JPH1040541A - Magnetic disc and magnetic disc apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable one and the same magnetic disc apparatus to cope with read only and reprogrammable magnetic discs, keeping constant the amount of floating of a head slider by adjusting a ratio of the projected area and recessed area in the data area and stepped position within a read only and reprogrammable magnetic discs. SOLUTION: A load capacity which is a parameter of the amount of floating of a head slider in a read only magnetic disc where the recessed area and projected area for parallel and vertical data track DT and guard band GB to the traveling direction of the head slider are mixed and the reprogrammable magnetic disc where the recessed area and projected area for parallel data zone and servo zone are provided is determined by a ratio and the recessed area and projected area and the stepped area. Therefore, a ratio of the stepped area of the recessed and projected areas of both discs is set to 0.65 to 1.0 and the ratio of the recessed area and projected area is adjusted. Thereby the amount of floating of head slider can be kept constant. Accordingly, the read only or reprogrammable disc can be used and stable reproduction can also be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a read-only magnetic disk in which data and programs are reproduced by a magnetic head mounted on a flying type head slider, a magnetic disk device having the magnetic disk, and a data disk. More specifically, the present invention relates to a magnetic disk having a read-only area for reproducing data and the like, and a rewritable area for recording and reproducing data and the like, and a magnetic disk device provided with the magnetic disk.

[0002]

2. Description of the Related Art As a read-only magnetic disk device, there is a hard disk device in which a so-called pre-emboss type magnetic disk is built. This magnetic disk has
A data recording area (hereinafter, referred to as a data zone) including an uneven portion and a control signal recording area (hereinafter, referred to as a servo zone).
Are formed radially.

That is, in the data zone, concentric data tracks for recording data or the like are formed so as to be uneven, and guard bands for separating adjacent data tracks are formed as recesses. It is formed as follows. In the servo zone, a gray code for specifying a data track, a clock mark as a reference for generating a servo clock, a fine pattern for tracking control of a magnetic head, and the like (hereinafter, referred to as a servo pattern). Are formed as convex portions or concave portions.

At least one of the gray code, the clock mark and the fine pattern is formed along the rotation trajectory of the magnetic head, and reproduces the gray code, the clock mark and the fine pattern. The operation of reproducing data and the like by the magnetic head is controlled in accordance with the signal obtained by the above operation. Further, the magnetic head measures a change amount corresponding to the eccentricity of the magnetic disk from a signal obtained by reproducing a gray code, a clock mark or a fine pattern. Is controlled.

[0005] According to the hard disk drive having the magnetic disk having such a configuration, since the guard band is formed as a physical concave portion with respect to the data track, there is little possibility that data or the like is reproduced from the guard band. Become. Therefore, it is not necessary to increase the width of the guard band in order to reduce the crosstalk, so that it is possible to narrow the track pitch and increase the recording capacity.

Further, since the gray code, clock mark or fine pattern is formed by a convex portion or a concave portion along the rotation trajectory of the magnetic head, it is extremely accurate by using, for example, optical technology. These codes and the like can be arranged at appropriate positions, and data and the like can be accurately reproduced even if the track pitch is narrowed. In addition, since the eccentricity of the magnetic disk is measured and the operation of reproducing data and the like is controlled correspondingly, even if the eccentricity due to the mounting error occurs when the magnetic disk is installed in the housing, It is possible to make the magnetic head accurately access the data track.

[0007]

However, the ratio of the convex portions to the concave portions in the data zone of the read-only magnetic disk is different from the ratio of the convex portions to the concave portions in the data zone of the rewritable magnetic disk. ,
The flying height of the head slider differs between a read-only magnetic disk and a rewritable magnetic disk.
Therefore, if the read-only magnetic disk and the rewritable magnetic disk are incorporated in the same hard disk drive, the flying height of the head slider fluctuates, and the magnetic head can stably reproduce data and the like. There was a problem that it disappeared.

In view of the above, the present invention provides a magnetic disk capable of maintaining a constant flying height of a head slider without distinction between a read-only magnetic disk and a rewritable magnetic disk, and a magnetic disk provided with the magnetic disk. It is intended to provide a disk device.

