JP3303859B2 - Magnetic recording medium and magnetic recording / reproducing apparatus using the same - Google Patents

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 in which information is recorded on a plurality of tracks concentrically or spirally, and more particularly, to increase the track density by defining a track layout and a recording / reproducing direction. And a magnetic recording and reproducing apparatus using the same.

[0002]

2. Description of the Related Art A magnetic recording / reproducing apparatus using a disk-type magnetic recording medium is used as an external recording apparatus or an image recording apparatus for a computer. Is evolving. One method of improving the recording density in a magnetic recording / reproducing apparatus is to increase the number of tracks per unit width, that is, the track density. In order to improve the track density, it is necessary to reduce the track pitch and the recording track width and the reproduction track width.

In a general magnetic recording / reproducing apparatus, FIG. 4 is used in consideration of a positioning error of a magnetic head so that even if recording and reproduction are performed at a position deviated from a target track position, no fatal error occurs. As shown, it is designed so that the relationship "track pitch 31> recording track width 32> reproduction track width 33" is established. Therefore, in order to reduce the track pitch 31 and improve the track density, it is important to first reduce the recording track width 32.

[0004]

However, when the recording track width is reduced, the following problem occurs.
. If the recording track width is made extremely small, the recording capability is reduced, and sufficient saturation recording cannot be performed, so that the overwrite characteristics and the like are significantly deteriorated. . Since the error occurrence probability due to the positioning error is directly related to the value of the recording track width, the manufacturing yield of the magnetic head is significantly reduced due to the variation in the processing accuracy of the recording track width.

[0005]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnetic recording medium capable of improving the track density without reducing the recording track width, and a magnetic recording / reproducing apparatus using the same.

[0006]

In order to solve the above-mentioned problems, the present inventor has disclosed in Japanese Patent Application No. 11-140766 (not disclosed) a magnetic recording medium having a high track density irrespective of the recording track width. A recording medium was devised. FIG. 5 shows the track layout. Information is recorded for each recording unit 41A composed of a plurality of tracks 40. In one recording unit 41A, the tracks 40 are sequentially recorded in the inner circumferential direction.

In this track layout, the recording direction 4
Since 2 is fixed, overwriting due to a positioning error from the adjacent track to the existing track occurs only on one side. Therefore, even if the track pitch 43 is smaller than the recording track width 32, a wide area where information from an adjacent track is not overwritten is secured. Therefore, the track pitch 43 can be smaller than the recording track width 32, and the recording track width 32
The track pitch 43 can be designed without considering the variation in the track pitch.

In this magnetic recording medium, random access is performed for each recording unit 41A composed of a plurality of tracks 40. This is because if different recording directions are adopted in one recording unit 41A,..., Overwriting from adjacent tracks on both sides occurs. Recording unit 4
Since the recording order with the adjacent recording unit 41B is unknown, the pitch of the track 40 at the end of 1A is
It is necessary to make the pitch larger than the track pitch 43 in A. For example, even when the recording unit 41A is recorded after the recording unit 41B has been recorded, the recording unit 41B is set so that the first track 40 of the recording unit 41B has a sufficient width.
It is necessary to provide a gap between the recording track width 32 and the track pitch 43 between the recording unit 41A and the recording unit 41A. This gap is defined as a recording unit interval 44.

The recording unit interval 44 is determined by each recording unit 41.
A,... Must be provided for each. Therefore, the recording unit 41
When the number of tracks 40 in A,... Is small or the recording track width 32 is large, the overall format efficiency is deteriorated, so that the effective track density does not increase.

The present inventor has continued his research to further improve the recording density, and as a result, has come up with a means for reducing the recording unit interval 44 by half.

That is, the magnetic recording medium according to the present invention comprises:
In a magnetic recording medium in which information is recorded on a large number of concentrically or spirally formed tracks, a plurality of recording units are formed for every fixed number of adjacent tracks, and information is recorded in each of these recording units. The direction is either the outer circumferential direction or the inner circumferential direction of the track, and the recording directions of adjacent recording units are opposite to each other.

In one recording unit, a plurality of tracks are sequentially recorded, for example, from the outer circumference to the inner circumference. At this time, the previously recorded track may be recorded on the inner circumference side by the track to be recorded later, but is not recorded on the outer circumference side. on the other hand,
In the prior art, there is a possibility that recording is performed on both the inner circumference side and the outer circumference side of the track, so that a margin has to be taken for each (see FIG. 4). On the other hand, in the present invention, the margin may be halved because there is a possibility that recording is performed on only one of the inner circumference side and the outer circumference side. Therefore, the track pitch can be reduced. If the track pitch is not reduced, the rate of occurrence of errors due to positioning errors can be reduced.

