JPH10255257A - Magnetic recording medium and magnetic recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium capable of suppressing deviation in an amount of floating when a floating slider travels over a servo zone while increasing a recording capacity without extending servo zone nor rendering the formation of the servo zones difficult. SOLUTION: A magnetic recording medium includes a plurality of servo zones 2 where a servo signal to be used for positioning a magnetic head, which performs recording and reproduction of signals, is pre-formed in the form of the concave and convex configuration. Circumferential interval between the adjacent servo zones 2, i.e., a width of a data zone 3, is set at a constant value over the whole surface of the magnetic recording medium, wherein the above- mentioned constant value is set to be equal to or less than a half of a length of a floating slider which floats and moves with the magnetic head mounted thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium and a magnetic recording apparatus using the magnetic recording medium, and more particularly to a magnetic recording medium in which data and programs are reproduced by a magnetic head mounted on a flying type slider. The present invention relates to a magnetic recording device using the magnetic recording medium.

[0002]

2. Description of the Related Art In computer systems and the like,
Hard disk devices are used as large-capacity storage devices. In order to realize a large storage capacity of the hard disk drive, a control signal storage area (hereinafter referred to as a servo zone) in which servo signals are preformed in an uneven shape on both sides of a magnetic disk and a data storage area in which data is stored. (Hereinafter referred to as a data zone), a so-called embossed magnetic disk has been proposed.

In such an embossed magnetic disk, the pattern shape of the servo zone is different from the pattern shape of the data zone. The reproduction of data from such a magnetic disk is performed by a magnetic head mounted on a flying slider that searches the magnetic disk while flying. When a flying slider passes over each magnetic reversal signal (hereinafter referred to as a servo pit) of a servo signal on a preformed magnetic disk, a flying height fluctuates at a boundary between a servo zone and a data zone. This is because the irregularities recorded in the servo zone and the data zone are different.

[0004] Such fluctuation of the flying height causes unstable recording and reproduction of data and the like by the magnetic head. In order to reduce the floating fluctuation amount, the inventor disclosed in Japanese Patent Laid-Open No.
In 9851, a certain condition is given to the depth of the concave portion and the ratio of the concave and convex portion, and the load capacity (Load Carring Capacit
y) and the load capacity of the data zone. Here, the load capacity means a mechanical levitation force received from the disk side when the floating head takes a certain floating amount.

In order to make the load capacities coincide, one of the servo zone pattern shape and the data zone pattern shape, or both, must be changed. However, originally, the pattern shape of the servo zone and the pattern shape of the data zone cannot be designed for the purpose of matching the additional capacity, but should be designed with the aim of improving the recording density and the head positioning accuracy. Of nature. Changing this pattern shape to match the load capacity would have to be repaired and compromised in terms of improving the recording density and improving the head positioning accuracy. .

In view of the above, instead of matching the load capacities largely depending on the shapes of the servo zone and the data zone, there may be conceived a method of reducing the flying fluctuation amount by other methods. For example, by designing the intervals of the servo zones so that the servo zones pass under the flying slider at intervals of 1/2 or less of the length of the long side of the flying slider on which the magnetic head is mounted, the servo zone and the data zone are designed. Without changing the shape of the magnetic head, it is possible to reduce the amount of flying fluctuation of the flying slider on which the magnetic head is mounted when passing through the servo zone. However, such a method also has problems.

In general, the servo zones are arranged at equal angular intervals on the magnetic disk because the magnetic disk moves at a constant rotation speed and the servo signals are managed by time. In recent years, a flying slider on which a magnetic head is mounted is becoming smaller in size in order to make the flying height follow fine waviness of a disk substrate. The most commonly used pico-slider has a long side of 1.4 mm and a short side of 1.1 mm.

When reading data on a 3.5 inch diameter magnetic disk using this pico slider, assuming that the servo zones are arranged at equal angular intervals, the servo zone interval at the outermost periphery is equal to or less than の of the slider long side length. If this is achieved, about 430 servo zones must be arranged in one round of the disk. In this case, not only does the ratio of the servo zone to the disk area increase, but also the pits have to be small on the innermost circumference, making it difficult to create a concavo-convex shape.

If the servo zones are arranged at equal angular intervals, the servo zone intervals, that is, the data zone lengths, differ greatly between the inner circumference and the outer circumference. Recording and playback of data in the data zone is generally performed by time management,
The amount of data recorded in one inner data zone is the same as the amount of data recorded in one outer data zone. Therefore, the recording density of the inner data zone is higher than that of the outer data zone. From an opposite viewpoint, it can be said that the recording capacity is not sufficiently exerted in the outer data zone, although there is still enough room to record data. If the servo zones are arranged at equal angular intervals in this manner, there is a problem that the number of servo zones increases unnecessarily, and such secondary adverse effects also occur.