[0009]

According to the present invention, there is provided a read-only magnetic disk in which data and the like are reproduced by a magnetic head mounted on a flying type head slider, the magnetic disk being formed on a surface thereof. In a magnetic disk radially divided into a data recording area and a control signal recording area by the formed uneven portion, the load capacity of the head slider is changed to the load capacity of the head slider in a rewritable magnetic disk on which data and the like are recorded and reproduced. Is achieved by making

[0010] According to the above configuration, paying attention to the fact that the flying height of the head slider depends on the ratio of the concave and convex portions and the step of the concave and convex portions, the rewritable capacity of the head slider and the load capacity of the read only magnetic disk. Since the load capacity of the head slider on the magnetic disk is the same, the flying height of the head slider can be kept constant in any case.

[0011]

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 configuration example of a hard disk drive which is an embodiment of the magnetic disk drive of the present invention. The hard disk drive 1 is provided with a spindle motor 9 disposed behind a plane portion of a housing 2 formed of an aluminum alloy or the like, and a magnetic disk 3 driven to rotate at a constant angular velocity by the spindle motor 9. Have been.

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. Magnets 7a and 7b are mounted on the housing 2 so as to sandwich the voice coil 5. With the voice coil 5 and the magnets 7a and 7b,
A voice coil motor 7 is formed.

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 as shown by an arrow X in FIG.
The magnetic disk 3 moves substantially in the radial direction. Therefore, the magnetic head 8 mounted on the head slider 6
(See FIG. 3) performs a seek operation on the magnetic disk 3 and reproduces data or the like on a predetermined data track or the like of the magnetic disk 3.

As shown in FIG. 3, the head slider 6 has rails 6a and 6b acting as air bearing surfaces on both sides of the lower surface thereof, and the air inflow ends of the rails 6a and 6b. Are formed with tapered portions 6c and 6d. Thus, when the head slider 6 approaches the surface of the rotating magnetic disk 3, the levitation force is increased by the airflow flowing between the rails 6 a and 6 b and the surface of the magnetic disk 3 with the rotation of the magnetic disk 3. receive. The head slider 6
In addition, the magnetic head 8 flies and travels from the surface of the magnetic disk 3 at a small interval (floating amount).

FIG. 4 is a plan view showing an embodiment of a magnetic disk according to the present invention, FIG.
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) each having an uneven portion are formed radially on a substrate 31 of the magnetic disk 3 made of synthetic resin, glass, aluminum, or the like. A magnetic film 32 is formed.

That is, in the data zone, a concentric data track DTR for recording data and the like is formed so as to form an uneven portion, and a guard band GBR for separating adjacent data tracks DTR is provided. It is formed so as to be a concave portion. In the servo zone, a gray code for specifying the data track DTR, a clock mark serving as a reference when generating a servo clock, and a servo pattern SPR such as a fine pattern for controlling the tracking of the magnetic head 8 are formed on the convex portion. Alternatively, it is formed so as to be a concave portion.

The above-described magnetic disk 3 can be manufactured by using optical technology.
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 magnetized by the following method.
The magnetic disk 3 is set on the magnetizing device 47 and is rotated and driven in the direction indicated by the arrow a in FIG. Then, as shown in FIG. 8 (A), while applying the first DC current to the magnetizing magnetic head 48, the magnetizing magnetic head 48 is
The magnetic film 32 is moved in the upper radial direction at a track pitch, and the magnetic film 32 of the convex portion and the concave portion of the magnetic disk 3 is once magnetized in the same direction. Thereafter, as shown in FIG. 4B, a second DC current having a polarity opposite to that of the first DC current and having a smaller current value than the first DC current is applied to the magnetizing magnetic head 48. Then, the magnetizing magnetic head 48 is moved at a track pitch in the radial direction on the magnetic disk 3 to magnetize only the magnetic film 32 on the convex portion of the magnetic disk 3 in the opposite direction, and the data and the like and the positioning signal (fine pattern, clock) Mark etc.).

