 and V2. Therefore, the integrated signal indicates the pulse width, and it is possible to measure the interval between both edges of the pattern.

On-track confirmation and even-odd track discrimination are performed by the voltages va and vb, and tracking is controlled. That is, when the voltage va and the voltage vb are smaller than the predetermined value, it is determined that the track is an odd number, and the voltage v
When a and the voltage vb are larger than a predetermined value, it is determined that the track is an even number. When the voltage va is larger than the voltage vb, it is confirmed that the A pattern side is off-tracking, and when the voltage vb is larger than the voltage va, it is confirmed that the B pattern side is off-tracking, and the voltage va is Is equal to the voltage vb, it is confirmed to be on-track.

For example, when the width of the magnetic head 8 is 3 μm,
0.6μ on the upper side (short side) of the fine pattern embossing
m, the lower side (long side) of the embossment is 1 μm, the spacing between the embossments is 1 μm, and the radial pitch of the magnetic disk 3 is 5 μm.
If the pattern length is 5 μm, the angle of the embossed hypotenuse is about 85 ° and the azimuth loss of the reproduced signal is 0.2.
dB. Therefore, there is almost no effect on the reproduction signal, and the hard disk device 1 operates without any problem. At this time, the amount of time difference to be detected is 0.04 μs if the linear velocity of the magnetic disk 3 is 10 m / s, and it can be said that there is a sufficient detection margin considering that the signal jitter is several ns.

FIG. 9 shows the hard disk device 1 shown in FIG.
3 is a block diagram showing a configuration example of a control unit of FIG. The recording / reproducing amplifier 11 of the control unit 10 amplifies the reproduction signal from the magnetic head 8 and outputs it to the servo zone identification circuit 12, the detection circuit 13 and the peak detection circuit 14. The servo zone identification circuit 12 outputs the servo zone identification signal to the timing control circuit 15 when the servo zone is identified by the reproduction signal from the recording / reproduction amplifier 11. The timing control circuit 16 outputs a timing signal for specifying each pattern of the reproduction signal to the detection circuit 13.

The detection circuit 13 includes a timing control circuit 15
A full-wave rectification of the reproduction signal from the recording / reproduction amplifier 11 is performed according to the timing signal from A
Output to the arithmetic circuit 16. The AB calculation circuit 16 calculates the difference between the voltage va and the voltage vb, which are the integrated output from the detection circuit 13, to obtain the off-track amount, and the polarity switching circuit 1
7 is output.

On the other hand, the peak detection circuit 14 detects the amplitude peak from the reproduction signal from the recording / reproducing amplifier 11 and outputs it to the time interval measuring circuit 18. Time interval measurement circuit 1
8 measures the peak interval from the amplitude peak from the peak detection circuit 14 and outputs it to the polarity switching circuit 17. The polarity switching circuit 18 discriminates between even and odd tracks based on the peak interval from the time interval measuring circuit 18, and outputs track position information to the tracking servo unit 19 according to the off-track amount. The tracking servo unit 19 generates a tracking error signal based on the track position information from the polarity switching circuit 18, and drives the arm 4 in response to this. As a result, the magnetic head 8 moves the magnetic disk 3
The tracking control is performed at a predetermined radial position.

FIG. 10 is a plan view showing another example of the fine pattern formed in the embodiment of the magnetic disk of the present invention. In the fine pattern shown in FIG. 6, only one side of the emboss has a gradient, but in the fine pattern of this example, both sides of the emboss have a gradient. Generally, since a rotary type actuator is used in the magnetic disk device, the azimuth angle changes depending on the position of the magnetic head 8. Therefore, if the gradients provided on both sides of the emboss are symmetrical with respect to the direction of the head gap and the angles are calculated from the azimuth angle of the magnetic head 8 at each radius, the azimuth loss becomes equal. In principle, the output difference between the trailing edge and the leading edge can be eliminated.