[0010]

As described above, the conventional magnetic recording medium employs a method of matching the load capacities of the servo zone and the data zone in order to reduce the flying fluctuation. This method is not preferable from the viewpoint of improving the recording density and the head positioning accuracy. In the method of arranging the servo zones so that the servo zones pass below the flying slider, arranging the servo zones at equal angular intervals not only increases the number of servo zones unnecessarily, but also records the data in the data zone. There is a problem that the zone has too much margin on the outer periphery and becomes cramped on the inner periphery according to the amount of data to be transmitted.

The present invention solves these problems and records and reproduces information while increasing the recording capacity without increasing the number of servo zones unnecessarily, and without making it more difficult to create irregularities. It is an object of the present invention to realize a magnetic recording medium capable of suppressing a flying fluctuation amount when a flying slider having a magnetic head mounted thereon passes a servo zone, and a magnetic recording apparatus using the magnetic recording medium.

[0012]

In order to achieve the above object, the present invention is directed to a plurality of control signals in which control signals used for positioning a magnetic head for recording / reproducing a signal are recorded in an uneven shape in advance. In a magnetic recording medium having a recording area, the circumferential distance between the control signal recording areas is constant over the entire surface of the magnetic recording medium, and the flying slider moves with the magnetic head mounted and moving. It is characterized in that the length is not more than 1/2 of the length.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the servo zone intervals are not equal to the conventional equiangular intervals but are equal intervals equal to or less than half the length of a flying slider on which a magnetic head is mounted. This makes it possible to reduce the amount of flying fluctuation when the flying slider on which the magnetic head is mounted passes through the servo zone. Further, by making the intervals of the servo zones equal, that is, constant, the length of the data zone is also determined, and a constant recording density can be achieved at any place on the disk. As a result, recording can be performed at a higher density than the conventional servo zone interval having the same angular interval.

Consider a specific example. In the data zone, concentric data tracks for recording data or the like are formed so as to have convex portions, and guard bands for separating adjacent data tracks are formed so as to have concave portions. With such a configuration, since the guard band is formed as a physical concave portion with respect to the data track, the risk of data or the like being reproduced from the guard band is reduced, and the guard band is formed in order to reduce crosstalk. There is no need to increase the width, and the recording capacity can be increased by narrowing the track pitch.

In the servo zone, there are provided a gray code for specifying a data track, a clock mark for dividing a circumference at equal intervals, a wobbled mark for tracking control of a magnetic head (hereinafter referred to as a servo track), and the like. It is formed so that it may become a convex part, and the space separating these codes may be formed as a concave part.

As described above, by forming the servo tracks so as to be convex, it is possible to arrange these codes at extremely accurate positions using, for example, optical technology or the like, and to reduce the track pitch. Can accurately record and reproduce data.

In the servo zone, the above-mentioned pico-slider is used as the floating slider, and the servo zone interval is set to 0.6 mm, which is less than half the length of the long side of the pico-slider. Then, at the innermost circumference of the 18 mm radius of the magnetic disk, 1
88 / rev. Thereafter, assuming that the servo zone is increased by one each time the circumference increases by 0.6 mm as compared with the case where the radius is 18 mm, the number of servo zones becomes 0.0
It will increase with each increase of 96 mm. Since the width of the slider rail is about 200 μm, there are two or more regions having different numbers of servo zones below the slider rail, and four or more regions when the left and right rails are taken into consideration.

In a region where the number of servo zones is different, the timing at which the servo zones appear naturally differs, so that the servo zones pass through the servo zones as compared with the case where the servo zones appear together in the rail of the flying slider. In this case, the flying fluctuation amount of the flying slider equipped with the magnetic head is reduced. This does not apply only to the case where the data zone is preformed with concavities and convexities in a concentric or spiral shape, but a so-called ROM in which the reproduction signal is preformed by the concavo-convex pits in the data zone. This is true even in the form of a disc.

The reason is that the preform is formed with ordinary concentric or spiral concavities and convexities.
From the standpoint of the flying slider, the difference is that the load capacity is simply different from the case of the M disk form. Originally, the present invention considers that the load capacity of the servo zone and the load capacity of the data zone are different. The reason for this is that the difference between the case where the preform is formed with concentric or spiral irregularities and the case where the ROM disk is formed falls within the range of the premise.