When the recording directions of adjacent recording units are the same, for example, when the recording direction is from the outer peripheral side to the inner peripheral side, the inner peripheral side of the last track of the recording unit to be recorded later is first. There is a possibility that the information is recorded so as to be superimposed on the outer peripheral side of the first track of the recorded recording unit. Therefore,
One margin must be provided for the last track of each recording unit (see FIG. 5). On the other hand, according to the present invention, since the recording directions of the adjacent recording units are opposite to each other, there is a possibility that one side of the last track of both recording units is overlapped and recorded. Therefore, one margin must be provided between the last tracks of both recording units. That is, the last track of each recording unit may have a half margin.

In other words, in the present invention, when the recording directions of the adjacent recording units are away from each other, the pitch of the last track of each recording unit can be made equal to the track pitch in the recording unit. On the other hand, if the recording directions of adjacent recording units are directions approaching each other, an interval between recording units that may be recorded from recording units on both sides is provided. Therefore, the intervals between recording units need only be provided every other boundary of the recording units, so that the format efficiency is improved and the effective track density is improved.

When information is recorded on a plurality of recording surfaces, information is recorded between the recording units on the plurality of recording surfaces by alternately changing the recording directions in the recording units on the adjacent recording surfaces. When reproducing, it is not necessary to seek the head, so that the throughput can be increased.

[0016]

FIG. 1 is a schematic plan view showing a part of a first embodiment of a magnetic recording medium according to the present invention. Hereinafter, description will be made based on this drawing.

In the magnetic recording medium of the present embodiment, a plurality of recording units 10A,... Are formed for each of a fixed number of adjacent tracks 40, and the recording direction 11A of information in each recording unit 10A,. The recording directions 11A,... Of the adjacent recording units 10A,.

Recording of information is performed for each recording unit 10A,. Each of the recording units 10A,... Is composed of a plurality of tracks 40. In each of the recording units 10A,. The track 40 is recorded in the. The track 40 has a predetermined track pitch 43 and the recording head
(Not shown) is moved and recorded. Track pitch 43
Need not necessarily be wider than the recording track width 32. That is, the track width remaining after the adjacent track 40 is recorded is selected depending on the reproduction track width 33 and the signal quality. When the track pitch 43 is smaller than the recording track width 32, the track width remaining after the recording is equal to the track pitch 43.

In the adjacent recording units 10A,..., The recording directions 11A,. That is, in the recording units 10A and 10C, the recording directions 11A and 11C are the inner circumferential directions, whereas
At 0B, the recording direction 11B is the outer circumferential direction.

A recording unit interval 44 is provided between the recording units 10A and 10B. The minimum value of the recording unit interval 44 is equal to the difference between the recording track width 32 and the track pitch 43. In this case, the recording unit interval 4
In the area of No. 4, the track 40 on the inner peripheral side of the recording unit 10A is
Information recorded after any one of the track 40 and the outer track 40 of the recording unit 10B is recorded. At this time, the width of the previously recorded track 40 is reduced because it is overwritten by the subsequently recorded track 40, but at least the other tracks 4 in the recording units 10A,.
It will have the same width as 0.

It is not necessary to provide a recording unit interval 44 between the recording units 10B and 10C. this is,
The inner track 40 of the recording unit 10B and the recording unit 10
This is because the track 40 on the outer peripheral side of C does not overlap.
However, in consideration of a positioning error at the time of recording, it is necessary to provide a recording unit interval (not shown) between the recording unit 10B and the recording unit 10C. At this time, the recording unit interval 44 between the recording units 10A and 10C also needs to be increased by the recording unit interval (not shown).

Next, the operation and effect of the magnetic recording medium of the present embodiment will be described. For simplicity, the recording track width is w, the reproduction track width is r, the track pitch in a recording unit is p (p <w), the interval between recording units is q, and the number of tracks in the recording unit is n. The principle will be described assuming that the positioning error is zero.

In the case of the magnetic recording medium shown in FIG. 5, the interval 44 between recording units needs to be q = wp between any of the recording units 10A,. This is because, for example, when the recording unit 41A is recorded after recording the recording unit 41B, it is necessary to secure a sufficient recording area in the first track of the recording unit 41B.

On the other hand, in the case of the magnetic recording medium of the present embodiment shown in FIG. 1, q = wp between the recording unit 10A and the recording unit 10B, and q = w-p between the recording unit 10B and the recording unit 10C. The recording unit interval 44, such as 0, may be set to 0 and wp alternately. Therefore, the average track pitch over the entire disk diameter in consideration of the recording unit interval 44 is p + (w-p) / n in the magnetic recording medium of FIG. p + (w-
p) / (2n). Thus, according to the magnetic recording medium of the present embodiment, a small track pitch, that is, a large track density can be obtained.