FIG. 11 is a plan view showing still another example of the fine pattern formed in the embodiment of the magnetic disk of the present invention. In the fine pattern shown in FIG. 6, A pattern and B pattern are formed on the center line of the data track DT.
Although the upper sides (short sides) or the lower sides (long sides) of the embosses of the pattern are arranged so as to ride on each other, in the fine pattern of this example, each of the A pattern and the B pattern is crossed over the center line of the data track DT. The upper side (short side) of the emboss is arranged. According to the fine pattern having such a configuration, since the reproduction width at the on-track position can be secured, the deterioration of the S / N of the reproduction signal can be reduced.

In the above-described embodiment, the pre-embossed magnetic disk has been described, but the present invention can be applied to a general flat magnetic disk.

[0033]

As described above, according to the present invention,
Since the area occupied by the pattern on the magnetic disk can be reduced, the area occupied by the data recording area can be increased to increase the recording capacity.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of a hard disk drive which is an embodiment of a magnetic disk drive of the present invention.

FIG. 2 is a plan view showing an embodiment of a magnetic disk of the present invention.

FIG. 3 is a sectional structural view of the embodiment of the magnetic disk shown in FIG.

FIG. 4 is a first diagram for explaining a manufacturing method of the embodiment of the magnetic disk shown in FIG.

FIG. 5 is a second diagram for explaining the manufacturing method of the embodiment of the magnetic disk shown in FIG.

6 is a plan view showing an example of a fine pattern formed in the embodiment of the magnetic disk shown in FIG.

FIG. 7 is a diagram showing an example of a signal waveform when the fine pattern shown in FIG. 6 is reproduced by a magnetic head.

8 is a waveform chart showing an example of processing the signal shown in FIG.

9 is a block diagram showing an example of a control unit of the embodiment of the magnetic disk device shown in FIG.

10 is a plan view showing another example of a fine pattern formed in the embodiment of the magnetic disk shown in FIG.

FIG. 11 is a plan view showing still another example of a fine pattern formed in the embodiment of the magnetic disk shown in FIG.

FIG. 12 is a plan view showing an example of a fine pattern formed on a conventional magnetic disk.

13 is a diagram showing an example of a signal waveform when the fine pattern shown in FIG. 12 is reproduced by a magnetic head.

14 is a waveform chart showing an example of processing the signal shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hard disk device, 2 ... Housing, 3 ...
Magnetic disk, 4 ... arm, 4a ... vertical axis, 5
... voice coil, 6 ... head slider, 6a
..Rail, 6b ... rail, 6c ... tapered part,
6d ... tapered portion, 7 ... voice coil motor, 7
a ... magnet, 7b ... magnet, 8 ...
Magnetic head, 9 ... motor, 10 ... control unit, 11
... Recording / reproducing amplifier, 12 ... Servo zone identification circuit, 13 ... Detection circuit, 14 ... Peak detection circuit,
15 ... Timing control circuit, 16 ... AB arithmetic circuit, 17 ... Polarity switching circuit, 18 ... Time interval measuring circuit, 19 ... Tracking servo section, 31 ...
..Substrate, 32 ... magnetic film, 41 ... glass master,
42 ... Photoresist, 43 ... Turntable, 44 ... Laser light, 45 ... Nickel, 46.
..Stampers, 47 ... Magnetizing device, 48 ... Magnetic heads for magnetizing

Claims (3)

[Claims] 1. A magnetic disk in which information is recorded and reproduced by a magnetic head mounted on a floating head slider, wherein the magnetic disk is radially divided into a data recording area and a control signal recording area. A magnetic disk, wherein a pattern configured so that amplitude information and phase information of a signal obtained from a magnetic head can be simultaneously detected is provided in the control signal recording area. 2. The pattern is arranged on both sides of a center line of a data track provided in the data recording area, and is provided with a gradient in a direction orthogonal to the center line of the data track. The magnetic disk according to claim 1. 3. A magnetic disk that is radially divided into a data recording area and a control signal recording area, a head slider that floats on the surface of the magnetic disk and moves in the radial direction of the magnetic disk, and the head slider. In a magnetic disk device equipped with a magnetic head for recording and reproducing data and the like on the magnetic disk, a pattern configured to simultaneously detect amplitude information and phase information of a signal obtained from the magnetic head. Is provided in the control signal recording area.