As described above, according to the present invention, the floating fluctuation amount can be reduced as compared with the conventional case where the servo zones are arranged at equal angles. However, unlike conventional systems in which servo zones are arranged at equal angles, if servo zones are arranged at equal intervals, the servo zone cycle differs between the inner and outer circumferences of the disk, and the conventional servo system It can no longer be used.

However, assuming a 3.5 inch diameter disk, if the servo zone length is 0.6 mm, the servo zone period is 188 / rev. At the innermost circumference and 472 / rev. At the outermost circumference.
rev. Comparing this value, it can be seen that there is only a little less than three times the opening between the innermost circumference and the outermost circumference. By the way, P which generates a synchronization signal for reading a servo signal
An LL (Phase Locked Loop) device can generate a synchronizing signal corresponding to such a frequency change without any problem depending on the adjustment if the period is about three times different. Therefore, it can be seen that it is not impossible to arrange the servo zone intervals at regular intervals instead of the conventional equal angular intervals.

Further, if a magnetic disk having servo zones arranged at equal intervals on the disk is used, not only the amount of floating fluctuation of the flying slider on which the magnetic head is mounted when passing through the servo zone is reduced, but as a result, Increase the storage capacity of the magnetic disk.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the magnetic recording medium according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, a pattern in which servo zone intervals are actually formed at equal intervals is represented on a disk in an uneven shape, and a flying slider is floated on the created pattern, and a servo of the flying amount is formed. Observe the floating fluctuation when passing through the zone.

The concave / convex pattern of the magnetic disk employs an etching method for a glass disk in consideration of productivity this time. In actual use, a magnetic film is formed on the surface of the manufactured glass disk, but in this experiment, measurement was performed without forming the magnetic film for the purpose of observing the amount of floating fluctuation. The other injection molding method using resin, which is a method of manufacturing a disk, is excellent in mass productivity, but requires more production steps than a glass etching method when used for an experiment using only one disc. The glass embossing method is also located between the resin injection molding method and the glass etching method in terms of mass productivity, and is almost the same as the resin injection molding method in terms of the number of manufacturing steps per sheet. .

FIG. 1 is a plan view of a magnetic recording medium to which the present invention is applied, and FIG. 2 is an enlarged view of a portion A in FIG. 1 showing an uneven pattern of an embodiment of the magnetic recording medium of the present invention. 1 and 2, 1 is a magnetic recording medium, 2 is a servo zone, 3 is a data zone, and 2-1 is a reference servo zone.

In this embodiment, a 3.5 inch diameter glass disk was used. The innermost circumference had a radius of 18 mm and the number of servo zones was 180 / rev. The servo zone interval at this time is 0.62832 mm. The length of the servo zone itself was 0.06 mm. The data zone is formed concentrically with a track pitch of 3.2 μm and a guard band of 1.0 μm.

The data tracks are not only concentric, but also
Even if it is formed in a spiral shape, it does not substantially affect the increase / decrease of the flying fluctuation amount when the flying slider passes through the servo zone and the data recording capacity. Therefore, the magnetic disk is generally formed in a concentric shape, although a concentric shape or a spiral shape may be used. In the present embodiment, the concentric shape is adopted.

In order to keep the servo zone interval constant, the format is such that the number of servo zones is increased by 1 / rev. Every time the radius increases by 0.1 mm. Radius is 0.1
As the mm increases, the circumference increases by 0.62832 mm.
This value is equal to the servo zone interval.

Further, in order to synchronize the servo signals, only one position where the position of the servo zone coincides from the inner circumference to the outer circumference in the radial direction of the disk is provided. Here, unlike the usual other servo zone, which is constituted by the track address signal and the fine tracking signal, only at this point, the servo synchronization signal is preformed by unevenness instead of the track address signal.

Also, the radius of the disk is 20 mm, 25 m
A flat area with a width of 0.4 mm where no pattern was cut was provided at m, 30 mm, 35 mm, and 40 mm to provide a reference for the amount of variation in flying height.

The flying slider used is a general 25%
This is a pico slider. The slider length is 1.4 mm and the slider width is 1.2 mm. The shape is a so-called TPC type with two rails. The rail width is 150 μm. Weight is 2.5gf, relative speed of disk and slider is 7m
/ S, the flying height is about 50 nm. The rotation speed of the disk was 4000 rpm in this experiment.

The experiments were performed at a radius of 20 mm, 25 mm, and 30 m.
m, 35 mm, and 40 mm. The angle was set to 0 ° using a servo zone including a synchronization signal as a reference point on the substrate. In this way, the angle dependence of the flying height variation at each radius was measured. FIG. 3 shows a configuration diagram of the measurement system at this time.