For example, if the recording track width w is 0.6 μm,
Consider a case where the track pitch p is 0.3 μm and the number n of tracks in a recording unit is 2. In this case, in the magnetic recording medium of FIG. 5, the average track pitch and the track density are 0.45 μm and 56 kTPI, respectively. On the other hand, in the magnetic recording medium of the present embodiment, 0.37
Since it is 5 μm and 67 kTPI, an improvement in track density of about 20% is expected.

FIG. 2 is a schematic sectional view showing a second embodiment of the magnetic recording medium according to the present invention. Hereinafter, description will be made based on this drawing.

The magnetic recording medium of the present embodiment is a combination of three magnetic recording media 121 to 123 of the first embodiment. The magnetic recording media 121 to 123 have recording surfaces 121a to 123a on the front side, respectively, and have recording surfaces 121b to 123b on the back side, respectively. Cylinder 15A
Are the recording surfaces 121a to 123a, 121b to 123b
Recording units 131a to 133 at the same distance from the center of
a, 131b to 133b. In the cylinder 15A, the recording units 131a to 133a on the front side
Recording directions 141a-143a and 131b-1
The recording directions 141b to 143b of 33b are opposite to each other. The same applies to each of the cylinders 15B to 15F.

For example, in the magnetic recording medium 121, when the recording direction 141a of the recording unit 131a on the front side is the inner peripheral direction, the recording direction 141b of the recording unit 131b on the rear side is the outer peripheral direction. A shaft 16 connected to a spindle motor (not shown) is inserted into the center of the magnetic recording media 121 to 123.

Next, the operation and effect of the magnetic recording medium of the present embodiment will be described.

In the magnetic recording medium of this embodiment, the recording directions 141a,... Are alternately arranged on the front side and the back side of each recording surface 121a,. Therefore, when replacing the active magnetic head (not shown) in the same cylinder 15A,..., For example, when continuously changing the recording from the front side to the back side of the magnetic recording medium 121, the moving distance of the magnetic head is reduced. Can be smaller. Therefore, the time for positioning the magnetic head can be shortened, and the throughput can be increased.

Although the recording direction in one cylinder is physically alternated between the front side and the back side in this embodiment, it may be determined depending on a head change algorithm. For example, the head change is performed on the front side of the magnetic recording medium 121 → the front side of the magnetic recording medium 122 → the front side of the magnetic recording medium 123 → the back side of the magnetic recording medium 121 →
Assuming that the recording is performed in the order of the back side of the magnetic recording medium 122 → the back side of the magnetic recording medium 123, the respective recording directions are also set in this order in the order of inner circumferential direction → outer circumferential direction → inner circumferential direction →.

FIG. 3 is a block diagram showing an embodiment of the magnetic recording / reproducing apparatus according to the present invention. Hereinafter, description will be made based on this drawing.

The magnetic recording / reproducing apparatus 20 of this embodiment includes a magnetic recording medium 21 of the first embodiment, a magnetic head 22 for recording and reproducing information on and from the magnetic recording medium 21, and a magnetic recording medium A voice coil motor (VCM) 23 and a spindle motor 24 as actuators positioned on the voice coil motor (VC) 21;
M) 23, a recording / reproducing channel 25 as a control unit for controlling the spindle motor 24 and the magnetic head 21, and a control unit 26.

The spindle motor 24 is provided for the magnetic recording medium 2
Rotate 1 The magnetic head 22 includes the magnetic recording medium 21.
Is mounted on the voice coil motor 23 via a suspension 27 and an arm 28 so as to face the recording surface of the voice coil motor 23. The magnetic head 22 tracks on the magnetic recording medium 21 by the voice coil motor 23. The magnetic recording / reproducing operation is performed by recording / reproducing channel 2 to the magnetic head 22.
5 is performed. Recording and reproduction channel 25,
The voice coil motor 23 and the spindle motor 24
Each is controlled by the control unit 26.

[0035]

According to the magnetic recording medium of the present invention, a plurality of recording units are formed for every fixed number of adjacent tracks, and the recording direction of information in each of these recording units is either the outer circumferential direction of the track or Since the recording directions of the adjacent recording units are opposite to each other in one of the inner circumferential directions, the recording is performed so as to be overlapped only on either the inner circumferential side or the outer circumferential side of each track. Therefore, the margin of each track can be reduced to half of the conventional one. Therefore, the error occurrence rate due to the positioning error can be reduced,
Since the track pitch can be reduced, the track density can be improved without reducing the recording track width. Further, since the recording directions of the adjacent recording units are opposite to each other, the margin of the last track of each recording unit can be halved compared to the case where the recording directions of the adjacent recording units are the same.