As a parameter for evaluating the variation of the flying height of the head slider 6, a load capacity obtained by calculating the pressure applied to the head slider 6 at that time with the head slider 6 fixed at an arbitrary flying height and an arbitrary posture. Can be used. The calculation of the load capacity of the head slider 6 uses the average gap theory. That is, the ratio of the convex portion and the concave portion parallel to the traveling direction of the head slider 6 and the step of the concave and convex portion are equal to the ratio of the convex portion and the concave portion and the step of the concave and convex portion perpendicular to the traveling direction of the head slider 6. If
The flying height of the head slider 6 on the surface provided with the parallel uneven portions is determined by the head slider 6 on the surface provided with the vertical uneven portions.
Is larger than the flying height of

Further, the flying height of the head slider 6 on the surface provided with a mixture of the uneven portion parallel to the traveling direction of the head slider 6 and the uneven portion perpendicular to the traveling direction of the head slider 6 is determined on the surface provided with the parallel uneven portion. Is a value between the flying height of the head slider 6 at the time and the flying height of the head slider 6 on the surface provided with the vertical uneven portion. The flying height of the head slider 6 decreases as the level difference between the parallel uneven portions and the vertical uneven portions increases. ("Averaged Reynolde Eq
nation Extended to Gas Lu
bridging Posting Surf
ace Roughness in the Slip
Flow Regime: Approximate
Method and Confirmation E
xperiments "ASME Journal o
f Tribology, vol. 111, 1989,
pp. 495-503, Mitsuya etc. reference).

The data tracks and guard bands in the data zone of the rewritable magnetic disk are similar to the uneven portions parallel to the traveling direction of the head slider 6. The data track DT and the guard band GB of the zone are formed by mixing uneven portions parallel to and perpendicular to the traveling direction of the head slider 6. Therefore, the load capacity of the head slider 6 in the data zone of the rewritable magnetic disk is made equal to the load capacity of the head slider 6 in the data zone of the read-only magnetic disk 3, that is, the ratio of the uneven portions and the step of the uneven portions. In any case, the flying height of the head slider can be kept constant by adjusting.

Therefore, the flying height of the head slider 6 in the read-only data zone and the change in the flying height of the head slider 6 in the rewritable data zone were examined. Here, the measurement disk is made of glass, and a data track DTR composed of read-only uneven portions (black portions are convex portions and white portions are concave portions) as shown in FIG. The data LGR shown in the drawing is formed in areas allocated in four kinds of angular directions with a radius of 15.5 mm to 35.0 mm so that track width (convex portion) / track pitch-track width (concave portion). In addition, a data track DTW including only rewritable protrusions as shown in FIG. 3B is formed between the regions so that the data LGR becomes 2.0.

And, these data tracks DTR,
The DTW is formed in the same manner as the actual magnetic disk 3. That is, a resist is applied to the surface of the glass disk, and the pattern of the data tracks DTR and DTW is exposed on the resist based on the cutting data. After the exposure, development is performed to complete a resist image, and the glass disk is etched by, for example, RIE (Reactive Ion Etching) according to the resist image to form data tracks DTR and DTW.

Region No. Data LGR 1 Flat 2 1.0 3 2.0 4 3.0

Three types of such glass disks were prepared, with the steps of the irregularities being 100 nm, 150 nm and 200 nm. Since the glass disk is used for measuring the flying height of the head slider 6, it is not provided with a magnetic layer, and the data track DTR composed of the concave and convex portions is not an actual data pattern but a data track shown in FIG. A) is composed of a repeating pattern of duty (a / b = 1) as shown in A). Although the actual data pattern is complicated, the DC component is prevented from remaining by signal processing. Therefore, when considering a sufficiently long range like the head slider 6, it is the same as the repetition of the duty 1.

The head slider 6 is a general two-rail taper flat 50% nano-slider having a slider length of 2.0 mm, a slider width of 1.6 mm, a rail width of 200 μm, and a load of 3.5 gf. It is. Such a head slider 6 has a radius of 30.2 m of the glass disk.
m, the relative speed between the head slider and the glass disk when the glass disk is rotated at 4000 rpm is 7.0 m / s, and the flying height of the head slider is about 50 nm.