In FIG. 3, 4 is a glass disk, 5 is a slider, 6 is a load beam, 7 is a flat area for measurement, 8 is LDV measurement light, and 9 is LDV reference light.

To measure the angle dependence of the flying height variation, the glass disk 4, the pico slider as the slider 5, and a differential LDV (Laser Doppler Vibrometer) were used.
An LDV reference beam 9 serving as a reference is applied to a flat area having a width of 0.4 mm, and an LDV measurement beam 8 is applied to the rear end of the flying slider 5. By subtracting the operation state of the disk 4 measured by the reference light 9 from the operation state of the slider rear end measured by the measurement light 8, the flying fluctuation amount of the slider rear end can be measured.

FIG. 4 shows the result of the measurement of the amount of flying fluctuation measured in this way. In FIG. 4, the vertical axis represents the amplitude value of the floating fluctuation amount, the horizontal axis represents the angle value indicating the position on the disk, and the parameter represents the measurement radius position.

As can be seen from the results shown in FIG. 4, under the conditions of this embodiment, the value of the floating fluctuation amount of the flying slider is 5n at maximum.
mp-p, and is suppressed within ± 5% of the flying height of 50 nm. If the amount of floating fluctuation is within ± 5% of the flying height, it is considered that there is almost no problem in practical use.

As can be seen from FIG. 4, the amount of floating fluctuation near the position 0 ° is the largest, and the amount of floating fluctuation decreases as the angle increases, and goes to a minimum around 180 °. When the angle increases beyond 180 °, the amount of floating fluctuation starts to increase again, and approaches the value of the amount of floating fluctuation near 0 ° as the angle approaches 360 °.

As shown in FIG. 2, near 0 °, the position of the servo zone (reference servo zone) 2-1 coincides in the radial direction, and the entire width of the slider is equal to that of the data zone 3 and the servo zone 2. It is considered that the load capacity difference is easily felt. However, as the position approaches 180 °, the position of the servo zone 2 gradually shifts in the radial direction.
It is considered that the difference in load capacity is hardly felt. 180 ° angle
In the position (3), the position of the servo zone 2 is the most displaced, so that the value of the floating fluctuation amount is about 1/3 around 0 °.

Further, the floating fluctuation amount is larger on the outer circumference of the disk radius. This may be because the position of the servo zone 2 is shifted toward the inner circumference of the disk. Therefore, since the servo zone position is shifted most on the inner peripheral side located at 180 ° from the reference servo zone 2-1, the floating amount is the smallest at this position. This is the case in the embodiment.

According to the results of the above-described experiments, in a magnetic disk in which servo signals and the like are preformed with concave and convex pits, by keeping the servo zone interval constant from the inner circumference to the outer circumference of the disk, a very short servo zone on the inner circumference is It was found that a data zone could be provided without forming a data zone, which was easy to create, and in which the amount of floating fluctuation was suppressed to ± 5% of the absolute value of the floating amount. At the same time, since the servo zone intervals are not equal angular intervals but equal intervals, the data recording area is from the inner radius 18 mm to the outer radius 46 mm, and the track pitch is 3.2 μm and the servo zone interval is 0.2 mm. 62832 mm, and assuming that recording with the same capacity is possible in one data zone,
This leads to an increase in recording capacity of about 68% as compared with the conventional magnetic disk.

It is needless to say that the present invention is not limited to the above embodiment. In particular, the method of producing a magnetic disk has been described in the above-described embodiment as an example using an etching method using a glass disk. However, a method capable of forming concave and convex pits on the disk, such as resin injection molding or glass embossing. Any method is acceptable. Further, in the present embodiment, the shape of the data zone on the disk is a concentric track shape, but any other shape such as a spiral shape may be used as long as it does not affect the stable floating of the slider. No problem.

[0042]

As described above, according to the first aspect of the present invention, a plurality of servo zones in which servo signals used for positioning a magnetic head for recording / reproducing a signal are recorded in an uneven shape in advance. In the magnetic recording medium having the servo zone, the circumferential distance between the servo zones is constant over the entire surface of the magnetic recording medium, and is 1/1/1 of the length of the flying slider on which the magnetic head is mounted and flies and moves. 2 or less. As described above, the flying height of the flying slider when passing through the servo zone is maintained by keeping the distance between the servo zones constant at any position on the disk and equal to or less than half the length of the flying slider. Can be suppressed to ± 5% of the flying height. As a result, stable recording and reproduction of information can be performed, and the data capacity that can be recorded on the disc can be significantly increased.