In other words, the average track density can be increased. Therefore, it is possible to realize a magnetic recording / reproducing apparatus having a larger capacity than a normal magnetic head and a magnetic recording medium. The reason for this is that by alternately changing the recording direction in adjacent recording units, it is possible to halve the places where the intervals between recording units need to be provided.

According to the magnetic recording medium of the present invention, the track pitch is smaller than the recording track width.
The track density can be further improved.

According to the magnetic recording medium of the third aspect, when the recording directions of the adjacent recording units are in a relationship facing each other, a fixed interval is provided between the recording units, so that a positioning error is caused. The error occurrence rate can be further reduced.

According to the magnetic recording medium of the fourth aspect, when the recording directions of the adjacent recording units are in a relationship facing each other, a fixed interval is provided between the recording units, and this interval is equal to the track pitch. Since the interval between recording units is minimized by corresponding to the difference from the recording track width, the track density can be further improved while reducing the error occurrence rate due to the positioning error.

According to the magnetic recording medium of the fifth aspect, the magnetic recording medium according to the present invention having the recording surfaces on the front and back sides, wherein the recording units at the same distance from the center of each recording surface form one cylinder. Since the recording directions in the cylinder are opposite to each other on the recording surfaces on the front side and the rear side in this cylinder, the moving distance of the magnetic head when switching the magnetic head can be reduced.

According to a sixth aspect of the present invention, there is provided a magnetic recording medium comprising one or two or more magnetic recording media according to the present invention having recording surfaces on the front and back, and recording units located at the same distance from the center of each recording surface. Constitute one cylinder, and the recording direction of each recording surface is determined in the cylinder so that the seek time is minimized when the magnetic head is switched according to the head change algorithm, so that the recording / reproducing throughput is increased. be able to.

According to the magnetic recording and reproducing apparatus of the present invention,
Since the magnetic recording medium according to the present invention is used, information can be recorded and reproduced with high density.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a part of a first embodiment of a magnetic recording medium according to the present invention.

FIG. 2 is a schematic sectional view showing a second embodiment of the magnetic recording medium according to the present invention.

FIG. 3 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus according to the present invention.

FIG. 4 is a schematic plan view showing a part of a conventional magnetic recording medium.

FIG. 5 is a schematic plan view showing a part of a magnetic recording medium on which the present invention is based.

[Explanation of symbols]

 10A, 10B, 10C Recording unit 11A, 11B, 11C Recording direction 121, 122, 123, 21 Magnetic recording medium 20 Magnetic recording / reproducing device 32 Recording track width 33 Reproducing track width 40 Track 43 Track pitch 44 Recording unit interval

Claims (7)

(57) [Claims] 1. A magnetic recording medium in which information is recorded on a large number of concentrically or spirally formed tracks, wherein a plurality of recording units are formed for each of a predetermined number of adjacent tracks. A magnetic recording medium, wherein the recording direction of information in the track is either the outer circumferential direction or the inner circumferential direction of the track, and the recording directions of the adjacent recording units are opposite to each other. . 2. The magnetic recording medium according to claim 1, wherein the track has a track pitch smaller than a recording track width. 3. The magnetic recording medium according to claim 1, wherein when the recording directions of the adjacent recording units are in a relationship facing each other, a fixed interval is provided between the recording units. 4. When the recording directions of the adjacent recording units are opposite to each other, a constant interval is provided between the recording units, and the interval is a difference between the track pitch and the recording track width. 3. The magnetic recording medium according to claim 2, wherein 5. The magnetic recording medium according to claim 1, which has one or two or more recording surfaces on the front and back sides, wherein the recording units located at the same distance from the center of each recording surface have one recording unit. A magnetic recording medium comprising two cylinders, in which the recording directions are opposite to each other on the recording surfaces on the front side and the back side. 6. The magnetic recording medium according to claim 1, wherein the recording unit has one or more recording surfaces on the front and back sides, and the recording units at the same distance from the center of each recording surface have one recording unit. A magnetic recording medium comprising one cylinder, wherein the recording direction of each of the recording surfaces in the cylinder is determined so that a seek time is shortest when a magnetic head is switched according to a head change algorithm. 7. A magnetic recording medium according to claim 1, 2, 3, 4, 5, or 6, a magnetic head for recording and reproducing information on and from the magnetic recording medium, and the magnetic recording medium A magnetic recording / reproducing apparatus comprising: an actuator positioned above; and a control unit that controls the actuator and the magnetic head.