FIG. 10 is a diagram showing the relationship between the difference between the flying height of the head slider 6 in the data track DTR and the flying height of the head slider 6 in the data track DTW, and the data LGR of the data track DTR. FIG. 11 shows the difference between the flying height of the head slider 6 in the data track DTR and the flying height of the head slider 6 in the data track DTW when the data LGR in FIG. FIG. 6 is a diagram showing a relationship between the data and the groove depth standardized by the step of the data track DTW.

As is apparent from FIG. 10, by adjusting the data LGR of the data track DTR, the flying height of the head slider 6 in the data track DTR can be made closer to the flying height of the head slider 6 in the data track DTW. It becomes possible. Further, the allowable value of the flying fluctuation amount of the head slider 6 is generally defined as ± 20%, preferably ± 10%. Therefore, when the flying height of the head slider 6 is 50 nm, the flying fluctuation amount of the head slider 6 is 20 nm pp, preferably 1 nm.
It suffices to set it to 0 nm pp. Therefore, FIG.
As is clear from FIG. 1, the level difference of the data track DTR is 0.65 or more and 1.0 or less of the level difference of the data track DTW, preferably 0.85 or more.
It may be set to 0 or less. In the above experiment, the ratio of the convex portion to the concave portion of the data zone was changed, but the same result was obtained without being affected by the type of zone such as the data zone and the servo zone.

From the above results, it is possible to make one surface of a single magnetic disk read-only as shown in FIG. 4 and make the other surface rewritable as shown in FIG. . That is, the load capacity of the head slider 6 in the data zone of the read-only surface and the load capacity of the head slider 6 in the data zone of the rewritable surface are made the same. By adjusting, the flying height of the head slider 6 can always be kept constant, so that the same head slider 6 can be used. Although the manufacturing process is complicated, a magnetic disk having a read-only area and a rewritable area on one side can be used.

In the case of a magnetic disk in which one surface is read-only and the other surface is rewritable,
The head sliders may be changed to the same flying height on each surface with the same level difference between the concave and convex portions on both surfaces. That is, when the steps of the concave and convex portions on both surfaces are the same, the flying height of the head slider 6 in the read-only data zone is higher than the flying height of the head slider 6 in the rewritable data zone. The head slider used in (1) is made to fly higher than the head slider used on the read-only surface by, for example, increasing the area of the air bearing surface so that the flying height is the same on each surface. To At this time, in order to prevent the magnetic disk from being inserted into the head slider side that does not correspond to each surface, for example, a guide groove or the like capable of determining the surface of the magnetic disk is provided.

One side as described above is read-only,
When a rewritable magnetic disk is used on the other side, for example, in the case of a computer without a hard disk device, conventionally, first, a magnetic disk storing a program operating on the computer is inserted, Next, the need to insert another magnetic disk for storing a file created using the program is eliminated. Therefore, handling and management of the magnetic disk become easy.

[0033]

As described above, according to the present invention,
Since the flying height of the head slider can be kept constant without distinction between a read-only magnetic disk and a rewritable magnetic disk, the same magnetic disk device can be used.

[Brief description of the 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 an exemplary perspective view showing an operation example of a head slider of the hard disk device shown in FIG. 1;

FIG. 3 is an exemplary perspective view showing a detailed example of a head slider of the hard disk device shown in FIG. 1;

FIG. 4 is a plan view showing an embodiment of the magnetic disk of the present invention.

5A and 5B are a sectional view in a radial direction and a sectional view in a circumferential direction of the magnetic disk shown in FIG. 4;

FIG. 6 is a first view for explaining a method of manufacturing the magnetic disk shown in FIG. 4;

FIG. 7 is a second diagram illustrating the method for manufacturing the magnetic disk shown in FIG. 4;

FIG. 8 is a third diagram illustrating the method for manufacturing the magnetic disk shown in FIG.

FIG. 9 is a plan view showing an example of a data track used in the experiment.

FIG. 10 is a diagram illustrating a relationship between a difference in flying height of a head slider in a data track and data LGR.

FIG. 11 is a diagram showing a relationship between a difference in flying height of a head slider in a data track and a groove depth obtained by standardizing a step of the data track when data LGR in FIG. 10 is 2.0.