According to a second aspect of the present invention, the magnetic recording medium includes a data zone for recording and reproducing data in a portion other than the servo zone, and a data track for recording and reproducing data in the data zone; It has a guard band for preventing data signal interference between tracks, and the data track and the guard band are formed in an uneven shape.

According to the invention of claim 3 of the present invention, the data track is formed on a concave-convex convex portion, and the guard band is formed on a concave-convex concave portion, and data is recorded on the data track which is the concave-convex convex portion. To do it. In this manner, by forming the guard band as a physical recess with respect to the data track, the risk of data or the like being reproduced from the guard band is reduced, and the width of the guard band is reduced in order to reduce crosstalk. There is no need to increase the width, and the track pitch can be narrowed to increase the recording capacity.

The invention according to claim 4 of the present invention is characterized in that data tracks and guard bands are formed concentrically or spirally in a data recording area.
This makes it possible to easily and quickly read and write data by the flying slider.

The invention according to claim 5 of the present invention is characterized in that data to be recorded on a data track in a data recording area is created in advance in an uneven shape. By doing so, data can be recorded at an extremely accurate position, the recording capacity can be increased, and a large amount of magnetic recording media having the same data can be produced.

According to a sixth aspect of the present invention, there is provided a magnetic recording medium having a plurality of control signal recording areas in which control signals are recorded in advance in an uneven shape and rotating during recording / reproducing, and a magnetic recording medium on a surface of the magnetic recording medium. A magnetic recording apparatus comprising: a flying slider that floats and moves in a radial direction of a magnetic recording medium and a magnetic head mounted on the flying slider and recording and reproducing signals on the magnetic recording medium; The distance between the control signal recording areas of the medium in the circumferential direction is constant over the entire surface of the magnetic recording medium, and is not more than half the length of the flying slider. By using the above-mentioned magnetic recording medium, it is possible to realize a magnetic recording apparatus capable of stably recording and reproducing data on the magnetic recording medium recorded at high density by the magnetic head.

[Brief description of the drawings]

FIG. 1 is a plan view of a magnetic recording medium to which the present invention is applied.

FIG. 2 is an explanatory view showing a concavo-convex pattern of one embodiment of the magnetic recording medium of the present invention.

FIG. 3 is a configuration diagram of a measurement system of a floating fluctuation amount.

FIG. 4 is a view showing a measurement result of an angle dependency of a floating fluctuation amount.

[Explanation of symbols]

1 ... magnetic recording medium, 2 ... servo zone, 2-1 ...
Reference servo zone, 3 ... Data zone, 4 ... Glass disk, 5 ... Slider, 6 ... Load beam, 7 ...
... Flat area for measurement, 8 ... LDV measurement light, 9 ...
LDV reference light.

Claims (6)

[Claims] 1. A magnetic recording medium having a plurality of control signal recording areas in which control signals used for positioning a magnetic head for recording / reproducing signals are recorded in an uneven shape in advance. The magnetic recording medium is characterized in that a circumferential interval between the flying sliders is constant over the entire surface of the magnetic recording medium, and is not more than の of a length of a flying slider on which the magnetic head is mounted and floats. recoding media. 2. A magnetic recording medium comprising a data recording area for recording and reproducing data in a portion other than the control signal recording area, wherein the data recording area is provided between a data track for recording and reproducing data and a data track between the data track. 2. The magnetic recording medium according to claim 1, further comprising a guard band for preventing data signal interference, wherein the data track and the guard band are formed in an uneven shape. 3. The data track is formed on a concave-convex convex portion, and the guard band is formed on a concave-convex concave portion, and data is recorded on the data track, which is a concave-convex convex portion. Item 3. The magnetic recording medium according to Item 2. 4. The magnetic recording medium according to claim 2, wherein the data track and the guard band are formed concentrically or spirally in the data recording area. 5. The magnetic recording medium according to claim 2, wherein data to be recorded on the data track in the data recording area is created in advance in an uneven shape. 6. A magnetic recording medium having a plurality of control signal recording areas in which control signals are recorded in advance in an uneven shape and rotating during recording / reproducing, and floating on the surface of the magnetic recording medium, A magnetic recording apparatus comprising: a flying slider that floats and moves in a radial direction of a magnetic recording medium; and a magnetic head that is mounted on the flying slider and records and reproduces signals on and from the magnetic recording medium. The circumferential distance between the control signal recording areas is constant over the entire surface of the magnetic recording medium,
A magnetic recording apparatus, wherein the length of the flying slider is 1/2 or less.