FIG. 12 is a plan view showing another embodiment of the magnetic disk of the present invention.

[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, 31 ... substrate, 32 ...
..Magnetic film, 41 ... glass master, 42 ... photoresist, 43 ... turntable, 44 ... laser light, 45 ... nickel, 46 ... stamper, 47
... Magnetizing device, 48 ... Magnetic head for magnetizing

Claims (13)

[Claims] 1. A read-only magnetic disk in which data and the like are reproduced by a magnetic head mounted on a flying type head slider, wherein a data recording area and a control signal recording area are formed by irregularities formed on the surface. A magnetic disk which is radially divided, wherein a load capacity of the head slider is the same as a load capacity of a head slider of a rewritable magnetic disk on which data and the like are recorded and reproduced. 2. The load capacity of the head slider is made equal to the load capacity of the head slider in a rewritable magnetic disk on which data and the like are recorded and reproduced by adjusting the ratio of the concave and convex portions. A magnetic disk according to claim 1. 3. The load capacity of the head slider and the data and the like are recorded and reproduced by making the step of the concave and convex portions smaller than the step of the concave and convex portions on a rewritable magnetic disk on which data and the like are recorded and reproduced. 2. The magnetic disk according to claim 1, wherein the load capacity of the head slider in the rewritable magnetic disk is the same. 4. A read-only magnetic disk in which data and the like are reproduced by a magnetic head mounted on a flying type head slider, and a data recording area and a control signal recording area are formed by uneven portions formed on the surface. In a magnetic disk that is radially divided, the ratio of the step of the uneven portion to the step of the uneven portion of a rewritable magnetic disk on which data and the like are recorded and reproduced is:
A magnetic disk having a diameter of 0.65 or more and 1.0 or less. 5. A read-only magnetic disk in which data and the like are reproduced by a magnetic head mounted on a flying type head slider, wherein a data recording area and a control signal recording area are formed by irregularities formed on the surface. In a magnetic disk that is radially divided, the ratio of the step of the uneven portion to the step of the uneven portion of a rewritable magnetic disk on which data and the like are recorded and reproduced is:
A magnetic disk characterized by being 0.85 or more and 1.0 or less. 6. A magnetic disk radially divided into a data recording area and a control signal recording area by an uneven portion formed on the surface, and floats on the surface of the magnetic disk and moves in a radial direction of the magnetic disk. And a magnetic head mounted on the head slider and reproducing data and the like on the magnetic disk. A magnetic disk drive characterized by having the same load capacity as a head slider in a possible magnetic disk. 7. A magnetic head mounted on a flying type head slider forms an uneven portion for reproducing data and the like on one surface and an uneven portion for recording and reproducing data and the like on the other surface. A magnetic disk characterized by being made. 8. The magnetic disk according to claim 7, wherein the load capacity of the head slider is the same on each surface. 9. The magnetic disk according to claim 8, wherein a load capacity of the head slider is made the same on each surface by adjusting a ratio of an uneven portion from which the data and the like are reproduced. 10. The load capacity of the head slider is made equal on each surface by making the step of the uneven portion from which the data and the like are reproduced smaller than the step of the uneven portion from which the data and the like are recorded and reproduced. A magnetic disk according to claim 8. 11. The method according to claim 7, wherein a ratio of a step of the concave / convex portion where the data or the like is reproduced to a step of the concave / convex portion where the data or the like is recorded / reproduced is 0.65 or more and 1.0 or less. Magnetic disk. 12. The method according to claim 7, wherein a ratio of a step of the concave / convex portion where the data or the like is reproduced to a step of the concave / convex portion where the data or the like is recorded / reproduced is 0.85 or more and 1.0 or less. Magnetic disk. 13. A magnetic disk in which an uneven portion for reproducing data and the like is formed on one surface and an uneven portion for recording and reproducing data and the like is formed on the other surface. A head slider that floats and moves in the radial direction of the magnetic disk; mounted on the head slider, reproduces data and the like on one surface of the magnetic disk, and records and reproduces data and the like on the other surface A magnetic disk drive comprising: a magnetic head;